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/*
*
* Copyright 2015 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
/* Posix implementation for gpr threads. */
#include <grpc/support/port_platform.h>
#ifdef GPR_POSIX_SYNC
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include <grpc/support/sync.h>
#include <grpc/support/thd.h>
#include <grpc/support/useful.h>
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include "src/core/lib/support/fork.h"
static gpr_mu g_mu;
static gpr_cv g_cv;
static int g_thread_count;
static int g_awaiting_threads;
struct thd_arg {
void (*body)(void* arg); /* body of a thread */
void* arg; /* argument to a thread */
const char* name; /* name of thread. Can be nullptr. */
};
static void inc_thd_count();
static void dec_thd_count();
/* Body of every thread started via gpr_thd_new. */
static void* thread_body(void* v) {
struct thd_arg a = *(struct thd_arg*)v;
free(v);
if (a.name != nullptr) {
#if GPR_APPLE_PTHREAD_NAME
/* Apple supports 64 characters, and will truncate if it's longer. */
pthread_setname_np(a.name);
#elif GPR_LINUX_PTHREAD_NAME
/* Linux supports 16 characters max, and will error if it's longer. */
char buf[16];
size_t buf_len = GPR_ARRAY_SIZE(buf) - 1;
strncpy(buf, a.name, buf_len);
buf[buf_len] = '\0';
pthread_setname_np(pthread_self(), buf);
#endif // GPR_APPLE_PTHREAD_NAME
}
(*a.body)(a.arg);
dec_thd_count();
return nullptr;
}
int gpr_thd_new(gpr_thd_id* t, const char* thd_name,
void (*thd_body)(void* arg), void* arg,
const gpr_thd_options* options) {
int thread_started;
pthread_attr_t attr;
pthread_t p;
/* don't use gpr_malloc as we may cause an infinite recursion with
* the profiling code */
struct thd_arg* a = (struct thd_arg*)malloc(sizeof(*a));
GPR_ASSERT(a != nullptr);
a->body = thd_body;
a->arg = arg;
a->name = thd_name;
inc_thd_count();
GPR_ASSERT(pthread_attr_init(&attr) == 0);
if (gpr_thd_options_is_detached(options)) {
GPR_ASSERT(pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED) ==
0);
} else {
GPR_ASSERT(pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE) ==
0);
}
thread_started = (pthread_create(&p, &attr, &thread_body, a) == 0);
GPR_ASSERT(pthread_attr_destroy(&attr) == 0);
if (!thread_started) {
/* don't use gpr_free, as this was allocated using malloc (see above) */
free(a);
dec_thd_count();
}
*t = (gpr_thd_id)p;
return thread_started;
}
gpr_thd_id gpr_thd_currentid(void) { return (gpr_thd_id)pthread_self(); }
void gpr_thd_join(gpr_thd_id t) { pthread_join((pthread_t)t, nullptr); }
/*****************************************
* Only used when fork support is enabled
*/
static void inc_thd_count() {
if (grpc_fork_support_enabled()) {
gpr_mu_lock(&g_mu);
g_thread_count++;
gpr_mu_unlock(&g_mu);
}
}
static void dec_thd_count() {
if (grpc_fork_support_enabled()) {
gpr_mu_lock(&g_mu);
g_thread_count--;
if (g_awaiting_threads && g_thread_count == 0) {
gpr_cv_signal(&g_cv);
}
gpr_mu_unlock(&g_mu);
}
}
void gpr_thd_init() {
gpr_mu_init(&g_mu);
gpr_cv_init(&g_cv);
g_thread_count = 0;
g_awaiting_threads = 0;
}
int gpr_await_threads(gpr_timespec deadline) {
gpr_mu_lock(&g_mu);
g_awaiting_threads = 1;
int res = 0;
if (g_thread_count > 0) {
res = gpr_cv_wait(&g_cv, &g_mu, deadline);
}
g_awaiting_threads = 0;
gpr_mu_unlock(&g_mu);
return res == 0;
}
#endif /* GPR_POSIX_SYNC */
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