| /* |
| * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers |
| * Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved. |
| * Copyright (c) 1996-1999 by Silicon Graphics. All rights reserved. |
| * Copyright (c) 1999 by Hewlett-Packard Company. All rights reserved. |
| * |
| * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED |
| * OR IMPLIED. ANY USE IS AT YOUR OWN RISK. |
| * |
| * Permission is hereby granted to use or copy this program |
| * for any purpose, provided the above notices are retained on all copies. |
| * Permission to modify the code and to distribute modified code is granted, |
| * provided the above notices are retained, and a notice that the code was |
| * modified is included with the above copyright notice. |
| */ |
| |
| # include "private/gc_priv.h" |
| |
| # if defined(LINUX) && !defined(POWERPC) |
| # include <linux/version.h> |
| # if (LINUX_VERSION_CODE <= 0x10400) |
| /* Ugly hack to get struct sigcontext_struct definition. Required */ |
| /* for some early 1.3.X releases. Will hopefully go away soon. */ |
| /* in some later Linux releases, asm/sigcontext.h may have to */ |
| /* be included instead. */ |
| # define __KERNEL__ |
| # include <asm/signal.h> |
| # undef __KERNEL__ |
| # else |
| /* Kernels prior to 2.1.1 defined struct sigcontext_struct instead of */ |
| /* struct sigcontext. libc6 (glibc2) uses "struct sigcontext" in */ |
| /* prototypes, so we have to include the top-level sigcontext.h to */ |
| /* make sure the former gets defined to be the latter if appropriate. */ |
| # include <features.h> |
| # if 2 <= __GLIBC__ |
| # if 2 == __GLIBC__ && 0 == __GLIBC_MINOR__ |
| /* glibc 2.1 no longer has sigcontext.h. But signal.h */ |
| /* has the right declaration for glibc 2.1. */ |
| # include <sigcontext.h> |
| # endif /* 0 == __GLIBC_MINOR__ */ |
| # else /* not 2 <= __GLIBC__ */ |
| /* libc5 doesn't have <sigcontext.h>: go directly with the kernel */ |
| /* one. Check LINUX_VERSION_CODE to see which we should reference. */ |
| # include <asm/sigcontext.h> |
| # endif /* 2 <= __GLIBC__ */ |
| # endif |
| # endif |
| # if !defined(OS2) && !defined(PCR) && !defined(AMIGA) && !defined(MACOS) \ |
| && !defined(MSWINCE) |
| # include <sys/types.h> |
| # if !defined(MSWIN32) && !defined(SUNOS4) |
| # include <unistd.h> |
| # endif |
| # endif |
| |
| # include <stdio.h> |
| # if defined(MSWINCE) |
| # define SIGSEGV 0 /* value is irrelevant */ |
| # else |
| # include <signal.h> |
| # endif |
| |
| /* Blatantly OS dependent routines, except for those that are related */ |
| /* to dynamic loading. */ |
| |
| # if defined(HEURISTIC2) || defined(SEARCH_FOR_DATA_START) |
| # define NEED_FIND_LIMIT |
| # endif |
| |
| # if !defined(STACKBOTTOM) && defined(HEURISTIC2) |
| # define NEED_FIND_LIMIT |
| # endif |
| |
| # if (defined(SUNOS4) && defined(DYNAMIC_LOADING)) && !defined(PCR) |
| # define NEED_FIND_LIMIT |
| # endif |
| |
| # if (defined(SVR4) || defined(AUX) || defined(DGUX) \ |
| || (defined(LINUX) && defined(SPARC))) && !defined(PCR) |
| # define NEED_FIND_LIMIT |
| # endif |
| |
| #if defined(FREEBSD) && defined(I386) |
| # include <machine/trap.h> |
| # if !defined(PCR) |
| # define NEED_FIND_LIMIT |
| # endif |
| #endif |
| |
| #ifdef NEED_FIND_LIMIT |
| # include <setjmp.h> |
| #endif |
| |
| #ifdef AMIGA |
| # define GC_AMIGA_DEF |
| # include "AmigaOS.c" |
| # undef GC_AMIGA_DEF |
| #endif |
| |
| #if defined(MSWIN32) || defined(MSWINCE) |
| # define WIN32_LEAN_AND_MEAN |
| # define NOSERVICE |
| # include <windows.h> |
| #endif |
| |
| #ifdef MACOS |
| # include <Processes.h> |
| #endif |
| |
| #ifdef IRIX5 |
| # include <sys/uio.h> |
| # include <malloc.h> /* for locking */ |
| #endif |
| #ifdef USE_MMAP |
| # include <sys/types.h> |
| # include <sys/mman.h> |
| # include <sys/stat.h> |
| #endif |
| |
| #ifdef UNIX_LIKE |
| # include <fcntl.h> |
| #endif |
| |
| #if defined(SUNOS5SIGS) || defined (HURD) || defined(LINUX) |
| # ifdef SUNOS5SIGS |
| # include <sys/siginfo.h> |
| # endif |
| # undef setjmp |
| # undef longjmp |
| # define setjmp(env) sigsetjmp(env, 1) |
| # define longjmp(env, val) siglongjmp(env, val) |
| # define jmp_buf sigjmp_buf |
| #endif |
| |
| #ifdef DARWIN |
| /* for get_etext and friends */ |
| #include <mach-o/getsect.h> |
| #endif |
| |
| #ifdef DJGPP |
| /* Apparently necessary for djgpp 2.01. May cause problems with */ |
| /* other versions. */ |
| typedef long unsigned int caddr_t; |
| #endif |
| |
| #ifdef PCR |
| # include "il/PCR_IL.h" |
| # include "th/PCR_ThCtl.h" |
| # include "mm/PCR_MM.h" |
| #endif |
| |
| #if !defined(NO_EXECUTE_PERMISSION) |
| # define OPT_PROT_EXEC PROT_EXEC |
| #else |
| # define OPT_PROT_EXEC 0 |
| #endif |
| |
| #if defined(LINUX) && \ |
| (defined(USE_PROC_FOR_LIBRARIES) || defined(IA64) || !defined(SMALL_CONFIG)) |
| |
| /* We need to parse /proc/self/maps, either to find dynamic libraries, */ |
| /* and/or to find the register backing store base (IA64). Do it once */ |
| /* here. */ |
| |
| #define READ read |
| |
| /* Repeatedly perform a read call until the buffer is filled or */ |
| /* we encounter EOF. */ |
| ssize_t GC_repeat_read(int fd, char *buf, size_t count) |
| { |
| ssize_t num_read = 0; |
| ssize_t result; |
| |
| while (num_read < count) { |
| result = READ(fd, buf + num_read, count - num_read); |
| if (result < 0) return result; |
| if (result == 0) break; |
| num_read += result; |
| } |
| return num_read; |
| } |
| |
| /* |
| * Apply fn to a buffer containing the contents of /proc/self/maps. |
| * Return the result of fn or, if we failed, 0. |
| */ |
| |
| word GC_apply_to_maps(word (*fn)(char *)) |
| { |
| int f; |
| int result; |
| int maps_size; |
| char maps_temp[32768]; |
| char *maps_buf; |
| |
| /* Read /proc/self/maps */ |
| /* Note that we may not allocate, and thus can't use stdio. */ |
| f = open("/proc/self/maps", O_RDONLY); |
| if (-1 == f) return 0; |
| /* stat() doesn't work for /proc/self/maps, so we have to |
| read it to find out how large it is... */ |
| maps_size = 0; |
| do { |
| result = GC_repeat_read(f, maps_temp, sizeof(maps_temp)); |
| if (result <= 0) return 0; |
| maps_size += result; |
| } while (result == sizeof(maps_temp)); |
| |
| if (maps_size > sizeof(maps_temp)) { |
| /* If larger than our buffer, close and re-read it. */ |
| close(f); |
| f = open("/proc/self/maps", O_RDONLY); |
| if (-1 == f) return 0; |
| maps_buf = alloca(maps_size); |
| if (NULL == maps_buf) return 0; |
| result = GC_repeat_read(f, maps_buf, maps_size); |
| if (result <= 0) return 0; |
| } else { |
| /* Otherwise use the fixed size buffer */ |
| maps_buf = maps_temp; |
| } |
| |
| close(f); |
| maps_buf[result] = '\0'; |
| |
| /* Apply fn to result. */ |
| return fn(maps_buf); |
| } |
| |
| #endif /* Need GC_apply_to_maps */ |
| |
| #if defined(LINUX) && (defined(USE_PROC_FOR_LIBRARIES) || defined(IA64)) |
| // |
| // GC_parse_map_entry parses an entry from /proc/self/maps so we can |
| // locate all writable data segments that belong to shared libraries. |
| // The format of one of these entries and the fields we care about |
| // is as follows: |
| // XXXXXXXX-XXXXXXXX r-xp 00000000 30:05 260537 name of mapping...\n |
| // ^^^^^^^^ ^^^^^^^^ ^^^^ ^^ |
| // start end prot maj_dev |
| // 0 9 18 32 |
| // |
| // For 64 bit ABIs: |
| // 0 17 34 56 |
| // |
| // The parser is called with a pointer to the entry and the return value |
| // is either NULL or is advanced to the next entry(the byte after the |
| // trailing '\n'.) |
| // |
| #if CPP_WORDSZ == 32 |
| # define OFFSET_MAP_START 0 |
| # define OFFSET_MAP_END 9 |
| # define OFFSET_MAP_PROT 18 |
| # define OFFSET_MAP_MAJDEV 32 |
| # define ADDR_WIDTH 8 |
| #endif |
| |
| #if CPP_WORDSZ == 64 |
| # define OFFSET_MAP_START 0 |
| # define OFFSET_MAP_END 17 |
| # define OFFSET_MAP_PROT 34 |
| # define OFFSET_MAP_MAJDEV 56 |
| # define ADDR_WIDTH 16 |
| #endif |
| |
| /* |
| * Assign various fields of the first line in buf_ptr to *start, *end, |
| * *prot_buf and *maj_dev. Only *prot_buf may be set for unwritable maps. |
| */ |
| char *GC_parse_map_entry(char *buf_ptr, word *start, word *end, |
| char *prot_buf, unsigned int *maj_dev) |
| { |
| int i; |
| char *tok; |
| |
| if (buf_ptr == NULL || *buf_ptr == '\0') { |
| return NULL; |
| } |
| |
| memcpy(prot_buf, buf_ptr+OFFSET_MAP_PROT, 4); |
| /* do the protections first. */ |
| prot_buf[4] = '\0'; |
| |
| if (prot_buf[1] == 'w') {/* we can skip all of this if it's not writable. */ |
| |
| tok = buf_ptr; |
| buf_ptr[OFFSET_MAP_START+ADDR_WIDTH] = '\0'; |
| *start = strtoul(tok, NULL, 16); |
| |
| tok = buf_ptr+OFFSET_MAP_END; |
| buf_ptr[OFFSET_MAP_END+ADDR_WIDTH] = '\0'; |
| *end = strtoul(tok, NULL, 16); |
| |
| buf_ptr += OFFSET_MAP_MAJDEV; |
| tok = buf_ptr; |
| while (*buf_ptr != ':') buf_ptr++; |
| *buf_ptr++ = '\0'; |
| *maj_dev = strtoul(tok, NULL, 16); |
| } |
| |
| while (*buf_ptr && *buf_ptr++ != '\n'); |
| |
| return buf_ptr; |
| } |
| |
| #endif /* Need to parse /proc/self/maps. */ |
| |
| #if defined(SEARCH_FOR_DATA_START) |
| /* The I386 case can be handled without a search. The Alpha case */ |
| /* used to be handled differently as well, but the rules changed */ |
| /* for recent Linux versions. This seems to be the easiest way to */ |
| /* cover all versions. */ |
| |
| # ifdef LINUX |
| /* Some Linux distributions arrange to define __data_start. Some */ |
| /* define data_start as a weak symbol. The latter is technically */ |
| /* broken, since the user program may define data_start, in which */ |
| /* case we lose. Nonetheless, we try both, prefering __data_start. */ |
| /* We assume gcc-compatible pragmas. */ |
| # pragma weak __data_start |
| extern int __data_start[]; |
| # pragma weak data_start |
| extern int data_start[]; |
| # endif /* LINUX */ |
| extern int _end[]; |
| |
| ptr_t GC_data_start; |
| |
| void GC_init_linux_data_start() |
| { |
| extern ptr_t GC_find_limit(); |
| |
| # ifdef LINUX |
| /* Try the easy approaches first: */ |
| if ((ptr_t)__data_start != 0) { |
| GC_data_start = (ptr_t)(__data_start); |
| return; |
| } |
| if ((ptr_t)data_start != 0) { |
| GC_data_start = (ptr_t)(data_start); |
| return; |
| } |
| # endif /* LINUX */ |
| GC_data_start = GC_find_limit((ptr_t)(_end), FALSE); |
| } |
| #endif |
| |
| # ifdef ECOS |
| |
| # ifndef ECOS_GC_MEMORY_SIZE |
| # define ECOS_GC_MEMORY_SIZE (448 * 1024) |
| # endif /* ECOS_GC_MEMORY_SIZE */ |
| |
| // setjmp() function, as described in ANSI para 7.6.1.1 |
| #define setjmp( __env__ ) hal_setjmp( __env__ ) |
| |
| // FIXME: This is a simple way of allocating memory which is |
| // compatible with ECOS early releases. Later releases use a more |
| // sophisticated means of allocating memory than this simple static |
| // allocator, but this method is at least bound to work. |
| static char memory[ECOS_GC_MEMORY_SIZE]; |
| static char *brk = memory; |
| |
| static void *tiny_sbrk(ptrdiff_t increment) |
| { |
| void *p = brk; |
| |
| brk += increment; |
| |
| if (brk > memory + sizeof memory) |
| { |
| brk -= increment; |
| return NULL; |
| } |
| |
| return p; |
| } |
| #define sbrk tiny_sbrk |
| # endif /* ECOS */ |
| |
| #if (defined(NETBSD) || defined(OPENBSD)) && defined(__ELF__) |
| ptr_t GC_data_start; |
| |
| void GC_init_netbsd_elf() |
| { |
| extern ptr_t GC_find_limit(); |
| extern char **environ; |
| /* This may need to be environ, without the underscore, for */ |
| /* some versions. */ |
| GC_data_start = GC_find_limit((ptr_t)&environ, FALSE); |
| } |
| #endif |
| |
| # ifdef OS2 |
| |
| # include <stddef.h> |
| |
| # if !defined(__IBMC__) && !defined(__WATCOMC__) /* e.g. EMX */ |
| |
| struct exe_hdr { |
| unsigned short magic_number; |
| unsigned short padding[29]; |
| long new_exe_offset; |
| }; |
| |
| #define E_MAGIC(x) (x).magic_number |
| #define EMAGIC 0x5A4D |
| #define E_LFANEW(x) (x).new_exe_offset |
| |
| struct e32_exe { |
| unsigned char magic_number[2]; |
| unsigned char byte_order; |
| unsigned char word_order; |
| unsigned long exe_format_level; |
| unsigned short cpu; |
| unsigned short os; |
| unsigned long padding1[13]; |
| unsigned long object_table_offset; |
| unsigned long object_count; |
| unsigned long padding2[31]; |
| }; |
| |
| #define E32_MAGIC1(x) (x).magic_number[0] |
| #define E32MAGIC1 'L' |
| #define E32_MAGIC2(x) (x).magic_number[1] |
| #define E32MAGIC2 'X' |
| #define E32_BORDER(x) (x).byte_order |
| #define E32LEBO 0 |
| #define E32_WORDER(x) (x).word_order |
| #define E32LEWO 0 |
| #define E32_CPU(x) (x).cpu |
| #define E32CPU286 1 |
| #define E32_OBJTAB(x) (x).object_table_offset |
| #define E32_OBJCNT(x) (x).object_count |
