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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 "src/core/iomgr/iomgr.h"
#include <stdlib.h>
#include "src/core/iomgr/iomgr_internal.h"
#include "src/core/iomgr/alarm_internal.h"
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include <grpc/support/thd.h>
#include <grpc/support/sync.h>
typedef struct delayed_callback {
grpc_iomgr_cb_func cb;
void *cb_arg;
int success;
struct delayed_callback *next;
} delayed_callback;
static gpr_mu g_mu;
static gpr_cv g_rcv;
static delayed_callback *g_cbs_head = NULL;
static delayed_callback *g_cbs_tail = NULL;
static int g_shutdown;
static int g_refs;
static gpr_event g_background_callback_executor_done;
/* Execute followup callbacks continuously.
Other threads may check in and help during pollset_work() */
static void background_callback_executor(void *ignored) {
gpr_mu_lock(&g_mu);
while (!g_shutdown) {
gpr_timespec deadline = gpr_inf_future;
gpr_timespec short_deadline =
gpr_time_add(gpr_now(), gpr_time_from_millis(100));
if (g_cbs_head) {
delayed_callback *cb = g_cbs_head;
g_cbs_head = cb->next;
if (!g_cbs_head) g_cbs_tail = NULL;
gpr_mu_unlock(&g_mu);
cb->cb(cb->cb_arg, cb->success);
gpr_free(cb);
gpr_mu_lock(&g_mu);
} else if (grpc_alarm_check(&g_mu, gpr_now(), &deadline)) {
} else {
gpr_mu_unlock(&g_mu);
gpr_sleep_until(gpr_time_min(short_deadline, deadline));
gpr_mu_lock(&g_mu);
}
}
gpr_mu_unlock(&g_mu);
gpr_event_set(&g_background_callback_executor_done, (void *)1);
}
void grpc_kick_poller(void) {
/* Empty. The background callback executor polls periodically. The activity
* the kicker is trying to draw the executor's attention to will be picked up
* either by one of the periodic wakeups or by one of the polling application
* threads. */
}
void grpc_iomgr_init(void) {
gpr_thd_id id;
gpr_mu_init(&g_mu);
gpr_cv_init(&g_rcv);
grpc_alarm_list_init(gpr_now());
g_refs = 0;
grpc_iomgr_platform_init();
gpr_event_init(&g_background_callback_executor_done);
gpr_thd_new(&id, background_callback_executor, NULL, NULL);
}
void grpc_iomgr_shutdown(void) {
delayed_callback *cb;
gpr_timespec shutdown_deadline =
gpr_time_add(gpr_now(), gpr_time_from_seconds(10));
gpr_mu_lock(&g_mu);
g_shutdown = 1;
while (g_cbs_head || g_refs) {
gpr_log(GPR_DEBUG, "Waiting for %d iomgr objects to be destroyed%s", g_refs,
g_cbs_head ? " and executing final callbacks" : "");
while (g_cbs_head) {
cb = g_cbs_head;
g_cbs_head = cb->next;
if (!g_cbs_head) g_cbs_tail = NULL;
gpr_mu_unlock(&g_mu);
cb->cb(cb->cb_arg, 0);
gpr_free(cb);
gpr_mu_lock(&g_mu);
}
if (g_refs) {
int timeout = 0;
gpr_timespec short_deadline = gpr_time_add(gpr_now(),
gpr_time_from_millis(100));
while (gpr_cv_wait(&g_rcv, &g_mu, short_deadline) && g_cbs_head == NULL) {
if (gpr_time_cmp(gpr_now(), shutdown_deadline) > 0) {
timeout = 1;
break;
}
}
if (timeout) {
gpr_log(GPR_DEBUG,
"Failed to free %d iomgr objects before shutdown deadline: "
"memory leaks are likely",
g_refs);
break;
}
}
}
gpr_mu_unlock(&g_mu);
grpc_kick_poller();
gpr_event_wait(&g_background_callback_executor_done, gpr_inf_future);
grpc_iomgr_platform_shutdown();
grpc_alarm_list_shutdown();
gpr_mu_destroy(&g_mu);
gpr_cv_destroy(&g_rcv);
}
void grpc_iomgr_ref(void) {
gpr_mu_lock(&g_mu);
++g_refs;
gpr_mu_unlock(&g_mu);
}
void grpc_iomgr_unref(void) {
gpr_mu_lock(&g_mu);
if (0 == --g_refs) {
gpr_cv_signal(&g_rcv);
}
gpr_mu_unlock(&g_mu);
}
void grpc_iomgr_add_delayed_callback(grpc_iomgr_cb_func cb, void *cb_arg,
int success) {
delayed_callback *dcb = gpr_malloc(sizeof(delayed_callback));
dcb->cb = cb;
dcb->cb_arg = cb_arg;
dcb->success = success;
gpr_mu_lock(&g_mu);
dcb->next = NULL;
if (!g_cbs_tail) {
g_cbs_head = g_cbs_tail = dcb;
} else {
g_cbs_tail->next = dcb;
g_cbs_tail = dcb;
}
gpr_mu_unlock(&g_mu);
}
void grpc_iomgr_add_callback(grpc_iomgr_cb_func cb, void *cb_arg) {
grpc_iomgr_add_delayed_callback(cb, cb_arg, 1);
}
int grpc_maybe_call_delayed_callbacks(gpr_mu *drop_mu, int success) {
int n = 0;
gpr_mu *retake_mu = NULL;
delayed_callback *cb;
for (;;) {
/* check for new work */
if (!gpr_mu_trylock(&g_mu)) {
break;
}
cb = g_cbs_head;
if (!cb) {
gpr_mu_unlock(&g_mu);
break;
}
g_cbs_head = cb->next;
if (!g_cbs_head) g_cbs_tail = NULL;
gpr_mu_unlock(&g_mu);
/* if we have a mutex to drop, do so before executing work */
if (drop_mu) {
gpr_mu_unlock(drop_mu);
retake_mu = drop_mu;
drop_mu = NULL;
}
cb->cb(cb->cb_arg, success && cb->success);
gpr_free(cb);
n++;
}
if (retake_mu) {
gpr_mu_lock(retake_mu);
}
return n;
}
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