// static
JSBool XPCJSRuntime::GCCallback(JSContext *cx, JSGCStatus status)
{
nsVoidArray* dyingWrappedJSArray;
XPCJSRuntime* self = nsXPConnect::GetRuntime();
if(self)
{
switch(status)
{
case JSGC_BEGIN:
{
if(!NS_IsMainThread())
{
return JS_FALSE;
}
break;
}
case JSGC_MARK_END:
{
NS_ASSERTION(!self->mDoingFinalization, "bad state");
// mThreadRunningGC indicates that GC is running
{ // scoped lock
XPCAutoLock lock(self->GetMapLock());
NS_ASSERTION(!self->mThreadRunningGC, "bad state");
self->mThreadRunningGC = PR_GetCurrentThread();
}
dyingWrappedJSArray = &self->mWrappedJSToReleaseArray;
{
JSDyingJSObjectData data = {cx, dyingWrappedJSArray};
// Add any wrappers whose JSObjects are to be finalized to
// this array. Note that this is a nsVoidArray because
// we do not want to be changing the refcount of these wrappers.
// We add them to the array now and Release the array members
// later to avoid the posibility of doing any JS GCThing
// allocations during the gc cycle.
self->mWrappedJSMap->
Enumerate(WrappedJSDyingJSObjectFinder, &data);
}
// Do cleanup in NativeInterfaces. This part just finds
// member cloned function objects that are about to be
// collected. It does not deal with collection of interfaces or
// sets at this point.
CX_AND_XPCRT_Data data = {cx, self};
self->mIID2NativeInterfaceMap->
Enumerate(NativeInterfaceGC, &data);
// Find dying scopes...
XPCWrappedNativeScope::FinishedMarkPhaseOfGC(cx, self);
self->mDoingFinalization = JS_TRUE;
break;
}
case JSGC_FINALIZE_END:
{
NS_ASSERTION(self->mDoingFinalization, "bad state");
self->mDoingFinalization = JS_FALSE;
// Release all the members whose JSObjects are now known
// to be dead.
dyingWrappedJSArray = &self->mWrappedJSToReleaseArray;
while(1)
{
nsXPCWrappedJS* wrapper;
PRInt32 count = dyingWrappedJSArray->Count();
if(!count)
{
dyingWrappedJSArray->Compact();
break;
}
wrapper = static_cast<nsXPCWrappedJS*>
(dyingWrappedJSArray->ElementAt(count-1));
dyingWrappedJSArray->RemoveElementAt(count-1);
NS_RELEASE(wrapper);
}
#ifdef XPC_REPORT_NATIVE_INTERFACE_AND_SET_FLUSHING
printf("--------------------------------------------------------------\n");
int setsBefore = (int) self->mNativeSetMap->Count();
int ifacesBefore = (int) self->mIID2NativeInterfaceMap->Count();
#endif
// We use this occasion to mark and sweep NativeInterfaces,
// NativeSets, and the WrappedNativeJSClasses...
// Do the marking...
XPCWrappedNativeScope::MarkAllWrappedNativesAndProtos();
self->mDetachedWrappedNativeProtoMap->
Enumerate(DetachedWrappedNativeProtoMarker, nsnull);
// Mark the sets used in the call contexts. There is a small
// chance that a wrapper's set will change *while* a call is
// happening which uses that wrapper's old interfface set. So,
// we need to do this marking to avoid collecting those sets
// that might no longer be otherwise reachable from the wrappers
// or the wrapperprotos.
// Skip this part if XPConnect is shutting down. We get into
// bad locking problems with the thread iteration otherwise.
if(!self->GetXPConnect()->IsShuttingDown())
{
PRLock* threadLock = XPCPerThreadData::GetLock();
if(threadLock)
{ // scoped lock
nsAutoLock lock(threadLock);
XPCPerThreadData* iterp = nsnull;
XPCPerThreadData* thread;
while(nsnull != (thread =
XPCPerThreadData::IterateThreads(&iterp)))
{
// Mark those AutoMarkingPtr lists!
thread->MarkAutoRootsAfterJSFinalize();
XPCCallContext* ccxp = thread->GetCallContext();
while(ccxp)
{
// Deal with the strictness of callcontext that
// complains if you ask for a set when
// it is in a state where the set could not
// possibly be valid.
if(ccxp->CanGetSet())
{
XPCNativeSet* set = ccxp->GetSet();
if(set)
set->Mark();
}
if(ccxp->CanGetInterface())
{
XPCNativeInterface* iface = ccxp->GetInterface();
if(iface)
iface->Mark();
}
ccxp = ccxp->GetPrevCallContext();
}
}
}
}
// Do the sweeping...
