786 lines
20 KiB
C
786 lines
20 KiB
C
// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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#include <errno.h>
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#include <limits.h>
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#include <signal.h>
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#include <stdlib.h>
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#include <pthread.h>
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#include <unistd.h>
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#include "config.h"
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#ifdef HAVE_DL_ITERATE_PHDR
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#include <link.h>
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#endif
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#include "runtime.h"
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#include "arch.h"
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#include "defs.h"
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#include "go-type.h"
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#ifdef USING_SPLIT_STACK
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/* FIXME: These are not declared anywhere. */
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extern void __splitstack_getcontext(void *context[10]);
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extern void __splitstack_setcontext(void *context[10]);
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extern void *__splitstack_makecontext(size_t, void *context[10], size_t *);
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extern void * __splitstack_resetcontext(void *context[10], size_t *);
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extern void *__splitstack_find(void *, void *, size_t *, void **, void **,
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void **);
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extern void __splitstack_block_signals (int *, int *);
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extern void __splitstack_block_signals_context (void *context[10], int *,
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int *);
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#endif
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#ifndef PTHREAD_STACK_MIN
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# define PTHREAD_STACK_MIN 8192
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#endif
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#if defined(USING_SPLIT_STACK) && defined(LINKER_SUPPORTS_SPLIT_STACK)
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# define StackMin PTHREAD_STACK_MIN
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#else
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# define StackMin ((sizeof(char *) < 8) ? 2 * 1024 * 1024 : 4 * 1024 * 1024)
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#endif
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uintptr runtime_stacks_sys;
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void gtraceback(G*)
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__asm__(GOSYM_PREFIX "runtime.gtraceback");
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#ifdef __rtems__
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#define __thread
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#endif
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static __thread G *g;
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#ifndef SETCONTEXT_CLOBBERS_TLS
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static inline void
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initcontext(void)
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{
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}
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static inline void
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fixcontext(ucontext_t *c __attribute__ ((unused)))
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{
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}
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#else
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# if defined(__x86_64__) && defined(__sun__)
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// x86_64 Solaris 10 and 11 have a bug: setcontext switches the %fs
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// register to that of the thread which called getcontext. The effect
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// is that the address of all __thread variables changes. This bug
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// also affects pthread_self() and pthread_getspecific. We work
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// around it by clobbering the context field directly to keep %fs the
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// same.
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static __thread greg_t fs;
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static inline void
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initcontext(void)
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{
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ucontext_t c;
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getcontext(&c);
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fs = c.uc_mcontext.gregs[REG_FSBASE];
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}
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static inline void
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fixcontext(ucontext_t* c)
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{
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c->uc_mcontext.gregs[REG_FSBASE] = fs;
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}
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# elif defined(__NetBSD__)
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// NetBSD has a bug: setcontext clobbers tlsbase, we need to save
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// and restore it ourselves.
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static __thread __greg_t tlsbase;
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static inline void
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initcontext(void)
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{
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ucontext_t c;
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getcontext(&c);
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tlsbase = c.uc_mcontext._mc_tlsbase;
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}
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static inline void
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fixcontext(ucontext_t* c)
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{
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c->uc_mcontext._mc_tlsbase = tlsbase;
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}
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# elif defined(__sparc__)
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static inline void
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initcontext(void)
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{
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}
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static inline void
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fixcontext(ucontext_t *c)
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{
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/* ??? Using
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register unsigned long thread __asm__("%g7");
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c->uc_mcontext.gregs[REG_G7] = thread;
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results in
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error: variable ‘thread’ might be clobbered by \
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‘longjmp’ or ‘vfork’ [-Werror=clobbered]
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which ought to be false, as %g7 is a fixed register. */
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if (sizeof (c->uc_mcontext.gregs[REG_G7]) == 8)
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asm ("stx %%g7, %0" : "=m"(c->uc_mcontext.gregs[REG_G7]));
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else
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asm ("st %%g7, %0" : "=m"(c->uc_mcontext.gregs[REG_G7]));
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}
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# elif defined(_AIX)
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static inline void
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initcontext(void)
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{
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}
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static inline void
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fixcontext(ucontext_t* c)
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{
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// Thread pointer is in r13, per 64-bit ABI.
