| // Copyright 2009 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| #include <errno.h> |
| #include <limits.h> |
| #include <signal.h> |
| #include <stdlib.h> |
| #include <pthread.h> |
| #include <unistd.h> |
| |
| #include "config.h" |
| |
| #ifdef HAVE_DL_ITERATE_PHDR |
| #include <link.h> |
| #endif |
| |
| #include "runtime.h" |
| #include "arch.h" |
| #include "defs.h" |
| #include "go-type.h" |
| |
| #ifdef USING_SPLIT_STACK |
| |
| /* FIXME: These are not declared anywhere. */ |
| |
| extern void __splitstack_getcontext(void *context[10]); |
| |
| extern void __splitstack_setcontext(void *context[10]); |
| |
| extern void *__splitstack_makecontext(size_t, void *context[10], size_t *); |
| |
| extern void * __splitstack_resetcontext(void *context[10], size_t *); |
| |
| extern void __splitstack_releasecontext(void *context[10]); |
| |
| extern void *__splitstack_find(void *, void *, size_t *, void **, void **, |
| void **); |
| |
| extern void __splitstack_block_signals (int *, int *); |
| |
| extern void __splitstack_block_signals_context (void *context[10], int *, |
| int *); |
| |
| #endif |
| |
| #ifndef PTHREAD_STACK_MIN |
| # define PTHREAD_STACK_MIN 8192 |
| #endif |
| |
| #if defined(USING_SPLIT_STACK) && defined(LINKER_SUPPORTS_SPLIT_STACK) |
| # define StackMin PTHREAD_STACK_MIN |
| #else |
| # define StackMin ((sizeof(char *) < 8) ? 2 * 1024 * 1024 : 4 * 1024 * 1024) |
| #endif |
| |
| uintptr runtime_stacks_sys; |
| |
| void gtraceback(G*) |
| __asm__(GOSYM_PREFIX "runtime.gtraceback"); |
| |
| #ifdef __rtems__ |
| #define __thread |
| #endif |
| |
| static __thread G *g; |
| |
| #ifndef SETCONTEXT_CLOBBERS_TLS |
| |
| static inline void |
| initcontext(void) |
| { |
| } |
| |
| static inline void |
| fixcontext(ucontext_t *c __attribute__ ((unused))) |
| { |
| } |
| |
| #else |
| |
| # if defined(__x86_64__) && defined(__sun__) |
| |
| // x86_64 Solaris 10 and 11 have a bug: setcontext switches the %fs |
| // register to that of the thread which called getcontext. The effect |
| // is that the address of all __thread variables changes. This bug |
| // also affects pthread_self() and pthread_getspecific. We work |
| // around it by clobbering the context field directly to keep %fs the |
| // same. |
| |
| static __thread greg_t fs; |
| |
| static inline void |
| initcontext(void) |
| { |
| ucontext_t c; |
| |
| getcontext(&c); |
| fs = c.uc_mcontext.gregs[REG_FSBASE]; |
| } |
| |
| static inline void |
| fixcontext(ucontext_t* c) |
| { |
| c->uc_mcontext.gregs[REG_FSBASE] = fs; |
| } |
| |
| # elif defined(__NetBSD__) |
| |
| // NetBSD has a bug: setcontext clobbers tlsbase, we need to save |
| // and restore it ourselves. |
| |
| static __thread __greg_t tlsbase; |
| |
| static inline void |
| initcontext(void) |
| { |
| ucontext_t c; |
| |
| getcontext(&c); |
| tlsbase = c.uc_mcontext._mc_tlsbase; |
| } |
| |
| static inline void |
| fixcontext(ucontext_t* c) |
| { |
| c->uc_mcontext._mc_tlsbase = tlsbase; |
| } |
| |
| # elif defined(__sparc__) |
| |
| static inline void |
| initcontext(void) |
| { |
| } |
| |
| static inline void |
| fixcontext(ucontext_t *c) |
| { |
| /* ??? Using |
| register unsigned long thread __asm__("%g7"); |
| c->uc_mcontext.gregs[REG_G7] = thread; |
| results in |
| error: variable ‘thread’ might be clobbered by \ |
| ‘longjmp’ or ‘vfork’ [-Werror=clobbered] |