| |
| struct o32_obj { |
| unsigned long size; |
| unsigned long base; |
| unsigned long flags; |
| unsigned long pagemap; |
| unsigned long mapsize; |
| unsigned long reserved; |
| }; |
| |
| #define O32_FLAGS(x) (x).flags |
| #define OBJREAD 0x0001L |
| #define OBJWRITE 0x0002L |
| #define OBJINVALID 0x0080L |
| #define O32_SIZE(x) (x).size |
| #define O32_BASE(x) (x).base |
| |
| # else /* IBM's compiler */ |
| |
| /* A kludge to get around what appears to be a header file bug */ |
| # ifndef WORD |
| # define WORD unsigned short |
| # endif |
| # ifndef DWORD |
| # define DWORD unsigned long |
| # endif |
| |
| # define EXE386 1 |
| # include <newexe.h> |
| # include <exe386.h> |
| |
| # endif /* __IBMC__ */ |
| |
| # define INCL_DOSEXCEPTIONS |
| # define INCL_DOSPROCESS |
| # define INCL_DOSERRORS |
| # define INCL_DOSMODULEMGR |
| # define INCL_DOSMEMMGR |
| # include <os2.h> |
| |
| |
| /* Disable and enable signals during nontrivial allocations */ |
| |
| void GC_disable_signals(void) |
| { |
| ULONG nest; |
| |
| DosEnterMustComplete(&nest); |
| if (nest != 1) ABORT("nested GC_disable_signals"); |
| } |
| |
| void GC_enable_signals(void) |
| { |
| ULONG nest; |
| |
| DosExitMustComplete(&nest); |
| if (nest != 0) ABORT("GC_enable_signals"); |
| } |
| |
| |
| # else |
| |
| # if !defined(PCR) && !defined(AMIGA) && !defined(MSWIN32) \ |
| && !defined(MSWINCE) \ |
| && !defined(MACOS) && !defined(DJGPP) && !defined(DOS4GW) \ |
| && !defined(NOSYS) && !defined(ECOS) |
| |
| # if defined(sigmask) && !defined(UTS4) && !defined(HURD) |
| /* Use the traditional BSD interface */ |
| # define SIGSET_T int |
| # define SIG_DEL(set, signal) (set) &= ~(sigmask(signal)) |
| # define SIG_FILL(set) (set) = 0x7fffffff |
| /* Setting the leading bit appears to provoke a bug in some */ |
| /* longjmp implementations. Most systems appear not to have */ |
| /* a signal 32. */ |
| # define SIGSETMASK(old, new) (old) = sigsetmask(new) |
| # else |
| /* Use POSIX/SYSV interface */ |
| # define SIGSET_T sigset_t |
| # define SIG_DEL(set, signal) sigdelset(&(set), (signal)) |
| # define SIG_FILL(set) sigfillset(&set) |
| # define SIGSETMASK(old, new) sigprocmask(SIG_SETMASK, &(new), &(old)) |
| # endif |
| |
| static GC_bool mask_initialized = FALSE; |
| |
| static SIGSET_T new_mask; |
| |
| static SIGSET_T old_mask; |
| |
| static SIGSET_T dummy; |
| |
| #if defined(PRINTSTATS) && !defined(THREADS) |
| # define CHECK_SIGNALS |
| int GC_sig_disabled = 0; |
| #endif |
| |
| void GC_disable_signals() |
| { |
| if (!mask_initialized) { |
| SIG_FILL(new_mask); |
| |
| SIG_DEL(new_mask, SIGSEGV); |
| SIG_DEL(new_mask, SIGILL); |
| SIG_DEL(new_mask, SIGQUIT); |
| # ifdef SIGBUS |
| SIG_DEL(new_mask, SIGBUS); |
| # endif |
| # ifdef SIGIOT |
| SIG_DEL(new_mask, SIGIOT); |
| # endif |
| # ifdef SIGEMT |
| SIG_DEL(new_mask, SIGEMT); |
| # endif |
| # ifdef SIGTRAP |
| SIG_DEL(new_mask, SIGTRAP); |
| # endif |
| mask_initialized = TRUE; |
| } |
| # ifdef CHECK_SIGNALS |
| if (GC_sig_disabled != 0) ABORT("Nested disables"); |
| GC_sig_disabled++; |
| # endif |
| SIGSETMASK(old_mask,new_mask); |
| } |
| |
| void GC_enable_signals() |
| { |
| # ifdef CHECK_SIGNALS |
| if (GC_sig_disabled != 1) ABORT("Unmatched enable"); |
| GC_sig_disabled--; |
| # endif |
| SIGSETMASK(dummy,old_mask); |
| } |
| |
| # endif /* !PCR */ |
| |
| # endif /*!OS/2 */ |
| |
| /* Ivan Demakov: simplest way (to me) */ |
| #if defined (DOS4GW) |
| void GC_disable_signals() { } |
| void GC_enable_signals() { } |
| #endif |
| |
| /* Find the page size */ |
| word GC_page_size; |
| |
| # if defined(MSWIN32) || defined(MSWINCE) |
| void GC_setpagesize() |
| { |
| GetSystemInfo(&GC_sysinfo); |
| GC_page_size = GC_sysinfo.dwPageSize; |
| } |
| |
| # else |
| # if defined(MPROTECT_VDB) || defined(PROC_VDB) || defined(USE_MMAP) \ |
| || defined(USE_MUNMAP) |
| void GC_setpagesize() |
| { |
| GC_page_size = GETPAGESIZE(); |
| } |
| # else |
| /* It's acceptable to fake it. */ |
| void GC_setpagesize() |
| { |
| GC_page_size = HBLKSIZE; |
| } |
| # endif |
| # endif |
| |
| /* |
| * Find the base of the stack. |
| * Used only in single-threaded environment. |
| * With threads, GC_mark_roots needs to know how to do this. |
| * Called with allocator lock held. |
| */ |
| # if defined(MSWIN32) || defined(MSWINCE) |
| # define is_writable(prot) ((prot) == PAGE_READWRITE \ |
| || (prot) == PAGE_WRITECOPY \ |
| || (prot) == PAGE_EXECUTE_READWRITE \ |
| || (prot) == PAGE_EXECUTE_WRITECOPY) |
| /* Return the number of bytes that are writable starting at p. */ |
| /* The pointer p is assumed to be page aligned. */ |
| /* If base is not 0, *base becomes the beginning of the */ |
| /* allocation region containing p. */ |
| word GC_get_writable_length(ptr_t p, ptr_t *base) |
| { |
| MEMORY_BASIC_INFORMATION buf; |
| word result; |
| word protect; |
| |
| result = VirtualQuery(p, &buf, sizeof(buf)); |
| if (result != sizeof(buf)) ABORT("Weird VirtualQuery result"); |
| if (base != 0) *base = (ptr_t)(buf.AllocationBase); |
| protect = (buf.Protect & ~(PAGE_GUARD | PAGE_NOCACHE)); |
| if (!is_writable(protect)) { |
| return(0); |
| } |
| if (buf.State != MEM_COMMIT) return(0); |
| return(buf.RegionSize); |
| } |
| |
| ptr_t GC_get_stack_base() |
| { |
| int dummy; |
| ptr_t sp = (ptr_t)(&dummy); |
| ptr_t trunc_sp = (ptr_t)((word)sp & ~(GC_page_size - 1)); |
| word size = GC_get_writable_length(trunc_sp, 0); |
| |
| return(trunc_sp + size); |
| } |
| |
| |
| # endif /* MS Windows */ |
| |
| # ifdef BEOS |
| # include <kernel/OS.h> |
| ptr_t GC_get_stack_base(){ |
| thread_info th; |
| get_thread_info(find_thread(NULL),&th); |
| return th.stack_end; |
| } |
| # endif /* BEOS */ |
| |
| |
| # ifdef OS2 |
| |
| ptr_t GC_get_stack_base() |
| { |
| PTIB ptib; |
| PPIB ppib; |
| |
| if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) { |
| GC_err_printf0("DosGetInfoBlocks failed\n"); |
| ABORT("DosGetInfoBlocks failed\n"); |
| } |
| return((ptr_t)(ptib -> tib_pstacklimit)); |
| } |
| |
| # endif /* OS2 */ |
| |
| # ifdef AMIGA |
| # define GC_AMIGA_SB |
| # include "AmigaOS.c" |
| # undef GC_AMIGA_SB |
| # endif /* AMIGA */ |
| |
| # if defined(NEED_FIND_LIMIT) || defined(UNIX_LIKE) |
| |
| # ifdef __STDC__ |
| typedef void (*handler)(int); |
| # else |
| typedef void (*handler)(); |
| # endif |
| |
| # if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) || defined(HURD) |
| static struct sigaction old_segv_act; |
| # if defined(_sigargs) /* !Irix6.x */ || defined(HPUX) || defined(HURD) |
| static struct sigaction old_bus_act; |
| # endif |
| # else |
| static handler old_segv_handler, old_bus_handler; |
| # endif |
| |
| # ifdef __STDC__ |
| void GC_set_and_save_fault_handler(handler h) |
| # else |
| void GC_set_and_save_fault_handler(h) |
| handler h; |
| # endif |
| { |
| # if defined(SUNOS5SIGS) || defined(IRIX5) \ |
| || defined(OSF1) || defined(HURD) |
| struct sigaction act; |
| |
| act.sa_handler = h; |
| # ifdef SUNOS5SIGS |
| act.sa_flags = SA_RESTART | SA_NODEFER; |
| # else |
| act.sa_flags = SA_RESTART; |
| # endif |
| /* The presence of SA_NODEFER represents yet another gross */ |
| /* hack. Under Solaris 2.3, siglongjmp doesn't appear to */ |
| /* interact correctly with -lthread. We hide the confusion */ |
| /* by making sure that signal handling doesn't affect the */ |
| /* signal mask. */ |
| |
| (void) sigemptyset(&act.sa_mask); |
| # ifdef GC_IRIX_THREADS |
| /* Older versions have a bug related to retrieving and */ |
| /* and setting a handler at the same time. */ |
| (void) sigaction(SIGSEGV, 0, &old_segv_act); |
| (void) sigaction(SIGSEGV, &act, 0); |
| # else |
| (void) sigaction(SIGSEGV, &act, &old_segv_act); |
| # if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \ |
| || defined(HPUX) || defined(HURD) |
| /* Under Irix 5.x or HP/UX, we may get SIGBUS. */ |
| /* Pthreads doesn't exist under Irix 5.x, so we */ |
| /* don't have to worry in the threads case. */ |
| (void) sigaction(SIGBUS, &act, &old_bus_act); |
| # endif |
| # endif /* GC_IRIX_THREADS */ |
| # else |
| old_segv_handler = signal(SIGSEGV, h); |
| # ifdef SIGBUS |
| old_bus_handler = signal(SIGBUS, h); |
| # endif |
| # endif |
| } |
| # endif /* NEED_FIND_LIMIT || UNIX_LIKE */ |
| |
| # ifdef NEED_FIND_LIMIT |
| /* Some tools to implement HEURISTIC2 */ |
| # define MIN_PAGE_SIZE 256 /* Smallest conceivable page size, bytes */ |
| /* static */ jmp_buf GC_jmp_buf; |
| |
| /*ARGSUSED*/ |
| void GC_fault_handler(sig) |
| int sig; |
| { |
| longjmp(GC_jmp_buf, 1); |
| } |
| |
| void GC_setup_temporary_fault_handler() |
| { |
| GC_set_and_save_fault_handler(GC_fault_handler); |
| } |
| |
| void GC_reset_fault_handler() |
| { |
| # if defined(SUNOS5SIGS) || defined(IRIX5) \ |
| || defined(OSF1) || defined(HURD) |
| (void) sigaction(SIGSEGV, &old_segv_act, 0); |
| # if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \ |
| || defined(HPUX) || defined(HURD) |
| (void) sigaction(SIGBUS, &old_bus_act, 0); |
| # endif |
| # else |
| (void) signal(SIGSEGV, old_segv_handler); |
| # ifdef SIGBUS |
| (void) signal(SIGBUS, old_bus_handler); |
| # endif |
| # endif |
| } |
| |
| /* Return the first nonaddressible location > p (up) or */ |
| /* the smallest location q s.t. [q,p) is addressable (!up). */ |
| /* We assume that p (up) or p-1 (!up) is addressable. */ |
| ptr_t GC_find_limit(p, up) |
| ptr_t p; |
| GC_bool up; |
| { |
| static VOLATILE ptr_t result; |
| /* Needs to be static, since otherwise it may not be */ |
| /* preserved across the longjmp. Can safely be */ |
| /* static since it's only called once, with the */ |
| /* allocation lock held. */ |
| |
| |
| GC_setup_temporary_fault_handler(); |
| if (setjmp(GC_jmp_buf) == 0) { |
| result = (ptr_t)(((word)(p)) |
| & ~(MIN_PAGE_SIZE-1)); |
| for (;;) { |
| if (up) { |
| result += MIN_PAGE_SIZE; |
| } else { |
| result -= MIN_PAGE_SIZE; |
| } |
| GC_noop1((word)(*result)); |
| } |
| } |
| GC_reset_fault_handler(); |
| if (!up) { |
| result += MIN_PAGE_SIZE; |
| } |
| return(result); |
| } |
| # endif |
| |
| #if defined(ECOS) || defined(NOSYS) |
| ptr_t GC_get_stack_base() |
| { |
| return STACKBOTTOM; |
| } |
| #endif |
| |
| #ifdef LINUX_STACKBOTTOM |
| |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include <ctype.h> |
| |
| # define STAT_SKIP 27 /* Number of fields preceding startstack */ |
| /* field in /proc/self/stat */ |
| |
| # pragma weak __libc_stack_end |
| extern ptr_t __libc_stack_end; |
| |
| # ifdef IA64 |
| /* Try to read the backing store base from /proc/self/maps. */ |
| /* We look for the writable mapping with a 0 major device, */ |
| /* which is as close to our frame as possible, but below it.*/ |
| static word backing_store_base_from_maps(char *maps) |
| { |
| char prot_buf[5]; |
| char *buf_ptr = maps; |
| word start, end; |
| unsigned int maj_dev; |
| word current_best = 0; |
| word dummy; |
| |
| for (;;) { |
| buf_ptr = GC_parse_map_entry(buf_ptr, &start, &end, prot_buf, &maj_dev); |
| if (buf_ptr == NULL) return current_best; |
| if (prot_buf[1] == 'w' && maj_dev == 0) { |
| if (end < (word)(&dummy) && start > current_best) current_best = start; |
| } |
| } |
| return current_best; |
| } |
| |
| static word backing_store_base_from_proc(void) |
| { |
| return GC_apply_to_maps(backing_store_base_from_maps); |
| } |
| |
| # pragma weak __libc_ia64_register_backing_store_base |
| extern ptr_t __libc_ia64_register_backing_store_base; |
| |
| ptr_t GC_get_register_stack_base(void) |
| { |
| if (0 != &__libc_ia64_register_backing_store_base |
| && 0 != __libc_ia64_register_backing_store_base) { |
| /* Glibc 2.2.4 has a bug such that for dynamically linked */ |
| /* executables __libc_ia64_register_backing_store_base is */ |
| /* defined but uninitialized during constructor calls. */ |
| /* Hence we check for both nonzero address and value. */ |
| return __libc_ia64_register_backing_store_base; |
| } else { |
| word result = backing_store_base_from_proc(); |
| if (0 == result) { |
| /* Use dumb heuristics. Works only for default configuration. */ |
| result = (word)GC_stackbottom - BACKING_STORE_DISPLACEMENT; |
| result += BACKING_STORE_ALIGNMENT - 1; |
| result &= ~(BACKING_STORE_ALIGNMENT - 1); |
| /* Verify that it's at least readable. If not, we goofed. */ |
| GC_noop1(*(word *)result); |
| } |
| return (ptr_t)result; |
| } |
| } |
| # endif |
| |
| ptr_t GC_linux_stack_base(void) |
| { |
| /* We read the stack base value from /proc/self/stat. We do this */ |
| /* using direct I/O system calls in order to avoid calling malloc */ |
| /* in case REDIRECT_MALLOC is defined. */ |
