From bab1896412f2d292ebd8d44bc9d6ddb58a8702b0 Mon Sep 17 00:00:00 2001
From: rpj <rpj>
Date: Thu, 28 Dec 2000 05:43:49 +0000
Subject: 2000-10-10  Ross Johnson  <rpj@setup1.ise.canberra.edu.au>

        * misc.c (pthread_self): Restore Win32 "last error"
        cleared by TlsGetValue() call in
        pthread_getspecific()
        - "Steven Reddie" <smr@essemer.com.au>

2000-09-20  Ross Johnson  <rpj@setup1.ise.canberra.edu.au>

        * mutex.c (pthread_mutex_lock): Record the owner
        of the mutex. This requires also keeping count of
        recursive locks ourselves rather than leaving it
        to Win32 since we need to know when to NULL the
        thread owner when the mutex is unlocked.
        (pthread_mutex_trylock): Likewise.
        (pthread_mutex_unlock): Check that the calling
        thread owns the mutex, decrement the recursive
        lock count, and NULL the owner if zero. Return
        EPERM if the mutex is owned by another thread.
        * implement.h (pthread_mutex_t_): Add ownerThread
        and lockCount members.
        - reported by Arthur Kantor <akantor@bexusa.com>
---
 mutex.c | 48 +++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 45 insertions(+), 3 deletions(-)

(limited to 'mutex.c')

diff --git a/mutex.c b/mutex.c
index 091c61e..d31b3b2 100644
--- a/mutex.c
+++ b/mutex.c
@@ -555,6 +555,12 @@ pthread_mutex_lock(pthread_mutex_t *mutex)
 	}
     }
 
+  if (result == 0)
+    {
+      mx->ownerThread = pthread_self();
+      mx->lockCount++;
+    }
+
   return(result);
 }
 
@@ -578,13 +584,43 @@ pthread_mutex_unlock(pthread_mutex_t *mutex)
    */
   if (mx != (pthread_mutex_t) PTW32_OBJECT_AUTO_INIT)
     {
-      if (mx->mutex == 0)
+      pthread_t self = pthread_self();
+
+      if (pthread_equal(mx->ownerThread, self) == 0)
 	{
-	  LeaveCriticalSection(&mx->cs);
+	  int oldCount = mx->lockCount;
+	  pthread_t oldOwner = mx->ownerThread;
+
+	  if (mx->lockCount > 0)
+	    {
+	      mx->lockCount--;
+	    }
+
+	  if (mx->lockCount == 0)
+	    {
+	      mx->ownerThread = NULL;
+	    }
+	      
+	  if (mx->mutex == 0)
+	    {
+	      LeaveCriticalSection(&mx->cs);
+	    }
+	  else
+	    {
+	      if (!ReleaseMutex(mx->mutex))
+		{
+		  result = EINVAL;
+		  /*
+		   * Put things back the way they were.
+		   */
+		  mx->lockCount = oldCount;
+		  mx->ownerThread = oldOwner;
+		}
+	    }
 	}
       else
 	{
-	  result = (ReleaseMutex (mx->mutex) ? 0 : EINVAL);
+	  result = EPERM;
 	}
     }
   else
@@ -643,5 +679,11 @@ pthread_mutex_trylock(pthread_mutex_t *mutex)
 	}
     }
 
+  if (result == 0)
+    {
+      mx->ownerThread = pthread_self();
+      mx->lockCount++;
+    }
+
   return(result);
 }
-- 
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