| which ought to be false, as %g7 is a fixed register. */ |
| |
| if (sizeof (c->uc_mcontext.gregs[REG_G7]) == 8) |
| asm ("stx %%g7, %0" : "=m"(c->uc_mcontext.gregs[REG_G7])); |
| else |
| asm ("st %%g7, %0" : "=m"(c->uc_mcontext.gregs[REG_G7])); |
| } |
| |
| # elif defined(_AIX) |
| |
| static inline void |
| initcontext(void) |
| { |
| } |
| |
| static inline void |
| fixcontext(ucontext_t* c) |
| { |
| // Thread pointer is in r13, per 64-bit ABI. |
| if (sizeof (c->uc_mcontext.jmp_context.gpr[13]) == 8) |
| asm ("std 13, %0" : "=m"(c->uc_mcontext.jmp_context.gpr[13])); |
| } |
| |
| # else |
| |
| # error unknown case for SETCONTEXT_CLOBBERS_TLS |
| |
| # endif |
| |
| #endif |
| |
| // ucontext_arg returns a properly aligned ucontext_t value. On some |
| // systems a ucontext_t value must be aligned to a 16-byte boundary. |
| // The g structure that has fields of type ucontext_t is defined in |
| // Go, and Go has no simple way to align a field to such a boundary. |
| // So we make the field larger in runtime2.go and pick an appropriate |
| // offset within the field here. |
| static ucontext_t* |
| ucontext_arg(uintptr_t* go_ucontext) |
| { |
| uintptr_t p = (uintptr_t)go_ucontext; |
| size_t align = __alignof__(ucontext_t); |
| if(align > 16) { |
| // We only ensured space for up to a 16 byte alignment |
| // in libgo/go/runtime/runtime2.go. |
| runtime_throw("required alignment of ucontext_t too large"); |
| } |
| p = (p + align - 1) &~ (uintptr_t)(align - 1); |
| return (ucontext_t*)p; |
| } |
| |
| // We can not always refer to the TLS variables directly. The |
| // compiler will call tls_get_addr to get the address of the variable, |
| // and it may hold it in a register across a call to schedule. When |
| // we get back from the call we may be running in a different thread, |
| // in which case the register now points to the TLS variable for a |
| // different thread. We use non-inlinable functions to avoid this |
| // when necessary. |
| |
| G* runtime_g(void) __attribute__ ((noinline, no_split_stack)); |
| |
| G* |
| runtime_g(void) |
| { |
| return g; |
| } |
| |
| M* runtime_m(void) __attribute__ ((noinline, no_split_stack)); |
| |
| M* |
| runtime_m(void) |
| { |
| if(g == nil) |
| return nil; |
| return g->m; |
| } |
| |
| // Set g. |
| void |
| runtime_setg(G* gp) |
| { |
| g = gp; |
| } |
| |
| void runtime_newosproc(M *) |
| __asm__(GOSYM_PREFIX "runtime.newosproc"); |
| |
| // Start a new thread. |
| void |
| runtime_newosproc(M *mp) |
| { |
| pthread_attr_t attr; |
| sigset_t clear, old; |
| pthread_t tid; |
| int tries; |
| int ret; |
| |
| if(pthread_attr_init(&attr) != 0) |
| runtime_throw("pthread_attr_init"); |
| if(pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED) != 0) |
| runtime_throw("pthread_attr_setdetachstate"); |
| |
| // Block signals during pthread_create so that the new thread |
| // starts with signals disabled. It will enable them in minit. |
| sigfillset(&clear); |
| |
| #ifdef SIGTRAP |
| // Blocking SIGTRAP reportedly breaks gdb on Alpha GNU/Linux. |
| sigdelset(&clear, SIGTRAP); |
| #endif |
| |
| sigemptyset(&old); |
| pthread_sigmask(SIG_BLOCK, &clear, &old); |
| |
| for (tries = 0; tries < 20; tries++) { |
| ret = pthread_create(&tid, &attr, runtime_mstart, mp); |
| if (ret != EAGAIN) { |
| break; |
| } |
| runtime_usleep((tries + 1) * 1000); // Milliseconds. |
