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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 "src/core/support/string.h"
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include <grpc/support/string_util.h>
#include <grpc/support/sync.h>
#include <grpc/support/thd.h>
#ifdef GRPC_IOMGR_REFCOUNT_DEBUG
static void iomgr_object_trace(const char *action, grpc_iomgr_object *obj,
const char *file, int line) {
gpr_log(GPR_DEBUG, "iomgr object %s: %p - %s from %s:%i", action,
obj, obj->name, file, line);
}
#else
#define iomgr_object_trace(action, obj, file, line)
#endif
static gpr_mu g_mu;
static gpr_cv g_rcv;
static grpc_iomgr_closure *g_cbs_head = NULL;
static grpc_iomgr_closure *g_cbs_tail = NULL;
static int g_shutdown;
static gpr_event g_background_callback_executor_done;
static grpc_iomgr_object g_root_object;
/* 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_CLOCK_MONOTONIC);
gpr_timespec short_deadline = gpr_time_add(
gpr_now(GPR_CLOCK_MONOTONIC), gpr_time_from_millis(100, GPR_TIMESPAN));
if (g_cbs_head) {
grpc_iomgr_closure *closure = g_cbs_head;
g_cbs_head = closure->next;
if (!g_cbs_head) g_cbs_tail = NULL;
gpr_mu_unlock(&g_mu);
closure->cb(closure->cb_arg, closure->success);
gpr_mu_lock(&g_mu);
} else if (grpc_alarm_check(&g_mu, gpr_now(GPR_CLOCK_MONOTONIC),
&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;
g_shutdown = 0;
gpr_mu_init(&g_mu);
gpr_cv_init(&g_rcv);
grpc_alarm_list_init(gpr_now(GPR_CLOCK_MONOTONIC));
g_root_object.next = g_root_object.prev = &g_root_object;
g_root_object.name = "root";
grpc_iomgr_platform_init();
gpr_event_init(&g_background_callback_executor_done);
gpr_thd_new(&id, background_callback_executor, NULL, NULL);
}
static size_t count_objects(void) {
grpc_iomgr_object *obj;
size_t n = 0;
for (obj = g_root_object.next; obj != &g_root_object; obj = obj->next) {
n++;
}
return n;
}
void grpc_iomgr_shutdown(void) {
grpc_iomgr_object *obj;
grpc_iomgr_closure *closure;
gpr_timespec shutdown_deadline = gpr_time_add(
gpr_now(GPR_CLOCK_REALTIME), gpr_time_from_seconds(10, GPR_TIMESPAN));
gpr_timespec last_warning_time = gpr_now(GPR_CLOCK_REALTIME);
gpr_mu_lock(&g_mu);
g_shutdown = 1;
while (g_cbs_head != NULL || g_root_object.next != &g_root_object) {
if (gpr_time_cmp(
gpr_time_sub(gpr_now(GPR_CLOCK_REALTIME), last_warning_time),
gpr_time_from_seconds(1, GPR_TIMESPAN)) >= 0) {
if (g_cbs_head != NULL && g_root_object.next != &g_root_object) {
gpr_log(GPR_DEBUG,
"Waiting for %d iomgr objects to be destroyed and executing "
"final callbacks",
count_objects());
} else if (g_cbs_head != NULL) {
gpr_log(GPR_DEBUG, "Executing final iomgr callbacks");
} else {
gpr_log(GPR_DEBUG, "Waiting for %d iomgr objects to be destroyed",
count_objects());
}
last_warning_time = gpr_now(GPR_CLOCK_REALTIME);
}
if (g_cbs_head) {
do {
closure = g_cbs_head;
g_cbs_head = closure->next;
if (!g_cbs_head) g_cbs_tail = NULL;
gpr_mu_unlock(&g_mu);
closure->cb(closure->cb_arg, 0);
