Changeset 939370c for lib

Timestamp:

2008-12-14T10:19:41Z (16 years ago)

Author:

Wilmer van der Gaast <wilmer@…>

Branches:

master

Children:

c0c43fb

Parents:

e1720ce

Message:

events_libevent now detects when the event currently being handled is
removed. This could otherwise cause unpredictable behaviour, especially
for timers.

File:

• lib/events_libevent.c (modified) (4 diffs)

lib/events_libevent.c

@@ -37 +37 @@
 
 static void b_main_restart();
-static guint id_next = 1;
+static guint id_next = 1; /* Next ID to be allocated to an event handler. */
+static guint id_cur = 0; /* Event ID that we're currently handling. */
+static guint id_dead; /* Set to 1 if b_event_remove removes id_cur. */
 static GHashTable *id_hash;
-static int quitting = 0;
+static int quitting = 0; /* Prepare to quit, stop handling events. */
 
 /* Since libevent doesn't handle two event handlers for one fd-condition
@@ -119 +121 @@
         struct b_event_data *b_ev = data;
         b_input_condition cond = 0;
-        int id;
+        gboolean st;
         
         if( fd >= 0 )
@@ -133 +135 @@
         /* Since the called function might cancel this handler already
            (which free()s b_ev), we have to remember the ID here. */
-        id = b_ev->id;
+        id_cur = b_ev->id;
+        id_dead = 0;
         
         if( quitting )
         {
-                b_event_remove( id );
+                b_event_remove( id_cur );
                 return;
         }
         
-        if( !b_ev->function( b_ev->data, fd, cond ) )
+        st = b_ev->function( b_ev->data, fd, cond );
+        if( id_dead )
+        {
+                /* This event was killed already, don't touch it! */
+                return;
+        }
+        else if( !st )
         {
                 event_debug( "Handler returned FALSE: " );
-                b_event_remove( id );
+                b_event_remove( id_cur );
         }
         else if( fd == -1 )
         {
+                /* fd == -1 means it was a timer. These can't be auto-repeated
+                   so it has to be recreated every time. */
                 struct timeval tv;
                 
@@ -236 +247 @@
         if( b_ev )
         {
+                if( id == id_cur )
+                        id_dead = TRUE;
+                
                 g_hash_table_remove( id_hash, &b_ev->id );
                 if( b_ev->evinfo.ev_fd >= 0 )