| } |
| |
| pthread_sigmask(SIG_SETMASK, &old, nil); |
| |
| if (ret != 0) { |
| runtime_printf("pthread_create failed: %d\n", ret); |
| runtime_throw("pthread_create"); |
| } |
| |
| if(pthread_attr_destroy(&attr) != 0) |
| runtime_throw("pthread_attr_destroy"); |
| } |
| |
| // Switch context to a different goroutine. This is like longjmp. |
| void runtime_gogo(G*) __attribute__ ((noinline)); |
| void |
| runtime_gogo(G* newg) |
| { |
| #ifdef USING_SPLIT_STACK |
| __splitstack_setcontext((void*)(&newg->stackcontext[0])); |
| #endif |
| g = newg; |
| newg->fromgogo = true; |
| fixcontext(ucontext_arg(&newg->context[0])); |
| setcontext(ucontext_arg(&newg->context[0])); |
| runtime_throw("gogo setcontext returned"); |
| } |
| |
| // Save context and call fn passing g as a parameter. This is like |
| // setjmp. Because getcontext always returns 0, unlike setjmp, we use |
| // g->fromgogo as a code. It will be true if we got here via |
| // setcontext. g == nil the first time this is called in a new m. |
| void runtime_mcall(FuncVal *) __attribute__ ((noinline)); |
| void |
| runtime_mcall(FuncVal *fv) |
| { |
| M *mp; |
| G *gp; |
| #ifndef USING_SPLIT_STACK |
| void *afterregs; |
| #endif |
| |
| // Ensure that all registers are on the stack for the garbage |
| // collector. |
| __builtin_unwind_init(); |
| flush_registers_to_secondary_stack(); |
| |
| gp = g; |
| mp = gp->m; |
| if(gp == mp->g0) |
| runtime_throw("runtime: mcall called on m->g0 stack"); |
| |
| if(gp != nil) { |
| |
| #ifdef USING_SPLIT_STACK |
| __splitstack_getcontext((void*)(&g->stackcontext[0])); |
| #else |
| // We have to point to an address on the stack that is |
| // below the saved registers. |
| gp->gcnextsp = (uintptr)(&afterregs); |
| gp->gcnextsp2 = (uintptr)(secondary_stack_pointer()); |
| #endif |
| gp->fromgogo = false; |
| getcontext(ucontext_arg(&gp->context[0])); |
| |
| // When we return from getcontext, we may be running |
| // in a new thread. That means that g may have |
| // changed. It is a global variables so we will |
| // reload it, but the address of g may be cached in |
| // our local stack frame, and that address may be |
| // wrong. Call the function to reload the value for |
| // this thread. |
| gp = runtime_g(); |
| mp = gp->m; |
| |
| if(gp->traceback != nil) |
| gtraceback(gp); |
| } |
| if (gp == nil || !gp->fromgogo) { |
| #ifdef USING_SPLIT_STACK |
| __splitstack_setcontext((void*)(&mp->g0->stackcontext[0])); |
| #endif |
| mp->g0->entry = fv; |
| mp->g0->param = gp; |
| |
| // It's OK to set g directly here because this case |
| // can not occur if we got here via a setcontext to |
| // the getcontext call just above. |
| g = mp->g0; |
| |
| fixcontext(ucontext_arg(&mp->g0->context[0])); |
| setcontext(ucontext_arg(&mp->g0->context[0])); |
| runtime_throw("runtime: mcall function returned"); |
| } |
| } |
| |
| // Goroutine scheduler |
| // The scheduler's job is to distribute ready-to-run goroutines over worker threads. |
| // |
| // The main concepts are: |
| // G - goroutine. |
| // M - worker thread, or machine. |
| // P - processor, a resource that is required to execute Go code. |
| // M must have an associated P to execute Go code, however it can be |
| // blocked or in a syscall w/o an associated P. |
| // |
| // Design doc at http://golang.org/s/go11sched. |
| |
| extern G* allocg(void) |