| # define STAT_BUF_SIZE 4096 |
| # define STAT_READ read |
| /* Should probably call the real read, if read is wrapped. */ |
| char stat_buf[STAT_BUF_SIZE]; |
| int f; |
| char c; |
| word result = 0; |
| size_t i, buf_offset = 0; |
| |
| /* First try the easy way. This should work for glibc 2.2 */ |
| if (0 != &__libc_stack_end) { |
| # ifdef IA64 |
| /* Some versions of glibc set the address 16 bytes too */ |
| /* low while the initialization code is running. */ |
| if (((word)__libc_stack_end & 0xfff) + 0x10 < 0x1000) { |
| return __libc_stack_end + 0x10; |
| } /* Otherwise it's not safe to add 16 bytes and we fall */ |
| /* back to using /proc. */ |
| # else |
| return __libc_stack_end; |
| # endif |
| } |
| f = open("/proc/self/stat", O_RDONLY); |
| if (f < 0 || STAT_READ(f, stat_buf, STAT_BUF_SIZE) < 2 * STAT_SKIP) { |
| ABORT("Couldn't read /proc/self/stat"); |
| } |
| c = stat_buf[buf_offset++]; |
| /* Skip the required number of fields. This number is hopefully */ |
| /* constant across all Linux implementations. */ |
| for (i = 0; i < STAT_SKIP; ++i) { |
| while (isspace(c)) c = stat_buf[buf_offset++]; |
| while (!isspace(c)) c = stat_buf[buf_offset++]; |
| } |
| while (isspace(c)) c = stat_buf[buf_offset++]; |
| while (isdigit(c)) { |
| result *= 10; |
| result += c - '0'; |
| c = stat_buf[buf_offset++]; |
| } |
| close(f); |
| if (result < 0x10000000) ABORT("Absurd stack bottom value"); |
| return (ptr_t)result; |
| } |
| |
| #endif /* LINUX_STACKBOTTOM */ |
| |
| #ifdef FREEBSD_STACKBOTTOM |
| |
| /* This uses an undocumented sysctl call, but at least one expert */ |
| /* believes it will stay. */ |
| |
| #include <unistd.h> |
| #include <sys/types.h> |
| #include <sys/sysctl.h> |
| |
| ptr_t GC_freebsd_stack_base(void) |
| { |
| int nm[2] = {CTL_KERN, KERN_USRSTACK}; |
| ptr_t base; |
| size_t len = sizeof(ptr_t); |
| int r = sysctl(nm, 2, &base, &len, NULL, 0); |
| |
| if (r) ABORT("Error getting stack base"); |
| |
| return base; |
| } |
| |
| #endif /* FREEBSD_STACKBOTTOM */ |
| |
| #if !defined(BEOS) && !defined(AMIGA) && !defined(MSWIN32) \ |
| && !defined(MSWINCE) && !defined(OS2) && !defined(NOSYS) && !defined(ECOS) |
| |
| ptr_t GC_get_stack_base() |
| { |
| # if defined(HEURISTIC1) || defined(HEURISTIC2) || \ |
| defined(LINUX_STACKBOTTOM) || defined(FREEBSD_STACKBOTTOM) |
| word dummy; |
| ptr_t result; |
| # endif |
| |
| # define STACKBOTTOM_ALIGNMENT_M1 ((word)STACK_GRAN - 1) |
| |
| # ifdef STACKBOTTOM |
| return(STACKBOTTOM); |
| # else |
| # ifdef HEURISTIC1 |
| # ifdef STACK_GROWS_DOWN |
| result = (ptr_t)((((word)(&dummy)) |
| + STACKBOTTOM_ALIGNMENT_M1) |
| & ~STACKBOTTOM_ALIGNMENT_M1); |
| # else |
| result = (ptr_t)(((word)(&dummy)) |
| & ~STACKBOTTOM_ALIGNMENT_M1); |
| # endif |
| # endif /* HEURISTIC1 */ |
| # ifdef LINUX_STACKBOTTOM |
| result = GC_linux_stack_base(); |
| # endif |
| # ifdef FREEBSD_STACKBOTTOM |
| result = GC_freebsd_stack_base(); |
| # endif |
| # ifdef HEURISTIC2 |
| # ifdef STACK_GROWS_DOWN |
| result = GC_find_limit((ptr_t)(&dummy), TRUE); |
| # ifdef HEURISTIC2_LIMIT |
| if (result > HEURISTIC2_LIMIT |
| && (ptr_t)(&dummy) < HEURISTIC2_LIMIT) { |
| result = HEURISTIC2_LIMIT; |
| } |
| # endif |
| # else |
| result = GC_find_limit((ptr_t)(&dummy), FALSE); |
| # ifdef HEURISTIC2_LIMIT |
| if (result < HEURISTIC2_LIMIT |
| && (ptr_t)(&dummy) > HEURISTIC2_LIMIT) { |
| result = HEURISTIC2_LIMIT; |
| } |
| # endif |
| # endif |
| |
| # endif /* HEURISTIC2 */ |
| # ifdef STACK_GROWS_DOWN |
| if (result == 0) result = (ptr_t)(signed_word)(-sizeof(ptr_t)); |
| # endif |
| return(result); |
| # endif /* STACKBOTTOM */ |
| } |
| |
| # endif /* ! AMIGA, !OS 2, ! MS Windows, !BEOS, !NOSYS, !ECOS */ |
| |
| /* |
| * Register static data segment(s) as roots. |
| * If more data segments are added later then they need to be registered |
| * add that point (as we do with SunOS dynamic loading), |
| * or GC_mark_roots needs to check for them (as we do with PCR). |
| * Called with allocator lock held. |
| */ |
| |
| # ifdef OS2 |
| |
| void GC_register_data_segments() |
| { |
| PTIB ptib; |
| PPIB ppib; |
| HMODULE module_handle; |
| # define PBUFSIZ 512 |
| UCHAR path[PBUFSIZ]; |
| FILE * myexefile; |
| struct exe_hdr hdrdos; /* MSDOS header. */ |
| struct e32_exe hdr386; /* Real header for my executable */ |
| struct o32_obj seg; /* Currrent segment */ |
| int nsegs; |
| |
| |
| if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) { |
| GC_err_printf0("DosGetInfoBlocks failed\n"); |
| ABORT("DosGetInfoBlocks failed\n"); |
| } |
| module_handle = ppib -> pib_hmte; |
| if (DosQueryModuleName(module_handle, PBUFSIZ, path) != NO_ERROR) { |
| GC_err_printf0("DosQueryModuleName failed\n"); |
| ABORT("DosGetInfoBlocks failed\n"); |
| } |
| myexefile = fopen(path, "rb"); |
| if (myexefile == 0) { |
| GC_err_puts("Couldn't open executable "); |
| GC_err_puts(path); GC_err_puts("\n"); |
| ABORT("Failed to open executable\n"); |
| } |
| if (fread((char *)(&hdrdos), 1, sizeof hdrdos, myexefile) < sizeof hdrdos) { |
| GC_err_puts("Couldn't read MSDOS header from "); |
| GC_err_puts(path); GC_err_puts("\n"); |
| ABORT("Couldn't read MSDOS header"); |
| } |
| if (E_MAGIC(hdrdos) != EMAGIC) { |
| GC_err_puts("Executable has wrong DOS magic number: "); |
| GC_err_puts(path); GC_err_puts("\n"); |
| ABORT("Bad DOS magic number"); |
| } |
| if (fseek(myexefile, E_LFANEW(hdrdos), SEEK_SET) != 0) { |
| GC_err_puts("Seek to new header failed in "); |
| GC_err_puts(path); GC_err_puts("\n"); |
| ABORT("Bad DOS magic number"); |
| } |
| if (fread((char *)(&hdr386), 1, sizeof hdr386, myexefile) < sizeof hdr386) { |
| GC_err_puts("Couldn't read MSDOS header from "); |
| GC_err_puts(path); GC_err_puts("\n"); |
| ABORT("Couldn't read OS/2 header"); |
| } |
| if (E32_MAGIC1(hdr386) != E32MAGIC1 || E32_MAGIC2(hdr386) != E32MAGIC2) { |
| GC_err_puts("Executable has wrong OS/2 magic number:"); |
| GC_err_puts(path); GC_err_puts("\n"); |
| ABORT("Bad OS/2 magic number"); |
| } |
| if ( E32_BORDER(hdr386) != E32LEBO || E32_WORDER(hdr386) != E32LEWO) { |
| GC_err_puts("Executable %s has wrong byte order: "); |
| GC_err_puts(path); GC_err_puts("\n"); |
| ABORT("Bad byte order"); |
| } |
| if ( E32_CPU(hdr386) == E32CPU286) { |
| GC_err_puts("GC can't handle 80286 executables: "); |
| GC_err_puts(path); GC_err_puts("\n"); |
| EXIT(); |
| } |
| if (fseek(myexefile, E_LFANEW(hdrdos) + E32_OBJTAB(hdr386), |
| SEEK_SET) != 0) { |
| GC_err_puts("Seek to object table failed: "); |
| GC_err_puts(path); GC_err_puts("\n"); |
| ABORT("Seek to object table failed"); |
| } |
| for (nsegs = E32_OBJCNT(hdr386); nsegs > 0; nsegs--) { |
| int flags; |
| if (fread((char *)(&seg), 1, sizeof seg, myexefile) < sizeof seg) { |
| GC_err_puts("Couldn't read obj table entry from "); |
| GC_err_puts(path); GC_err_puts("\n"); |
| ABORT("Couldn't read obj table entry"); |
| } |
| flags = O32_FLAGS(seg); |
| if (!(flags & OBJWRITE)) continue; |
| if (!(flags & OBJREAD)) continue; |
| if (flags & OBJINVALID) { |
| GC_err_printf0("Object with invalid pages?\n"); |
| continue; |
| } |
| GC_add_roots_inner(O32_BASE(seg), O32_BASE(seg)+O32_SIZE(seg), FALSE); |
| } |
| } |
| |
| # else /* !OS2 */ |
| |
| # if defined(MSWIN32) || defined(MSWINCE) |
| |
| # ifdef MSWIN32 |
| /* Unfortunately, we have to handle win32s very differently from NT, */ |
| /* Since VirtualQuery has very different semantics. In particular, */ |
| /* under win32s a VirtualQuery call on an unmapped page returns an */ |
| /* invalid result. Under NT, GC_register_data_segments is a noop and */ |
| /* all real work is done by GC_register_dynamic_libraries. Under */ |
| /* win32s, we cannot find the data segments associated with dll's. */ |
| /* We register the main data segment here. */ |
| GC_bool GC_no_win32_dlls = FALSE; |
| /* This used to be set for gcc, to avoid dealing with */ |
| /* the structured exception handling issues. But we now have */ |
| /* assembly code to do that right. */ |
| |
| void GC_init_win32() |
| { |
| /* if we're running under win32s, assume that no DLLs will be loaded */ |
| DWORD v = GetVersion(); |
| GC_no_win32_dlls |= ((v & 0x80000000) && (v & 0xff) <= 3); |
| } |
| |
| /* Return the smallest address a such that VirtualQuery */ |
| /* returns correct results for all addresses between a and start. */ |
| /* Assumes VirtualQuery returns correct information for start. */ |
| ptr_t GC_least_described_address(ptr_t start) |
| { |
| MEMORY_BASIC_INFORMATION buf; |
| DWORD result; |
| LPVOID limit; |
| ptr_t p; |
| LPVOID q; |
| |
| limit = GC_sysinfo.lpMinimumApplicationAddress; |
| p = (ptr_t)((word)start & ~(GC_page_size - 1)); |
| for (;;) { |
| q = (LPVOID)(p - GC_page_size); |
| if ((ptr_t)q > (ptr_t)p /* underflow */ || q < limit) break; |
| result = VirtualQuery(q, &buf, sizeof(buf)); |
| if (result != sizeof(buf) || buf.AllocationBase == 0) break; |
| p = (ptr_t)(buf.AllocationBase); |
| } |
| return(p); |
| } |
| # endif |
| |
| # ifndef REDIRECT_MALLOC |
| /* We maintain a linked list of AllocationBase values that we know */ |
| /* correspond to malloc heap sections. Currently this is only called */ |
| /* during a GC. But there is some hope that for long running */ |
| /* programs we will eventually see most heap sections. */ |
| |
| /* In the long run, it would be more reliable to occasionally walk */ |
| /* the malloc heap with HeapWalk on the default heap. But that */ |
| /* apparently works only for NT-based Windows. */ |
| |
| /* In the long run, a better data structure would also be nice ... */ |
| struct GC_malloc_heap_list { |
| void * allocation_base; |
| struct GC_malloc_heap_list *next; |
| } *GC_malloc_heap_l = 0; |
| |
| /* Is p the base of one of the malloc heap sections we already know */ |
| /* about? */ |
| GC_bool GC_is_malloc_heap_base(ptr_t p) |
| { |
| struct GC_malloc_heap_list *q = GC_malloc_heap_l; |
| |
| while (0 != q) { |
| if (q -> allocation_base == p) return TRUE; |
| q = q -> next; |
| } |
| return FALSE; |
| } |
| |
| void *GC_get_allocation_base(void *p) |
| { |
| MEMORY_BASIC_INFORMATION buf; |
| DWORD result = VirtualQuery(p, &buf, sizeof(buf)); |
| if (result != sizeof(buf)) { |
| ABORT("Weird VirtualQuery result"); |
| } |
| return buf.AllocationBase; |
| } |
| |
| size_t GC_max_root_size = 100000; /* Appr. largest root size. */ |
| |
| void GC_add_current_malloc_heap() |
| { |
| struct GC_malloc_heap_list *new_l = |
| malloc(sizeof(struct GC_malloc_heap_list)); |
| void * candidate = GC_get_allocation_base(new_l); |
| |
| if (new_l == 0) return; |
| if (GC_is_malloc_heap_base(candidate)) { |
| /* Try a little harder to find malloc heap. */ |
| size_t req_size = 10000; |
| do { |
| void *p = malloc(req_size); |
| if (0 == p) { free(new_l); return; } |
| candidate = GC_get_allocation_base(p); |
| free(p); |
| req_size *= 2; |
| } while (GC_is_malloc_heap_base(candidate) |
| && req_size < GC_max_root_size/10 && req_size < 500000); |
| if (GC_is_malloc_heap_base(candidate)) { |
| free(new_l); return; |
| } |
| } |
| # ifdef CONDPRINT |
| if (GC_print_stats) |
| GC_printf1("Found new system malloc AllocationBase at 0x%lx\n", |
| candidate); |
| # endif |
| new_l -> allocation_base = candidate; |
| new_l -> next = GC_malloc_heap_l; |
| GC_malloc_heap_l = new_l; |
| } |
| # endif /* REDIRECT_MALLOC */ |
| |
| /* Is p the start of either the malloc heap, or of one of our */ |
| /* heap sections? */ |
| GC_bool GC_is_heap_base (ptr_t p) |
| { |
| |
| unsigned i; |
| |
| # ifndef REDIRECT_MALLOC |
| static word last_gc_no = -1; |
| |
| if (last_gc_no != GC_gc_no) { |
| GC_add_current_malloc_heap(); |
| last_gc_no = GC_gc_no; |
| } |
| if (GC_root_size > GC_max_root_size) GC_max_root_size = GC_root_size; |
| if (GC_is_malloc_heap_base(p)) return TRUE; |
| # endif |
| for (i = 0; i < GC_n_heap_bases; i++) { |
| if (GC_heap_bases[i] == p) return TRUE; |
| } |
| return FALSE ; |
| } |
| |
| # ifdef MSWIN32 |
| void GC_register_root_section(ptr_t static_root) |
| { |
| MEMORY_BASIC_INFORMATION buf; |
| DWORD result; |
| DWORD protect; |
| LPVOID p; |
| char * base; |
| char * limit, * new_limit; |
| |
| if (!GC_no_win32_dlls) return; |
| p = base = limit = GC_least_described_address(static_root); |
| while (p < GC_sysinfo.lpMaximumApplicationAddress) { |
| result = VirtualQuery(p, &buf, sizeof(buf)); |
| if (result != sizeof(buf) || buf.AllocationBase == 0 |
| || GC_is_heap_base(buf.AllocationBase)) break; |
| new_limit = (char *)p + buf.RegionSize; |
| protect = buf.Protect; |
| if (buf.State == MEM_COMMIT |
| && is_writable(protect)) { |
| if ((char *)p == limit) { |
| limit = new_limit; |
