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bind9/lib/isc/async.c
Daniel Baumann f66ff7eae6
Adding upstream version 1:9.20.9.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
2025-06-21 13:32:37 +02:00

122 lines
3.2 KiB
C

/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* SPDX-License-Identifier: MPL-2.0
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, you can obtain one at https://mozilla.org/MPL/2.0/.
*
* See the COPYRIGHT file distributed with this work for additional
* information regarding copyright ownership.
*/
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#include <isc/async.h>
#include <isc/atomic.h>
#include <isc/barrier.h>
#include <isc/condition.h>
#include <isc/job.h>
#include <isc/loop.h>
#include <isc/magic.h>
#include <isc/mem.h>
#include <isc/mutex.h>
#include <isc/refcount.h>
#include <isc/result.h>
#include <isc/signal.h>
#include <isc/strerr.h>
#include <isc/thread.h>
#include <isc/util.h>
#include <isc/uv.h>
#include <isc/work.h>
#include "async_p.h"
#include "job_p.h"
#include "loop_p.h"
void
isc_async_run(isc_loop_t *loop, isc_job_cb cb, void *cbarg) {
REQUIRE(VALID_LOOP(loop));
REQUIRE(cb != NULL);
isc_job_t *job = isc_mem_get(loop->mctx, sizeof(*job));
*job = (isc_job_t){
.cb = cb,
.cbarg = cbarg,
};
cds_wfcq_node_init(&job->wfcq_node);
/*
* cds_wfcq_enqueue() is non-blocking and enqueues the job to async
* queue.
*
* The function returns 'false' in case the queue was empty - in such
* case we need to trigger the async callback.
*/
if (!cds_wfcq_enqueue(&loop->async_jobs.head, &loop->async_jobs.tail,
&job->wfcq_node))
{
int r = uv_async_send(&loop->async_trigger);
UV_RUNTIME_CHECK(uv_async_send, r);
}
}
void
isc__async_cb(uv_async_t *handle) {
isc_loop_t *loop = uv_handle_get_data(handle);
isc_jobqueue_t jobs;
REQUIRE(VALID_LOOP(loop));
/* Initialize local wfcqueue */
__cds_wfcq_init(&jobs.head, &jobs.tail);
/*
* Move all the elements from loop->async_jobs to a local jobs queue.
*
* __cds_wfcq_splice_blocking() assumes that synchronization is
* done externally - there's no internal locking, unlike
* cds_wfcq_splice_blocking(), and we do not need to check whether
* it needs to block, unlike __cds_wfcq_splice_nonblocking().
*
* The reason we can use __cds_wfcq_splice_blocking() is that the
* only other function we use is cds_wfcq_enqueue() which doesn't
* require any synchronization (see the table in urcu/wfcqueue.h
* for more details).
*/
enum cds_wfcq_ret ret = __cds_wfcq_splice_blocking(
&jobs.head, &jobs.tail, &loop->async_jobs.head,
&loop->async_jobs.tail);
INSIST(ret != CDS_WFCQ_RET_WOULDBLOCK);
if (ret == CDS_WFCQ_RET_SRC_EMPTY) {
/*
* Nothing to do, the source queue was empty - most
* probably we were called from isc__async_close() below.
*/
return;
}
/*
* Walk through the local queue which has now all the members copied
* locally, and call the callbacks and free all the isc_job_t(s).
*/
struct cds_wfcq_node *node, *next;
__cds_wfcq_for_each_blocking_safe(&jobs.head, &jobs.tail, node, next) {
isc_job_t *job = caa_container_of(node, isc_job_t, wfcq_node);
job->cb(job->cbarg);
isc_mem_put(loop->mctx, job, sizeof(*job));
}
}
void
isc__async_close(uv_handle_t *handle) {
isc_loop_t *loop = uv_handle_get_data(handle);
isc__async_cb(&loop->async_trigger);
}