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if (sizeof (c->uc_mcontext.jmp_context.gpr[13]) == 8)
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asm ("std 13, %0" : "=m"(c->uc_mcontext.jmp_context.gpr[13]));
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}
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# else
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# error unknown case for SETCONTEXT_CLOBBERS_TLS
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# endif
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#endif
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// ucontext_arg returns a properly aligned ucontext_t value. On some
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// systems a ucontext_t value must be aligned to a 16-byte boundary.
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// The g structure that has fields of type ucontext_t is defined in
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// Go, and Go has no simple way to align a field to such a boundary.
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// So we make the field larger in runtime2.go and pick an appropriate
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// offset within the field here.
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static ucontext_t*
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ucontext_arg(uintptr* go_ucontext)
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{
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uintptr_t p = (uintptr_t)go_ucontext;
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size_t align = __alignof__(ucontext_t);
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if(align > 16) {
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// We only ensured space for up to a 16 byte alignment
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// in libgo/go/runtime/runtime2.go.
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runtime_throw("required alignment of ucontext_t too large");
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}
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p = (p + align - 1) &~ (uintptr_t)(align - 1);
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return (ucontext_t*)p;
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}
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// We can not always refer to the TLS variables directly. The
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// compiler will call tls_get_addr to get the address of the variable,
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// and it may hold it in a register across a call to schedule. When
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// we get back from the call we may be running in a different thread,
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// in which case the register now points to the TLS variable for a
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// different thread. We use non-inlinable functions to avoid this
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// when necessary.
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G* runtime_g(void) __attribute__ ((noinline, no_split_stack));
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G*
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runtime_g(void)
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{
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return g;
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}
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M* runtime_m(void) __attribute__ ((noinline, no_split_stack));
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M*
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runtime_m(void)
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{
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if(g == nil)
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return nil;
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return g->m;
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}
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// Set g.
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void
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runtime_setg(G* gp)
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{
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g = gp;
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}
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void runtime_newosproc(M *)
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__asm__(GOSYM_PREFIX "runtime.newosproc");
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// Start a new thread.
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void
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runtime_newosproc(M *mp)
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{
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pthread_attr_t attr;
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sigset_t clear, old;
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pthread_t tid;
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int tries;
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int ret;
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if(pthread_attr_init(&attr) != 0)
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runtime_throw("pthread_attr_init");
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if(pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED) != 0)
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runtime_throw("pthread_attr_setdetachstate");
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// Block signals during pthread_create so that the new thread
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// starts with signals disabled. It will enable them in minit.
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sigfillset(&clear);
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#ifdef SIGTRAP
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// Blocking SIGTRAP reportedly breaks gdb on Alpha GNU/Linux.
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sigdelset(&clear, SIGTRAP);
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#endif
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sigemptyset(&old);
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pthread_sigmask(SIG_BLOCK, &clear, &old);
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for (tries = 0; tries < 20; tries++) {
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ret = pthread_create(&tid, &attr, runtime_mstart, mp);
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if (ret != EAGAIN) {
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break;
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}
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runtime_usleep((tries + 1) * 1000); // Milliseconds.
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}
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pthread_sigmask(SIG_SETMASK, &old, nil);
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if (ret != 0) {
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runtime_printf("pthread_create failed: %d\n", ret);
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runtime_throw("pthread_create");
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}
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}
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// Switch context to a different goroutine. This is like longjmp.
