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Repair isc_task_purgeevent(), clean isc_task_unsend{,range}()

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The isc_task_purgerange() was walking through all events on the task to
find a matching task.  Instead use the ISC_LINK_LINKED to find whether
the event is active.

Cleanup the related isc_task_unsend() and isc_task_unsendrange()
functions that were not used anywhere.

(cherry picked from commit 17aed2f895)
This commit is contained in:
Ondřej Surý 2022-03-31 21:55:15 +02:00
parent 29bc0daed1
commit be99507488
No known key found for this signature in database
GPG key ID: 2820F37E873DEA41
4 changed files with 15 additions and 90 deletions
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56
lib/isc/include/isc/task.h
View file

@ -54,18 +54,6 @@
*
* Purging calls isc_event_free() on the matching events.
*
* Unsending returns a list of events that matched the pattern.
* The caller is then responsible for them.
*
* Consumers of events should purge, not unsend.
*
* Producers of events often want to remove events when the caller indicates
* it is no longer interested in the object, e.g. by canceling a timer.
* Sometimes this can be done by purging, but for some event types, the
* calls to isc_event_free() cause deadlock because the event free routine
* wants to acquire a lock the caller is already holding. Unsending instead
* of purging solves this problem. As a general rule, producers should only
* unsend events which they have sent.
*/
/***
@ -337,34 +325,6 @@ isc_task_purgeevent(isc_task_t *task, isc_event_t *event);
* or was marked unpurgeable.
*/
unsigned int
isc_task_unsendrange(isc_task_t *task, void *sender, isc_eventtype_t first,
isc_eventtype_t last, void *tag, isc_eventlist_t *events);
/*%<
* Remove events from a task's event queue.
*
* Requires:
*
*\li 'task' is a valid task.
*
*\li last >= first.
*
*\li *events is a valid list.
*
* Ensures:
*
*\li Events in the event queue of 'task' whose sender is 'sender', whose
* type is >= first and <= last, and whose tag is 'tag' will be dequeued
* and appended to *events.
*
*\li A sender of NULL will match any sender. A NULL tag matches any
* tag.
*
* Returns:
*
*\li The number of events unsent.
*/
unsigned int
isc_task_unsend(isc_task_t *task, void *sender, isc_eventtype_t type, void *tag,
isc_eventlist_t *events);
@ -373,27 +333,27 @@ isc_task_unsend(isc_task_t *task, void *sender, isc_eventtype_t type, void *tag,
*
* Notes:
*
*\li This function is equivalent to
*\li This function is equivalent to
*
*\code
* isc_task_unsendrange(task, sender, type, type, tag, events);
* isc_task_unsendrange(task, sender, type, type, tag, events);
*\endcode
*
* Requires:
*
*\li 'task' is a valid task.
*\li 'task' is a valid task.
*
*\li *events is a valid list.
*\li *events is a valid list.
*
* Ensures:
*
*\li Events in the event queue of 'task' whose sender is 'sender', whose
* type is 'type', and whose tag is 'tag' will be dequeued and appended
* to *events.
*\li Events in the event queue of 'task' whose sender is 'sender', whose
* type is 'type', and whose tag is 'tag' will be dequeued and appended
* to *events.
*
* Returns:
*
*\li The number of events unsent.
*\li The number of events unsent.
*/
isc_result_t

34
lib/isc/task.c
View file

@ -614,12 +614,10 @@ isc_task_purge(isc_task_t *task, void *sender, isc_eventtype_t type,
bool
isc_task_purgeevent(isc_task_t *task, isc_event_t *event) {
isc_event_t *curr_event, *next_event;
bool found = false;
/*
* Purge 'event' from a task's event queue.
*
* XXXRTH: WARNING: This method may be removed before beta.
*/
REQUIRE(VALID_TASK(task));
@ -635,40 +633,22 @@ isc_task_purgeevent(isc_task_t *task, isc_event_t *event) {
*/
LOCK(&task->lock);
for (curr_event = HEAD(task->events); curr_event != NULL;
curr_event = next_event)
{
next_event = NEXT(curr_event, ev_link);
if (curr_event == event && PURGE_OK(event)) {
DEQUEUE(task->events, curr_event, ev_link);
task->nevents--;
break;
}
if (ISC_LINK_LINKED(event, ev_link)) {
DEQUEUE(task->events, event, ev_link);
task->nevents--;
found = true;
}
UNLOCK(&task->lock);
if (curr_event == NULL) {
if (!found) {
return (false);
}
isc_event_free(&curr_event);
isc_event_free(&event);
return (true);
}
unsigned int
isc_task_unsendrange(isc_task_t *task, void *sender, isc_eventtype_t first,
isc_eventtype_t last, void *tag, isc_eventlist_t *events) {
/*
* Remove events from a task's event queue.
*/
REQUIRE(VALID_TASK(task));
XTRACE("isc_task_unsendrange");
return (dequeue_events(task, sender, first, last, tag, events, false));
}
unsigned int
isc_task_unsend(isc_task_t *task, void *sender, isc_eventtype_t type, void *tag,
isc_eventlist_t *events) {

1
lib/isc/tests
View file

@ -1 +0,0 @@
../../tests/isc

14
tests/isc/task_test.c
View file

@ -1389,19 +1389,6 @@ ISC_RUN_TEST_IMPL(purgeevent) {
try_purgeevent(true);
}
/*
* Purge event not purgeable test:
* When the event is not marked as purgable, a call to
* isc_task_purgeevent(task, event) does not purge the event
* 'event' from the task's queue and returns false.
*/
ISC_RUN_TEST_IMPL(purgeevent_notpurge) {
UNUSED(state);
try_purgeevent(false);
}
ISC_TEST_LIST_START
ISC_TEST_ENTRY_CUSTOM(manytasks, _setup4, _teardown)
@ -1413,7 +1400,6 @@ ISC_TEST_ENTRY_CUSTOM(privilege_drop, _setup, _teardown)
ISC_TEST_ENTRY_CUSTOM(privileged_events, _setup, _teardown)
ISC_TEST_ENTRY_CUSTOM(purge, _setup2, _teardown)
ISC_TEST_ENTRY_CUSTOM(purgeevent, _setup2, _teardown)
ISC_TEST_ENTRY_CUSTOM(purgeevent_notpurge, _setup2, _teardown)
ISC_TEST_ENTRY_CUSTOM(task_shutdown, _setup4, _teardown)
ISC_TEST_ENTRY_CUSTOM(task_exclusive, _setup4, _teardown)