| __asm__ (GOSYM_PREFIX "runtime.allocg"); |
| |
| Sched* runtime_sched; |
| |
| bool runtime_isarchive; |
| |
| extern void kickoff(void) |
| __asm__(GOSYM_PREFIX "runtime.kickoff"); |
| extern void minit(void) |
| __asm__(GOSYM_PREFIX "runtime.minit"); |
| extern void mstart1(int32) |
| __asm__(GOSYM_PREFIX "runtime.mstart1"); |
| extern void stopm(void) |
| __asm__(GOSYM_PREFIX "runtime.stopm"); |
| extern void mexit(bool) |
| __asm__(GOSYM_PREFIX "runtime.mexit"); |
| extern void handoffp(P*) |
| __asm__(GOSYM_PREFIX "runtime.handoffp"); |
| extern void wakep(void) |
| __asm__(GOSYM_PREFIX "runtime.wakep"); |
| extern void stoplockedm(void) |
| __asm__(GOSYM_PREFIX "runtime.stoplockedm"); |
| extern void schedule(void) |
| __asm__(GOSYM_PREFIX "runtime.schedule"); |
| extern void execute(G*, bool) |
| __asm__(GOSYM_PREFIX "runtime.execute"); |
| extern void reentersyscall(uintptr, uintptr) |
| __asm__(GOSYM_PREFIX "runtime.reentersyscall"); |
| extern void reentersyscallblock(uintptr, uintptr) |
| __asm__(GOSYM_PREFIX "runtime.reentersyscallblock"); |
| extern G* gfget(P*) |
| __asm__(GOSYM_PREFIX "runtime.gfget"); |
| extern void acquirep(P*) |
| __asm__(GOSYM_PREFIX "runtime.acquirep"); |
| extern P* releasep(void) |
| __asm__(GOSYM_PREFIX "runtime.releasep"); |
| extern void incidlelocked(int32) |
| __asm__(GOSYM_PREFIX "runtime.incidlelocked"); |
| extern void globrunqput(G*) |
| __asm__(GOSYM_PREFIX "runtime.globrunqput"); |
| extern P* pidleget(void) |
| __asm__(GOSYM_PREFIX "runtime.pidleget"); |
| extern struct mstats* getMemstats(void) |
| __asm__(GOSYM_PREFIX "runtime.getMemstats"); |
| |
| bool runtime_isstarted; |
| |
| // Used to determine the field alignment. |
| |
| struct field_align |
| { |
| char c; |
| Hchan *p; |
| }; |
| |
| void getTraceback(G*, G*) __asm__(GOSYM_PREFIX "runtime.getTraceback"); |
| |
| // getTraceback stores a traceback of gp in the g's traceback field |
| // and then returns to me. We expect that gp's traceback is not nil. |
| // It works by saving me's current context, and checking gp's traceback field. |
| // If gp's traceback field is not nil, it starts running gp. |
| // In places where we call getcontext, we check the traceback field. |
| // If it is not nil, we collect a traceback, and then return to the |
| // goroutine stored in the traceback field, which is me. |
| void getTraceback(G* me, G* gp) |
| { |
| #ifdef USING_SPLIT_STACK |
| __splitstack_getcontext((void*)(&me->stackcontext[0])); |
| #endif |
| getcontext(ucontext_arg(&me->context[0])); |
| |
| if (gp->traceback != nil) { |
| runtime_gogo(gp); |
| } |
| } |
| |
| // Do a stack trace of gp, and then restore the context to |
| // gp->traceback->gp. |
| |
| void |
| gtraceback(G* gp) |
| { |
| Traceback* traceback; |
| M* holdm; |
| |
| traceback = gp->traceback; |
| gp->traceback = nil; |
| holdm = gp->m; |
| if(holdm != nil && holdm != g->m) |
| runtime_throw("gtraceback: m is not nil"); |
| gp->m = traceback->gp->m; |
| traceback->c = runtime_callers(1, traceback->locbuf, |
| sizeof traceback->locbuf / sizeof traceback->locbuf[0], false); |
| gp->m = holdm; |
| runtime_gogo(traceback->gp); |
| } |
| |
| // Called by pthread_create to start an M. |
| void* |
| runtime_mstart(void *arg) |
| { |
| M* mp; |
| G* gp; |
| |
| mp = (M*)(arg); |
| gp = mp->g0; |
| gp->m = mp; |
| |
| g = gp; |
| |