| } else { |
| if (base != limit) GC_add_roots_inner(base, limit, FALSE); |
| base = p; |
| limit = new_limit; |
| } |
| } |
| if (p > (LPVOID)new_limit /* overflow */) break; |
| p = (LPVOID)new_limit; |
| } |
| if (base != limit) GC_add_roots_inner(base, limit, FALSE); |
| } |
| #endif |
| |
| void GC_register_data_segments() |
| { |
| # ifdef MSWIN32 |
| static char dummy; |
| GC_register_root_section((ptr_t)(&dummy)); |
| # endif |
| } |
| |
| # else /* !OS2 && !Windows */ |
| |
| # if (defined(SVR4) || defined(AUX) || defined(DGUX) \ |
| || (defined(LINUX) && defined(SPARC))) && !defined(PCR) |
| ptr_t GC_SysVGetDataStart(max_page_size, etext_addr) |
| int max_page_size; |
| int * etext_addr; |
| { |
| word text_end = ((word)(etext_addr) + sizeof(word) - 1) |
| & ~(sizeof(word) - 1); |
| /* etext rounded to word boundary */ |
| word next_page = ((text_end + (word)max_page_size - 1) |
| & ~((word)max_page_size - 1)); |
| word page_offset = (text_end & ((word)max_page_size - 1)); |
| VOLATILE char * result = (char *)(next_page + page_offset); |
| /* Note that this isnt equivalent to just adding */ |
| /* max_page_size to &etext if &etext is at a page boundary */ |
| |
| GC_setup_temporary_fault_handler(); |
| if (setjmp(GC_jmp_buf) == 0) { |
| /* Try writing to the address. */ |
| *result = *result; |
| GC_reset_fault_handler(); |
| } else { |
| GC_reset_fault_handler(); |
| /* We got here via a longjmp. The address is not readable. */ |
| /* This is known to happen under Solaris 2.4 + gcc, which place */ |
| /* string constants in the text segment, but after etext. */ |
| /* Use plan B. Note that we now know there is a gap between */ |
| /* text and data segments, so plan A bought us something. */ |
| result = (char *)GC_find_limit((ptr_t)(DATAEND), FALSE); |
| } |
| return((ptr_t)result); |
| } |
| # endif |
| |
| # if defined(FREEBSD) && defined(I386) && !defined(PCR) |
| /* Its unclear whether this should be identical to the above, or */ |
| /* whether it should apply to non-X86 architectures. */ |
| /* For now we don't assume that there is always an empty page after */ |
| /* etext. But in some cases there actually seems to be slightly more. */ |
| /* This also deals with holes between read-only data and writable data. */ |
| ptr_t GC_FreeBSDGetDataStart(max_page_size, etext_addr) |
| int max_page_size; |
| int * etext_addr; |
| { |
| word text_end = ((word)(etext_addr) + sizeof(word) - 1) |
| & ~(sizeof(word) - 1); |
| /* etext rounded to word boundary */ |
| VOLATILE word next_page = (text_end + (word)max_page_size - 1) |
| & ~((word)max_page_size - 1); |
| VOLATILE ptr_t result = (ptr_t)text_end; |
| GC_setup_temporary_fault_handler(); |
| if (setjmp(GC_jmp_buf) == 0) { |
| /* Try reading at the address. */ |
| /* This should happen before there is another thread. */ |
| for (; next_page < (word)(DATAEND); next_page += (word)max_page_size) |
| *(VOLATILE char *)next_page; |
| GC_reset_fault_handler(); |
| } else { |
| GC_reset_fault_handler(); |
| /* As above, we go to plan B */ |
| result = GC_find_limit((ptr_t)(DATAEND), FALSE); |
| } |
| return(result); |
| } |
| |
| # endif |
| |
| |
| #ifdef AMIGA |
| |
| # define GC_AMIGA_DS |
| # include "AmigaOS.c" |
| # undef GC_AMIGA_DS |
| |
| #else /* !OS2 && !Windows && !AMIGA */ |
| |
| void GC_register_data_segments() |
| { |
| # if !defined(PCR) && !defined(SRC_M3) && !defined(MACOS) |
| # if defined(REDIRECT_MALLOC) && defined(GC_SOLARIS_THREADS) |
| /* As of Solaris 2.3, the Solaris threads implementation */ |
| /* allocates the data structure for the initial thread with */ |
| /* sbrk at process startup. It needs to be scanned, so that */ |
| /* we don't lose some malloc allocated data structures */ |
| /* hanging from it. We're on thin ice here ... */ |
| extern caddr_t sbrk(); |
| |
| GC_add_roots_inner(DATASTART, (char *)sbrk(0), FALSE); |
| # else |
| GC_add_roots_inner(DATASTART, (char *)(DATAEND), FALSE); |
| # if defined(DATASTART2) |
| GC_add_roots_inner(DATASTART2, (char *)(DATAEND2), FALSE); |
| # endif |
| # endif |
| # endif |
| # if defined(MACOS) |
| { |
| # if defined(THINK_C) |
| extern void* GC_MacGetDataStart(void); |
| /* globals begin above stack and end at a5. */ |
| GC_add_roots_inner((ptr_t)GC_MacGetDataStart(), |
| (ptr_t)LMGetCurrentA5(), FALSE); |
| # else |
| # if defined(__MWERKS__) |
| # if !__POWERPC__ |
| extern void* GC_MacGetDataStart(void); |
| /* MATTHEW: Function to handle Far Globals (CW Pro 3) */ |
| # if __option(far_data) |
| extern void* GC_MacGetDataEnd(void); |
| # endif |
| /* globals begin above stack and end at a5. */ |
| GC_add_roots_inner((ptr_t)GC_MacGetDataStart(), |
| (ptr_t)LMGetCurrentA5(), FALSE); |
| /* MATTHEW: Handle Far Globals */ |
| # if __option(far_data) |
| /* Far globals follow he QD globals: */ |
| GC_add_roots_inner((ptr_t)LMGetCurrentA5(), |
| (ptr_t)GC_MacGetDataEnd(), FALSE); |
| # endif |
| # else |
| extern char __data_start__[], __data_end__[]; |
| GC_add_roots_inner((ptr_t)&__data_start__, |
| (ptr_t)&__data_end__, FALSE); |
| # endif /* __POWERPC__ */ |
| # endif /* __MWERKS__ */ |
| # endif /* !THINK_C */ |
| } |
| # endif /* MACOS */ |
| |
| /* Dynamic libraries are added at every collection, since they may */ |
| /* change. */ |
| } |
| |
| # endif /* ! AMIGA */ |
| # endif /* ! MSWIN32 && ! MSWINCE*/ |
| # endif /* ! OS2 */ |
| |
| /* |
| * Auxiliary routines for obtaining memory from OS. |
| */ |
| |
| # if !defined(OS2) && !defined(PCR) && !defined(AMIGA) \ |
| && !defined(MSWIN32) && !defined(MSWINCE) \ |
| && !defined(MACOS) && !defined(DOS4GW) |
| |
| # ifdef SUNOS4 |
| extern caddr_t sbrk(); |
| # endif |
| # ifdef __STDC__ |
| # define SBRK_ARG_T ptrdiff_t |
| # else |
| # define SBRK_ARG_T int |
| # endif |
| |
| |
| # ifdef RS6000 |
| /* The compiler seems to generate speculative reads one past the end of */ |
| /* an allocated object. Hence we need to make sure that the page */ |
| /* following the last heap page is also mapped. */ |
| ptr_t GC_unix_get_mem(bytes) |
| word bytes; |
| { |
| caddr_t cur_brk = (caddr_t)sbrk(0); |
| caddr_t result; |
| SBRK_ARG_T lsbs = (word)cur_brk & (GC_page_size-1); |
| static caddr_t my_brk_val = 0; |
| |
| if ((SBRK_ARG_T)bytes < 0) return(0); /* too big */ |
| if (lsbs != 0) { |
| if((caddr_t)(sbrk(GC_page_size - lsbs)) == (caddr_t)(-1)) return(0); |
| } |
| if (cur_brk == my_brk_val) { |
| /* Use the extra block we allocated last time. */ |
| result = (ptr_t)sbrk((SBRK_ARG_T)bytes); |
| if (result == (caddr_t)(-1)) return(0); |
| result -= GC_page_size; |
| } else { |
| result = (ptr_t)sbrk(GC_page_size + (SBRK_ARG_T)bytes); |
| if (result == (caddr_t)(-1)) return(0); |
| } |
| my_brk_val = result + bytes + GC_page_size; /* Always page aligned */ |
| return((ptr_t)result); |
| } |
| |
| #else /* Not RS6000 */ |
| |
| #if defined(USE_MMAP) |
| /* Tested only under Linux, IRIX5 and Solaris 2 */ |
| |
| #ifdef USE_MMAP_FIXED |
| # define GC_MMAP_FLAGS MAP_FIXED | MAP_PRIVATE |
| /* Seems to yield better performance on Solaris 2, but can */ |
| /* be unreliable if something is already mapped at the address. */ |
| #else |
| # define GC_MMAP_FLAGS MAP_PRIVATE |
| #endif |
| |
| #ifndef HEAP_START |
| # define HEAP_START 0 |
| #endif |
| |
| ptr_t GC_unix_get_mem(bytes) |
| word bytes; |
| { |
| void *result; |
| static ptr_t last_addr = HEAP_START; |
| |
| # ifndef USE_MMAP_ANON |
| static GC_bool initialized = FALSE; |
| static int fd; |
| |
| if (!initialized) { |
| fd = open("/dev/zero", O_RDONLY); |
| fcntl(fd, F_SETFD, FD_CLOEXEC); |
| initialized = TRUE; |
| } |
| # endif |
| |
| if (bytes & (GC_page_size -1)) ABORT("Bad GET_MEM arg"); |
| # ifdef USE_MMAP_ANON |
| result = mmap(last_addr, bytes, PROT_READ | PROT_WRITE | OPT_PROT_EXEC, |
| GC_MMAP_FLAGS | MAP_ANON, -1, 0/* offset */); |
| # else |
| result = mmap(last_addr, bytes, PROT_READ | PROT_WRITE | OPT_PROT_EXEC, |
| GC_MMAP_FLAGS, fd, 0/* offset */); |
| # endif |
| if (result == MAP_FAILED) return(0); |
| last_addr = (ptr_t)result + bytes + GC_page_size - 1; |
| last_addr = (ptr_t)((word)last_addr & ~(GC_page_size - 1)); |
| # if !defined(LINUX) |
| if (last_addr == 0) { |
| /* Oops. We got the end of the address space. This isn't */ |
| /* usable by arbitrary C code, since one-past-end pointers */ |
| /* don't work, so we discard it and try again. */ |
| munmap(result, (size_t)(-GC_page_size) - (size_t)result); |
| /* Leave last page mapped, so we can't repeat. */ |
| return GC_unix_get_mem(bytes); |
| } |
| # else |
| GC_ASSERT(last_addr != 0); |
| # endif |
| return((ptr_t)result); |
| } |
| |
| #else /* Not RS6000, not USE_MMAP */ |
| ptr_t GC_unix_get_mem(bytes) |
| word bytes; |
| { |
| ptr_t result; |
| # ifdef IRIX5 |
| /* Bare sbrk isn't thread safe. Play by malloc rules. */ |
| /* The equivalent may be needed on other systems as well. */ |
| __LOCK_MALLOC(); |
| # endif |
| { |
| ptr_t cur_brk = (ptr_t)sbrk(0); |
| SBRK_ARG_T lsbs = (word)cur_brk & (GC_page_size-1); |
| |
| if ((SBRK_ARG_T)bytes < 0) return(0); /* too big */ |
| if (lsbs != 0) { |
| if((ptr_t)sbrk(GC_page_size - lsbs) == (ptr_t)(-1)) return(0); |
| } |
| result = (ptr_t)sbrk((SBRK_ARG_T)bytes); |
| if (result == (ptr_t)(-1)) result = 0; |
| } |
| # ifdef IRIX5 |
| __UNLOCK_MALLOC(); |
| # endif |
| return(result); |
| } |
| |
| #endif /* Not USE_MMAP */ |
| #endif /* Not RS6000 */ |
| |
| # endif /* UN*X */ |
| |
| # ifdef OS2 |
| |
| void * os2_alloc(size_t bytes) |
| { |
| void * result; |
| |
| if (DosAllocMem(&result, bytes, PAG_EXECUTE | PAG_READ | |
| PAG_WRITE | PAG_COMMIT) |
| != NO_ERROR) { |
| return(0); |
| } |
| if (result == 0) return(os2_alloc(bytes)); |
| return(result); |
| } |
| |
| # endif /* OS2 */ |
| |
| |
| # if defined(MSWIN32) || defined(MSWINCE) |
| SYSTEM_INFO GC_sysinfo; |
| # endif |
| |
| # ifdef MSWIN32 |
| |
| # ifdef USE_GLOBAL_ALLOC |
| # define GLOBAL_ALLOC_TEST 1 |
| # else |
| # define GLOBAL_ALLOC_TEST GC_no_win32_dlls |
| # endif |
| |
| word GC_n_heap_bases = 0; |
| |
| ptr_t GC_win32_get_mem(bytes) |
| word bytes; |
| { |
| ptr_t result; |
| |
| if (GLOBAL_ALLOC_TEST) { |
| /* VirtualAlloc doesn't like PAGE_EXECUTE_READWRITE. */ |
| /* There are also unconfirmed rumors of other */ |
| /* problems, so we dodge the issue. */ |
| result = (ptr_t) GlobalAlloc(0, bytes + HBLKSIZE); |
| result = (ptr_t)(((word)result + HBLKSIZE) & ~(HBLKSIZE-1)); |
| } else { |
| /* VirtualProtect only works on regions returned by a */ |
| /* single VirtualAlloc call. Thus we allocate one */ |
| /* extra page, which will prevent merging of blocks */ |
| /* in separate regions, and eliminate any temptation */ |
| /* to call VirtualProtect on a range spanning regions. */ |
| /* This wastes a small amount of memory, and risks */ |
| /* increased fragmentation. But better alternatives */ |
| /* would require effort. */ |
| result = (ptr_t) VirtualAlloc(NULL, bytes + 1, |
| MEM_COMMIT | MEM_RESERVE, |
| PAGE_EXECUTE_READWRITE); |
| } |
| if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result"); |
| /* If I read the documentation correctly, this can */ |
| /* only happen if HBLKSIZE > 64k or not a power of 2. */ |
| if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections"); |
| GC_heap_bases[GC_n_heap_bases++] = result; |
| return(result); |
| } |
| |
| void GC_win32_free_heap () |
| { |
| if (GC_no_win32_dlls) { |
| while (GC_n_heap_bases > 0) { |
| GlobalFree (GC_heap_bases[--GC_n_heap_bases]); |
| GC_heap_bases[GC_n_heap_bases] = 0; |
| } |
| } |
| } |
| # endif |
| |
| #ifdef AMIGA |
| # define GC_AMIGA_AM |
| # include "AmigaOS.c" |
| # undef GC_AMIGA_AM |
| #endif |
| |
| |
| # ifdef MSWINCE |
| word GC_n_heap_bases = 0; |
| |
| ptr_t GC_wince_get_mem(bytes) |
| word bytes; |
| { |
| ptr_t result; |
| word i; |
| |
| /* Round up allocation size to multiple of page size */ |
| bytes = (bytes + GC_page_size-1) & ~(GC_page_size-1); |
| |
| /* Try to find reserved, uncommitted pages */ |
| for (i = 0; i < GC_n_heap_bases; i++) { |
| if (((word)(-(signed_word)GC_heap_lengths[i]) |
| & (GC_sysinfo.dwAllocationGranularity-1)) |
| >= bytes) { |
| result = GC_heap_bases[i] + GC_heap_lengths[i]; |
| break; |
| } |
| } |
| |
| if (i == GC_n_heap_bases) { |
| /* Reserve more pages */ |
| word res_bytes = (bytes + GC_sysinfo.dwAllocationGranularity-1) |
| & ~(GC_sysinfo.dwAllocationGranularity-1); |
| /* If we ever support MPROTECT_VDB here, we will probably need to */ |
| /* ensure that res_bytes is strictly > bytes, so that VirtualProtect */ |
| /* never spans regions. It seems to be OK for a VirtualFree argument */ |
| /* to span regions, so we should be OK for now. */ |
