src/core/lib/iomgr/wakeup_fd_posix.c

/*
 *
 * 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
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */

#include "src/core/lib/iomgr/port.h"

#ifdef GRPC_POSIX_WAKEUP_FD

#include <stddef.h>
#include "src/core/lib/iomgr/wakeup_fd_cv.h"
#include "src/core/lib/iomgr/wakeup_fd_pipe.h"
#include "src/core/lib/iomgr/wakeup_fd_posix.h"

extern grpc_wakeup_fd_vtable grpc_cv_wakeup_fd_vtable;
static const grpc_wakeup_fd_vtable *wakeup_fd_vtable = NULL;

int grpc_allow_specialized_wakeup_fd = 1;
int grpc_allow_pipe_wakeup_fd = 1;

int has_real_wakeup_fd = 1;
int cv_wakeup_fds_enabled = 0;

void grpc_wakeup_fd_global_init(void) {
  if (grpc_allow_specialized_wakeup_fd &&
      grpc_specialized_wakeup_fd_vtable.check_availability()) {
    wakeup_fd_vtable = &grpc_specialized_wakeup_fd_vtable;
  } else if (grpc_allow_pipe_wakeup_fd &&
             grpc_pipe_wakeup_fd_vtable.check_availability()) {
    wakeup_fd_vtable = &grpc_pipe_wakeup_fd_vtable;
  } else {
    has_real_wakeup_fd = 0;
  }
}

void grpc_wakeup_fd_global_destroy(void) { wakeup_fd_vtable = NULL; }

int grpc_has_wakeup_fd(void) { return has_real_wakeup_fd; }

int grpc_cv_wakeup_fds_enabled(void) { return cv_wakeup_fds_enabled; }

void grpc_enable_cv_wakeup_fds(int enable) { cv_wakeup_fds_enabled = enable; }

grpc_error *grpc_wakeup_fd_init(grpc_wakeup_fd *fd_info) {
  if (cv_wakeup_fds_enabled) {
    return grpc_cv_wakeup_fd_vtable.init(fd_info);
  }
  return wakeup_fd_vtable->init(fd_info);
}

grpc_error *grpc_wakeup_fd_consume_wakeup(grpc_wakeup_fd *fd_info) {
  if (cv_wakeup_fds_enabled) {
    return grpc_cv_wakeup_fd_vtable.consume(fd_info);
  }
  return wakeup_fd_vtable->consume(fd_info);
}

grpc_error *grpc_wakeup_fd_wakeup(grpc_wakeup_fd *fd_info) {
  if (cv_wakeup_fds_enabled) {
    return grpc_cv_wakeup_fd_vtable.wakeup(fd_info);
  }
  return wakeup_fd_vtable->wakeup(fd_info);
}

void grpc_wakeup_fd_destroy(grpc_wakeup_fd *fd_info) {
  if (cv_wakeup_fds_enabled) {
    grpc_cv_wakeup_fd_vtable.destroy(fd_info);
  } else {
    wakeup_fd_vtable->destroy(fd_info);
  }
}

#endif /* GRPC_POSIX_WAKEUP_FD */