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void runtime_gogo(G*) __attribute__ ((noinline));
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void
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runtime_gogo(G* newg)
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{
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#ifdef USING_SPLIT_STACK
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__splitstack_setcontext((void*)(&newg->stackcontext[0]));
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#endif
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g = newg;
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newg->fromgogo = true;
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fixcontext(ucontext_arg(&newg->context[0]));
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setcontext(ucontext_arg(&newg->context[0]));
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runtime_throw("gogo setcontext returned");
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}
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// Save context and call fn passing g as a parameter. This is like
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// setjmp. Because getcontext always returns 0, unlike setjmp, we use
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// g->fromgogo as a code. It will be true if we got here via
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// setcontext. g == nil the first time this is called in a new m.
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void runtime_mcall(FuncVal *) __attribute__ ((noinline));
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void
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runtime_mcall(FuncVal *fv)
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{
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M *mp;
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G *gp;
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#ifndef USING_SPLIT_STACK
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void *afterregs;
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#endif
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// Ensure that all registers are on the stack for the garbage
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// collector.
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__builtin_unwind_init();
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gp = g;
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mp = gp->m;
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if(gp == mp->g0)
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runtime_throw("runtime: mcall called on m->g0 stack");
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if(gp != nil) {
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#ifdef USING_SPLIT_STACK
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__splitstack_getcontext((void*)(&g->stackcontext[0]));
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#else
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// We have to point to an address on the stack that is
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// below the saved registers.
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gp->gcnextsp = (uintptr)(&afterregs);
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#endif
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gp->fromgogo = false;
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getcontext(ucontext_arg(&gp->context[0]));
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// When we return from getcontext, we may be running
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// in a new thread. That means that g may have
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// changed. It is a global variables so we will
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// reload it, but the address of g may be cached in
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// our local stack frame, and that address may be
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// wrong. Call the function to reload the value for
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// this thread.
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gp = runtime_g();
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mp = gp->m;
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if(gp->traceback != nil)
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gtraceback(gp);
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}
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if (gp == nil || !gp->fromgogo) {
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#ifdef USING_SPLIT_STACK
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__splitstack_setcontext((void*)(&mp->g0->stackcontext[0]));
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#endif
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mp->g0->entry = fv;
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mp->g0->param = gp;
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// It's OK to set g directly here because this case
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// can not occur if we got here via a setcontext to
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// the getcontext call just above.
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g = mp->g0;
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fixcontext(ucontext_arg(&mp->g0->context[0]));
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setcontext(ucontext_arg(&mp->g0->context[0]));
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runtime_throw("runtime: mcall function returned");
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}
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}
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// Goroutine scheduler
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// The scheduler's job is to distribute ready-to-run goroutines over worker threads.
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//
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// The main concepts are:
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// G - goroutine.
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// M - worker thread, or machine.
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// P - processor, a resource that is required to execute Go code.
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// M must have an associated P to execute Go code, however it can be
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// blocked or in a syscall w/o an associated P.
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//
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// Design doc at http://golang.org/s/go11sched.
