| // |
| // |
| // 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 <grpc/support/port_platform.h> |
| |
| #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/gprpp/crash.h" |
| #include "src/core/lib/gprpp/strerror.h" |
| #include "src/core/lib/iomgr/wakeup_fd_posix.h" |
| |
| static grpc_error_handle eventfd_create(grpc_wakeup_fd* fd_info) { |
| fd_info->read_fd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC); |
| fd_info->write_fd = -1; |
| if (fd_info->read_fd < 0) { |
| return GRPC_OS_ERROR(errno, "eventfd"); |
| } |
| return absl::OkStatus(); |
| } |
| |
| static grpc_error_handle 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 absl::OkStatus(); |
| } |
| |
| static grpc_error_handle eventfd_wakeup(grpc_wakeup_fd* fd_info) { |
| int err; |
| do { |
| err = eventfd_write(fd_info->read_fd, 1); |
| } while (err < 0 && errno == EINTR); |
| if (err < 0) { |
| return GRPC_OS_ERROR(errno, "eventfd_write"); |
| } |
| return absl::OkStatus(); |
| } |
| |
| 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 |