| result = (ptr_t) VirtualAlloc(NULL, res_bytes, |
| MEM_RESERVE | MEM_TOP_DOWN, |
| PAGE_EXECUTE_READWRITE); |
| if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result"); |
| /* If I read the documentation correctly, this can */ |
| /* only happen if HBLKSIZE > 64k or not a power of 2. */ |
| if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections"); |
| GC_heap_bases[GC_n_heap_bases] = result; |
| GC_heap_lengths[GC_n_heap_bases] = 0; |
| GC_n_heap_bases++; |
| } |
| |
| /* Commit pages */ |
| result = (ptr_t) VirtualAlloc(result, bytes, |
| MEM_COMMIT, |
| PAGE_EXECUTE_READWRITE); |
| if (result != NULL) { |
| if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result"); |
| GC_heap_lengths[i] += bytes; |
| } |
| |
| return(result); |
| } |
| # endif |
| |
| #ifdef USE_MUNMAP |
| |
| /* For now, this only works on Win32/WinCE and some Unix-like */ |
| /* systems. If you have something else, don't define */ |
| /* USE_MUNMAP. */ |
| /* We assume ANSI C to support this feature. */ |
| |
| #if !defined(MSWIN32) && !defined(MSWINCE) |
| |
| #include <unistd.h> |
| #include <sys/mman.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| |
| #endif |
| |
| /* Compute a page aligned starting address for the unmap */ |
| /* operation on a block of size bytes starting at start. */ |
| /* Return 0 if the block is too small to make this feasible. */ |
| ptr_t GC_unmap_start(ptr_t start, word bytes) |
| { |
| ptr_t result = start; |
| /* Round start to next page boundary. */ |
| result += GC_page_size - 1; |
| result = (ptr_t)((word)result & ~(GC_page_size - 1)); |
| if (result + GC_page_size > start + bytes) return 0; |
| return result; |
| } |
| |
| /* Compute end address for an unmap operation on the indicated */ |
| /* block. */ |
| ptr_t GC_unmap_end(ptr_t start, word bytes) |
| { |
| ptr_t end_addr = start + bytes; |
| end_addr = (ptr_t)((word)end_addr & ~(GC_page_size - 1)); |
| return end_addr; |
| } |
| |
| /* Under Win32/WinCE we commit (map) and decommit (unmap) */ |
| /* memory using VirtualAlloc and VirtualFree. These functions */ |
| /* work on individual allocations of virtual memory, made */ |
| /* previously using VirtualAlloc with the MEM_RESERVE flag. */ |
| /* The ranges we need to (de)commit may span several of these */ |
| /* allocations; therefore we use VirtualQuery to check */ |
| /* allocation lengths, and split up the range as necessary. */ |
| |
| /* We assume that GC_remap is called on exactly the same range */ |
| /* as a previous call to GC_unmap. It is safe to consistently */ |
| /* round the endpoints in both places. */ |
| void GC_unmap(ptr_t start, word bytes) |
| { |
| ptr_t start_addr = GC_unmap_start(start, bytes); |
| ptr_t end_addr = GC_unmap_end(start, bytes); |
| word len = end_addr - start_addr; |
| if (0 == start_addr) return; |
| # if defined(MSWIN32) || defined(MSWINCE) |
| while (len != 0) { |
| MEMORY_BASIC_INFORMATION mem_info; |
| GC_word free_len; |
| if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info)) |
| != sizeof(mem_info)) |
| ABORT("Weird VirtualQuery result"); |
| free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize; |
| if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT)) |
| ABORT("VirtualFree failed"); |
| GC_unmapped_bytes += free_len; |
| start_addr += free_len; |
| len -= free_len; |
| } |
| # else |
| if (munmap(start_addr, len) != 0) ABORT("munmap failed"); |
| GC_unmapped_bytes += len; |
| # endif |
| } |
| |
| |
| void GC_remap(ptr_t start, word bytes) |
| { |
| static int zero_descr = -1; |
| ptr_t start_addr = GC_unmap_start(start, bytes); |
| ptr_t end_addr = GC_unmap_end(start, bytes); |
| word len = end_addr - start_addr; |
| ptr_t result; |
| |
| # if defined(MSWIN32) || defined(MSWINCE) |
| if (0 == start_addr) return; |
| while (len != 0) { |
| MEMORY_BASIC_INFORMATION mem_info; |
| GC_word alloc_len; |
| if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info)) |
| != sizeof(mem_info)) |
| ABORT("Weird VirtualQuery result"); |
| alloc_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize; |
| result = VirtualAlloc(start_addr, alloc_len, |
| MEM_COMMIT, |
| PAGE_EXECUTE_READWRITE); |
| if (result != start_addr) { |
| ABORT("VirtualAlloc remapping failed"); |
| } |
| GC_unmapped_bytes -= alloc_len; |
| start_addr += alloc_len; |
| len -= alloc_len; |
| } |
| # else |
| if (-1 == zero_descr) zero_descr = open("/dev/zero", O_RDWR); |
| fcntl(zero_descr, F_SETFD, FD_CLOEXEC); |
| if (0 == start_addr) return; |
| result = mmap(start_addr, len, PROT_READ | PROT_WRITE | OPT_PROT_EXEC, |
| MAP_FIXED | MAP_PRIVATE, zero_descr, 0); |
| if (result != start_addr) { |
| ABORT("mmap remapping failed"); |
| } |
| GC_unmapped_bytes -= len; |
| # endif |
| } |
| |
| /* Two adjacent blocks have already been unmapped and are about to */ |
| /* be merged. Unmap the whole block. This typically requires */ |
| /* that we unmap a small section in the middle that was not previously */ |
| /* unmapped due to alignment constraints. */ |
| void GC_unmap_gap(ptr_t start1, word bytes1, ptr_t start2, word bytes2) |
| { |
| ptr_t start1_addr = GC_unmap_start(start1, bytes1); |
| ptr_t end1_addr = GC_unmap_end(start1, bytes1); |
| ptr_t start2_addr = GC_unmap_start(start2, bytes2); |
| ptr_t end2_addr = GC_unmap_end(start2, bytes2); |
| ptr_t start_addr = end1_addr; |
| ptr_t end_addr = start2_addr; |
| word len; |
| GC_ASSERT(start1 + bytes1 == start2); |
| if (0 == start1_addr) start_addr = GC_unmap_start(start1, bytes1 + bytes2); |
| if (0 == start2_addr) end_addr = GC_unmap_end(start1, bytes1 + bytes2); |
| if (0 == start_addr) return; |
| len = end_addr - start_addr; |
| # if defined(MSWIN32) || defined(MSWINCE) |
| while (len != 0) { |
| MEMORY_BASIC_INFORMATION mem_info; |
| GC_word free_len; |
| if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info)) |
| != sizeof(mem_info)) |
| ABORT("Weird VirtualQuery result"); |
| free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize; |
| if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT)) |
| ABORT("VirtualFree failed"); |
| GC_unmapped_bytes += free_len; |
| start_addr += free_len; |
| len -= free_len; |
| } |
| # else |
| if (len != 0 && munmap(start_addr, len) != 0) ABORT("munmap failed"); |
| GC_unmapped_bytes += len; |
| # endif |
| } |
| |
| #endif /* USE_MUNMAP */ |
| |
| /* Routine for pushing any additional roots. In THREADS */ |
| /* environment, this is also responsible for marking from */ |
| /* thread stacks. */ |
| #ifndef THREADS |
| void (*GC_push_other_roots)() = 0; |
| #else /* THREADS */ |
| |
| # ifdef PCR |
| PCR_ERes GC_push_thread_stack(PCR_Th_T *t, PCR_Any dummy) |
| { |
| struct PCR_ThCtl_TInfoRep info; |
| PCR_ERes result; |
| |
| info.ti_stkLow = info.ti_stkHi = 0; |
| result = PCR_ThCtl_GetInfo(t, &info); |
| GC_push_all_stack((ptr_t)(info.ti_stkLow), (ptr_t)(info.ti_stkHi)); |
| return(result); |
| } |
| |
| /* Push the contents of an old object. We treat this as stack */ |
| /* data only becasue that makes it robust against mark stack */ |
| /* overflow. */ |
| PCR_ERes GC_push_old_obj(void *p, size_t size, PCR_Any data) |
| { |
| GC_push_all_stack((ptr_t)p, (ptr_t)p + size); |
| return(PCR_ERes_okay); |
| } |
| |
| |
| void GC_default_push_other_roots GC_PROTO((void)) |
| { |
| /* Traverse data allocated by previous memory managers. */ |
| { |
| extern struct PCR_MM_ProcsRep * GC_old_allocator; |
| |
| if ((*(GC_old_allocator->mmp_enumerate))(PCR_Bool_false, |
| GC_push_old_obj, 0) |
| != PCR_ERes_okay) { |
| ABORT("Old object enumeration failed"); |
| } |
| } |
| /* Traverse all thread stacks. */ |
| if (PCR_ERes_IsErr( |
| PCR_ThCtl_ApplyToAllOtherThreads(GC_push_thread_stack,0)) |
| || PCR_ERes_IsErr(GC_push_thread_stack(PCR_Th_CurrThread(), 0))) { |
| ABORT("Thread stack marking failed\n"); |
| } |
| } |
| |
| # endif /* PCR */ |
| |
| # ifdef SRC_M3 |
| |
| # ifdef ALL_INTERIOR_POINTERS |
| --> misconfigured |
| # endif |
| |
| void GC_push_thread_structures GC_PROTO((void)) |
| { |
| /* Not our responsibibility. */ |
| } |
| |
| extern void ThreadF__ProcessStacks(); |
| |
| void GC_push_thread_stack(start, stop) |
| word start, stop; |
| { |
| GC_push_all_stack((ptr_t)start, (ptr_t)stop + sizeof(word)); |
| } |
| |
| /* Push routine with M3 specific calling convention. */ |
| GC_m3_push_root(dummy1, p, dummy2, dummy3) |
| word *p; |
| ptr_t dummy1, dummy2; |
| int dummy3; |
| { |
| word q = *p; |
| |
| GC_PUSH_ONE_STACK(q, p); |
| } |
| |
| /* M3 set equivalent to RTHeap.TracedRefTypes */ |
| typedef struct { int elts[1]; } RefTypeSet; |
| RefTypeSet GC_TracedRefTypes = {{0x1}}; |
| |
| void GC_default_push_other_roots GC_PROTO((void)) |
| { |
| /* Use the M3 provided routine for finding static roots. */ |
| /* This is a bit dubious, since it presumes no C roots. */ |
| /* We handle the collector roots explicitly in GC_push_roots */ |
| RTMain__GlobalMapProc(GC_m3_push_root, 0, GC_TracedRefTypes); |
| if (GC_words_allocd > 0) { |
| ThreadF__ProcessStacks(GC_push_thread_stack); |
| } |
| /* Otherwise this isn't absolutely necessary, and we have */ |
| /* startup ordering problems. */ |
| } |
| |
| # endif /* SRC_M3 */ |
| |
| # if defined(GC_SOLARIS_THREADS) || defined(GC_PTHREADS) || \ |
| defined(GC_WIN32_THREADS) |
| |
| extern void GC_push_all_stacks(); |
| |
| void GC_default_push_other_roots GC_PROTO((void)) |
| { |
| GC_push_all_stacks(); |
| } |
| |
| # endif /* GC_SOLARIS_THREADS || GC_PTHREADS */ |
| |
| void (*GC_push_other_roots) GC_PROTO((void)) = GC_default_push_other_roots; |
| |
| #endif /* THREADS */ |
| |
| /* |
| * Routines for accessing dirty bits on virtual pages. |
| * We plan to eventually implement four strategies for doing so: |
| * DEFAULT_VDB: A simple dummy implementation that treats every page |
| * as possibly dirty. This makes incremental collection |
| * useless, but the implementation is still correct. |
| * PCR_VDB: Use PPCRs virtual dirty bit facility. |
| * PROC_VDB: Use the /proc facility for reading dirty bits. Only |
| * works under some SVR4 variants. Even then, it may be |
| * too slow to be entirely satisfactory. Requires reading |
| * dirty bits for entire address space. Implementations tend |
| * to assume that the client is a (slow) debugger. |
| * MPROTECT_VDB:Protect pages and then catch the faults to keep track of |
| * dirtied pages. The implementation (and implementability) |
| * is highly system dependent. This usually fails when system |
| * calls write to a protected page. We prevent the read system |
| * call from doing so. It is the clients responsibility to |
| * make sure that other system calls are similarly protected |
| * or write only to the stack. |
| */ |
| GC_bool GC_dirty_maintained = FALSE; |
| |
| # ifdef DEFAULT_VDB |
| |
| /* All of the following assume the allocation lock is held, and */ |
| /* signals are disabled. */ |
| |
| /* The client asserts that unallocated pages in the heap are never */ |
| /* written. */ |
| |
| /* Initialize virtual dirty bit implementation. */ |
| void GC_dirty_init() |
| { |
| # ifdef PRINTSTATS |
| GC_printf0("Initializing DEFAULT_VDB...\n"); |
| # endif |
| GC_dirty_maintained = TRUE; |
| } |
| |
| /* Retrieve system dirty bits for heap to a local buffer. */ |
| /* Restore the systems notion of which pages are dirty. */ |
| void GC_read_dirty() |
| {} |
| |
| /* Is the HBLKSIZE sized page at h marked dirty in the local buffer? */ |
| /* If the actual page size is different, this returns TRUE if any */ |
| /* of the pages overlapping h are dirty. This routine may err on the */ |
| /* side of labelling pages as dirty (and this implementation does). */ |
| /*ARGSUSED*/ |
| GC_bool GC_page_was_dirty(h) |
| struct hblk *h; |
| { |
| return(TRUE); |
| } |
| |
| /* |
| * The following two routines are typically less crucial. They matter |
| * most with large dynamic libraries, or if we can't accurately identify |
| * stacks, e.g. under Solaris 2.X. Otherwise the following default |
| * versions are adequate. |
| */ |
| |
| /* Could any valid GC heap pointer ever have been written to this page? */ |
| /*ARGSUSED*/ |
| GC_bool GC_page_was_ever_dirty(h) |
| struct hblk *h; |
| { |
| return(TRUE); |
| } |
| |
| /* Reset the n pages starting at h to "was never dirty" status. */ |
| void GC_is_fresh(h, n) |
| struct hblk *h; |
| word n; |
| { |
| } |
| |
| /* A call that: */ |
| /* I) hints that [h, h+nblocks) is about to be written. */ |
| /* II) guarantees that protection is removed. */ |
| /* (I) may speed up some dirty bit implementations. */ |
| /* (II) may be essential if we need to ensure that */ |
