This is the mail archive of the
java-patches@gcc.gnu.org
mailing list for the Java project.
Re: Patch for Review: PR/9254 and other Win32 Threading Fixes
- From: Ranjit Mathew <rmathew at hotmail dot com>
- To: java-patches at gcc dot gnu dot org
- Cc: adam at megacz dot com
- Date: Mon, 27 Jan 2003 23:21:18 +0530
- Subject: Re: Patch for Review: PR/9254 and other Win32 Threading Fixes
- References: <3E2F9C87.60306@hotmail.com>
Ranjit Mathew wrote:
This patch proposes to clean up the Win32 threads support in
libgcj a bit and contains fixes for a few problems reported
on the main list. These include:
Resubmitting in "diff -u2" format on Adam's request:
-------------------------------- 8< --------------------------------
2003-01-27 Ranjit Mathew <rmathew@hotmail.com>
* include/win32-threads.h (_Jv_Mutex_t): Convert to a struct
containing id of the owner thread as well.
(_Jv_MutexInit): Initialise owner thread id to 0.
(_Jv_MutexDestroy): Reset owner thread id to 0.
(_Jv_MutexUnlock): Check if really the owner thread, reset
owner thread id to 0 before leaving.
(_Jv_MutexLock): Set owner thread id in the mutex.
(_Jv_ThreadYield): Yield using Win32 Sleep(0).
* win32-threads.cc (_Jv_CondWait): Check if really owner of
the passed mutex.
Pass handle of 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.
--- include/win32-threads.h 2003-01-14 20:23:56.000000000 +0530
+++ include/win32-threads.h 2003-01-27 20:57:05.000000000 +0530
@@ -2,5 +2,6 @@
// 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.
@@ -19,11 +20,27 @@
//
-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;
+
+ // The actual Windows construct used to implement this mutex
+ CRITICAL_SECTION cs;
+
+} _Jv_Mutex_t;
typedef struct
@@ -61,5 +78,6 @@
inline void _Jv_MutexInit (_Jv_Mutex_t *mu)
{
- InitializeCriticalSection(mu);
+ mu->owner = 0UL;
+ InitializeCriticalSection (&(mu->cs));
}
@@ -67,5 +85,6 @@
inline void _Jv_MutexDestroy (_Jv_Mutex_t *mu)
{
- DeleteCriticalSection(mu);
+ mu->owner = 0UL;
+ DeleteCriticalSection (&(mu->cs));
mu = NULL;
}
@@ -73,11 +92,18 @@
inline int _Jv_MutexUnlock (_Jv_Mutex_t *mu)
{
- LeaveCriticalSection(mu);
- return 0;
+ if (mu->owner == GetCurrentThreadId ( ))
+ {
+ 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 ( );
return 0;
}
@@ -105,7 +131,5 @@
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);
}
--- win32-threads.cc 2003-01-14 20:23:53.000000000 +0530
+++ win32-threads.cc 2003-01-27 20:51:24.000000000 +0530
@@ -1,5 +1,6 @@
// win32-threads.cc - interface between libjava and Win32 threads.
-/* Copyright (C) 1998, 1999 Free Software Foundation, Inc.
+/* Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003 Free Software
+ Foundation, Inc.
This file is part of libgcj.
@@ -71,10 +72,12 @@
ensure_condvar_initialized(_Jv_ConditionVariable_t *cv)
{
- if (cv->ev[0] == 0) {
- cv->ev[0] = CreateEvent (NULL, 0, 0, NULL);
- if (cv->ev[0] == 0) JvFail("CreateEvent() failed");
- cv->ev[1] = CreateEvent (NULL, 1, 0, NULL);
- if (cv->ev[1] == 0) JvFail("CreateEvent() failed");
- }
+ if (cv->ev[0] == 0)
+ {
+ cv->ev[0] = CreateEvent (NULL, 0, 0, NULL);
+ if (cv->ev[0] == 0) JvFail("CreateEvent() failed");
+
+ cv->ev[1] = CreateEvent (NULL, 1, 0, NULL);
+ if (cv->ev[1] == 0) JvFail("CreateEvent() failed");
+ }
}
@@ -86,9 +89,11 @@
_Jv_CondWait(_Jv_ConditionVariable_t *cv, _Jv_Mutex_t *mu, jlong millis, jint nanos)
{
+ if (mu->owner != GetCurrentThreadId ( ))
+ return _JV_NOT_OWNER;
- EnterCriticalSection(&cv->count_mutex);
- ensure_condvar_initialized(cv);
+ EnterCriticalSection (&cv->count_mutex);
+ ensure_condvar_initialized (cv);
cv->blocked_count++;
- LeaveCriticalSection(&cv->count_mutex);
+ LeaveCriticalSection (&cv->count_mutex);
DWORD time;
@@ -103,16 +108,15 @@
EnterCriticalSection(&cv->count_mutex);
cv->blocked_count--;
- // If we were unblocked by the second event (the broadcast one) and nobody is
- // left, then reset the signal.
