3 * Copyright 2015 gRPC authors.
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
19 #include <grpc/support/port_platform.h>
21 #include "src/core/lib/iomgr/port.h"
23 #ifdef GRPC_LINUX_EVENTFD
26 #include <sys/eventfd.h>
29 #include <grpc/support/log.h>
31 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
32 #include "src/core/lib/profiling/timers.h"
34 static grpc_error* eventfd_create(grpc_wakeup_fd* fd_info) {
35 fd_info->read_fd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
36 fd_info->write_fd = -1;
37 if (fd_info->read_fd < 0) {
38 return GRPC_OS_ERROR(errno, "eventfd");
40 return GRPC_ERROR_NONE;
43 static grpc_error* eventfd_consume(grpc_wakeup_fd* fd_info) {
47 err = eventfd_read(fd_info->read_fd, &value);
48 } while (err < 0 && errno == EINTR);
49 if (err < 0 && errno != EAGAIN) {
50 return GRPC_OS_ERROR(errno, "eventfd_read");
52 return GRPC_ERROR_NONE;
55 static grpc_error* eventfd_wakeup(grpc_wakeup_fd* fd_info) {
56 GPR_TIMER_SCOPE("eventfd_wakeup", 0);
59 err = eventfd_write(fd_info->read_fd, 1);
60 } while (err < 0 && errno == EINTR);
62 return GRPC_OS_ERROR(errno, "eventfd_write");
64 return GRPC_ERROR_NONE;
67 static void eventfd_destroy(grpc_wakeup_fd* fd_info) {
68 if (fd_info->read_fd != 0) close(fd_info->read_fd);
71 static int eventfd_check_availability(void) {
72 const int efd = eventfd(0, 0);
73 const int is_available = efd >= 0;
74 if (is_available) close(efd);
78 const grpc_wakeup_fd_vtable grpc_specialized_wakeup_fd_vtable = {
79 eventfd_create, eventfd_consume, eventfd_wakeup, eventfd_destroy,
80 eventfd_check_availability};
82 #endif /* GRPC_LINUX_EVENTFD */