| /* pointer-free system call buffers in the heap are */ |
| /* not protected. */ |
| /*ARGSUSED*/ |
| void GC_remove_protection(h, nblocks, is_ptrfree) |
| struct hblk *h; |
| word nblocks; |
| GC_bool is_ptrfree; |
| { |
| } |
| |
| # endif /* DEFAULT_VDB */ |
| |
| |
| # ifdef MPROTECT_VDB |
| |
| /* |
| * See DEFAULT_VDB for interface descriptions. |
| */ |
| |
| /* |
| * This implementation maintains dirty bits itself by catching write |
| * faults and keeping track of them. We assume nobody else catches |
| * SIGBUS or SIGSEGV. We assume no write faults occur in system calls. |
| * This means that clients must ensure that system calls don't write |
| * to the write-protected heap. Probably the best way to do this is to |
| * ensure that system calls write at most to POINTERFREE objects in the |
| * heap, and do even that only if we are on a platform on which those |
| * are not protected. Another alternative is to wrap system calls |
| * (see example for read below), but the current implementation holds |
| * a lock across blocking calls, making it problematic for multithreaded |
| * applications. |
| * We assume the page size is a multiple of HBLKSIZE. |
| * We prefer them to be the same. We avoid protecting POINTERFREE |
| * objects only if they are the same. |
| */ |
| |
| # if !defined(MSWIN32) && !defined(MSWINCE) && !defined(DARWIN) |
| |
| # include <sys/mman.h> |
| # include <signal.h> |
| # include <sys/syscall.h> |
| |
| # define PROTECT(addr, len) \ |
| if (mprotect((caddr_t)(addr), (size_t)(len), \ |
| PROT_READ | OPT_PROT_EXEC) < 0) { \ |
| ABORT("mprotect failed"); \ |
| } |
| # define UNPROTECT(addr, len) \ |
| if (mprotect((caddr_t)(addr), (size_t)(len), \ |
| PROT_WRITE | PROT_READ | OPT_PROT_EXEC ) < 0) { \ |
| ABORT("un-mprotect failed"); \ |
| } |
| |
| # else |
| |
| # ifdef DARWIN |
| /* Using vm_protect (mach syscall) over mprotect (BSD syscall) seems to |
| decrease the likelihood of some of the problems described below. */ |
| #include <mach/vm_map.h> |
| extern mach_port_t GC_task_self; |
| #define PROTECT(addr,len) \ |
| if(vm_protect(GC_task_self,(vm_address_t)(addr),(vm_size_t)(len), \ |
| FALSE,VM_PROT_READ) != KERN_SUCCESS) { \ |
| ABORT("vm_portect failed"); \ |
| } |
| #define UNPROTECT(addr,len) \ |
| if(vm_protect(GC_task_self,(vm_address_t)(addr),(vm_size_t)(len), \ |
| FALSE,VM_PROT_READ|VM_PROT_WRITE) != KERN_SUCCESS) { \ |
| ABORT("vm_portect failed"); \ |
| } |
| # else |
| |
| # ifndef MSWINCE |
| # include <signal.h> |
| # endif |
| |
| static DWORD protect_junk; |
| # define PROTECT(addr, len) \ |
| if (!VirtualProtect((addr), (len), PAGE_EXECUTE_READ, \ |
| &protect_junk)) { \ |
| DWORD last_error = GetLastError(); \ |
| GC_printf1("Last error code: %lx\n", last_error); \ |
| ABORT("VirtualProtect failed"); \ |
| } |
| # define UNPROTECT(addr, len) \ |
| if (!VirtualProtect((addr), (len), PAGE_EXECUTE_READWRITE, \ |
| &protect_junk)) { \ |
| ABORT("un-VirtualProtect failed"); \ |
| } |
| # endif /* !DARWIN */ |
| # endif /* MSWIN32 || MSWINCE || DARWIN */ |
| |
| #if defined(SUNOS4) || defined(FREEBSD) |
| typedef void (* SIG_PF)(); |
| #endif /* SUNOS4 || FREEBSD */ |
| |
| #if defined(SUNOS5SIGS) || defined(OSF1) || defined(LINUX) \ |
| || defined(HURD) |
| # ifdef __STDC__ |
| typedef void (* SIG_PF)(int); |
| # else |
| typedef void (* SIG_PF)(); |
| # endif |
| #endif /* SUNOS5SIGS || OSF1 || LINUX || HURD */ |
| |
| #if defined(MSWIN32) |
| typedef LPTOP_LEVEL_EXCEPTION_FILTER SIG_PF; |
| # undef SIG_DFL |
| # define SIG_DFL (LPTOP_LEVEL_EXCEPTION_FILTER) (-1) |
| #endif |
| #if defined(MSWINCE) |
| typedef LONG (WINAPI *SIG_PF)(struct _EXCEPTION_POINTERS *); |
| # undef SIG_DFL |
| # define SIG_DFL (SIG_PF) (-1) |
| #endif |
| |
| #if defined(IRIX5) || defined(OSF1) || defined(HURD) |
| typedef void (* REAL_SIG_PF)(int, int, struct sigcontext *); |
| #endif /* IRIX5 || OSF1 || HURD */ |
| |
| #if defined(SUNOS5SIGS) |
| # ifdef HPUX |
| # define SIGINFO __siginfo |
| # else |
| # define SIGINFO siginfo |
| # endif |
| # ifdef __STDC__ |
| typedef void (* REAL_SIG_PF)(int, struct SIGINFO *, void *); |
| # else |
| typedef void (* REAL_SIG_PF)(); |
| # endif |
| #endif /* SUNOS5SIGS */ |
| |
| #if defined(LINUX) |
| # if __GLIBC__ > 2 || __GLIBC__ == 2 && __GLIBC_MINOR__ >= 2 |
| typedef struct sigcontext s_c; |
| # else /* glibc < 2.2 */ |
| # include <linux/version.h> |
| # if (LINUX_VERSION_CODE >= 0x20100) && !defined(M68K) || defined(ALPHA) || defined(ARM32) |
| typedef struct sigcontext s_c; |
| # else |
| typedef struct sigcontext_struct s_c; |
| # endif |
| # endif /* glibc < 2.2 */ |
| # if defined(ALPHA) || defined(M68K) |
| typedef void (* REAL_SIG_PF)(int, int, s_c *); |
| # else |
| # if defined(IA64) || defined(HP_PA) |
| typedef void (* REAL_SIG_PF)(int, siginfo_t *, s_c *); |
| # else |
| typedef void (* REAL_SIG_PF)(int, s_c); |
| # endif |
| # endif |
| # ifdef ALPHA |
| /* Retrieve fault address from sigcontext structure by decoding */ |
| /* instruction. */ |
| char * get_fault_addr(s_c *sc) { |
| unsigned instr; |
| word faultaddr; |
| |
| instr = *((unsigned *)(sc->sc_pc)); |
| faultaddr = sc->sc_regs[(instr >> 16) & 0x1f]; |
| faultaddr += (word) (((int)instr << 16) >> 16); |
| return (char *)faultaddr; |
| } |
| # endif /* !ALPHA */ |
| # endif /* LINUX */ |
| |
| #ifndef DARWIN |
| SIG_PF GC_old_bus_handler; |
| SIG_PF GC_old_segv_handler; /* Also old MSWIN32 ACCESS_VIOLATION filter */ |
| #endif /* !DARWIN */ |
| |
| #if defined(THREADS) |
| /* We need to lock around the bitmap update in the write fault handler */ |
| /* in order to avoid the risk of losing a bit. We do this with a */ |
| /* test-and-set spin lock if we know how to do that. Otherwise we */ |
| /* check whether we are already in the handler and use the dumb but */ |
| /* safe fallback algorithm of setting all bits in the word. */ |
| /* Contention should be very rare, so we do the minimum to handle it */ |
| /* correctly. */ |
| #ifdef GC_TEST_AND_SET_DEFINED |
| static VOLATILE unsigned int fault_handler_lock = 0; |
| void async_set_pht_entry_from_index(VOLATILE page_hash_table db, int index) { |
| while (GC_test_and_set(&fault_handler_lock)) {} |
| /* Could also revert to set_pht_entry_from_index_safe if initial */ |
| /* GC_test_and_set fails. */ |
| set_pht_entry_from_index(db, index); |
| GC_clear(&fault_handler_lock); |
| } |
| #else /* !GC_TEST_AND_SET_DEFINED */ |
| /* THIS IS INCORRECT! The dirty bit vector may be temporarily wrong, */ |
| /* just before we notice the conflict and correct it. We may end up */ |
| /* looking at it while it's wrong. But this requires contention */ |
| /* exactly when a GC is triggered, which seems far less likely to */ |
| /* fail than the old code, which had no reported failures. Thus we */ |
| /* leave it this way while we think of something better, or support */ |
| /* GC_test_and_set on the remaining platforms. */ |
| static VOLATILE word currently_updating = 0; |
| void async_set_pht_entry_from_index(VOLATILE page_hash_table db, int index) { |
| unsigned int update_dummy; |
| currently_updating = (word)(&update_dummy); |
| set_pht_entry_from_index(db, index); |
| /* If we get contention in the 10 or so instruction window here, */ |
| /* and we get stopped by a GC between the two updates, we lose! */ |
| if (currently_updating != (word)(&update_dummy)) { |
| set_pht_entry_from_index_safe(db, index); |
| /* We claim that if two threads concurrently try to update the */ |
| /* dirty bit vector, the first one to execute UPDATE_START */ |
| /* will see it changed when UPDATE_END is executed. (Note that */ |
| /* &update_dummy must differ in two distinct threads.) It */ |
| /* will then execute set_pht_entry_from_index_safe, thus */ |
| /* returning us to a safe state, though not soon enough. */ |
| } |
| } |
| #endif /* !GC_TEST_AND_SET_DEFINED */ |
| #else /* !THREADS */ |
| # define async_set_pht_entry_from_index(db, index) \ |
| set_pht_entry_from_index(db, index) |
| #endif /* !THREADS */ |
| |
| /*ARGSUSED*/ |
| #if !defined(DARWIN) |
| # if defined (SUNOS4) || defined(FREEBSD) |
| void GC_write_fault_handler(sig, code, scp, addr) |
| int sig, code; |
| struct sigcontext *scp; |
| char * addr; |
| # ifdef SUNOS4 |
| # define SIG_OK (sig == SIGSEGV || sig == SIGBUS) |
| # define CODE_OK (FC_CODE(code) == FC_PROT \ |
| || (FC_CODE(code) == FC_OBJERR \ |
| && FC_ERRNO(code) == FC_PROT)) |
| # endif |
| # ifdef FREEBSD |
| # define SIG_OK (sig == SIGBUS) |
| # define CODE_OK (code == BUS_PAGE_FAULT) |
| # endif |
| # endif /* SUNOS4 || FREEBSD */ |
| |
| # if defined(IRIX5) || defined(OSF1) || defined(HURD) |
| # include <errno.h> |
| void GC_write_fault_handler(int sig, int code, struct sigcontext *scp) |
| # ifdef OSF1 |
| # define SIG_OK (sig == SIGSEGV) |
| # define CODE_OK (code == 2 /* experimentally determined */) |
| # endif |
| # ifdef IRIX5 |
| # define SIG_OK (sig == SIGSEGV) |
| # define CODE_OK (code == EACCES) |
| # endif |
| # ifdef HURD |
| # define SIG_OK (sig == SIGBUS || sig == SIGSEGV) |
| # define CODE_OK TRUE |
| # endif |
| # endif /* IRIX5 || OSF1 || HURD */ |
| |
| # if defined(LINUX) |
| # if defined(ALPHA) || defined(M68K) |
| void GC_write_fault_handler(int sig, int code, s_c * sc) |
| # else |
| # if defined(IA64) || defined(HP_PA) |
| void GC_write_fault_handler(int sig, siginfo_t * si, s_c * scp) |
| # else |
| # if defined(ARM32) |
| void GC_write_fault_handler(int sig, int a2, int a3, int a4, s_c sc) |
| # else |
| void GC_write_fault_handler(int sig, s_c sc) |
| # endif |
| # endif |
| # endif |
| # define SIG_OK (sig == SIGSEGV) |
| # define CODE_OK TRUE |
| /* Empirically c.trapno == 14, on IA32, but is that useful? */ |
| /* Should probably consider alignment issues on other */ |
| /* architectures. */ |
| # endif /* LINUX */ |
| |
| # if defined(SUNOS5SIGS) |
| # ifdef __STDC__ |
| void GC_write_fault_handler(int sig, struct SIGINFO *scp, void * context) |
| # else |
| void GC_write_fault_handler(sig, scp, context) |
| int sig; |
| struct SIGINFO *scp; |
| void * context; |
| # endif |
| # ifdef HPUX |
| # define SIG_OK (sig == SIGSEGV || sig == SIGBUS) |
| # define CODE_OK (scp -> si_code == SEGV_ACCERR) \ |
| || (scp -> si_code == BUS_ADRERR) \ |
| || (scp -> si_code == BUS_UNKNOWN) \ |
| || (scp -> si_code == SEGV_UNKNOWN) \ |
| || (scp -> si_code == BUS_OBJERR) |
| # else |
| # define SIG_OK (sig == SIGSEGV) |
| # define CODE_OK (scp -> si_code == SEGV_ACCERR) |
| # endif |
| # endif /* SUNOS5SIGS */ |
| |
| # if defined(MSWIN32) || defined(MSWINCE) |
| LONG WINAPI GC_write_fault_handler(struct _EXCEPTION_POINTERS *exc_info) |
| # define SIG_OK (exc_info -> ExceptionRecord -> ExceptionCode == \ |
| STATUS_ACCESS_VIOLATION) |
| # define CODE_OK (exc_info -> ExceptionRecord -> ExceptionInformation[0] == 1) |
| /* Write fault */ |
| # endif /* MSWIN32 || MSWINCE */ |
| { |
| register unsigned i; |
| # if defined(HURD) |
| char *addr = (char *) code; |
| # endif |
| # ifdef IRIX5 |
| char * addr = (char *) (size_t) (scp -> sc_badvaddr); |
| # endif |
| # if defined(OSF1) && defined(ALPHA) |
| char * addr = (char *) (scp -> sc_traparg_a0); |
| # endif |
| # ifdef SUNOS5SIGS |
| char * addr = (char *) (scp -> si_addr); |
| # endif |
| # ifdef LINUX |
| # if defined(I386) || defined (X86_64) |
| char * addr = (char *) (sc.cr2); |
| # else |
| # if defined(M68K) |
| char * addr = NULL; |
| |
| struct sigcontext *scp = (struct sigcontext *)(sc); |
| |
| int format = (scp->sc_formatvec >> 12) & 0xf; |
| unsigned long *framedata = (unsigned long *)(scp + 1); |
| unsigned long ea; |
| |
| if (format == 0xa || format == 0xb) { |
| /* 68020/030 */ |
| ea = framedata[2]; |
| } else if (format == 7) { |
| /* 68040 */ |
| ea = framedata[3]; |
| if (framedata[1] & 0x08000000) { |
| /* correct addr on misaligned access */ |
| ea = (ea+4095)&(~4095); |
| } |
| } else if (format == 4) { |
| /* 68060 */ |
| ea = framedata[0]; |
| if (framedata[1] & 0x08000000) { |
| /* correct addr on misaligned access */ |
| ea = (ea+4095)&(~4095); |
| } |
| } |
| addr = (char *)ea; |
| # else |
| # ifdef ALPHA |
| char * addr = get_fault_addr(sc); |
| # else |
| # if defined(IA64) || defined(HP_PA) |
| char * addr = si -> si_addr; |
| /* I believe this is claimed to work on all platforms for */ |
| /* Linux 2.3.47 and later. Hopefully we don't have to */ |
| /* worry about earlier kernels on IA64. */ |
| # else |
| # if defined(POWERPC) |
| char * addr = (char *) (sc.regs->dar); |
| # else |
| # if defined(ARM32) |
| char * addr = (char *)sc.fault_address; |
| # else |
| --> architecture not supported |
