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gnu / gcc / 75bbfcfa8623f5b211475a54f52ced32201575e7 / . / boehm-gc / os_dep.c
blob: 5372d7fb0c9d3336dcbd759992ba44de36a04ddc [file] [log] [blame]
/*
* Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved.
* Copyright (c) 1996-1997 by Silicon Graphics. 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 "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__
# include <sigcontext.h>
# 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)
# include <sys/types.h>
# if !defined(MSWIN32) && !defined(SUNOS4)
# include <unistd.h>
# endif
# endif
# include <stdio.h>
# include <signal.h>
/* Blatantly OS dependent routines, except for those that are related */
/* dynamic loading. */
# if !defined(THREADS) && !defined(STACKBOTTOM) && defined(HEURISTIC2)
# define NEED_FIND_LIMIT
# endif
# if defined(IRIX_THREADS)
# 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(PCR)
# define NEED_FIND_LIMIT
# endif
# if defined(LINUX) && defined(POWERPC)
# define NEED_FIND_LIMIT
# endif
#ifdef NEED_FIND_LIMIT
# include <setjmp.h>
#endif
#ifdef FREEBSD
# include <machine/trap.h>
#endif
#ifdef AMIGA
# include <proto/exec.h>
# include <proto/dos.h>
# include <dos/dosextens.h>
# include <workbench/startup.h>
#endif
#ifdef MSWIN32
# 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>
# include <fcntl.h>
#endif
#ifdef SUNOS5SIGS
# include <sys/siginfo.h>
# undef setjmp
# undef longjmp
# define setjmp(env) sigsetjmp(env, 1)
# define longjmp(env, val) siglongjmp(env, val)
# define jmp_buf sigjmp_buf
#endif
#ifdef DJGPP
/* Apparently necessary for djgpp 2.01. May casuse 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(POWERPC)
ptr_t GC_data_start;
void GC_init_linuxppc()
{
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 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 */
# 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(MACOS) && !defined(DJGPP) && !defined(DOS4GW) \
&& !defined(NO_SIGSET)
# if defined(sigmask) && !defined(UTS4)
/* 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) || defined (NO_SIGSET)
void GC_disable_signals() { }
void GC_enable_signals() { }
#endif
/* Find the page size */
word GC_page_size;
# ifdef MSWIN32
void GC_setpagesize()
{
SYSTEM_INFO sysinfo;
GetSystemInfo(&sysinfo);
GC_page_size = sysinfo.dwPageSize;
}
# else
# if defined(MPROTECT_VDB) || defined(PROC_VDB) || defined(USE_MMAP)
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.
*/
# ifdef MSWIN32
# 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);
}
# else
# 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));
}
# else
# ifdef AMIGA
ptr_t GC_get_stack_base()
{
extern struct WBStartup *_WBenchMsg;
extern long __base;
extern long __stack;
struct Task *task;
struct Process *proc;
struct CommandLineInterface *cli;
long size;
if ((task = FindTask(0)) == 0) {
GC_err_puts("Cannot find own task structure\n");
ABORT("task missing");
}
proc = (struct Process *)task;
cli = BADDR(proc->pr_CLI);
if (_WBenchMsg != 0 || cli == 0) {
size = (char *)task->tc_SPUpper - (char *)task->tc_SPLower;
} else {
size = cli->cli_DefaultStack * 4;
}
return (ptr_t)(__base + GC_max(size, __stack));
}
# else
# 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);
}
# ifdef __STDC__
typedef void (*handler)(int);
# else
typedef void (*handler)();
# endif
# if defined(SUNOS5SIGS) || defined(IRIX5)
static struct sigaction old_segv_act;
static struct sigaction old_bus_act;
# else
static handler old_segv_handler, old_bus_handler;
# endif
void GC_setup_temporary_fault_handler()
{
# ifndef ECOS
# if defined(SUNOS5SIGS) || defined(IRIX5)
struct sigaction act;
act.sa_handler = GC_fault_handler;
act.sa_flags = SA_RESTART | SA_NODEFER;
/* 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 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);
# ifdef _sigargs /* Irix 5.x, not 6.x */
/* Under 5.x, we may get SIGBUS. */
/* Pthreads doesn't exist under 5.x, so we don't */
/* have to worry in the threads case. */
(void) sigaction(SIGBUS, &act, &old_bus_act);
# endif
# endif /* IRIX_THREADS */
# else
old_segv_handler = signal(SIGSEGV, GC_fault_handler);
# ifdef SIGBUS
old_bus_handler = signal(SIGBUS, GC_fault_handler);
# endif
# endif
# endif /* ECOS */
}
void GC_reset_fault_handler()
{
# ifndef ECOS
# if defined(SUNOS5SIGS) || defined(IRIX5)
(void) sigaction(SIGSEGV, &old_segv_act, 0);
