Sat Feb 20 16:03:30 1999 Ross Johnson <rpj@ixobrychus.canberra.edu.au>

        * dll.c (DLLMain): Expand TryEnterCriticalSection support test.
        * mutex.c (pthread_mutex_trylock): The check for
        _pthread_try_enter_critical_section == NULL should have been
        removed long ago.

3 files changed, 32 insertions, 8 deletions

diff --git a/ChangeLog b/ChangeLog
index ca8a885..1d340f6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,11 +1,19 @@
-Fri Feb 19 16:2s1703:30 1999  Ross Johnson  <rpj@ixobrychus.canberra.edu.au>
+Sat Feb 20 16:03:30 1999  Ross Johnson  <rpj@ixobrychus.canberra.edu.au>
+
+	* dll.c (DLLMain): Expand TryEnterCriticalSection support test.
+
+	* mutex.c (pthread_mutex_trylock): The check for
+	_pthread_try_enter_critical_section == NULL should have been
+	removed long ago.
+
+Fri Feb 19 16:03:30 1999  Ross Johnson  <rpj@ixobrychus.canberra.edu.au>
 
 	* sync.c (pthread_join): Fix pthread_equal() test.
 
 	* mutex.c (pthread_mutex_trylock): Check mutex != NULL before
 	using it.
 
-Thu Feb 18 16:2s1703:30 1999  Ross Johnson  <rpj@ixobrychus.canberra.edu.au>
+Thu Feb 18 16:17:30 1999  Ross Johnson  <rpj@ixobrychus.canberra.edu.au>
 
 	* misc.c (pthread_equal): Fix inverted result.
 
diff --git a/dll.c b/dll.c
index b440500..25d89c3 100644
--- a/dll.c
+++ b/dll.c
@@ -16,6 +16,11 @@
 BOOL (WINAPI *_pthread_try_enter_critical_section)(LPCRITICAL_SECTION) = NULL;
 
 /*
+ * We use this to double-check that TryEnterCriticalSection works.
+ */
+CRITICAL_SECTION cs;
+
+/*
  * Handle to kernel32.dll 
  */
 static HINSTANCE _pthread_h_kernel32;
@@ -67,6 +72,23 @@ DllMain (
 	(BOOL (PT_STDCALL *)(LPCRITICAL_SECTION))
 	GetProcAddress(_pthread_h_kernel32,
 		       (LPCSTR) "TryEnterCriticalSection");
+
+      if (_pthread_try_enter_critical_section != NULL)
+        {
+          InitializeCriticalSection(&cs);
+          if ((*_pthread_try_enter_critical_section)(&cs))
+            {
+              LeaveCriticalSection(&cs);
+            }
+          else
+            {
+              /*
+               * Not really supported (Win98?).
+               */
+              _pthread_try_enter_critical_section = NULL;
+            }
+          DeleteCriticalSection(&cs);
+        }
       break;
 
     case DLL_THREAD_ATTACH:
diff --git a/mutex.c b/mutex.c
index 2b28cec..578617d 100644
--- a/mutex.c
+++ b/mutex.c
@@ -513,12 +513,6 @@ pthread_mutex_trylock(pthread_mutex_t *mutex)
       return EINVAL;
     }
 
-  if (mutex->mutex == 0 && _pthread_try_enter_critical_section == NULL)
-    {
-      /* TryEnterCriticalSection does not exist in the OS; return ENOSYS. */
-      return ENOSYS;
-    }
-      
   /*
    * We do a quick check to see if we need to do more work
    * to initialise a static mutex. We check 'staticinit'