| /* |
| * |
| * Copyright 2016 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. |
| * |
| */ |
| |
| /* |
| * wakeup_fd_cv uses condition variables to implement wakeup fds. |
| * |
| * It is intended for use only in cases when eventfd() and pipe() are not |
| * available. It can only be used with the "poll" engine. |
| * |
| * Implementation: |
| * A global table of cv wakeup fds is mantained. A cv wakeup fd is a negative |
| * file descriptor. poll() is then run in a background thread with only the |
| * real socket fds while we wait on a condition variable trigged by either the |
| * poll() completion or a wakeup_fd() call. |
| * |
| */ |
| |
| #ifndef GRPC_CORE_LIB_IOMGR_WAKEUP_FD_CV_H |
| #define GRPC_CORE_LIB_IOMGR_WAKEUP_FD_CV_H |
| |
| #include <grpc/support/port_platform.h> |
| |
| #include <grpc/support/sync.h> |
| |
| #include "src/core/lib/iomgr/ev_posix.h" |
| |
| #define GRPC_FD_TO_IDX(fd) (-(fd)-1) |
| #define GRPC_IDX_TO_FD(idx) (-(idx)-1) |
| |
| typedef struct grpc_cv_node { |
| gpr_cv* cv; |
| struct grpc_cv_node* next; |
| struct grpc_cv_node* prev; |
| } grpc_cv_node; |
| |
| typedef struct grpc_fd_node { |
| int is_set; |
| grpc_cv_node* cvs; |
| struct grpc_fd_node* next_free; |
| } grpc_fd_node; |
| |
| typedef struct grpc_cv_fd_table { |
| gpr_mu mu; |
| gpr_refcount pollcount; |
| gpr_cv shutdown_cv; |
| grpc_fd_node* cvfds; |
| grpc_fd_node* free_fds; |
| unsigned int size; |
| grpc_poll_function_type poll; |
| } grpc_cv_fd_table; |
| |
| extern const grpc_wakeup_fd_vtable grpc_cv_wakeup_fd_vtable; |
| |
| #endif /* GRPC_CORE_LIB_IOMGR_WAKEUP_FD_CV_H */ |