# ifdef _sigargs /* Irix 5.x, not 6.x */
(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
# endif /* ECOS */
}
/* Return the first nonaddressible location > p (up) or */
/* the smallest location q s.t. [q,p] is addressible (!up). */
ptr_t GC_find_limit(p, up)
ptr_t p;
GC_bool up;
{
# ifndef ECOS
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);
# else /* ECOS */
abort();
# endif /* ECOS */
}
# endif
# ifndef ECOS
ptr_t GC_get_stack_base()
{
word dummy;
ptr_t result;
# define STACKBOTTOM_ALIGNMENT_M1 ((word)STACK_GRAN - 1)
# if defined(STACKBASE)
extern ptr_t STACKBASE;
return(STACKBASE);
# else
# 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 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 */
return(result);
# endif /* STACKBOTTOM */
# endif /* STACKBASE */
}
# endif /* ECOS */
# endif /* ! AMIGA */
# endif /* ! OS2 */
# endif /* ! MSWIN32 */
/*
* 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
# 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 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 rgister the main data segment here. */
GC_bool GC_win32s = FALSE; /* We're running under win32s. */
GC_bool GC_is_win32s()
{
DWORD v = GetVersion();
/* Check that this is not NT, and Windows major version <= 3 */
return ((v & 0x80000000) && (v & 0xff) <= 3);
}
void GC_init_win32()
{
GC_win32s = GC_is_win32s();
}
/* 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;
SYSTEM_INFO sysinfo;
DWORD result;
LPVOID limit;
ptr_t p;
LPVOID q;
GetSystemInfo(&sysinfo);
limit = 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);
}
/* 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)
{
register unsigned i;
# ifndef REDIRECT_MALLOC
static ptr_t malloc_heap_pointer = 0;
if (0 == malloc_heap_pointer) {
MEMORY_BASIC_INFORMATION buf;
register DWORD result = VirtualQuery(malloc(1), &buf, sizeof(buf));
if (result != sizeof(buf)) {
ABORT("Weird VirtualQuery result");
}
malloc_heap_pointer = (ptr_t)(buf.AllocationBase);
}
if (p == malloc_heap_pointer) return(TRUE);
# endif
for (i = 0; i < GC_n_heap_bases; i++) {
if (GC_heap_bases[i] == p) return(TRUE);
}
return(FALSE);
}
void GC_register_root_section(ptr_t static_root)
{
MEMORY_BASIC_INFORMATION buf;
SYSTEM_INFO sysinfo;
DWORD result;
DWORD protect;
LPVOID p;
char * base;
char * limit, * new_limit;
if (!GC_win32s) return;
p = base = limit = GC_least_described_address(static_root);
GetSystemInfo(&sysinfo);
while (p < 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);
}
void GC_register_data_segments()
{
static char dummy;
GC_register_root_section((ptr_t)(&dummy));
}
# else
# ifdef AMIGA
void GC_register_data_segments()
{
extern struct WBStartup *_WBenchMsg;
struct Process *proc;
struct CommandLineInterface *cli;
BPTR myseglist;
ULONG *data;
if ( _WBenchMsg != 0 ) {
if ((myseglist = _WBenchMsg->sm_Segment) == 0) {
GC_err_puts("No seglist from workbench\n");
return;
}
} else {
if ((proc = (struct Process *)FindTask(0)) == 0) {
GC_err_puts("Cannot find process structure\n");
return;
}
if ((cli = BADDR(proc->pr_CLI)) == 0) {
GC_err_puts("No CLI\n");
return;
}
if ((myseglist = cli->cli_Module) == 0) {
GC_err_puts("No seglist from CLI\n");
return;
}
}
for (data = (ULONG *)BADDR(myseglist); data != 0;
data = (ULONG *)BADDR(data[0])) {
# ifdef AMIGA_SKIP_SEG
if (((ULONG) GC_register_data_segments < (ULONG) &data[1]) ||
((ULONG) GC_register_data_segments > (ULONG) &data[1] + data[-1])) {
# else
{
# endif /* AMIGA_SKIP_SEG */
GC_add_roots_inner((char *)&data[1],
((char *)&data[1]) + data[-1], FALSE);
}
}
}
# else
# if (defined(SVR4) || defined(AUX) || defined(DGUX)) && !defined(PCR)
char * 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) - MIN_PAGE_SIZE, FALSE);
}
return((char *)result);
}
# endif
void GC_register_data_segments()
{
# if !defined(PCR) && !defined(SRC_M3) && !defined(NEXT) && !defined(MACOS)
# if defined(REDIRECT_MALLOC) && defined(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);
# endif
# endif
# if !defined(PCR) && defined(NEXT)
GC_add_roots_inner(DATASTART, (char *) get_end(), FALSE);
# 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);
/* globals begin above stack and end at a5. */
GC_add_roots_inner((ptr_t)GC_MacGetDataStart(),
(ptr_t)LMGetCurrentA5(), FALSE);
# 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 */
# endif /* ! OS2 */
/*
* Auxiliary routines for obtaining memory from OS.
