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/*
*
* Copyright 2015, Google Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <grpc/support/port_platform.h>
#ifdef GPR_LINUX_EVENTFD
#include <errno.h>
#include <sys/eventfd.h>
#include <unistd.h>
#include <grpc/support/log.h>
#include "src/core/lib/iomgr/wakeup_fd_posix.h"
#include "src/core/lib/profiling/timers.h"
static grpc_error* eventfd_create(grpc_wakeup_fd* fd_info) {
int efd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
if (efd < 0) {
return GRPC_OS_ERROR(errno, "eventfd");
}
fd_info->read_fd = efd;
fd_info->write_fd = -1;
return GRPC_ERROR_NONE;
}
static grpc_error* 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 GRPC_ERROR_NONE;
}
static grpc_error* eventfd_wakeup(grpc_wakeup_fd* fd_info) {
int err;
GPR_TIMER_BEGIN("eventfd_wakeup", 0);
do {
err = eventfd_write(fd_info->read_fd, 1);
} while (err < 0 && errno == EINTR);
if (err < 0) {
return GRPC_OS_ERROR(errno, "eventfd_write");
}
GPR_TIMER_END("eventfd_wakeup", 0);
return GRPC_ERROR_NONE;
}
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 /* GPR_LINUX_EVENTFD */
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