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_LINUX_EVENTFD
      37             : 
      38             : #include <errno.h>
      39             : #include <sys/eventfd.h>
      40             : #include <unistd.h>
      41             : 
      42             : #include <grpc/support/log.h>
      43             : 
      44             : #include "src/core/iomgr/wakeup_fd_posix.h"
      45             : #include "src/core/profiling/timers.h"
      46             : 
      47        9513 : static void eventfd_create(grpc_wakeup_fd* fd_info) {
      48        9513 :   int efd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
      49             :   /* TODO(klempner): Handle failure more gracefully */
      50        9513 :   GPR_ASSERT(efd >= 0);
      51        9513 :   fd_info->read_fd = efd;
      52        9513 :   fd_info->write_fd = -1;
      53        9513 : }
      54             : 
      55      318312 : static void eventfd_consume(grpc_wakeup_fd* fd_info) {
      56             :   eventfd_t value;
      57             :   int err;
      58             :   do {
      59      318312 :     err = eventfd_read(fd_info->read_fd, &value);
      60      318337 :   } while (err < 0 && errno == EINTR);
      61      318337 : }
      62             : 
      63     1116371 : static void eventfd_wakeup(grpc_wakeup_fd* fd_info) {
      64             :   int err;
      65             :   GPR_TIMER_BEGIN("eventfd_wakeup", 0);
      66             :   do {
      67     1116371 :     err = eventfd_write(fd_info->read_fd, 1);
      68     1116394 :   } while (err < 0 && errno == EINTR);
      69             :   GPR_TIMER_END("eventfd_wakeup", 0);
      70     1116394 : }
      71             : 
      72        9495 : static void eventfd_destroy(grpc_wakeup_fd* fd_info) {
      73        9495 :   if (fd_info->read_fd != 0) close(fd_info->read_fd);
      74        9495 : }
      75             : 
      76        3457 : static int eventfd_check_availability(void) {
      77             :   /* TODO(klempner): Actually check if eventfd is available */
      78        3457 :   return 1;
      79             : }
      80             : 
      81             : const grpc_wakeup_fd_vtable grpc_specialized_wakeup_fd_vtable = {
      82             :     eventfd_create, eventfd_consume, eventfd_wakeup, eventfd_destroy,
      83             :     eventfd_check_availability};
      84             : 
      85             : #endif /* GPR_LINUX_EVENTFD */