bk commit into maria tree (bell:1.2628) BUG#35040

[sanja]

Below is the list of changes that have just been committed into a local
maria repository of bell.  When bell does a push these changes
will be propagated to the main repository and, within 24 hours after the
push, to the public repository.
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see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html

ChangeSet@stripped, 2008-04-09 15:20:58+03:00, bell@stripped +2 -0
  Problems of partially freed waiting quque fixed (BUG#35040)

  mysys/wqueue.c@stripped, 2008-04-09 15:20:55+03:00, bell@stripped +14 -15
    Problems of partially freed waiting quque fixed.

  storage/maria/unittest/ma_pagecache_rwconsist.c@stripped, 2008-04-09 15:20:55+03:00,
bell@stripped +5 -5
    Explicitly assigned initial value for increasing readability.
    Dbug file flush after each line for better debugging.
    Fixed code style.

diff -Nrup a/mysys/wqueue.c b/mysys/wqueue.c
--- a/mysys/wqueue.c	2008-02-25 23:31:56 +02:00
+++ b/mysys/wqueue.c	2008-04-09 15:20:55 +03:00
@@ -147,9 +147,8 @@ void wqueue_release_one_locktype_from_qu
 {
   struct st_my_thread_var *last= wqueue->last_thread;
   struct st_my_thread_var *next= last->next;
-  struct st_my_thread_var **prev= &last->next;
   struct st_my_thread_var *thread;
-  struct st_my_thread_var *new_last= NULL;
+  struct st_my_thread_var *new_list= NULL;
   uint first_type= next->lock_type;
   if (first_type == MY_PTHREAD_LOCK_WRITE)
   {
@@ -157,8 +156,12 @@ void wqueue_release_one_locktype_from_qu
     thread= next;
     pthread_cond_signal(&thread->suspend);
     if (thread == last)
+    {
+      DBUG_ASSERT(thread->next == thread);
       wqueue->last_thread= NULL;
-    *prev= thread->next;
+    }
+    else
+      last->next= thread->next;
     thread->next= NULL;
     return;
   }
@@ -169,26 +172,22 @@ void wqueue_release_one_locktype_from_qu
     if (thread->lock_type == MY_PTHREAD_LOCK_WRITE)
     {
       /* skip waiting for write lock */
-      *prev= thread;
-      prev= &thread->next;
-      new_last= NULL;
+      if (new_list)
+      {
+        thread->next= new_list->next;
+        new_list= new_list->next= thread;
+      }
+      else
+        new_list= thread->next= thread;
     }
     else
     {
       /* release waiting for read lock */
       pthread_cond_signal(&thread->suspend);
-      new_last= thread->next;
       thread->next= NULL;
     }
   } while (thread != last);
-  if (new_last)
-  {
-    /* last was deleted */
-    if (new_last == last)
-      wqueue->last_thread= NULL; /* empty list */
-    else
-      wqueue->last_thread= new_last;
-  }
+  wqueue->last_thread= new_list;
 }
 
 
diff -Nrup a/storage/maria/unittest/ma_pagecache_rwconsist.c
b/storage/maria/unittest/ma_pagecache_rwconsist.c
--- a/storage/maria/unittest/ma_pagecache_rwconsist.c	2008-03-04 18:07:52 +02:00
+++ b/storage/maria/unittest/ma_pagecache_rwconsist.c	2008-04-09 15:20:55 +03:00
@@ -37,7 +37,7 @@ static char *file1_name= (char*)"page_ca
 static PAGECACHE_FILE file1;
 static pthread_cond_t COND_thread_count;
 static pthread_mutex_t LOCK_thread_count;
-static uint thread_count;
+static uint thread_count= 0;
 static PAGECACHE pagecache;
 
 static uint number_of_readers= 5;
@@ -212,9 +212,9 @@ int main(int argc __attribute__((unused)
 
 #ifndef DBUG_OFF
 #if defined(__WIN__)
-  default_dbug_option= "d:t:i:O,\\test_pagecache_consist.trace";
+  default_dbug_option= "d:f:i:O,\\test_pagecache_consist.trace";
 #else
-  default_dbug_option= "d:t:i:o,/tmp/test_pagecache_consist.trace";
+  default_dbug_option= "d:t:i:O,/tmp/test_pagecache_consist.trace";
 #endif
   if (argc > 1)
   {
@@ -335,8 +335,8 @@ int main(int argc __attribute__((unused)
   pthread_mutex_lock(&LOCK_thread_count);
   while (thread_count)
   {
-    if ((error= pthread_cond_wait(&COND_thread_count,&LOCK_thread_count)))
-      diag("COND_thread_count: %d from pthread_cond_wait\n",error);
+    if ((error= pthread_cond_wait(&COND_thread_count, &LOCK_thread_count)))
+      diag("COND_thread_count: %d from pthread_cond_wait\n", error);
   }
   pthread_mutex_unlock(&LOCK_thread_count);
   DBUG_PRINT("info", ("thread ended"));