| gp->entry = nil; |
| gp->param = nil; |
| |
| // We have to call minit before we call getcontext, |
| // because getcontext will copy the signal mask. |
| minit(); |
| |
| initcontext(); |
| |
| // Record top of stack for use by mcall. |
| // Once we call schedule we're never coming back, |
| // so other calls can reuse this stack space. |
| #ifdef USING_SPLIT_STACK |
| __splitstack_getcontext((void*)(&gp->stackcontext[0])); |
| #else |
| gp->gcinitialsp = &arg; |
| // Setting gcstacksize to 0 is a marker meaning that gcinitialsp |
| // is the top of the stack, not the bottom. |
| gp->gcstacksize = 0; |
| gp->gcnextsp = (uintptr)(&arg); |
| gp->gcinitialsp2 = secondary_stack_pointer(); |
| gp->gcnextsp2 = (uintptr)(gp->gcinitialsp2); |
| #endif |
| |
| // Save the currently active context. This will return |
| // multiple times via the setcontext call in mcall. |
| getcontext(ucontext_arg(&gp->context[0])); |
| |
| if(gp->traceback != nil) { |
| // Got here from getTraceback. |
| // I'm not sure this ever actually happens--getTraceback |
| // may always go to the getcontext call in mcall. |
| gtraceback(gp); |
| } |
| |
| if(gp->entry != nil) { |
| // Got here from mcall. |
| FuncVal *fv = gp->entry; |
| void (*pfn)(G*) = (void (*)(G*))fv->fn; |
| G* gp1 = (G*)gp->param; |
| gp->entry = nil; |
| gp->param = nil; |
| __builtin_call_with_static_chain(pfn(gp1), fv); |
| *(int*)0x21 = 0x21; |
| } |
| |
| if(mp->exiting) { |
| mexit(true); |
| return nil; |
| } |
| |
| // Initial call to getcontext--starting thread. |
| |
| #ifdef USING_SPLIT_STACK |
| { |
| int dont_block_signals = 0; |
| __splitstack_block_signals(&dont_block_signals, nil); |
| } |
| #endif |
| |
| mstart1(0); |
| |
| // mstart1 does not return, but we need a return statement |
| // here to avoid a compiler warning. |
| return nil; |
| } |
| |
| typedef struct CgoThreadStart CgoThreadStart; |
| struct CgoThreadStart |
| { |
| M *m; |
| G *g; |
| uintptr *tls; |
| void (*fn)(void); |
| }; |
| |
| void setGContext(void) __asm__ (GOSYM_PREFIX "runtime.setGContext"); |
| |
| // setGContext sets up a new goroutine context for the current g. |
| void |
| setGContext(void) |
| { |
| int val; |
| G *gp; |
| |
| initcontext(); |
| gp = g; |
| gp->entry = nil; |
| gp->param = nil; |
| #ifdef USING_SPLIT_STACK |
| __splitstack_getcontext((void*)(&gp->stackcontext[0])); |
| val = 0; |
| __splitstack_block_signals(&val, nil); |
| #else |
| gp->gcinitialsp = &val; |
| gp->gcstack = 0; |
| gp->gcstacksize = 0; |
| gp->gcnextsp = (uintptr)(&val); |
| gp->gcinitialsp2 = secondary_stack_pointer(); |
| gp->gcnextsp2 = (uintptr)(gp->gcinitialsp2); |
| #endif |
| getcontext(ucontext_arg(&gp->context[0])); |
| |
| if(gp->entry != nil) { |
| // Got here from mcall. |
| FuncVal *fv = gp->entry; |
| void (*pfn)(G*) = (void (*)(G*))fv->fn; |
| G* gp1 = (G*)gp->param; |
| gp->entry = nil; |
| gp->param = nil; |
| __builtin_call_with_static_chain(pfn(gp1), fv); |
| *(int*)0x22 = 0x22; |
| } |
| } |
| |
| void makeGContext(G*, byte*, uintptr) |
| __asm__(GOSYM_PREFIX "runtime.makeGContext"); |
| |
| // makeGContext makes a new context for a g. |
| void |
| makeGContext(G* gp, byte* sp, uintptr spsize) { |
| ucontext_t *uc; |
| |
| uc = ucontext_arg(&gp->context[0]); |
| getcontext(uc); |
| uc->uc_stack.ss_sp = sp; |
| uc->uc_stack.ss_size = (size_t)spsize; |
| makecontext(uc, kickoff, 0); |
