| // Copyright 2015 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. |
| |
| // +build cgo |
| // +build darwin dragonfly freebsd linux netbsd openbsd solaris |
| |
| #include <pthread.h> |
| #include <errno.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> // strerror |
| #include <time.h> |
| #include "libcgo.h" |
| #include "libcgo_unix.h" |
| |
| static pthread_cond_t runtime_init_cond = PTHREAD_COND_INITIALIZER; |
| static pthread_mutex_t runtime_init_mu = PTHREAD_MUTEX_INITIALIZER; |
| static int runtime_init_done; |
| |
| // The context function, used when tracing back C calls into Go. |
| static void (*cgo_context_function)(struct context_arg*); |
| |
| void |
| x_cgo_sys_thread_create(void* (*func)(void*), void* arg) { |
| pthread_t p; |
| int err = _cgo_try_pthread_create(&p, NULL, func, arg); |
| if (err != 0) { |
| fprintf(stderr, "pthread_create failed: %s", strerror(err)); |
| abort(); |
| } |
| } |
| |
| uintptr_t |
| _cgo_wait_runtime_init_done() { |
| void (*pfn)(struct context_arg*); |
| |
| pthread_mutex_lock(&runtime_init_mu); |
| while (runtime_init_done == 0) { |
| pthread_cond_wait(&runtime_init_cond, &runtime_init_mu); |
| } |
| |
| // TODO(iant): For the case of a new C thread calling into Go, such |
| // as when using -buildmode=c-archive, we know that Go runtime |
| // initialization is complete but we do not know that all Go init |
| // functions have been run. We should not fetch cgo_context_function |
| // until they have been, because that is where a call to |
| // SetCgoTraceback is likely to occur. We are going to wait for Go |
| // initialization to be complete anyhow, later, by waiting for |
| // main_init_done to be closed in cgocallbackg1. We should wait here |
| // instead. See also issue #15943. |
| pfn = cgo_context_function; |
| |
| pthread_mutex_unlock(&runtime_init_mu); |
| if (pfn != nil) { |
| struct context_arg arg; |
| |
| arg.Context = 0; |
| (*pfn)(&arg); |
| return arg.Context; |
| } |
| return 0; |
| } |
| |
| void |
| x_cgo_notify_runtime_init_done(void* dummy __attribute__ ((unused))) { |
| pthread_mutex_lock(&runtime_init_mu); |
| runtime_init_done = 1; |
| pthread_cond_broadcast(&runtime_init_cond); |
| pthread_mutex_unlock(&runtime_init_mu); |
| } |
| |
| // Sets the context function to call to record the traceback context |
| // when calling a Go function from C code. Called from runtime.SetCgoTraceback. |
| void x_cgo_set_context_function(void (*context)(struct context_arg*)) { |
| pthread_mutex_lock(&runtime_init_mu); |
| cgo_context_function = context; |
| pthread_mutex_unlock(&runtime_init_mu); |
| } |
| |
| // Gets the context function. |
| void (*(_cgo_get_context_function(void)))(struct context_arg*) { |
| void (*ret)(struct context_arg*); |
| |
| pthread_mutex_lock(&runtime_init_mu); |
| ret = cgo_context_function; |
| pthread_mutex_unlock(&runtime_init_mu); |
| return ret; |
| } |
| |
| // _cgo_try_pthread_create retries pthread_create if it fails with |
| // EAGAIN. |
| int |
| _cgo_try_pthread_create(pthread_t* thread, const pthread_attr_t* attr, void* (*pfn)(void*), void* arg) { |
| int tries; |
| int err; |
| struct timespec ts; |
| |
| for (tries = 0; tries < 20; tries++) { |
| err = pthread_create(thread, attr, pfn, arg); |
| if (err == 0) { |
| pthread_detach(*thread); |
| return 0; |
| } |
| if (err != EAGAIN) { |
| return err; |
| } |
| ts.tv_sec = 0; |
| ts.tv_nsec = (tries + 1) * 1000 * 1000; // Milliseconds. |
| nanosleep(&ts, nil); |
| } |
| return EAGAIN; |
| } |