[Spice-devel] [PATCH] timer: use TLS to store and set current timer queue

[Frediano Ziglio]

Avoid locking, list and complicated stuff and use TLS.

Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
---
 server/spice_timer_queue.c | 63 ++++++----------------------------------------
 1 file changed, 8 insertions(+), 55 deletions(-)

diff --git a/server/spice_timer_queue.c b/server/spice_timer_queue.c
index 60017cc..abab878 100644
--- a/server/spice_timer_queue.c
+++ b/server/spice_timer_queue.c
@@ -21,15 +21,6 @@
 #include "spice_timer_queue.h"
 #include "common/ring.h"
 
-static Ring timer_queue_list;
-static int queue_count = 0;
-static pthread_mutex_t queue_list_lock = PTHREAD_MUTEX_INITIALIZER;
-
-static void spice_timer_queue_init(void)
-{
-    ring_init(&timer_queue_list);
-}
-
 struct SpiceTimer {
     RingItem link;
     RingItem active_link;
@@ -45,48 +36,18 @@ struct SpiceTimer {
 };
 
 struct SpiceTimerQueue {
-    RingItem link;
     pthread_t thread;
     Ring timers;
     Ring active_timers;
 };
 
-static SpiceTimerQueue *spice_timer_queue_find(void)
-{
-    pthread_t self = pthread_self();
-    RingItem *queue_item;
-
-    RING_FOREACH(queue_item, &timer_queue_list) {
-         SpiceTimerQueue *queue = SPICE_CONTAINEROF(queue_item, SpiceTimerQueue, link);
-
-         if (pthread_equal(self, queue->thread) != 0) {
-            return queue;
-         }
-    }
-
-    return NULL;
-}
-
-static SpiceTimerQueue *spice_timer_queue_find_with_lock(void)
-{
-    SpiceTimerQueue *queue;
-
-    pthread_mutex_lock(&queue_list_lock);
-    queue = spice_timer_queue_find();
-    pthread_mutex_unlock(&queue_list_lock);
-    return queue;
-}
+static __thread SpiceTimerQueue *current_queue = NULL;
 
 int spice_timer_queue_create(void)
 {
     SpiceTimerQueue *queue;
 
-    pthread_mutex_lock(&queue_list_lock);
-    if (queue_count == 0) {
-        spice_timer_queue_init();
-    }
-
-    if (spice_timer_queue_find() != NULL) {
+    if (current_queue != NULL) {
         spice_printerr("timer queue was already created for the thread");
         return FALSE;
     }
@@ -96,10 +57,7 @@ int spice_timer_queue_create(void)
     ring_init(&queue->timers);
     ring_init(&queue->active_timers);
 
-    ring_add(&timer_queue_list, &queue->link);
-    queue_count++;
-
-    pthread_mutex_unlock(&queue_list_lock);
+    current_queue = queue;
 
     return TRUE;
 }
@@ -107,10 +65,9 @@ int spice_timer_queue_create(void)
 void spice_timer_queue_destroy(void)
 {
     RingItem *item;
-    SpiceTimerQueue *queue;
+    SpiceTimerQueue *queue = current_queue;
 
-    pthread_mutex_lock(&queue_list_lock);
-    queue = spice_timer_queue_find();
+    current_queue = NULL;
 
     spice_assert(queue != NULL);
 
@@ -121,17 +78,13 @@ void spice_timer_queue_destroy(void)
         spice_timer_remove(timer);
     }
 
-    ring_remove(&queue->link);
     free(queue);
-    queue_count--;
-
-    pthread_mutex_unlock(&queue_list_lock);
 }
 
 SpiceTimer *spice_timer_queue_add(SpiceTimerFunc func, void *opaque)
 {
     SpiceTimer *timer = spice_new0(SpiceTimer, 1);
-    SpiceTimerQueue *queue = spice_timer_queue_find_with_lock();
+    SpiceTimerQueue *queue = current_queue;
 
     spice_assert(queue != NULL);
 
@@ -221,7 +174,7 @@ unsigned int spice_timer_queue_get_timeout_ms(void)
     int64_t now_ms;
     RingItem *head;
     SpiceTimer *head_timer;
-    SpiceTimerQueue *queue = spice_timer_queue_find_with_lock();
+    SpiceTimerQueue *queue = current_queue;
 
     spice_assert(queue != NULL);
 
@@ -244,7 +197,7 @@ void spice_timer_queue_cb(void)
     struct timespec now;
     uint64_t now_ms;
     RingItem *head;
-    SpiceTimerQueue *queue = spice_timer_queue_find_with_lock();
+    SpiceTimerQueue *queue = current_queue;
 
     spice_assert(queue != NULL);
 
-- 
2.4.3