*/
# if !defined(OS2) && !defined(PCR) && !defined(AMIGA) \
&& !defined(MSWIN32) && !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 IRIX5 */
ptr_t GC_unix_get_mem(bytes)
word bytes;
{
static GC_bool initialized = FALSE;
static int fd;
void *result;
static ptr_t last_addr = HEAP_START;
if (!initialized) {
fd = open("/dev/zero", O_RDONLY);
initialized = TRUE;
}
if (bytes & (GC_page_size -1)) ABORT("Bad GET_MEM arg");
result = mmap(last_addr, bytes, PROT_READ | PROT_WRITE | OPT_PROT_EXEC,
MAP_PRIVATE | MAP_FIXED, fd, 0/* offset */);
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));
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 */
# ifdef MSWIN32
word GC_n_heap_bases = 0;
ptr_t GC_win32_get_mem(bytes)
word bytes;
{
ptr_t result;
if (GC_win32s) {
/* 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 {
result = (ptr_t) VirtualAlloc(NULL, bytes,
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);
}
# endif
/* Routine for pushing any additional roots. In THREADS */
/* environment, this is also responsible for marking from */
/* thread stacks. In the SRC_M3 case, it also handles */
/* global variables. */
#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()
{
/* 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
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;
if ((ptr_t)(q) >= GC_least_plausible_heap_addr
&& (ptr_t)(q) < GC_greatest_plausible_heap_addr) {
GC_push_one_checked(q,FALSE);
}
}
/* M3 set equivalent to RTHeap.TracedRefTypes */
typedef struct { int elts[1]; } RefTypeSet;
RefTypeSet GC_TracedRefTypes = {{0x1}};
/* From finalize.c */
extern void GC_push_finalizer_structures();
/* From stubborn.c: */
# ifdef STUBBORN_ALLOC
extern GC_PTR * GC_changing_list_start;
# endif
void GC_default_push_other_roots()
{
/* 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. */
{
# ifdef STUBBORN_ALLOC
GC_push_one(GC_changing_list_start);
# endif
GC_push_finalizer_structures();
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(SOLARIS_THREADS) || defined(WIN32_THREADS) \
|| defined(IRIX_THREADS) || defined(LINUX_THREADS) \
|| defined(QUICK_THREADS)
extern void GC_push_all_stacks();
void GC_default_push_other_roots()
{
GC_push_all_stacks();
}
# endif /* SOLARIS_THREADS || ... */
void (*GC_push_other_roots)() = GC_default_push_other_roots;
#endif
/*
* Routines for accessing dirty bits on virtual pages.
* We plan to eventaually 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()
{
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 hints that h is about to be written. */
/* May speed up some dirty bit implementations. */
/*ARGSUSED*/
void GC_write_hint(h)
struct hblk *h;
{
}
# 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
* except as a result of a read system call. This means clients must
* either ensure that system calls do not touch the heap, or must
* provide their own wrappers analogous to the one for read.
* We assume the page size is a multiple of HBLKSIZE.
* This implementation is currently SunOS 4.X and IRIX 5.X specific, though we
* tried to use portable code where easily possible. It is known
* not to work under a number of other systems.
