Assert that the incoming thread and monitor objects are not NULL. The

old implementation allowed monitors to be NULL when they were unlocked
and otherwise unowned.  With the new lock word format, a NULL monitor
object can only mean that an invariant has been lost.  Also, nix some
trailing whitespace that crept into a comment.

diff --git a/vm/Sync.c b/vm/Sync.c
index 5f9c2fa..5505166 100644 (file)
--- a/vm/Sync.c
+++ b/vm/Sync.c
@@ -108,7 +108,7 @@ static void expandObjClear(ExpandingObjectList* pList);
  *
  * The LSB of the lock value encodes its state.  If cleared, the lock
  * is in the "thin" state and its bits are formatted as follows:
- * 
+ *
  *    [31 ---- 19] [18 ---- 3] [2 ---- 1] [0]
  *     lock count   thread id  hash state  0
  *
@@ -470,8 +470,11 @@ static void waitMonitor(Thread* self, Monitor* mon, s8 msec, s4 nsec,
     bool timed;
     int cc;
 
+    assert(self != NULL);
+    assert(mon != NULL);
+
     /* Make sure that we hold the lock. */
-    if (mon == NULL || mon->owner != self) {
+    if (mon->owner != self) {
         dvmThrowException("Ljava/lang/IllegalMonitorStateException;",
             "object not locked by thread before wait()");
         return;
@@ -676,8 +679,11 @@ done:
  */
 static void notifyMonitor(Thread* self, Monitor* mon)
 {
+    assert(self != NULL);
+    assert(mon != NULL);
+
     /* Make sure that we hold the lock. */
-    if (mon == NULL || mon->owner != self) {
+    if (mon->owner != self) {
         dvmThrowException("Ljava/lang/IllegalMonitorStateException;",
             "object not locked by thread before notify()");
         return;
@@ -710,8 +716,11 @@ static void notifyMonitor(Thread* self, Monitor* mon)
  */
 static void notifyAllMonitor(Thread* self, Monitor* mon)
 {
+    assert(self != NULL);
+    assert(mon != NULL);
+
     /* Make sure that we hold the lock. */
-    if (mon == NULL || mon->owner != self) {
+    if (mon->owner != self) {
         dvmThrowException("Ljava/lang/IllegalMonitorStateException;",
             "object not locked by thread before notifyAll()");
         return;