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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_POSIX_SOCKET
#include "src/core/iomgr/pollset_kick.h"
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include "src/core/iomgr/socket_utils_posix.h"
#include "src/core/iomgr/wakeup_fd_posix.h"
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
/* This implementation is based on a freelist of wakeup fds, with extra logic to
* handle kicks while there is no attached fd. */
/* TODO(klempner): Autosize this, and consider providing a way to disable the
* cap entirely on systems with large fd limits */
#define GRPC_MAX_CACHED_WFDS 50
static grpc_kick_fd_info *fd_freelist = NULL;
static int fd_freelist_count = 0;
static gpr_mu fd_freelist_mu;
static grpc_kick_fd_info *allocate_wfd(void) {
grpc_kick_fd_info *info = NULL;
gpr_mu_lock(&fd_freelist_mu);
if (fd_freelist != NULL) {
info = fd_freelist;
fd_freelist = fd_freelist->next;
--fd_freelist_count;
}
gpr_mu_unlock(&fd_freelist_mu);
if (info == NULL) {
info = gpr_malloc(sizeof(*info));
grpc_wakeup_fd_create(&info->wakeup_fd);
info->next = NULL;
}
return info;
}
static void destroy_wfd(grpc_kick_fd_info* wfd) {
grpc_wakeup_fd_destroy(&wfd->wakeup_fd);
gpr_free(wfd);
}
static void free_wfd(grpc_kick_fd_info *fd_info) {
gpr_mu_lock(&fd_freelist_mu);
if (fd_freelist_count < GRPC_MAX_CACHED_WFDS) {
fd_info->next = fd_freelist;
fd_freelist = fd_info;
fd_freelist_count++;
fd_info = NULL;
}
gpr_mu_unlock(&fd_freelist_mu);
if (fd_info) {
destroy_wfd(fd_info);
}
}
void grpc_pollset_kick_init(grpc_pollset_kick_state *kick_state) {
gpr_mu_init(&kick_state->mu);
kick_state->kicked = 0;
kick_state->fd_info = NULL;
}
void grpc_pollset_kick_destroy(grpc_pollset_kick_state *kick_state) {
gpr_mu_destroy(&kick_state->mu);
GPR_ASSERT(kick_state->fd_info == NULL);
}
int grpc_pollset_kick_pre_poll(grpc_pollset_kick_state *kick_state) {
gpr_mu_lock(&kick_state->mu);
if (kick_state->kicked) {
kick_state->kicked = 0;
gpr_mu_unlock(&kick_state->mu);
return -1;
}
kick_state->fd_info = allocate_wfd();
gpr_mu_unlock(&kick_state->mu);
return GRPC_WAKEUP_FD_GET_READ_FD(&kick_state->fd_info->wakeup_fd);
}
void grpc_pollset_kick_consume(grpc_pollset_kick_state *kick_state) {
grpc_wakeup_fd_consume_wakeup(&kick_state->fd_info->wakeup_fd);
}
void grpc_pollset_kick_post_poll(grpc_pollset_kick_state *kick_state) {
gpr_mu_lock(&kick_state->mu);
free_wfd(kick_state->fd_info);
kick_state->fd_info = NULL;
gpr_mu_unlock(&kick_state->mu);
}
void grpc_pollset_kick_kick(grpc_pollset_kick_state *kick_state) {
gpr_mu_lock(&kick_state->mu);
if (kick_state->fd_info != NULL) {
grpc_wakeup_fd_wakeup(&kick_state->fd_info->wakeup_fd);
} else {
kick_state->kicked = 1;
}
gpr_mu_unlock(&kick_state->mu);
}
void grpc_pollset_kick_global_init_fallback_fd(void) {
gpr_mu_init(&fd_freelist_mu);
grpc_wakeup_fd_global_init_force_fallback();
}
void grpc_pollset_kick_global_init(void) {
gpr_mu_init(&fd_freelist_mu);
grpc_wakeup_fd_global_init();
}
void grpc_pollset_kick_global_destroy(void) {
while (fd_freelist != NULL) {
grpc_kick_fd_info *current = fd_freelist;
fd_freelist = fd_freelist->next;
destroy_wfd(current);
}
grpc_wakeup_fd_global_destroy();
gpr_mu_destroy(&fd_freelist_mu);
}
#endif /* GPR_POSIX_SOCKET */
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