*/
# ifndef MSWIN32
# include <sys/mman.h>
# include <signal.h>
# include <sys/syscall.h>
# define PROTECT(addr, len) \
if (mprotect((caddr_t)(addr), (int)(len), \
PROT_READ | OPT_PROT_EXEC) < 0) { \
ABORT("mprotect failed"); \
}
# define UNPROTECT(addr, len) \
if (mprotect((caddr_t)(addr), (int)(len), \
PROT_WRITE | PROT_READ | OPT_PROT_EXEC ) < 0) { \
ABORT("un-mprotect failed"); \
}
# else
# include <signal.h>
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
VOLATILE page_hash_table GC_dirty_pages;
/* Pages dirtied since last GC_read_dirty. */
#if defined(SUNOS4) || defined(FREEBSD)
typedef void (* SIG_PF)();
#endif
#if defined(SUNOS5SIGS) || defined(OSF1) || defined(LINUX)
typedef void (* SIG_PF)(int);
#endif
#if defined(MSWIN32)
typedef LPTOP_LEVEL_EXCEPTION_FILTER SIG_PF;
# undef SIG_DFL
# define SIG_DFL (LPTOP_LEVEL_EXCEPTION_FILTER) (-1)
#endif
#if defined(IRIX5) || defined(OSF1)
typedef void (* REAL_SIG_PF)(int, int, struct sigcontext *);
#endif
#if defined(SUNOS5SIGS)
typedef void (* REAL_SIG_PF)(int, struct siginfo *, void *);
#endif
#if defined(LINUX)
# include <linux/version.h>
# if (LINUX_VERSION_CODE >= 0x20100)
typedef void (* REAL_SIG_PF)(int, struct sigcontext);
# else
typedef void (* REAL_SIG_PF)(int, struct sigcontext_struct);
# endif
# endif
SIG_PF GC_old_bus_handler;
SIG_PF GC_old_segv_handler; /* Also old MSWIN32 ACCESS_VIOLATION filter */
/*ARGSUSED*/
# 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
# if defined(IRIX5) || defined(OSF1)
# include <errno.h>
void GC_write_fault_handler(int sig, int code, struct sigcontext *scp)
# define SIG_OK (sig == SIGSEGV)
# ifdef OSF1
# define CODE_OK (code == 2 /* experimentally determined */)
# endif
# ifdef IRIX5
# define CODE_OK (code == EACCES)
# endif
# endif
# if defined(LINUX)
# if (LINUX_VERSION_CODE >= 0x20100)
void GC_write_fault_handler(int sig, struct sigcontext sc)
# else
void GC_write_fault_handler(int sig, struct sigcontext_struct sc)
# endif
# define SIG_OK (sig == SIGSEGV)
# define CODE_OK TRUE
/* Empirically c.trapno == 14, but is that useful? */
/* We assume Intel architecture, so alignment */
/* faults are not possible. */
# endif
# if defined(SUNOS5SIGS)
void GC_write_fault_handler(int sig, struct siginfo *scp, void * context)
# define SIG_OK (sig == SIGSEGV)
# define CODE_OK (scp -> si_code == SEGV_ACCERR)
# endif
# if defined(MSWIN32)
LONG WINAPI GC_write_fault_handler(struct _EXCEPTION_POINTERS *exc_info)
# define SIG_OK (exc_info -> ExceptionRecord -> ExceptionCode == \
EXCEPTION_ACCESS_VIOLATION)
# define CODE_OK (exc_info -> ExceptionRecord -> ExceptionInformation[0] == 1)
/* Write fault */
# endif
{
register unsigned i;
# 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
# ifdef I386
char * addr = (char *) (sc.cr2);
# else
char * addr = /* As of 1.3.90 there seemed to be no way to do this. */;
# endif
# endif
# if defined(MSWIN32)
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) {
# ifndef MSWIN32
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)
(*(REAL_SIG_PF)old_handler) (sig, sc);
return;
# endif
# if defined (IRIX5) || defined(OSF1)
(*(REAL_SIG_PF)old_handler) (sig, code, scp);
return;
# endif
# ifdef MSWIN32
return((*old_handler)(exc_info));
# endif
}
}
for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
register int index = PHT_HASH(h+i);
set_pht_entry_from_index(GC_dirty_pages, index);
}
UNPROTECT(h, GC_page_size);
# if defined(OSF1) || defined(LINUX)
/* 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 ... */
# ifdef MSWIN32
return(EXCEPTION_CONTINUE_EXECUTION);
# else
return;
# endif
}
#ifdef MSWIN32
return EXCEPTION_CONTINUE_SEARCH;
#else
ABORT("Unexpected bus error or segmentation fault");
#endif
}
/*
* We hold the allocation lock. We expect block h to be written
* shortly.
