RR(XXS) 8023478: Test fails with HS crash in GCNotifier.

[Kevin Walls]

Hi,

If I have my CHECK and THREAD thinking straight, I have a small review 
request in gcNotifier, to avoid a crash that came up in testing recently.

The report is a hotspot crash in a test, where there's an exception 
pending when calling java_lang_String::create_from_str, which allocates.

We are in GCNotifier::sendNotificationInternal  and before the call that 
crashes, we called createGcInfo which have several allocations can 
return a null handle if an exception occurs.

If we have returned from createGcInfo, which returns null for an exception,
we need to return rather than continue in sendNotificationInternal, 
which will try to allocate again.

sendNotificationInternal has a caller that clears any exception.

So that should be a very small change:

$ hg diff src/share/vm/services/gcNotifier.cpp
diff --git a/src/share/vm/services/gcNotifier.cpp 
b/src/share/vm/services/gcNotifier.cpp
--- a/src/share/vm/services/gcNotifier.cpp
+++ b/src/share/vm/services/gcNotifier.cpp
@@ -209,7 +209,7 @@
    GCNotificationRequest *request = getRequest();
    if (request != NULL) {
      NotificationMark nm(request);
-    Handle objGcInfo = createGcInfo(request->gcManager, 
request->gcStatInfo, THREAD);
+    Handle objGcInfo = createGcInfo(request->gcManager, 
request->gcStatInfo, CHECK);

      Handle objName = 
java_lang_String::create_from_str(request->gcManager->name(), CHECK);
      Handle objAction = 
java_lang_String::create_from_str(request->gcAction, CHECK);
kwalls at klaptop:~/work/bugs/8023478.gcbean/hotspot-rt$



http://bugs.sun.com/view_bug.do?bug_id=8023478
http://cr.openjdk.java.net/~kevinw/8023478/webrev.00/ (the above one line)


Thanks
Kevin
--------
PS
As the bug is not available on the bugs site at the moment, this is part 
of the crashing stack to give some context:

V [libjvm.so+0x7069d0] void report_vm_error(const char*,int,const 
char*,const char*)+0x78;; __1cPreport_vm_error6Fpkci11_v_+0x78
V [libjvm.so+0x63125c] void 
CollectedHeap::check_for_valid_allocation_state()+0x4c;; 
__1cNCollectedHeapbGcheck_for_valid_allocation_state6F_v_+0x4c
V [libjvm.so+0x911f68] instanceOop 
InstanceKlass::allocate_instance(Thread*)+0x78;; 
__1cNInstanceKlassRallocate_instance6MpnGThread__nLinstanceOop__+0x78
V [libjvm.so+0x9ffd7c] Handle 
java_lang_String::basic_create(int,Thread*)+0x174;; 
__1cQjava_lang_StringMbasic_create6FipnGThread__nGHandle__+0x174
V [libjvm.so+0xa00520] Handle java_lang_String::create_from_str(const 
char*,Thread*)+0x40;; 
__1cQjava_lang_StringPcreate_from_str6FpkcpnGThread__nGHandle__+0x40
V [libjvm.so+0x83eb0c] void 
GCNotifier::sendNotificationInternal(Thread*)+0x8c;; 
__1cKGCNotifierYsendNotificationInternal6FpnGThread__v_+0x8c
V [libjvm.so+0x83ea4c] void GCNotifier::sendNotification(Thread*)+0xc;; 
__1cKGCNotifierQsendNotification6FpnGThread__v_+0xc
V [libjvm.so+0x103faf8] void 
ServiceThread::service_thread_entry(JavaThread*,Thread*)+0x4a0;; 
__1cNServiceThreadUservice_thread_entry6FpnKJavaThread_pnGThread__v_+0x4a0