gpr_mu_lock(&g_mu);
} while (g_cbs_head);
continue;
}
if (grpc_alarm_check(&g_mu, gpr_inf_future(GPR_CLOCK_MONOTONIC), NULL)) {
continue;
}
if (g_root_object.next != &g_root_object) {
int timeout = 0;
gpr_timespec short_deadline = gpr_time_add(
gpr_now(GPR_CLOCK_REALTIME), gpr_time_from_millis(100, GPR_TIMESPAN));
while (gpr_cv_wait(&g_rcv, &g_mu, short_deadline) && g_cbs_head == NULL) {
if (gpr_time_cmp(gpr_now(GPR_CLOCK_REALTIME), 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",
count_objects());
for (obj = g_root_object.next; obj != &g_root_object; obj = obj->next) {
gpr_log(GPR_DEBUG, "LEAKED OBJECT: %s %p", obj->name, obj);
}
break;
}
}
}
gpr_mu_unlock(&g_mu);
grpc_kick_poller();
gpr_event_wait(&g_background_callback_executor_done,
gpr_inf_future(GPR_CLOCK_REALTIME));
grpc_alarm_list_shutdown();
grpc_iomgr_platform_shutdown();
gpr_mu_destroy(&g_mu);
gpr_cv_destroy(&g_rcv);
}
void grpc_iomgr_register_object_internal(grpc_iomgr_object *obj,
const char *name,
const char *file,
int line) {
obj->name = gpr_strdup(name);
iomgr_object_trace("register", obj, file, line);
gpr_mu_lock(&g_mu);
obj->next = &g_root_object;
obj->prev = obj->next->prev;
obj->next->prev = obj->prev->next = obj;
gpr_mu_unlock(&g_mu);
}
void grpc_iomgr_unregister_object_internal(grpc_iomgr_object *obj,
const char *file,
int line) {
iomgr_object_trace("unregister", obj, file, line);
gpr_mu_lock(&g_mu);
obj->next->prev = obj->prev;
obj->prev->next = obj->next;
gpr_cv_signal(&g_rcv);
gpr_mu_unlock(&g_mu);
gpr_free(obj->name);
}
void grpc_iomgr_closure_init(grpc_iomgr_closure *closure, grpc_iomgr_cb_func cb,
void *cb_arg) {
closure->cb = cb;
closure->cb_arg = cb_arg;
closure->next = NULL;
}
static void assert_not_scheduled_locked(grpc_iomgr_closure *closure) {
#ifndef NDEBUG
grpc_iomgr_closure *c;
for (c = g_cbs_head; c; c = c->next) {
GPR_ASSERT(c != closure);
}
#endif
}
void grpc_iomgr_add_delayed_callback(grpc_iomgr_closure *closure, int success) {
closure->success = success;
GPR_ASSERT(closure->cb);
gpr_mu_lock(&g_mu);
assert_not_scheduled_locked(closure);
closure->next = NULL;
if (!g_cbs_tail) {
g_cbs_head = g_cbs_tail = closure;
} else {
g_cbs_tail->next = closure;
g_cbs_tail = closure;
}
if (g_shutdown) {
gpr_cv_signal(&g_rcv);
}
gpr_mu_unlock(&g_mu);
}
void grpc_iomgr_add_callback(grpc_iomgr_closure *closure) {
grpc_iomgr_add_delayed_callback(closure, 1 /* GPR_TRUE */);
}
int grpc_maybe_call_delayed_callbacks(gpr_mu *drop_mu, int success) {
int n = 0;
gpr_mu *retake_mu = NULL;
grpc_iomgr_closure *closure;
for (;;) {
/* check for new work */
if (!gpr_mu_trylock(&g_mu)) {
break;
}
closure = g_cbs_head;
if (!closure) {
gpr_mu_unlock(&g_mu);
break;
}
g_cbs_head = closure->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;
}
closure->cb(closure->cb_arg, success && closure->success);
n++;
}
if (retake_mu) {
gpr_mu_lock(retake_mu);
}
return n;
}
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