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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.
*
*/
#include "src/core/lib/iomgr/port.h"
#ifdef GRPC_LINUX_EVENTFD
#include <errno.h>
#include <sys/eventfd.h>
#include <unistd.h>
#include <grpc/support/log.h>
#include "src/core/lib/iomgr/wakeup_fd_posix.h"
#include "src/core/lib/profiling/timers.h"
static grpc_error* eventfd_create(grpc_wakeup_fd* fd_info) {
int efd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
if (efd < 0) {
return GRPC_OS_ERROR(errno, "eventfd");
}
fd_info->read_fd = efd;
fd_info->write_fd = -1;
return GRPC_ERROR_NONE;
}
static grpc_error* eventfd_consume(grpc_wakeup_fd* fd_info) {
eventfd_t value;
int err;
do {
err = eventfd_read(fd_info->read_fd, &value);
} while (err < 0 && errno == EINTR);
if (err < 0 && errno != EAGAIN) {
return GRPC_OS_ERROR(errno, "eventfd_read");
}
return GRPC_ERROR_NONE;
}
static grpc_error* eventfd_wakeup(grpc_wakeup_fd* fd_info) {
int err;
GPR_TIMER_BEGIN("eventfd_wakeup", 0);
do {
err = eventfd_write(fd_info->read_fd, 1);
} while (err < 0 && errno == EINTR);
if (err < 0) {
return GRPC_OS_ERROR(errno, "eventfd_write");
}
GPR_TIMER_END("eventfd_wakeup", 0);
return GRPC_ERROR_NONE;
}
static void eventfd_destroy(grpc_wakeup_fd* fd_info) {
if (fd_info->read_fd != 0) close(fd_info->read_fd);
}
static int eventfd_check_availability(void) {
const int efd = eventfd(0, 0);
const int is_available = efd >= 0;
if (is_available) close(efd);
return is_available;
}
const grpc_wakeup_fd_vtable grpc_specialized_wakeup_fd_vtable = {
eventfd_create, eventfd_consume, eventfd_wakeup, eventfd_destroy,
eventfd_check_availability};
#endif /* GRPC_LINUX_EVENTFD */
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