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extern bool* runtime_getCgoHasExtraM()
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__asm__ (GOSYM_PREFIX "runtime.getCgoHasExtraM");
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extern G* allocg(void)
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__asm__ (GOSYM_PREFIX "runtime.allocg");
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Sched* runtime_sched;
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bool runtime_isarchive;
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extern void kickoff(void)
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__asm__(GOSYM_PREFIX "runtime.kickoff");
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extern void minit(void)
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__asm__(GOSYM_PREFIX "runtime.minit");
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extern void mstart1(void)
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__asm__(GOSYM_PREFIX "runtime.mstart1");
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extern void stopm(void)
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__asm__(GOSYM_PREFIX "runtime.stopm");
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extern void handoffp(P*)
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__asm__(GOSYM_PREFIX "runtime.handoffp");
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extern void wakep(void)
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__asm__(GOSYM_PREFIX "runtime.wakep");
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extern void stoplockedm(void)
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__asm__(GOSYM_PREFIX "runtime.stoplockedm");
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extern void schedule(void)
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__asm__(GOSYM_PREFIX "runtime.schedule");
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extern void execute(G*, bool)
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__asm__(GOSYM_PREFIX "runtime.execute");
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extern void reentersyscall(uintptr, uintptr)
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__asm__(GOSYM_PREFIX "runtime.reentersyscall");
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extern void reentersyscallblock(uintptr, uintptr)
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__asm__(GOSYM_PREFIX "runtime.reentersyscallblock");
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extern G* gfget(P*)
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__asm__(GOSYM_PREFIX "runtime.gfget");
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extern void acquirep(P*)
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__asm__(GOSYM_PREFIX "runtime.acquirep");
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extern P* releasep(void)
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__asm__(GOSYM_PREFIX "runtime.releasep");
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extern void incidlelocked(int32)
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__asm__(GOSYM_PREFIX "runtime.incidlelocked");
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extern void globrunqput(G*)
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__asm__(GOSYM_PREFIX "runtime.globrunqput");
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extern P* pidleget(void)
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__asm__(GOSYM_PREFIX "runtime.pidleget");
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extern struct mstats* getMemstats(void)
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__asm__(GOSYM_PREFIX "runtime.getMemstats");
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bool runtime_isstarted;
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|
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// Used to determine the field alignment.
|
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|
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struct field_align
|
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{
|
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char c;
|
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Hchan *p;
|
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};
|
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|
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void getTraceback(G*, G*) __asm__(GOSYM_PREFIX "runtime.getTraceback");
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// getTraceback stores a traceback of gp in the g's traceback field
|
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// and then returns to me. We expect that gp's traceback is not nil.
|
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// It works by saving me's current context, and checking gp's traceback field.
|
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// If gp's traceback field is not nil, it starts running gp.
|
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// In places where we call getcontext, we check the traceback field.
|
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// If it is not nil, we collect a traceback, and then return to the
|
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// goroutine stored in the traceback field, which is me.
|
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void getTraceback(G* me, G* gp)
|
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{
|
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#ifdef USING_SPLIT_STACK
|
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__splitstack_getcontext((void*)(&me->stackcontext[0]));
|
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#endif
|
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getcontext(ucontext_arg(&me->context[0]));
|
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|
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if (gp->traceback != nil) {
|
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runtime_gogo(gp);
|
||
}
|
||
}
|
||
|
||
// Do a stack trace of gp, and then restore the context to
|
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// gp->traceback->gp.
|
||
|
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void
|
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gtraceback(G* gp)
|
||
{
|
||
Traceback* traceback;
|
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M* holdm;
|
||
|
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traceback = gp->traceback;
|
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gp->traceback = nil;
|
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holdm = gp->m;
|
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if(holdm != nil && holdm != g->m)
|
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runtime_throw("gtraceback: m is not nil");
|
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gp->m = traceback->gp->m;
|
||
traceback->c = runtime_callers(1, traceback->locbuf,
|
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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);
|
||
#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;
|
||
}
|
||
|
||
// Initial call to getcontext--starting thread.
|
||
|
||
#ifdef USING_SPLIT_STACK
|
||
{
|
||
int dont_block_signals = 0;
|
||
__splitstack_block_signals(&dont_block_signals, nil);
|
||
}
|
||
#endif
|
||
|
||
mstart1();
|
||
|
||
// 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()
|
||
{
|
||
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);
|
||
#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);
|
||
}
|
||
#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);
|
||
}
|
||
#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;
|
||
#endif
|
||
}
|
||
return newg;
|
||
}
|
||
|
||
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);
|
||
#endif
|
||
}
|
||
|
||
// Return whether we are waiting for a GC. This gc toolchain uses
|
||
// preemption instead.
|
||
bool
|
||
runtime_gcwaiting(void)
|
||
{
|
||
return runtime_sched->gcwaiting;
|
||
}
|