| # endif |
| # endif |
| # endif |
| # endif |
| # endif |
| # endif |
| # endif |
| # if defined(MSWIN32) || defined(MSWINCE) |
| char * addr = (char *) (exc_info -> ExceptionRecord |
| -> ExceptionInformation[1]); |
| # define sig SIGSEGV |
| # endif |
| |
| if (SIG_OK && CODE_OK) { |
| register struct hblk * h = |
| (struct hblk *)((word)addr & ~(GC_page_size-1)); |
| GC_bool in_allocd_block; |
| |
| # ifdef SUNOS5SIGS |
| /* Address is only within the correct physical page. */ |
| in_allocd_block = FALSE; |
| for (i = 0; i < divHBLKSZ(GC_page_size); i++) { |
| if (HDR(h+i) != 0) { |
| in_allocd_block = TRUE; |
| } |
| } |
| # else |
| in_allocd_block = (HDR(addr) != 0); |
| # endif |
| if (!in_allocd_block) { |
| /* Heap blocks now begin and end on page boundaries */ |
| SIG_PF old_handler; |
| |
| if (sig == SIGSEGV) { |
| old_handler = GC_old_segv_handler; |
| } else { |
| old_handler = GC_old_bus_handler; |
| } |
| if (old_handler == SIG_DFL) { |
| # if !defined(MSWIN32) && !defined(MSWINCE) |
| GC_err_printf1("Segfault at 0x%lx\n", addr); |
| ABORT("Unexpected bus error or segmentation fault"); |
| # else |
| return(EXCEPTION_CONTINUE_SEARCH); |
| # endif |
| } else { |
| # if defined (SUNOS4) || defined(FREEBSD) |
| (*old_handler) (sig, code, scp, addr); |
| return; |
| # endif |
| # if defined (SUNOS5SIGS) |
| (*(REAL_SIG_PF)old_handler) (sig, scp, context); |
| return; |
| # endif |
| # if defined (LINUX) |
| # if defined(ALPHA) || defined(M68K) |
| (*(REAL_SIG_PF)old_handler) (sig, code, sc); |
| # else |
| # if defined(IA64) || defined(HP_PA) |
| (*(REAL_SIG_PF)old_handler) (sig, si, scp); |
| # else |
| (*(REAL_SIG_PF)old_handler) (sig, sc); |
| # endif |
| # endif |
| return; |
| # endif |
| # if defined (IRIX5) || defined(OSF1) || defined(HURD) |
| (*(REAL_SIG_PF)old_handler) (sig, code, scp); |
| return; |
| # endif |
| # ifdef MSWIN32 |
| return((*old_handler)(exc_info)); |
| # endif |
| } |
| } |
| UNPROTECT(h, GC_page_size); |
| /* We need to make sure that no collection occurs between */ |
| /* the UNPROTECT and the setting of the dirty bit. Otherwise */ |
| /* a write by a third thread might go unnoticed. Reversing */ |
| /* the order is just as bad, since we would end up unprotecting */ |
| /* a page in a GC cycle during which it's not marked. */ |
| /* Currently we do this by disabling the thread stopping */ |
| /* signals while this handler is running. An alternative might */ |
| /* be to record the fact that we're about to unprotect, or */ |
| /* have just unprotected a page in the GC's thread structure, */ |
| /* and then to have the thread stopping code set the dirty */ |
| /* flag, if necessary. */ |
| for (i = 0; i < divHBLKSZ(GC_page_size); i++) { |
| register int index = PHT_HASH(h+i); |
| |
| async_set_pht_entry_from_index(GC_dirty_pages, index); |
| } |
| # if defined(OSF1) |
| /* These reset the signal handler each time by default. */ |
| signal(SIGSEGV, (SIG_PF) GC_write_fault_handler); |
| # endif |
| /* The write may not take place before dirty bits are read. */ |
| /* But then we'll fault again ... */ |
| # if defined(MSWIN32) || defined(MSWINCE) |
| return(EXCEPTION_CONTINUE_EXECUTION); |
| # else |
| return; |
| # endif |
| } |
| #if defined(MSWIN32) || defined(MSWINCE) |
| return EXCEPTION_CONTINUE_SEARCH; |
| #else |
| GC_err_printf1("Segfault at 0x%lx\n", addr); |
| ABORT("Unexpected bus error or segmentation fault"); |
| #endif |
| } |
| #endif /* !DARWIN */ |
| |
| /* |
| * We hold the allocation lock. We expect block h to be written |
| * shortly. Ensure that all pages containing any part of the n hblks |
| * starting at h are no longer protected. If is_ptrfree is false, |
| * also ensure that they will subsequently appear to be dirty. |
| */ |
| void GC_remove_protection(h, nblocks, is_ptrfree) |
| struct hblk *h; |
| word nblocks; |
| GC_bool is_ptrfree; |
| { |
| struct hblk * h_trunc; /* Truncated to page boundary */ |
| struct hblk * h_end; /* Page boundary following block end */ |
| struct hblk * current; |
| GC_bool found_clean; |
| |
| if (!GC_dirty_maintained) return; |
| h_trunc = (struct hblk *)((word)h & ~(GC_page_size-1)); |
| h_end = (struct hblk *)(((word)(h + nblocks) + GC_page_size-1) |
| & ~(GC_page_size-1)); |
| found_clean = FALSE; |
| for (current = h_trunc; current < h_end; ++current) { |
| int index = PHT_HASH(current); |
| |
| if (!is_ptrfree || current < h || current >= h + nblocks) { |
| async_set_pht_entry_from_index(GC_dirty_pages, index); |
| } |
| } |
| UNPROTECT(h_trunc, (ptr_t)h_end - (ptr_t)h_trunc); |
| } |
| |
| #if !defined(DARWIN) |
| void GC_dirty_init() |
| { |
| # if defined(SUNOS5SIGS) || defined(IRIX5) || defined(LINUX) || \ |
| defined(OSF1) || defined(HURD) |
| struct sigaction act, oldact; |
| /* We should probably specify SA_SIGINFO for Linux, and handle */ |
| /* the different architectures more uniformly. */ |
| # if defined(IRIX5) || defined(LINUX) || defined(OSF1) || defined(HURD) |
| act.sa_flags = SA_RESTART; |
| act.sa_handler = (SIG_PF)GC_write_fault_handler; |
| # else |
| act.sa_flags = SA_RESTART | SA_SIGINFO; |
| act.sa_sigaction = GC_write_fault_handler; |
| # endif |
| (void)sigemptyset(&act.sa_mask); |
| # ifdef SIG_SUSPEND |
| /* Arrange to postpone SIG_SUSPEND while we're in a write fault */ |
| /* handler. This effectively makes the handler atomic w.r.t. */ |
| /* stopping the world for GC. */ |
| (void)sigaddset(&act.sa_mask, SIG_SUSPEND); |
| # endif /* SIG_SUSPEND */ |
| # endif |
| # ifdef PRINTSTATS |
| GC_printf0("Inititalizing mprotect virtual dirty bit implementation\n"); |
| # endif |
| GC_dirty_maintained = TRUE; |
| if (GC_page_size % HBLKSIZE != 0) { |
| GC_err_printf0("Page size not multiple of HBLKSIZE\n"); |
| ABORT("Page size not multiple of HBLKSIZE"); |
| } |
| # if defined(SUNOS4) || defined(FREEBSD) |
| GC_old_bus_handler = signal(SIGBUS, GC_write_fault_handler); |
| if (GC_old_bus_handler == SIG_IGN) { |
| GC_err_printf0("Previously ignored bus error!?"); |
| GC_old_bus_handler = SIG_DFL; |
| } |
| if (GC_old_bus_handler != SIG_DFL) { |
| # ifdef PRINTSTATS |
| GC_err_printf0("Replaced other SIGBUS handler\n"); |
| # endif |
| } |
| # endif |
| # if defined(SUNOS4) |
| GC_old_segv_handler = signal(SIGSEGV, (SIG_PF)GC_write_fault_handler); |
| if (GC_old_segv_handler == SIG_IGN) { |
| GC_err_printf0("Previously ignored segmentation violation!?"); |
| GC_old_segv_handler = SIG_DFL; |
| } |
| if (GC_old_segv_handler != SIG_DFL) { |
| # ifdef PRINTSTATS |
| GC_err_printf0("Replaced other SIGSEGV handler\n"); |
| # endif |
| } |
| # endif |
| # if defined(SUNOS5SIGS) || defined(IRIX5) || defined(LINUX) \ |
| || defined(OSF1) || defined(HURD) |
| /* SUNOS5SIGS includes HPUX */ |
| # if defined(GC_IRIX_THREADS) |
| sigaction(SIGSEGV, 0, &oldact); |
| sigaction(SIGSEGV, &act, 0); |
| # else |
| { |
| int res = sigaction(SIGSEGV, &act, &oldact); |
| if (res != 0) ABORT("Sigaction failed"); |
| } |
| # endif |
| # if defined(_sigargs) || defined(HURD) || !defined(SA_SIGINFO) |
| /* This is Irix 5.x, not 6.x. Irix 5.x does not have */ |
| /* sa_sigaction. */ |
| GC_old_segv_handler = oldact.sa_handler; |
| # else /* Irix 6.x or SUNOS5SIGS or LINUX */ |
| if (oldact.sa_flags & SA_SIGINFO) { |
| GC_old_segv_handler = (SIG_PF)(oldact.sa_sigaction); |
| } else { |
| GC_old_segv_handler = oldact.sa_handler; |
| } |
| # endif |
| if (GC_old_segv_handler == SIG_IGN) { |
| GC_err_printf0("Previously ignored segmentation violation!?"); |
| GC_old_segv_handler = SIG_DFL; |
| } |
| if (GC_old_segv_handler != SIG_DFL) { |
| # ifdef PRINTSTATS |
| GC_err_printf0("Replaced other SIGSEGV handler\n"); |
| # endif |
| } |
| # endif |
| # if defined(HPUX) || defined(LINUX) || defined(HURD) |
| sigaction(SIGBUS, &act, &oldact); |
| GC_old_bus_handler = oldact.sa_handler; |
| if (GC_old_bus_handler == SIG_IGN) { |
| GC_err_printf0("Previously ignored bus error!?"); |
| GC_old_bus_handler = SIG_DFL; |
| } |
| if (GC_old_bus_handler != SIG_DFL) { |
| # ifdef PRINTSTATS |
| GC_err_printf0("Replaced other SIGBUS handler\n"); |
| # endif |
| } |
| # endif /* HPUX || LINUX || HURD */ |
| # if defined(MSWIN32) |
| GC_old_segv_handler = SetUnhandledExceptionFilter(GC_write_fault_handler); |
| if (GC_old_segv_handler != NULL) { |
| # ifdef PRINTSTATS |
| GC_err_printf0("Replaced other UnhandledExceptionFilter\n"); |
| # endif |
| } else { |
| GC_old_segv_handler = SIG_DFL; |
| } |
| # endif |
| } |
| #endif /* !DARWIN */ |
| |
| int GC_incremental_protection_needs() |
| { |
| if (GC_page_size == HBLKSIZE) { |
| return GC_PROTECTS_POINTER_HEAP; |
| } else { |
| return GC_PROTECTS_POINTER_HEAP | GC_PROTECTS_PTRFREE_HEAP; |
| } |
| } |
| |
| #define HAVE_INCREMENTAL_PROTECTION_NEEDS |
| |
| #define IS_PTRFREE(hhdr) ((hhdr)->hb_descr == 0) |
| |
| #define PAGE_ALIGNED(x) !((word)(x) & (GC_page_size - 1)) |
| void GC_protect_heap() |
| { |
| ptr_t start; |
| word len; |
| struct hblk * current; |
| struct hblk * current_start; /* Start of block to be protected. */ |
| struct hblk * limit; |
| unsigned i; |
| GC_bool protect_all = |
| (0 != (GC_incremental_protection_needs() & GC_PROTECTS_PTRFREE_HEAP)); |
| for (i = 0; i < GC_n_heap_sects; i++) { |
| start = GC_heap_sects[i].hs_start; |
| len = GC_heap_sects[i].hs_bytes; |
| if (protect_all) { |
| PROTECT(start, len); |
| } else { |
| GC_ASSERT(PAGE_ALIGNED(len)) |
| GC_ASSERT(PAGE_ALIGNED(start)) |
| current_start = current = (struct hblk *)start; |
| limit = (struct hblk *)(start + len); |
| while (current < limit) { |
| hdr * hhdr; |
| word nhblks; |
| GC_bool is_ptrfree; |
| |
| GC_ASSERT(PAGE_ALIGNED(current)); |
| GET_HDR(current, hhdr); |
| if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) { |
| /* This can happen only if we're at the beginning of a */ |
| /* heap segment, and a block spans heap segments. */ |
| /* We will handle that block as part of the preceding */ |
| /* segment. */ |
| GC_ASSERT(current_start == current); |
| current_start = ++current; |
| continue; |
| } |
| if (HBLK_IS_FREE(hhdr)) { |
| GC_ASSERT(PAGE_ALIGNED(hhdr -> hb_sz)); |
| nhblks = divHBLKSZ(hhdr -> hb_sz); |
| is_ptrfree = TRUE; /* dirty on alloc */ |
| } else { |
| nhblks = OBJ_SZ_TO_BLOCKS(hhdr -> hb_sz); |
| is_ptrfree = IS_PTRFREE(hhdr); |
| } |
| if (is_ptrfree) { |
| if (current_start < current) { |
| PROTECT(current_start, (ptr_t)current - (ptr_t)current_start); |
| } |
| current_start = (current += nhblks); |
| } else { |
| current += nhblks; |
| } |
| } |
| if (current_start < current) { |
| PROTECT(current_start, (ptr_t)current - (ptr_t)current_start); |
| } |
| } |
| } |
| } |
| |
| /* We assume that either the world is stopped or its OK to lose dirty */ |
| /* bits while this is happenning (as in GC_enable_incremental). */ |
| void GC_read_dirty() |
| { |
| BCOPY((word *)GC_dirty_pages, GC_grungy_pages, |
| (sizeof GC_dirty_pages)); |
| BZERO((word *)GC_dirty_pages, (sizeof GC_dirty_pages)); |
| GC_protect_heap(); |
| } |
| |
| GC_bool GC_page_was_dirty(h) |
| struct hblk * h; |
| { |
| register word index = PHT_HASH(h); |
| |
| return(HDR(h) == 0 || get_pht_entry_from_index(GC_grungy_pages, index)); |
| } |
| |
| /* |
| * Acquiring the allocation lock here is dangerous, since this |
| * can be called from within GC_call_with_alloc_lock, and the cord |
| * package does so. On systems that allow nested lock acquisition, this |
| * happens to work. |
| * On other systems, SET_LOCK_HOLDER and friends must be suitably defined. |
| */ |
| |
| static GC_bool syscall_acquired_lock = FALSE; /* Protected by GC lock. */ |
| |
| void GC_begin_syscall() |
| { |
| if (!I_HOLD_LOCK()) { |
| LOCK(); |
| syscall_acquired_lock = TRUE; |
| } |
| } |
| |
| void GC_end_syscall() |
| { |
| if (syscall_acquired_lock) { |
| syscall_acquired_lock = FALSE; |
| UNLOCK(); |
| } |
| } |
| |
| void GC_unprotect_range(addr, len) |
| ptr_t addr; |
| word len; |
| { |
| struct hblk * start_block; |
| struct hblk * end_block; |
| register struct hblk *h; |
| ptr_t obj_start; |
| |
| if (!GC_dirty_maintained) return; |
| obj_start = GC_base(addr); |
| if (obj_start == 0) return; |
| if (GC_base(addr + len - 1) != obj_start) { |
| ABORT("GC_unprotect_range(range bigger than object)"); |
| } |
| start_block = (struct hblk *)((word)addr & ~(GC_page_size - 1)); |
| end_block = (struct hblk *)((word)(addr + len - 1) & ~(GC_page_size - 1)); |
| end_block += GC_page_size/HBLKSIZE - 1; |
| for (h = start_block; h <= end_block; h++) { |
| register word index = PHT_HASH(h); |
| |
| async_set_pht_entry_from_index(GC_dirty_pages, index); |
| } |
| UNPROTECT(start_block, |
