From 65b8e87409edd85c85352d333c39efb90d7cd80c Mon Sep 17 00:00:00 2001
From: Ranjit Mathew <rmathew@hotmail.com>
Date: Tue, 28 Jan 2003 22:23:36 +0000
Subject: re PR java/9254 (java::lang::Object::wait(), threads-win32.cc returns
 wrong return codes)

2003-01-28  Ranjit Mathew  <rmathew@hotmail.com>

	Fixes PR java/9254:
	* include/win32-threads.h (_Jv_Mutex_t): Convert to a struct
	additionally containing id of the owner thread as well as
	the number of nested times the thread has acquired the mutex.
	(_Jv_MutexInit): Initialise owner thread id and refcount to 0.
	(_Jv_MutexDestroy): Reset owner thread id and refcount to 0.
	(_Jv_MutexUnlock): Check if really the owner thread, reset
	owner thread id to 0 before leaving, if leaving for the last
	time.
	(_Jv_MutexLock): Set owner thread id in the mutex and increment
	refcount.
	(_Jv_ThreadYield): Yield using a call to Sleep(0).
	* win32-threads.cc (_Jv_CondWait): Check if really owner of
	the passed mutex.
	Pass handle of the broadcast event, instead of a pointer to it
	in Win32 ResetEvent( ) call.
	Remove incorrect return values.
	(_Jv_CondDestroy): Close both event handles and delete
	critical section.
	(_Jv_CondNotify): Check if really the owner thread.
	(_Jv_CondNotifyAll): Check if really the owner thread.
	(_Jv_InitThreads): Change daemon_cond to a manual-reset event.
	(really_start): Use SetEvent( ) to signal daemon_cond.
	(_Jv_ThreadWait): Remove SignalObjectAndWait( ) and use
	WaitForSingleObject( ) instead to wait for daemon_cond to be
	signalled.

From-SVN: r62033
---
 libjava/include/win32-threads.h | 58 ++++++++++++++++++++++++++++++++---------
 1 file changed, 45 insertions(+), 13 deletions(-)

(limited to 'libjava/include/win32-threads.h')

diff --git a/libjava/include/win32-threads.h b/libjava/include/win32-threads.h
index e8cf805..5e40ae2 100644
--- a/libjava/include/win32-threads.h
+++ b/libjava/include/win32-threads.h
@@ -1,7 +1,8 @@
 // -*- c++ -*-
 // win32-threads.h - Defines for using Win32 threads.
 
-/* Copyright (C) 1998, 1999, 2000  Free Software Foundation
+/* Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003 Free Software
+   Foundation
 
    This file is part of libgcj.
 
@@ -18,13 +19,32 @@ details.  */
 // Typedefs.
 //
 
-typedef struct _Jv_ConditionVariable_t {
+typedef struct
+{
+  // ev[0] (signal) is a Win32 auto-reset event for _Jv_CondNotify
+  // ev[1] (broadcast) is a Win32 manual-reset event for _Jv_CondNotifyAll
   HANDLE ev[2];
-  CRITICAL_SECTION count_mutex;
+
+  // Number of threads waiting on this condition variable
   int blocked_count;
-};
 
-typedef CRITICAL_SECTION _Jv_Mutex_t;
+  // Protects access to the blocked_count variable
+  CRITICAL_SECTION count_mutex;
+
+} _Jv_ConditionVariable_t;
+
+typedef struct
+{
+  // The thread-id of the owner thread if any, 0 otherwise
+  DWORD owner;
+
+  // Track nested mutex acquisitions by the same thread
+  int refcount;
+
+  // The actual Windows construct used to implement this mutex
+  CRITICAL_SECTION cs;
+
+} _Jv_Mutex_t;
 
 typedef struct
 {
@@ -60,25 +80,39 @@ int _Jv_CondNotifyAll (_Jv_ConditionVariable_t *cv, _Jv_Mutex_t *);
 
 inline void _Jv_MutexInit (_Jv_Mutex_t *mu)
 {
-  InitializeCriticalSection(mu);
+  mu->owner = 0UL;
+  mu->refcount = 0;
+  InitializeCriticalSection (&(mu->cs));
 }
 
 #define _Jv_HaveMutexDestroy
 inline void _Jv_MutexDestroy (_Jv_Mutex_t *mu)
 {
-  DeleteCriticalSection(mu);
+  mu->owner = 0UL;
+  mu->refcount = 0;
+  DeleteCriticalSection (&(mu->cs));
   mu = NULL;
 }
 
 inline int _Jv_MutexUnlock (_Jv_Mutex_t *mu)
 {
-  LeaveCriticalSection(mu);
-  return 0;
+  if (mu->owner == GetCurrentThreadId ( ))
+    {
+      mu->refcount--;
+      if (mu->refcount == 0)
+        mu->owner = 0UL;
+      LeaveCriticalSection (&(mu->cs));
+      return 0;
+    }
+  else
+    return 1;
 }
 
 inline int _Jv_MutexLock (_Jv_Mutex_t *mu)
 {
-  EnterCriticalSection(mu);
+  EnterCriticalSection (&(mu->cs));
+  mu->owner = GetCurrentThreadId ( );
+  mu->refcount++;
   return 0;
 }
 
@@ -104,9 +138,7 @@ inline _Jv_Thread_t *_Jv_ThreadCurrentData(void)
 
 inline void _Jv_ThreadYield (void)
 {
-  // FIXME: win98 freezes hard (OS hang) when we use this --
-  //        for now, we simply don't yield
-  // Sleep (0);
+  Sleep (0);
 }
 
 void _Jv_ThreadRegister (_Jv_Thread_t *data);
-- 
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