Line data    Source code

       1             : /*
       2             :  *
       3             :  * Copyright 2015, Google Inc.
       4             :  * All rights reserved.
       5             :  *
       6             :  * Redistribution and use in source and binary forms, with or without
       7             :  * modification, are permitted provided that the following conditions are
       8             :  * met:
       9             :  *
      10             :  *     * Redistributions of source code must retain the above copyright
      11             :  * notice, this list of conditions and the following disclaimer.
      12             :  *     * Redistributions in binary form must reproduce the above
      13             :  * copyright notice, this list of conditions and the following disclaimer
      14             :  * in the documentation and/or other materials provided with the
      15             :  * distribution.
      16             :  *     * Neither the name of Google Inc. nor the names of its
      17             :  * contributors may be used to endorse or promote products derived from
      18             :  * this software without specific prior written permission.
      19             :  *
      20             :  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
      21             :  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
      22             :  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
      23             :  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
      24             :  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
      25             :  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
      26             :  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
      27             :  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
      28             :  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
      29             :  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
      30             :  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
      31             :  *
      32             :  */
      33             : 
      34             : #include <grpc/support/port_platform.h>
      35             : 
      36             : #ifdef GPR_POSIX_WAKEUP_FD
      37             : 
      38             : #include "src/core/iomgr/wakeup_fd_posix.h"
      39             : 
      40             : #include <errno.h>
      41             : #include <string.h>
      42             : #include <unistd.h>
      43             : 
      44             : #include "src/core/iomgr/socket_utils_posix.h"
      45             : #include <grpc/support/log.h>
      46             : 
      47           0 : static void pipe_init(grpc_wakeup_fd* fd_info) {
      48             :   int pipefd[2];
      49             :   /* TODO(klempner): Make this nonfatal */
      50           0 :   GPR_ASSERT(0 == pipe(pipefd));
      51           0 :   GPR_ASSERT(grpc_set_socket_nonblocking(pipefd[0], 1));
      52           0 :   GPR_ASSERT(grpc_set_socket_nonblocking(pipefd[1], 1));
      53           0 :   fd_info->read_fd = pipefd[0];
      54           0 :   fd_info->write_fd = pipefd[1];
      55           0 : }
      56             : 
      57           0 : static void pipe_consume(grpc_wakeup_fd* fd_info) {
      58             :   char buf[128];
      59             :   ssize_t r;
      60             : 
      61             :   for (;;) {
      62           0 :     r = read(fd_info->read_fd, buf, sizeof(buf));
      63           0 :     if (r > 0) continue;
      64           0 :     if (r == 0) return;
      65           0 :     switch (errno) {
      66             :       case EAGAIN:
      67           0 :         return;
      68             :       case EINTR:
      69           0 :         continue;
      70             :       default:
      71           0 :         gpr_log(GPR_ERROR, "error reading pipe: %s", strerror(errno));
      72           0 :         return;
      73             :     }
      74           0 :   }
      75             : }
      76             : 
      77           0 : static void pipe_wakeup(grpc_wakeup_fd* fd_info) {
      78           0 :   char c = 0;
      79           0 :   while (write(fd_info->write_fd, &c, 1) != 1 && errno == EINTR)
      80             :     ;
      81           0 : }
      82             : 
      83           0 : static void pipe_destroy(grpc_wakeup_fd* fd_info) {
      84           0 :   if (fd_info->read_fd != 0) close(fd_info->read_fd);
      85           0 :   if (fd_info->write_fd != 0) close(fd_info->write_fd);
      86           0 : }
      87             : 
      88           0 : static int pipe_check_availability(void) {
      89             :   /* Assume that pipes are always available. */
      90           0 :   return 1;
      91             : }
      92             : 
      93             : const grpc_wakeup_fd_vtable grpc_pipe_wakeup_fd_vtable = {
      94             :     pipe_init, pipe_consume, pipe_wakeup, pipe_destroy,
      95             :     pipe_check_availability};
      96             : 
      97             : #endif /* GPR_POSIX_WAKUP_FD */