From: Michael Vrable <mvrable@cs.ucsd.edu>
Date: Fri, 5 Mar 2010 22:25:00 +0000 (-0800)
Subject: Do not signal barrier until all notifiers have run.
X-Git-Url: https://git.vrable.net/?a=commitdiff_plain;h=e560d8b120a5f2ed5057506f91bc8d9e818229a7;p=bluesky.git

Do not signal barrier until all notifiers have run.
---

diff --git a/bluesky/bluesky-private.h b/bluesky/bluesky-private.h
index 058c5bd..852b04e 100644
--- a/bluesky/bluesky-private.h
+++ b/bluesky/bluesky-private.h
@@ -47,7 +47,8 @@ typedef enum {
 } BlueSkyAsyncStatus;
 
 struct BlueSkyNotifierList;
-typedef struct {
+typedef struct _BlueSkyStoreAsync BlueSkyStoreAsync;
+struct _BlueSkyStoreAsync {
     BlueSkyStore *store;
 
     GMutex *lock;
@@ -65,10 +66,15 @@ typedef struct {
     struct BlueSkyNotifierList *notifiers;
     gint notifier_count;
 
+    /* The barrier waiting on this operation.  Support for more than one
+     * barrier for a single async is not well-supported and should be avoided
+     * if possible. */
+    BlueSkyStoreAsync *barrier;
+
     bluesky_time_hires start_time;  /* Time operation was submitted. */
 
     gpointer store_private;     /* For use by the storage implementation */
-} BlueSkyStoreAsync;
+};
 
 /* Support for notification lists.  These are lists of one-shot functions which
  * can be called when certain events--primarily, competed storage
diff --git a/bluesky/store.c b/bluesky/store.c
index 200cd3e..888bd1b 100644
--- a/bluesky/store.c
+++ b/bluesky/store.c
@@ -97,6 +97,7 @@ BlueSkyStoreAsync *bluesky_store_async_new(BlueSkyStore *store)
     async->result = -1;
     async->notifiers = NULL;
     async->notifier_count = 0;
+    async->barrier = NULL;
     async->store_private = NULL;
 
     return async;
@@ -171,6 +172,22 @@ void bluesky_store_async_add_notifier(BlueSkyStoreAsync *async,
     g_mutex_unlock(async->lock);
 }
 
+static void op_complete(gpointer a, gpointer b)
+{
+    BlueSkyStoreAsync *barrier = (BlueSkyStoreAsync *)b;
+
+    bluesky_store_async_ref(barrier);
+    g_mutex_lock(barrier->lock);
+    barrier->store_private
+        = GINT_TO_POINTER(GPOINTER_TO_INT(barrier->store_private) - 1);
+    if (GPOINTER_TO_INT(barrier->store_private) == 0
+            && barrier->status != ASYNC_NEW) {
+        bluesky_store_async_mark_complete(barrier);
+    }
+    g_mutex_unlock(barrier->lock);
+    bluesky_store_async_unref(barrier);
+}
+
 /* Mark an asynchronous operation as complete.  This should only be called by
  * the store implementations.  The lock should be held when calling this
  * function.  Any notifier functions will be called, but in a separate thread
@@ -190,6 +207,9 @@ void bluesky_store_async_mark_complete(BlueSkyStoreAsync *async)
     async->status = ASYNC_COMPLETE;
     g_cond_broadcast(async->completion_cond);
 
+    if (async->barrier != NULL && async->notifiers == NULL)
+        op_complete(async, async->barrier);
+
     while (async->notifiers != NULL) {
         struct BlueSkyNotifierList *nl = async->notifiers;
         async->notifiers = nl->next;
@@ -234,31 +254,26 @@ void bluesky_store_async_submit(BlueSkyStoreAsync *async)
         bluesky_store_async_wait(async);
 }
 
-static void op_complete(gpointer a, gpointer b)
-{
-    BlueSkyStoreAsync *barrier = (BlueSkyStoreAsync *)b;
-
-    bluesky_store_async_ref(barrier);
-    g_mutex_lock(barrier->lock);
-    barrier->store_private
-        = GINT_TO_POINTER(GPOINTER_TO_INT(barrier->store_private) - 1);
-    if (GPOINTER_TO_INT(barrier->store_private) == 0
-            && barrier->status != ASYNC_NEW) {
-        bluesky_store_async_mark_complete(barrier);
-    }
-    g_mutex_unlock(barrier->lock);
-    bluesky_store_async_unref(barrier);
-}
-
 /* Add the given operation to the barrier.  The barrier will not complete until
  * all operations added to it have completed. */
 void bluesky_store_add_barrier(BlueSkyStoreAsync *barrier,
                                BlueSkyStoreAsync *async)
 {
     g_return_if_fail(barrier->op == STORE_OP_BARRIER);
+
+    g_mutex_lock(barrier->lock);
     barrier->store_private
         = GINT_TO_POINTER(GPOINTER_TO_INT(barrier->store_private) + 1);
-    bluesky_store_async_add_notifier(async, op_complete, barrier);
+    g_mutex_unlock(barrier->lock);
+
+    g_mutex_lock(async->lock);
+    if (async->barrier == NULL) {
+        async->barrier = barrier;
+    } else {
+        g_warning("Adding async to more than one barrier!\n");
+        bluesky_store_async_add_notifier(async, op_complete, barrier);
+    }
+    g_mutex_unlock(async->lock);
 }
 
 static void notifier_task(gpointer n, gpointer s)
@@ -267,7 +282,11 @@ static void notifier_task(gpointer n, gpointer s)
 
     notifier->func(notifier->async, notifier->user_data);
     if (g_atomic_int_dec_and_test(&notifier->async->notifier_count)) {
+        g_mutex_lock(notifier->async->lock);
+        if (notifier->async->barrier != NULL)
+            op_complete(notifier->async, notifier->async->barrier);
         g_cond_broadcast(notifier->async->completion_cond);
+        g_mutex_unlock(notifier->async->lock);
     }
     bluesky_store_async_unref(notifier->async);
     g_free(notifier);