*/
void GC_write_hint(h)
struct hblk *h;
{
register struct hblk * h_trunc;
register unsigned i;
register GC_bool found_clean;
if (!GC_dirty_maintained) return;
h_trunc = (struct hblk *)((word)h & ~(GC_page_size-1));
found_clean = FALSE;
for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
register int index = PHT_HASH(h_trunc+i);
if (!get_pht_entry_from_index(GC_dirty_pages, index)) {
found_clean = TRUE;
set_pht_entry_from_index(GC_dirty_pages, index);
}
}
if (found_clean) {
UNPROTECT(h_trunc, GC_page_size);
}
}
void GC_dirty_init()
{
#if defined(SUNOS5SIGS) || defined(IRIX5)
struct sigaction act, oldact;
# ifdef IRIX5
act.sa_flags = SA_RESTART;
act.sa_handler = 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);
#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(OSF1) || defined(SUNOS4) || defined(LINUX)
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)
# ifdef IRIX_THREADS
sigaction(SIGSEGV, 0, &oldact);
sigaction(SIGSEGV, &act, 0);
# else
sigaction(SIGSEGV, &act, &oldact);
# endif
# if defined(_sigargs)
/* 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 */
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(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
}
void GC_protect_heap()
{
ptr_t start;
word len;
unsigned i;
for (i = 0; i < GC_n_heap_sects; i++) {
start = GC_heap_sects[i].hs_start;
len = GC_heap_sects[i].hs_bytes;
PROTECT(start, len);
}
}
/* 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.
*/
void GC_begin_syscall()
{
if (!I_HOLD_LOCK()) LOCK();
}
void GC_end_syscall()
{
if (!I_HOLD_LOCK()) 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_incremental) 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);
set_pht_entry_from_index(GC_dirty_pages, index);
}
UNPROTECT(start_block,
((ptr_t)end_block - (ptr_t)start_block) + HBLKSIZE);
}
#ifndef MSWIN32
/* Replacement for UNIX system call. */
/* Other calls that write to the heap */
/* should be handled similarly. */
# if defined(__STDC__) && !defined(SUNOS4)
# include <unistd.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);
# ifdef IRIX5
/* Indirect system call may not always be easily available. */
/* We could call _read, but that would interfere with the */
/* libpthread interception of read. */
{
struct iovec iov;
iov.iov_base = buf;
iov.iov_len = nbyte;
result = readv(fd, &iov, 1);
}
# else
result = syscall(SYS_read, fd, buf, nbyte);
# endif
GC_end_syscall();
return(result);
}
#endif /* !MSWIN32 */
/*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>
#include <fcntl.h>
#define INITIAL_BUF_SZ 4096
word GC_proc_buf_size = INITIAL_BUF_SZ;
char *GC_proc_buf;
page_hash_table GC_written_pages = { 0 }; /* Pages ever dirtied */
#ifdef 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);
if (GC_proc_fd < 0) {
ABORT("/proc ioctl failed");
}
GC_proc_buf = GC_scratch_alloc(GC_proc_buf_size);
# ifdef 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_write_hint(h)
struct hblk *h;
{
}
#ifdef 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 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 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 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 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 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 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_write_hint(h)
struct hblk *h;
{
PCR_VD_WriteProtectDisable(h, HBLKSIZE);
PCR_VD_WriteProtectEnable(h, HBLKSIZE);
}
# endif /* PCR_VDB */
/*
* Call stack save code for debugging.
* Should probably be in mach_dep.c, but that requires reorganization.
*/
#if defined(SPARC)
# if defined(SUNOS4)
# include <machine/frame.h>
# else
# if defined (DRSNX)
# include <sys/sparc/frame.h>
# else
# include <sys/frame.h>
# endif
# endif
# if NARGS > 6
--> We only know how to to get the first 6 arguments
# endif
#ifdef SAVE_CALL_CHAIN
/* Fill in the pc and argument information for up to NFRAMES of my */
/* callers. Ignore my frame and my callers frame. */
void GC_save_callers (info)
struct callinfo info[NFRAMES];
{
struct frame *frame;
struct frame *fp;
int nframes = 0;
word GC_save_regs_in_stack();
frame = (struct frame *) GC_save_regs_in_stack ();
for (fp = frame -> fr_savfp; fp != 0 && nframes < NFRAMES;
fp = fp -> fr_savfp, nframes++) {
register int i;
info[nframes].ci_pc = fp->fr_savpc;
for (i = 0; i < NARGS; i++) {
info[nframes].ci_arg[i] = ~(fp->fr_arg[i]);
}
}
if (nframes < NFRAMES) info[nframes].ci_pc = 0;
}
#endif /* SAVE_CALL_CHAIN */
#endif /* SPARC */