| } |
| |
| // The goroutine g is about to enter a system call. |
| // Record that it's not using the cpu anymore. |
| // This is called only from the go syscall library and cgocall, |
| // not from the low-level system calls used by the runtime. |
| // |
| // Entersyscall cannot split the stack: the runtime_gosave must |
| // make g->sched refer to the caller's stack segment, because |
| // entersyscall is going to return immediately after. |
| |
| void runtime_entersyscall(int32) __attribute__ ((no_split_stack)); |
| static void doentersyscall(uintptr, uintptr) |
| __attribute__ ((no_split_stack, noinline)); |
| |
| void |
| runtime_entersyscall(int32 dummy __attribute__ ((unused))) |
| { |
| // Save the registers in the g structure so that any pointers |
| // held in registers will be seen by the garbage collector. |
| getcontext(ucontext_arg(&g->gcregs[0])); |
| |
| // Note that if this function does save any registers itself, |
| // we might store the wrong value in the call to getcontext. |
| // FIXME: This assumes that we do not need to save any |
| // callee-saved registers to access the TLS variable g. We |
| // don't want to put the ucontext_t on the stack because it is |
| // large and we can not split the stack here. |
| doentersyscall((uintptr)runtime_getcallerpc(&dummy), |
| (uintptr)runtime_getcallersp(&dummy)); |
| } |
| |
| static void |
| doentersyscall(uintptr pc, uintptr sp) |
| { |
| // Leave SP around for GC and traceback. |
| #ifdef USING_SPLIT_STACK |
| { |
| size_t gcstacksize; |
| g->gcstack = (uintptr)(__splitstack_find(nil, nil, &gcstacksize, |
| (void**)(&g->gcnextsegment), |
| (void**)(&g->gcnextsp), |
| &g->gcinitialsp)); |
| g->gcstacksize = (uintptr)gcstacksize; |
| } |
| #else |
| { |
| void *v; |
| |
| g->gcnextsp = (uintptr)(&v); |
| g->gcnextsp2 = (uintptr)(secondary_stack_pointer()); |
| } |
| #endif |
| |
| reentersyscall(pc, sp); |
| } |
| |
| static void doentersyscallblock(uintptr, uintptr) |
| __attribute__ ((no_split_stack, noinline)); |
| |
| // The same as runtime_entersyscall(), but with a hint that the syscall is blocking. |
| void |
| runtime_entersyscallblock(int32 dummy __attribute__ ((unused))) |
| { |
| // Save the registers in the g structure so that any pointers |
| // held in registers will be seen by the garbage collector. |
| getcontext(ucontext_arg(&g->gcregs[0])); |
| |
| // See comment in runtime_entersyscall. |
| doentersyscallblock((uintptr)runtime_getcallerpc(&dummy), |
| (uintptr)runtime_getcallersp(&dummy)); |
| } |
| |
| static void |
| doentersyscallblock(uintptr pc, uintptr sp) |
| { |
| // Leave SP around for GC and traceback. |
| #ifdef USING_SPLIT_STACK |
| { |
| size_t gcstacksize; |
| g->gcstack = (uintptr)(__splitstack_find(nil, nil, &gcstacksize, |
| (void**)(&g->gcnextsegment), |
| (void**)(&g->gcnextsp), |
| &g->gcinitialsp)); |
| g->gcstacksize = (uintptr)gcstacksize; |
| } |
| #else |
| { |
| void *v; |
| |
| g->gcnextsp = (uintptr)(&v); |
| g->gcnextsp2 = (uintptr)(secondary_stack_pointer()); |
| } |
| #endif |
| |
| reentersyscallblock(pc, sp); |
| } |
| |
| // Allocate a new g, with a stack big enough for stacksize bytes. |
| G* |
| runtime_malg(bool allocatestack, bool signalstack, byte** ret_stack, uintptr* ret_stacksize) |
| { |
| uintptr stacksize; |
| G *newg; |
| byte* unused_stack; |
| uintptr unused_stacksize; |
