From 97cb4b33462735b93ac9522df6bf4d43d0b7fe71 Mon Sep 17 00:00:00 2001
From: bje <bje>
Date: Sun, 4 Oct 1998 18:32:15 +0000
Subject: 1998-10-05  Ben Elliston  <bje@cygnus.com> 	* global.c
 (PTHREAD_MUTEX_INITIALIZER): Move to pthread.h. 	* pthread.h
 (PTHREAD_MUTEX_INITIALIZER): Define. 	(pthread_mutex_t): Reimplement as a
 struct containing a valid 	flag. If the flag is ever down upon entry to a
 mutex operation, 	we call pthread_mutex_create() to initialise the
 object. This 	fixes the problem of how to handle statically initialised
 objects 	that can't call InitializeCriticalSection() due to their
 context. 	* mutex.c (pthread_mutex_init): Set valid flag. 
 (pthread_mutex_destroy): Clear valid flag. 	(pthread_mutex_lock): Check
 and handle the valid flag. 	(pthread_mutex_unlock): Likewise. 
 (pthread_mutex_trylock): Likewise. 	* tests/mutex3.c: New file; test for
 the static initialisation 	macro. Passes.

---
 mutex.c | 30 +++++++++++++++++++++++++-----
 1 file changed, 25 insertions(+), 5 deletions(-)

(limited to 'mutex.c')

diff --git a/mutex.c b/mutex.c
index aaf4ff4..03f3f48 100644
--- a/mutex.c
+++ b/mutex.c
@@ -19,7 +19,10 @@ pthread_mutex_init(pthread_mutex_t *mutex, const pthread_mutexattr_t *attr)
     }
 
   /* Create a critical section. */
-  InitializeCriticalSection(mutex);
+  InitializeCriticalSection(&mutex->cs);
+
+  /* Mark as valid. */
+  mutex->valid = 1;
 
   return 0;
 }
@@ -32,7 +35,11 @@ pthread_mutex_destroy(pthread_mutex_t *mutex)
       return EINVAL;
     }
 
-  DeleteCriticalSection(mutex);
+  DeleteCriticalSection(&mutex->cs);
+  
+  /* Mark as invalid. */
+  mutex->valid = 0;
+
   return 0;
 }
 
@@ -59,14 +66,22 @@ pthread_mutexattr_destroy(pthread_mutexattr_t *attr)
 int
 pthread_mutex_lock(pthread_mutex_t *mutex)
 {
-  EnterCriticalSection(mutex);
+  if (!mutex->valid)
+    {
+      pthread_mutex_init(mutex, NULL);
+    }
+  EnterCriticalSection(&mutex->cs);
   return 0;
 }
 
 int
 pthread_mutex_unlock(pthread_mutex_t *mutex)
 {
-  LeaveCriticalSection(mutex);
+  if (!mutex->valid)
+    {
+      return EINVAL;
+    }
+  LeaveCriticalSection(&mutex->cs);
   return 0;
 }
 
@@ -87,5 +102,10 @@ pthread_mutex_trylock(pthread_mutex_t *mutex)
       return EINVAL;
     }
 
-  return (TryEnterCriticalSection(mutex) != TRUE) ? EBUSY : 0;
+  if (!mutex->valid)
+    {
+      pthread_mutex_init(mutex, NULL);
+    }
+
+  return (TryEnterCriticalSection(&mutex->cs) != TRUE) ? EBUSY : 0;
 }
-- 
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