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bind/lib/isc/managers.c
Ondřej Surý b5bf58b419 Destroy netmgr before destroying taskmgr
With taskmgr running on top of netmgr, the ordering of how the tasks and
netmgr shutdown interacts was wrong as previously isc_taskmgr_destroy()
was waiting until all tasks were properly shutdown and detached.  This
responsibility was moved to netmgr, so we now need to do the following:

  1. shutdown all the tasks - this schedules all shutdown events onto
     the netmgr queue

  2. shutdown the netmgr - this also makes sure all the tasks and
     events are properly executed

  3. Shutdown the taskmgr - this now waits for all the tasks to finish
     running before returning

  4. Shutdown the netmgr - this call waits for all the netmgr netievents
     to finish before returning

This solves the race when the taskmgr object would be destroyed before
all the tasks were finished running in the netmgr loops.
2021-05-07 14:28:30 -07:00

145 lines
3.6 KiB
C

/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* 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 <isc/hp.h>
#include <isc/managers.h>
#include <isc/util.h>
#include "netmgr_p.h"
#include "socket_p.h"
#include "task_p.h"
#include "timer_p.h"
isc_result_t
isc_managers_create(isc_mem_t *mctx, size_t workers, size_t quantum,
size_t sockets, isc_nm_t **netmgrp,
isc_taskmgr_t **taskmgrp, isc_timermgr_t **timermgrp,
isc_socketmgr_t **socketmgrp) {
isc_result_t result;
isc_nm_t *netmgr = NULL;
isc_socketmgr_t *socketmgr = NULL;
isc_taskmgr_t *taskmgr = NULL;
isc_timermgr_t *timermgr = NULL;
/*
* We have ncpus network threads, ncpus old network threads - make
* it 4x just to be on the safe side.
*/
isc_hp_init(4 * workers);
REQUIRE(netmgrp != NULL && *netmgrp == NULL);
isc__netmgr_create(mctx, workers, &netmgr);
*netmgrp = netmgr;
INSIST(netmgr != NULL);
REQUIRE(taskmgrp == NULL || *taskmgrp == NULL);
if (taskmgrp != NULL) {
INSIST(netmgr != NULL);
result = isc__taskmgr_create(mctx, quantum, netmgr, &taskmgr);
if (result != ISC_R_SUCCESS) {
UNEXPECTED_ERROR(__FILE__, __LINE__,
"isc_taskmgr_create() failed: %s",
isc_result_totext(result));
goto fail;
}
*taskmgrp = taskmgr;
}
REQUIRE(timermgrp == NULL || *timermgrp == NULL);
if (timermgrp != NULL) {
result = isc__timermgr_create(mctx, &timermgr);
if (result != ISC_R_SUCCESS) {
UNEXPECTED_ERROR(__FILE__, __LINE__,
"isc_timermgr_create() failed: %s",
isc_result_totext(result));
goto fail;
}
*timermgrp = timermgr;
}
REQUIRE(socketmgrp == NULL || *socketmgrp == NULL);
if (socketmgrp != NULL) {
result = isc__socketmgr_create(mctx, &socketmgr, sockets,
workers);
if (result != ISC_R_SUCCESS) {
UNEXPECTED_ERROR(__FILE__, __LINE__,
"isc_socketmgr_create() failed: %s",
isc_result_totext(result));
goto fail;
}
*socketmgrp = socketmgr;
}
return (ISC_R_SUCCESS);
fail:
isc_managers_destroy(netmgrp, taskmgrp, timermgrp, socketmgrp);
return (result);
}
void
isc_managers_destroy(isc_nm_t **netmgrp, isc_taskmgr_t **taskmgrp,
isc_timermgr_t **timermgrp, isc_socketmgr_t **socketmgrp) {
/*
* If we have a taskmgr to clean up, then we must also have a netmgr.
*/
REQUIRE(taskmgrp != NULL || netmgrp == NULL);
/*
* The sequence of operations here is important:
*
* 1. Initiate shutdown of the taskmgr, sending shutdown events to
* all tasks that are not already shutting down.
*/
if (taskmgrp != NULL) {
INSIST(*taskmgrp != NULL);
isc__taskmgr_shutdown(*taskmgrp);
}
/*
* 2. Initiate shutdown of the network manager, freeing clients
* and other resources and preventing new connections, but do
* not stop processing of existing events.
*/
if (netmgrp != NULL) {
INSIST(*netmgrp != NULL);
isc__netmgr_shutdown(*netmgrp);
}
/*
* 3. Finish destruction of the task manager when all tasks
* have completed.
*/
if (taskmgrp != NULL) {
isc__taskmgr_destroy(taskmgrp);
}
/*
* 4. Finish destruction of the netmgr, and wait until all
* references have been released.
*/
if (netmgrp != NULL) {
isc__netmgr_destroy(netmgrp);
}
/*
* 5. Clean up the remaining managers.
*/
if (timermgrp != NULL) {
INSIST(*timermgrp != NULL);
isc__timermgr_destroy(timermgrp);
}
if (socketmgrp != NULL) {
INSIST(*socketmgrp != NULL);
isc__socketmgr_destroy(socketmgrp);
}
}