- int last_waiter = rval == WAIT_OBJECT_0 + 1 && cv->blocked_count == 0;
+ // If we were unblocked by the second event (the broadcast one)
+ // and nobody is left, then reset the event.
+ int last_waiter = (rval == (WAIT_OBJECT_0 + 1)) && (cv->blocked_count == 0);
LeaveCriticalSection(&cv->count_mutex);
- if (last_waiter) ResetEvent(&cv->ev[1]);
+ if (last_waiter)
+ ResetEvent (cv->ev[1]);
_Jv_MutexLock (mu);
- if (rval == WAIT_FAILED) return GetLastError();
- else if (rval == WAIT_TIMEOUT) return ETIMEDOUT;
- else return 0;
+ return 0;
}
@@ -122,5 +126,5 @@
// we do lazy creation of Events since CreateEvent() is insanely expensive
cv->ev[0] = 0;
- InitializeCriticalSection(&cv->count_mutex);
+ InitializeCriticalSection (&cv->count_mutex);
cv->blocked_count = 0;
}
@@ -129,30 +133,49 @@
_Jv_CondDestroy (_Jv_ConditionVariable_t *cv)
{
- if (cv->ev[0] != 0) CloseHandle(cv->ev[0]);
+ if (cv->ev[0] != 0)
+ {
+ CloseHandle (cv->ev[0]);
+ CloseHandle (cv->ev[1]);
+
+ cv->ev[0] = 0;
+ }
+
+ DeleteCriticalSection (&cv->count_mutex);
+
cv = NULL;
}
int
-_Jv_CondNotify (_Jv_ConditionVariable_t *cv, _Jv_Mutex_t *)
+_Jv_CondNotify (_Jv_ConditionVariable_t *cv, _Jv_Mutex_t *mu)
{
- EnterCriticalSection(&cv->count_mutex);
- ensure_condvar_initialized(cv);
+ if (mu->owner != GetCurrentThreadId ( ))
+ return _JV_NOT_OWNER;
+
+ EnterCriticalSection (&cv->count_mutex);
+ ensure_condvar_initialized (cv);
int somebody_is_blocked = cv->blocked_count > 0;
- LeaveCriticalSection(&cv->count_mutex);
+ LeaveCriticalSection (&cv->count_mutex);
+
+ if (somebody_is_blocked)
+ SetEvent (cv->ev[0]);
- if (somebody_is_blocked) return SetEvent (cv->ev[0]) ? 0 : GetLastError();
- else return 0;
+ return 0;
}
int
-_Jv_CondNotifyAll (_Jv_ConditionVariable_t *cv, _Jv_Mutex_t *)
+_Jv_CondNotifyAll (_Jv_ConditionVariable_t *cv, _Jv_Mutex_t *mu)
{
- EnterCriticalSection(&cv->count_mutex);
- ensure_condvar_initialized(cv);
+ if (mu->owner != GetCurrentThreadId ( ))
+ return _JV_NOT_OWNER;
+
+ EnterCriticalSection (&cv->count_mutex);
+ ensure_condvar_initialized (cv);
int somebody_is_blocked = cv->blocked_count > 0;
- LeaveCriticalSection(&cv->count_mutex);
+ LeaveCriticalSection (&cv->count_mutex);
- if (somebody_is_blocked) return SetEvent (cv->ev[1]) ? 0 : GetLastError();
- else return 0;
+ if (somebody_is_blocked)
+ SetEvent (cv->ev[1]);
+
+ return 0;
}
@@ -166,6 +189,6 @@
_Jv_ThreadKey = TlsAlloc();
_Jv_ThreadDataKey = TlsAlloc();
- daemon_mutex = CreateMutex(NULL, 0, NULL);
- daemon_cond = CreateEvent(NULL, 0, 0, NULL);
+ daemon_mutex = CreateMutex (NULL, 0, NULL);
+ daemon_cond = CreateEvent (NULL, 1, 0, NULL);
non_daemon_count = 0;
}
@@ -256,5 +279,5 @@
non_daemon_count--;
if (! non_daemon_count)
- PulseEvent (daemon_cond);
+ SetEvent (daemon_cond);
ReleaseMutex (daemon_mutex);
}
@@ -298,8 +321,10 @@
_Jv_ThreadWait (void)
{
- WaitForSingleObject(daemon_mutex, INFINITE);
- if(non_daemon_count)
- SignalObjectAndWait(daemon_mutex, daemon_cond, INFINITE, 0);
- ReleaseMutex(daemon_mutex);
+ WaitForSingleObject (daemon_mutex, INFINITE);
+ if (non_daemon_count)
+ {
+ ReleaseMutex (daemon_mutex);
+ WaitForSingleObject (daemon_cond, INFINITE);
+ }
}
-------------------------------- 8< --------------------------------
Sincerely Yours,
Ranjit.
--
Ranjit Mathew Email: rmathew AT hotmail DOT com
Bangalore,
INDIA. Web: http://ranjitmathew.tripod.com/