| #if USING_SPLIT_STACK |
| int dont_block_signals = 0; |
| size_t ss_stacksize; |
| #endif |
| |
| if (ret_stack == nil) { |
| ret_stack = &unused_stack; |
| } |
| if (ret_stacksize == nil) { |
| ret_stacksize = &unused_stacksize; |
| } |
| newg = allocg(); |
| if(allocatestack) { |
| stacksize = StackMin; |
| if(signalstack) { |
| stacksize = 32 * 1024; // OS X wants >= 8K, GNU/Linux >= 2K |
| #ifdef SIGSTKSZ |
| if(stacksize < SIGSTKSZ) |
| stacksize = SIGSTKSZ; |
| #endif |
| } |
| |
| #if USING_SPLIT_STACK |
| *ret_stack = __splitstack_makecontext(stacksize, |
| (void*)(&newg->stackcontext[0]), |
| &ss_stacksize); |
| *ret_stacksize = (uintptr)ss_stacksize; |
| __splitstack_block_signals_context((void*)(&newg->stackcontext[0]), |
| &dont_block_signals, nil); |
| #else |
| // In 64-bit mode, the maximum Go allocation space is |
| // 128G. Our stack size is 4M, which only permits 32K |
| // goroutines. In order to not limit ourselves, |
| // allocate the stacks out of separate memory. In |
| // 32-bit mode, the Go allocation space is all of |
| // memory anyhow. |
| if(sizeof(void*) == 8) { |
| void *p = runtime_sysAlloc(stacksize, &getMemstats()->stacks_sys); |
| if(p == nil) |
| runtime_throw("runtime: cannot allocate memory for goroutine stack"); |
| *ret_stack = (byte*)p; |
| } else { |
| *ret_stack = runtime_mallocgc(stacksize, nil, false); |
| runtime_xadd(&runtime_stacks_sys, stacksize); |
| } |
| *ret_stacksize = (uintptr)stacksize; |
| newg->gcinitialsp = *ret_stack; |
| newg->gcstacksize = (uintptr)stacksize; |
| newg->gcinitialsp2 = initial_secondary_stack_pointer(*ret_stack); |
| #endif |
| } |
| return newg; |
| } |
| |
| void stackfree(G*) |
| __asm__(GOSYM_PREFIX "runtime.stackfree"); |
| |
| // stackfree frees the stack of a g. |
| void |
| stackfree(G* gp) |
| { |
| #if USING_SPLIT_STACK |
| __splitstack_releasecontext((void*)(&gp->stackcontext[0])); |
| #else |
| // If gcstacksize is 0, the stack is allocated by libc and will be |
| // released when the thread exits. Otherwise, in 64-bit mode it was |
| // allocated using sysAlloc and in 32-bit mode it was allocated |
| // using garbage collected memory. |
| if (gp->gcstacksize != 0) { |
| if (sizeof(void*) == 8) { |
| runtime_sysFree(gp->gcinitialsp, gp->gcstacksize, &getMemstats()->stacks_sys); |
| } |
| gp->gcinitialsp = nil; |
| gp->gcstacksize = 0; |
| } |
| #endif |
| } |
| |
| void resetNewG(G*, void **, uintptr*) |
| __asm__(GOSYM_PREFIX "runtime.resetNewG"); |
| |
| // Reset stack information for g pulled out of the cache to start a |
| // new goroutine. |
| void |
| resetNewG(G *newg, void **sp, uintptr *spsize) |
| { |
| #ifdef USING_SPLIT_STACK |
| int dont_block_signals = 0; |
| size_t ss_spsize; |
| |
| *sp = __splitstack_resetcontext((void*)(&newg->stackcontext[0]), &ss_spsize); |
| *spsize = ss_spsize; |
| __splitstack_block_signals_context((void*)(&newg->stackcontext[0]), |
| &dont_block_signals, nil); |
| #else |
| *sp = newg->gcinitialsp; |
| *spsize = newg->gcstacksize; |
| if(*spsize == 0) |
| runtime_throw("bad spsize in resetNewG"); |
| newg->gcnextsp = (uintptr)(*sp); |
| newg->gcnextsp2 = (uintptr)(newg->gcinitialsp2); |
| #endif |
| } |
| |
| // Return whether we are waiting for a GC. This gc toolchain uses |
| // preemption instead. |
| bool |
| runtime_gcwaiting(void) |
| { |
| return runtime_sched->gcwaiting; |
| } |