src/core/iomgr/workqueue_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
 * (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_POSIX_SOCKET

#include "src/core/iomgr/workqueue.h"

#include <stdio.h>

#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include <grpc/support/useful.h>

#include "src/core/iomgr/fd_posix.h"

static void on_readable (grpc_exec_ctx * exec_ctx, void *arg, int success);

grpc_workqueue *
grpc_workqueue_create (grpc_closure_list * closure_list)
{
  char name[32];
  grpc_workqueue *workqueue = gpr_malloc (sizeof (grpc_workqueue));
  gpr_ref_init (&workqueue->refs, 1);
  gpr_mu_init (&workqueue->mu);
  workqueue->closure_list.head = workqueue->closure_list.tail = NULL;
  grpc_wakeup_fd_init (&workqueue->wakeup_fd);
  sprintf (name, "workqueue:%p", (void *) workqueue);
  workqueue->wakeup_read_fd = grpc_fd_create (GRPC_WAKEUP_FD_GET_READ_FD (&workqueue->wakeup_fd), name);
  grpc_closure_init (&workqueue->read_closure, on_readable, workqueue);
  grpc_fd_notify_on_read (exec_ctx, workqueue->wakeup_read_fd, &workqueue->read_closure);
  return workqueue;
}

static void
workqueue_destroy (grpc_exec_ctx * exec_ctx, grpc_workqueue * workqueue)
{
  GPR_ASSERT (grpc_closure_list_empty (workqueue->closure_list));
  grpc_fd_shutdown (exec_ctx, workqueue->wakeup_read_fd);
}

#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
void
grpc_workqueue_ref (grpc_workqueue * workqueue, const char *file, int line, const char *reason)
{
  gpr_log (file, line, GPR_LOG_SEVERITY_DEBUG, "WORKQUEUE:%p   ref %d -> %d %s", workqueue, (int) workqueue->refs.count, (int) workqueue->refs.count + 1, reason);
#else
void
grpc_workqueue_ref (grpc_workqueue * workqueue)
{
#endif
  gpr_ref (&workqueue->refs);
}

#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
void
grpc_workqueue_unref (grpc_workqueue * workqueue, grpc_closure_list * closure_list, const char *file, int line, const char *reason)
{
  gpr_log (file, line, GPR_LOG_SEVERITY_DEBUG, "WORKQUEUE:%p unref %d -> %d %s", workqueue, (int) workqueue->refs.count, (int) workqueue->refs.count - 1, reason);
#else
void
grpc_workqueue_unref (grpc_exec_ctx * exec_ctx, grpc_workqueue * workqueue)
{
#endif
  if (gpr_unref (&workqueue->refs))
    {
      workqueue_destroy (exec_ctx, workqueue);
    }
}

void
grpc_workqueue_add_to_pollset (grpc_exec_ctx * exec_ctx, grpc_workqueue * workqueue, grpc_pollset * pollset)
{
  grpc_pollset_add_fd (exec_ctx, pollset, workqueue->wakeup_read_fd);
}

void
grpc_workqueue_flush (grpc_exec_ctx * exec_ctx, grpc_workqueue * workqueue)
{
  gpr_mu_lock (&workqueue->mu);
  grpc_closure_list_move (exec_ctx, &workqueue->closure_list);
  gpr_mu_unlock (&workqueue->mu);
}

static void
on_readable (grpc_exec_ctx * exec_ctx, void *arg, int success)
{
  grpc_workqueue *workqueue = arg;

  if (!success)
    {
      gpr_mu_destroy (&workqueue->mu);
      /* HACK: let wakeup_fd code know that we stole the fd */
      workqueue->wakeup_fd.read_fd = 0;
      grpc_wakeup_fd_destroy (&workqueue->wakeup_fd);
      grpc_fd_orphan (exec_ctx, workqueue->wakeup_read_fd, NULL, "destroy");
      gpr_free (workqueue);
    }
  else
    {
      gpr_mu_lock (&workqueue->mu);
      grpc_closure_list_move (exec_ctx, &workqueue->closure_list);
      grpc_wakeup_fd_consume_wakeup (&workqueue->wakeup_fd);
      gpr_mu_unlock (&workqueue->mu);
      grpc_fd_notify_on_read (exec_ctx, workqueue->wakeup_read_fd, &workqueue->read_closure);
    }
}

void
grpc_workqueue_push (grpc_workqueue * workqueue, grpc_closure * closure, int success)
{
  closure->success = success;
  closure->next = NULL;
  gpr_mu_lock (&workqueue->mu);
  if (grpc_closure_list_empty (workqueue->closure_list))
    {
      grpc_wakeup_fd_wakeup (&workqueue->wakeup_fd);
    }
  grpc_closure_list_add (&workqueue->closure_list, closure, success);
  gpr_mu_unlock (&workqueue->mu);
}

#endif /* GPR_POSIX_SOCKET */