kenmirrors/asterisk
1
0
Fork 0
mirror of https://github.com/asterisk/asterisk.git synced 2025-10-03 11:11:05 +00:00
Code Issues Packages Projects Releases Wiki Activity

sched.c: Ensure oldest expiring entry runs first.

Browse Source 
This patch is part of a series to resolve deadlocks in chan_sip.c.

* Updated sched unit test to check new behavior.

ASTERISK-25023

Change-Id: Ib69437327b3cda5e14c4238d9ff91b2531b34ef3
This commit is contained in:
Richard Mudgett
2016-03-07 15:50:22 -06:00
parent dcebcaa3da
commit b2d2906445
2 changed files with 144 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

45
main/sched.c
View File

@@ -83,6 +83,14 @@ struct sched {
/*! The ID that has been popped off the scheduler context's queue */
struct sched_id *sched_id;
struct timeval when; /*!< Absolute time event should take place */
/*!
* \brief Tie breaker in case the when is the same for multiple entries.
*
* \note The oldest expiring entry in the scheduler heap goes first.
* This is possible when multiple events are scheduled to expire at
* the same time by internal coding.
*/
unsigned int tie_breaker;
int resched; /*!< When to reschedule */
int variable; /*!< Use return value from callback to reschedule */
const void *data; /*!< Data */
@@ -107,6 +115,8 @@ struct ast_sched_context {
ast_mutex_t lock;
unsigned int eventcnt; /*!< Number of events processed */
unsigned int highwater; /*!< highest count so far */
/*! Next tie breaker in case events expire at the same time. */
unsigned int tie_breaker;
struct ast_heap *sched_heap;
struct sched_thread *sched_thread;
/*! The scheduled task that is currently executing */
@@ -213,9 +223,17 @@ int ast_sched_start_thread(struct ast_sched_context *con)
return 0;
}
static int sched_time_cmp(void *a, void *b)
static int sched_time_cmp(void *va, void *vb)
{
return ast_tvcmp(((struct sched *) b)->when, ((struct sched *) a)->when);
struct sched *a = va;
struct sched *b = vb;
int cmp;
cmp = ast_tvcmp(b->when, a->when);
if (!cmp) {
cmp = b->tie_breaker - a->tie_breaker;
}
return cmp;
}
struct ast_sched_context *ast_sched_context_create(void)
@@ -442,11 +460,28 @@ int ast_sched_wait(struct ast_sched_context *con)
*/
static void schedule(struct ast_sched_context *con, struct sched *s)
{
ast_heap_push(con->sched_heap, s);
size_t size;
if (ast_heap_size(con->sched_heap) > con->highwater) {
con->highwater = ast_heap_size(con->sched_heap);
size = ast_heap_size(con->sched_heap);
/* Record the largest the scheduler heap became for reporting purposes. */
if (con->highwater <= size) {
con->highwater = size + 1;
}
/* Determine the tie breaker value for the new entry. */
if (size) {
++con->tie_breaker;
} else {
/*
* Restart the sequence for the first entry to make integer
* roll over more unlikely.
*/
con->tie_breaker = 0;
}
s->tie_breaker = con->tie_breaker;
ast_heap_push(con->sched_heap, s);
}
/*! \brief