| ((ptr_t)end_block - (ptr_t)start_block) + HBLKSIZE); |
| } |
| |
| #if 0 |
| |
| /* We no longer wrap read by default, since that was causing too many */ |
| /* problems. It is preferred that the client instead avoids writing */ |
| /* to the write-protected heap with a system call. */ |
| /* This still serves as sample code if you do want to wrap system calls.*/ |
| |
| #if !defined(MSWIN32) && !defined(MSWINCE) && !defined(GC_USE_LD_WRAP) |
| /* Replacement for UNIX system call. */ |
| /* Other calls that write to the heap should be handled similarly. */ |
| /* Note that this doesn't work well for blocking reads: It will hold */ |
| /* the allocation lock for the entire duration of the call. Multithreaded */ |
| /* clients should really ensure that it won't block, either by setting */ |
| /* the descriptor nonblocking, or by calling select or poll first, to */ |
| /* make sure that input is available. */ |
| /* Another, preferred alternative is to ensure that system calls never */ |
| /* write to the protected heap (see above). */ |
| # if defined(__STDC__) && !defined(SUNOS4) |
| # include <unistd.h> |
| # include <sys/uio.h> |
| ssize_t read(int fd, void *buf, size_t nbyte) |
| # else |
| # ifndef LINT |
| int read(fd, buf, nbyte) |
| # else |
| int GC_read(fd, buf, nbyte) |
| # endif |
| int fd; |
| char *buf; |
| int nbyte; |
| # endif |
| { |
| int result; |
| |
| GC_begin_syscall(); |
| GC_unprotect_range(buf, (word)nbyte); |
| # if defined(IRIX5) || defined(GC_LINUX_THREADS) |
| /* Indirect system call may not always be easily available. */ |
| /* We could call _read, but that would interfere with the */ |
| /* libpthread interception of read. */ |
| /* On Linux, we have to be careful with the linuxthreads */ |
| /* read interception. */ |
| { |
| struct iovec iov; |
| |
| iov.iov_base = buf; |
| iov.iov_len = nbyte; |
| result = readv(fd, &iov, 1); |
| } |
| # else |
| # if defined(HURD) |
| result = __read(fd, buf, nbyte); |
| # else |
| /* The two zero args at the end of this list are because one |
| IA-64 syscall() implementation actually requires six args |
| to be passed, even though they aren't always used. */ |
| result = syscall(SYS_read, fd, buf, nbyte, 0, 0); |
| # endif /* !HURD */ |
| # endif |
| GC_end_syscall(); |
| return(result); |
| } |
| #endif /* !MSWIN32 && !MSWINCE && !GC_LINUX_THREADS */ |
| |
| #if defined(GC_USE_LD_WRAP) && !defined(THREADS) |
| /* We use the GNU ld call wrapping facility. */ |
| /* This requires that the linker be invoked with "--wrap read". */ |
| /* This can be done by passing -Wl,"--wrap read" to gcc. */ |
| /* I'm not sure that this actually wraps whatever version of read */ |
| /* is called by stdio. That code also mentions __read. */ |
| # include <unistd.h> |
| ssize_t __wrap_read(int fd, void *buf, size_t nbyte) |
| { |
| int result; |
| |
| GC_begin_syscall(); |
| GC_unprotect_range(buf, (word)nbyte); |
| result = __real_read(fd, buf, nbyte); |
| GC_end_syscall(); |
| return(result); |
| } |
| |
| /* We should probably also do this for __read, or whatever stdio */ |
| /* actually calls. */ |
| #endif |
| |
| #endif /* 0 */ |
| |
| /*ARGSUSED*/ |
| GC_bool GC_page_was_ever_dirty(h) |
| struct hblk *h; |
| { |
| return(TRUE); |
| } |
| |
| /* Reset the n pages starting at h to "was never dirty" status. */ |
| /*ARGSUSED*/ |
| void GC_is_fresh(h, n) |
| struct hblk *h; |
| word n; |
| { |
| } |
| |
| # endif /* MPROTECT_VDB */ |
| |
| # ifdef PROC_VDB |
| |
| /* |
| * See DEFAULT_VDB for interface descriptions. |
| */ |
| |
| /* |
| * This implementaion assumes a Solaris 2.X like /proc pseudo-file-system |
| * from which we can read page modified bits. This facility is far from |
| * optimal (e.g. we would like to get the info for only some of the |
| * address space), but it avoids intercepting system calls. |
| */ |
| |
| #include <errno.h> |
| #include <sys/types.h> |
| #include <sys/signal.h> |
| #include <sys/fault.h> |
| #include <sys/syscall.h> |
| #include <sys/procfs.h> |
| #include <sys/stat.h> |
| |
| #define INITIAL_BUF_SZ 4096 |
| word GC_proc_buf_size = INITIAL_BUF_SZ; |
| char *GC_proc_buf; |
| |
| #ifdef GC_SOLARIS_THREADS |
| /* We don't have exact sp values for threads. So we count on */ |
| /* occasionally declaring stack pages to be fresh. Thus we */ |
| /* need a real implementation of GC_is_fresh. We can't clear */ |
| /* entries in GC_written_pages, since that would declare all */ |
| /* pages with the given hash address to be fresh. */ |
| # define MAX_FRESH_PAGES 8*1024 /* Must be power of 2 */ |
| struct hblk ** GC_fresh_pages; /* A direct mapped cache. */ |
| /* Collisions are dropped. */ |
| |
| # define FRESH_PAGE_SLOT(h) (divHBLKSZ((word)(h)) & (MAX_FRESH_PAGES-1)) |
| # define ADD_FRESH_PAGE(h) \ |
| GC_fresh_pages[FRESH_PAGE_SLOT(h)] = (h) |
| # define PAGE_IS_FRESH(h) \ |
| (GC_fresh_pages[FRESH_PAGE_SLOT(h)] == (h) && (h) != 0) |
| #endif |
| |
| /* Add all pages in pht2 to pht1 */ |
| void GC_or_pages(pht1, pht2) |
| page_hash_table pht1, pht2; |
| { |
| register int i; |
| |
| for (i = 0; i < PHT_SIZE; i++) pht1[i] |= pht2[i]; |
| } |
| |
| int GC_proc_fd; |
| |
| void GC_dirty_init() |
| { |
| int fd; |
| char buf[30]; |
| |
| GC_dirty_maintained = TRUE; |
| if (GC_words_allocd != 0 || GC_words_allocd_before_gc != 0) { |
| register int i; |
| |
| for (i = 0; i < PHT_SIZE; i++) GC_written_pages[i] = (word)(-1); |
| # ifdef PRINTSTATS |
| GC_printf1("Allocated words:%lu:all pages may have been written\n", |
| (unsigned long) |
| (GC_words_allocd + GC_words_allocd_before_gc)); |
| # endif |
| } |
| sprintf(buf, "/proc/%d", getpid()); |
| fd = open(buf, O_RDONLY); |
| if (fd < 0) { |
| ABORT("/proc open failed"); |
| } |
| GC_proc_fd = syscall(SYS_ioctl, fd, PIOCOPENPD, 0); |
| close(fd); |
| syscall(SYS_fcntl, GC_proc_fd, F_SETFD, FD_CLOEXEC); |
| if (GC_proc_fd < 0) { |
| ABORT("/proc ioctl failed"); |
| } |
| GC_proc_buf = GC_scratch_alloc(GC_proc_buf_size); |
| # ifdef GC_SOLARIS_THREADS |
| GC_fresh_pages = (struct hblk **) |
| GC_scratch_alloc(MAX_FRESH_PAGES * sizeof (struct hblk *)); |
| if (GC_fresh_pages == 0) { |
| GC_err_printf0("No space for fresh pages\n"); |
| EXIT(); |
| } |
| BZERO(GC_fresh_pages, MAX_FRESH_PAGES * sizeof (struct hblk *)); |
| # endif |
| } |
| |
| /* Ignore write hints. They don't help us here. */ |
| /*ARGSUSED*/ |
| void GC_remove_protection(h, nblocks, is_ptrfree) |
| struct hblk *h; |
| word nblocks; |
| GC_bool is_ptrfree; |
| { |
| } |
| |
| #ifdef GC_SOLARIS_THREADS |
| # define READ(fd,buf,nbytes) syscall(SYS_read, fd, buf, nbytes) |
| #else |
| # define READ(fd,buf,nbytes) read(fd, buf, nbytes) |
| #endif |
| |
| void GC_read_dirty() |
| { |
| unsigned long ps, np; |
| int nmaps; |
| ptr_t vaddr; |
| struct prasmap * map; |
| char * bufp; |
| ptr_t current_addr, limit; |
| int i; |
| int dummy; |
| |
| BZERO(GC_grungy_pages, (sizeof GC_grungy_pages)); |
| |
| bufp = GC_proc_buf; |
| if (READ(GC_proc_fd, bufp, GC_proc_buf_size) <= 0) { |
| # ifdef PRINTSTATS |
| GC_printf1("/proc read failed: GC_proc_buf_size = %lu\n", |
| GC_proc_buf_size); |
| # endif |
| { |
| /* Retry with larger buffer. */ |
| word new_size = 2 * GC_proc_buf_size; |
| char * new_buf = GC_scratch_alloc(new_size); |
| |
| if (new_buf != 0) { |
| GC_proc_buf = bufp = new_buf; |
| GC_proc_buf_size = new_size; |
| } |
| if (syscall(SYS_read, GC_proc_fd, bufp, GC_proc_buf_size) <= 0) { |
| WARN("Insufficient space for /proc read\n", 0); |
| /* Punt: */ |
| memset(GC_grungy_pages, 0xff, sizeof (page_hash_table)); |
| memset(GC_written_pages, 0xff, sizeof(page_hash_table)); |
| # ifdef GC_SOLARIS_THREADS |
| BZERO(GC_fresh_pages, |
| MAX_FRESH_PAGES * sizeof (struct hblk *)); |
| # endif |
| return; |
| } |
| } |
| } |
| /* Copy dirty bits into GC_grungy_pages */ |
| nmaps = ((struct prpageheader *)bufp) -> pr_nmap; |
| /* printf( "nmaps = %d, PG_REFERENCED = %d, PG_MODIFIED = %d\n", |
| nmaps, PG_REFERENCED, PG_MODIFIED); */ |
| bufp = bufp + sizeof(struct prpageheader); |
| for (i = 0; i < nmaps; i++) { |
| map = (struct prasmap *)bufp; |
| vaddr = (ptr_t)(map -> pr_vaddr); |
| ps = map -> pr_pagesize; |
| np = map -> pr_npage; |
| /* printf("vaddr = 0x%X, ps = 0x%X, np = 0x%X\n", vaddr, ps, np); */ |
| limit = vaddr + ps * np; |
| bufp += sizeof (struct prasmap); |
| for (current_addr = vaddr; |
| current_addr < limit; current_addr += ps){ |
| if ((*bufp++) & PG_MODIFIED) { |
| register struct hblk * h = (struct hblk *) current_addr; |
| |
| while ((ptr_t)h < current_addr + ps) { |
| register word index = PHT_HASH(h); |
| |
| set_pht_entry_from_index(GC_grungy_pages, index); |
| # ifdef GC_SOLARIS_THREADS |
| { |
| register int slot = FRESH_PAGE_SLOT(h); |
| |
| if (GC_fresh_pages[slot] == h) { |
| GC_fresh_pages[slot] = 0; |
| } |
| } |
| # endif |
| h++; |
| } |
| } |
| } |
| bufp += sizeof(long) - 1; |
| bufp = (char *)((unsigned long)bufp & ~(sizeof(long)-1)); |
| } |
| /* Update GC_written_pages. */ |
| GC_or_pages(GC_written_pages, GC_grungy_pages); |
| # ifdef GC_SOLARIS_THREADS |
| /* Make sure that old stacks are considered completely clean */ |
| /* unless written again. */ |
| GC_old_stacks_are_fresh(); |
| # endif |
| } |
| |
| #undef READ |
| |
| GC_bool GC_page_was_dirty(h) |
| struct hblk *h; |
| { |
| register word index = PHT_HASH(h); |
| register GC_bool result; |
| |
| result = get_pht_entry_from_index(GC_grungy_pages, index); |
| # ifdef GC_SOLARIS_THREADS |
| if (result && PAGE_IS_FRESH(h)) result = FALSE; |
| /* This happens only if page was declared fresh since */ |
| /* the read_dirty call, e.g. because it's in an unused */ |
| /* thread stack. It's OK to treat it as clean, in */ |
| /* that case. And it's consistent with */ |
| /* GC_page_was_ever_dirty. */ |
| # endif |
| return(result); |
| } |
| |
| GC_bool GC_page_was_ever_dirty(h) |
| struct hblk *h; |
| { |
| register word index = PHT_HASH(h); |
| register GC_bool result; |
| |
| result = get_pht_entry_from_index(GC_written_pages, index); |
| # ifdef GC_SOLARIS_THREADS |
| if (result && PAGE_IS_FRESH(h)) result = FALSE; |
| # endif |
| return(result); |
| } |
| |
| /* Caller holds allocation lock. */ |
| void GC_is_fresh(h, n) |
| struct hblk *h; |
| word n; |
| { |
| |
| register word index; |
| |
| # ifdef GC_SOLARIS_THREADS |
| register word i; |
| |
| if (GC_fresh_pages != 0) { |
| for (i = 0; i < n; i++) { |
| ADD_FRESH_PAGE(h + i); |
| } |
| } |
| # endif |
| } |
| |
| # endif /* PROC_VDB */ |
| |
| |
| # ifdef PCR_VDB |
| |
| # include "vd/PCR_VD.h" |
| |
| # define NPAGES (32*1024) /* 128 MB */ |
| |
| PCR_VD_DB GC_grungy_bits[NPAGES]; |
| |
| ptr_t GC_vd_base; /* Address corresponding to GC_grungy_bits[0] */ |
| /* HBLKSIZE aligned. */ |
| |
| void GC_dirty_init() |
| { |
| GC_dirty_maintained = TRUE; |
| /* For the time being, we assume the heap generally grows up */ |
| GC_vd_base = GC_heap_sects[0].hs_start; |
| if (GC_vd_base == 0) { |
| ABORT("Bad initial heap segment"); |
| } |
| if (PCR_VD_Start(HBLKSIZE, GC_vd_base, NPAGES*HBLKSIZE) |
| != PCR_ERes_okay) { |
| ABORT("dirty bit initialization failed"); |
| } |
| } |
| |
| void GC_read_dirty() |
| { |
| /* lazily enable dirty bits on newly added heap sects */ |
| { |
| static int onhs = 0; |
| int nhs = GC_n_heap_sects; |
| for( ; onhs < nhs; onhs++ ) { |
| PCR_VD_WriteProtectEnable( |
| GC_heap_sects[onhs].hs_start, |
| GC_heap_sects[onhs].hs_bytes ); |
| } |
| } |
| |
| |
| if (PCR_VD_Clear(GC_vd_base, NPAGES*HBLKSIZE, GC_grungy_bits) |
| != PCR_ERes_okay) { |
| ABORT("dirty bit read failed"); |
| } |
| } |
| |
| GC_bool GC_page_was_dirty(h) |
| struct hblk *h; |
| { |
| if((ptr_t)h < GC_vd_base || (ptr_t)h >= GC_vd_base + NPAGES*HBLKSIZE) { |
| return(TRUE); |
| } |
| return(GC_grungy_bits[h - (struct hblk *)GC_vd_base] & PCR_VD_DB_dirtyBit); |
| } |
| |
| /*ARGSUSED*/ |
| void GC_remove_protection(h, nblocks, is_ptrfree) |
| struct hblk *h; |
| word nblocks; |
| GC_bool is_ptrfree; |
| { |
| PCR_VD_WriteProtectDisable(h, nblocks*HBLKSIZE); |
| PCR_VD_WriteProtectEnable(h, nblocks*HBLKSIZE); |
| } |
| |
| # endif /* PCR_VDB */ |
| |
| #if defined(MPROTECT_VDB) && defined(DARWIN) |
| /* The following sources were used as a *reference* for this exception handling |
| code: |
| 1. Apple's mach/xnu documentation |
| 2. Timothy J. Wood's "Mach Exception Handlers 101" post to the |
| omnigroup's macosx-dev list. |
| www.omnigroup.com/mailman/archive/macosx-dev/2000-June/002030.html |
| 3. macosx-nat.c from Apple's GDB source code. |
| */ |
| |
| /* The bug that caused all this trouble should now be fixed. This should |
| eventually be removed if all goes well. */ |
|