[kaffe] CVS kaffe (guilhem): Important fix for the locking subsystem.

[Kaffe CVS]

PatchSet 7149 
Date: 2006/03/11 11:09:46
Author: guilhem
Branch: HEAD
Tag: (none) 
Log:
Important fix for the locking subsystem.

        * kaffe/kaffevm/thread.c
        (startThread, startSpecialThread, createDaemon, firstStartThread):
        Secured KSEM(get) calls against interruption.

        * kaffe/kaffevm/locks.c
        (getHeavyLock): Optimized the number of increments/decrements.
        (slowLockMutex): Secure the call to KSEM(get) against
        interruption.

Members: 
	ChangeLog:1.4667->1.4668 
	kaffe/kaffevm/locks.c:1.69->1.70 
	kaffe/kaffevm/thread.c:1.107->1.108 

Index: kaffe/ChangeLog
diff -u kaffe/ChangeLog:1.4667 kaffe/ChangeLog:1.4668
--- kaffe/ChangeLog:1.4667	Thu Mar  9 02:14:03 2006
+++ kaffe/ChangeLog	Sat Mar 11 11:09:46 2006
@@ -1,3 +1,14 @@
+2006-03-11  Guilhem Lavaux  <guilhem at kaffe.org>
+
+	* kaffe/kaffevm/thread.c
+	(startThread, startSpecialThread, createDaemon, firstStartThread):
+	Secured KSEM(get) calls against interruption.
+
+	* kaffe/kaffevm/locks.c
+	(getHeavyLock): Optimized the number of increments/decrements.
+	(slowLockMutex): Secure the call to KSEM(get) against
+	interruption.
+	
 2006-03-09  Dalibor Topic  <robilad at kaffe.org>
 
 	* kaffe/kaffevm/thread.c (linkNativeAndJavaThread),
Index: kaffe/kaffe/kaffevm/locks.c
diff -u kaffe/kaffe/kaffevm/locks.c:1.69 kaffe/kaffe/kaffevm/locks.c:1.70
--- kaffe/kaffe/kaffevm/locks.c:1.69	Wed Dec 28 19:05:54 2005
+++ kaffe/kaffe/kaffevm/locks.c	Sat Mar 11 11:09:51 2006
@@ -153,13 +153,12 @@
   lk = GET_HEAVYLOCK(lk);
   
   /* The lock is allocated and ready to use. */
+  atomic_increment(&(lk->num_wait));
   for (;;) {
     /* Try to acquire the lock. We try to do an "atomic" incrementation. */
-    atomic_increment(&(lk->num_wait));
     if (!COMPARE_AND_EXCHANGE(&(lk->in_progress), 0, 1))
       {
 	KSEM(get)(&lk->sem, (jlong)0);
-        atomic_decrement(&(lk->num_wait));
 	continue;
       }
     lk->hlockHolder = KTHREAD(current)();
@@ -219,6 +218,7 @@
   volatile iLock* lk;
   jthread_t cur = KTHREAD(current) ();
   threadData *tdata;
+  int r;
 
 DBG(SLOWLOCKS,
     dprintf("slowLockMutex(lk=%p, th=%p)\n",
@@ -256,8 +256,15 @@
    /* Otherwise wait for holder to release it */
    tdata->nextlk = lk->mux;
    lk->mux = cur;
+
    putHeavyLock(lk);
-   KSEM(get)(&tdata->sem, (jlong)0);
+   /* KSEM(get) cannot have a timeout because it is infinite.
+    * However, it can be interrupted and we do not want that for
+    * locking.
+    */
+   do {
+     r = KSEM(get)(&tdata->sem, (jlong)0);
+   } while (!r);
  }
 }
 
@@ -342,7 +349,7 @@
       !COMPARE_AND_EXCHANGE(lkp, (iLock*)cur, LOCKFREE))
     return;
 
-  /* ok, it is a heavy lock and it is acquire by someone. */
+  /* ok, it is a heavy lock and it is acquired by someone. */
   lk = getHeavyLock((volatile iLock *volatile *)lkp, heavyLock);
   holder = lk->holder;
   putHeavyLock(lk);
Index: kaffe/kaffe/kaffevm/thread.c
diff -u kaffe/kaffe/kaffevm/thread.c:1.107 kaffe/kaffe/kaffevm/thread.c:1.108
--- kaffe/kaffe/kaffevm/thread.c:1.107	Thu Mar  9 02:14:07 2006
+++ kaffe/kaffe/kaffevm/thread.c	Sat Mar 11 11:09:51 2006
@@ -170,6 +170,7 @@
 {
 	jthread_t nativeTid;
 	struct _errorInfo info;
+	int r;
 
 DBG(VMTHREAD, dprintf ("%p starting thread %p (vmthread %p)\n\n", KTHREAD(current)(), unhand(tid)->thread, tid); );
 
@@ -184,7 +185,9 @@
 	if (nativeTid == NULL) {
 		throwError(&info);
 	}
-	KSEM(get)(&THREAD_DATA()->sem, (jlong)0);
+	do {
+	  r = KSEM(get)(&THREAD_DATA()->sem, (jlong)0);
+	} while (!r);
 
 	linkNativeAndJavaThread (nativeTid, tid);
 
@@ -323,6 +326,7 @@
 	void *argument;
 	jthread_t calling_thread;
 	threadData *thread_data = THREAD_DATA();
+	int r;
 
 	KSEM(init)(&thread_data->sem);
 
@@ -338,7 +342,9 @@
 	/* We have now to wait the parent to synchronize the data
 	 * and link the thread to the Java VM.
 	 */
-	KSEM(get)(&thread_data->sem, (jlong)0);
+	do {
+	  r = KSEM(get)(&thread_data->sem, (jlong)0);
+	} while (!r);
 
 	thread_data->exceptObj = NULL;
 
@@ -364,6 +370,7 @@
   Hjava_lang_String* name;
   void *specialArgument[3];
   jvalue retval;
+  int r;
 
 DBG(VMTHREAD,	dprintf("createDaemon %s\n", nm);	);
   
@@ -408,7 +415,9 @@
   KTHREAD(get_data)(nativeTid)->exceptPtr = NULL;
   KTHREAD(get_data)(nativeTid)->exceptObj = NULL;
 
-  KSEM(get)(&THREAD_DATA()->sem, (jlong)0);
+  do {
+    r = KSEM(get)(&THREAD_DATA()->sem, (jlong)0);
+  } while (!r);
   
   linkNativeAndJavaThread (nativeTid, vmtid);
 
@@ -430,6 +439,8 @@
 	jmethodID runmethod;
 	jthread_t calling_thread = (jthread_t) arg;
 	threadData *thread_data;
+	int r;
+
 
 	cur = KTHREAD(current)();
 	thread_data = KTHREAD(get_data)(cur);
@@ -439,7 +450,9 @@
 	/* We acknowledge the parent thread that this thread has been started. */
 	KSEM(put)(&KTHREAD(get_data)(calling_thread)->sem);
 	/* Now we must wait the parent to link the thread to the Java VM. */
-	KSEM(get)(&thread_data->sem, (jlong)0);
+	do {
+	  r = KSEM(get)(&thread_data->sem, (jlong)0);
+	} while (!r);
  
 	tid = (Hjava_lang_VMThread *)(thread_data->jlThread);
 	env = &thread_data->jniEnv;