memtrap: properly lock access to memtrap changer

This commit is contained in:
Lennart Poettering 2009-07-01 20:22:38 +02:00
parent 28e4625a52
commit 7dabe051cd

View file

@ -37,6 +37,7 @@
#include <pulsecore/aupdate.h>
#include <pulsecore/atomic.h>
#include <pulsecore/once.h>
#include <pulsecore/mutex.h>
#include "memtrap.h"
@ -49,6 +50,7 @@ struct pa_memtrap {
static pa_memtrap *memtraps[2] = { NULL, NULL };
static pa_aupdate *aupdate;
static pa_static_mutex mutex = PA_STATIC_MUTEX_INIT; /* only required to serialize access to the write side */
static void allocate_aupdate(void) {
PA_ONCE_BEGIN {
@ -124,6 +126,7 @@ static void memtrap_unlink(pa_memtrap *m, unsigned j) {
pa_memtrap* pa_memtrap_add(const void *start, size_t size) {
pa_memtrap *m = NULL;
unsigned j;
pa_mutex *mx;
pa_assert(start);
pa_assert(size > 0);
@ -138,33 +141,45 @@ pa_memtrap* pa_memtrap_add(const void *start, size_t size) {
allocate_aupdate();
mx = pa_static_mutex_get(&mutex, FALSE, TRUE);
pa_mutex_lock(mx);
j = pa_aupdate_write_begin(aupdate);
memtrap_link(m, j);
j = pa_aupdate_write_swap(aupdate);
memtrap_link(m, j);
pa_aupdate_write_end(aupdate);
pa_mutex_unlock(mx);
return m;
}
void pa_memtrap_remove(pa_memtrap *m) {
unsigned j;
pa_mutex *mx;
pa_assert(m);
allocate_aupdate();
mx = pa_static_mutex_get(&mutex, FALSE, TRUE);
pa_mutex_lock(mx);
j = pa_aupdate_write_begin(aupdate);
memtrap_unlink(m, j);
j = pa_aupdate_write_swap(aupdate);
memtrap_unlink(m, j);
pa_aupdate_write_end(aupdate);
pa_mutex_unlock(mx);
pa_xfree(m);
}
pa_memtrap *pa_memtrap_update(pa_memtrap *m, const void *start, size_t size) {
unsigned j;
pa_mutex *mx;
pa_assert(m);
@ -176,6 +191,9 @@ pa_memtrap *pa_memtrap_update(pa_memtrap *m, const void *start, size_t size) {
allocate_aupdate();
mx = pa_static_mutex_get(&mutex, FALSE, TRUE);
pa_mutex_lock(mx);
j = pa_aupdate_write_begin(aupdate);
if (m->start == start && m->size == size)
@ -194,6 +212,8 @@ pa_memtrap *pa_memtrap_update(pa_memtrap *m, const void *start, size_t size) {
unlock:
pa_aupdate_write_end(aupdate);
pa_mutex_unlock(mx);
return m;
}