// We don't want to sweep the JSClasses at shutdown time.
// At this point there may be JSObjects using them that have
// been removed from the other maps.
if(!self->GetXPConnect()->IsShuttingDown())
{
self->mNativeScriptableSharedMap->
Enumerate(JSClassSweeper, nsnull);
}
self->mClassInfo2NativeSetMap->
Enumerate(NativeUnMarkedSetRemover, nsnull);
self->mNativeSetMap->
Enumerate(NativeSetSweeper, nsnull);
CX_AND_XPCRT_Data data = {cx, self};
self->mIID2NativeInterfaceMap->
Enumerate(NativeInterfaceSweeper, &data);
#ifdef DEBUG
XPCWrappedNativeScope::ASSERT_NoInterfaceSetsAreMarked();
#endif
#ifdef XPC_REPORT_NATIVE_INTERFACE_AND_SET_FLUSHING
int setsAfter = (int) self->mNativeSetMap->Count();
int ifacesAfter = (int) self->mIID2NativeInterfaceMap->Count();
printf("\n");
printf("XPCNativeSets: before: %d collected: %d remaining: %d\n",
setsBefore, setsBefore - setsAfter, setsAfter);
printf("XPCNativeInterfaces: before: %d collected: %d remaining: %d\n",
ifacesBefore, ifacesBefore - ifacesAfter, ifacesAfter);
printf("--------------------------------------------------------------\n");
#endif
// Sweep scopes needing cleanup
XPCWrappedNativeScope::FinishedFinalizationPhaseOfGC(cx);
// Now we are going to recycle any unused WrappedNativeTearoffs.
// We do this by iterating all the live callcontexts (on all
// threads!) and marking the tearoffs in use. And then we
// iterate over all the WrappedNative wrappers and sweep their
// tearoffs.
//
// This allows us to perhaps minimize the growth of the
// tearoffs. And also makes us not hold references to interfaces
// on our wrapped natives that we are not actually using.
//
// XXX We may decide to not do this on *every* gc cycle.
// Skip this part if XPConnect is shutting down. We get into
// bad locking problems with the thread iteration otherwise.
if(!self->GetXPConnect()->IsShuttingDown())
{
PRLock* threadLock = XPCPerThreadData::GetLock();
if(threadLock)
{
// Do the marking...
{ // scoped lock
nsAutoLock lock(threadLock);
XPCPerThreadData* iterp = nsnull;
XPCPerThreadData* thread;
while(nsnull != (thread =
XPCPerThreadData::IterateThreads(&iterp)))
{
XPCCallContext* ccxp = thread->GetCallContext();
while(ccxp)
{
// Deal with the strictness of callcontext that
// complains if you ask for a tearoff when
// it is in a state where the tearoff could not
// possibly be valid.
if(ccxp->CanGetTearOff())
{
XPCWrappedNativeTearOff* to =
ccxp->GetTearOff();
if(to)
to->Mark();
}
ccxp = ccxp->GetPrevCallContext();
}
}
}
// Do the sweeping...
XPCWrappedNativeScope::SweepAllWrappedNativeTearOffs();
}
}
// Now we need to kill the 'Dying' XPCWrappedNativeProtos.
// We transfered these native objects to this table when their
// JSObject's were finalized. We did not destroy them immediately
// at that point because the ordering of JS finalization is not
// deterministic and we did not yet know if any wrappers that
// might still be referencing the protos where still yet to be
// finalized and destroyed. We *do* know that the protos'
// JSObjects would not have been finalized if there were any
// wrappers that referenced the proto but where not themselves
// slated for finalization in this gc cycle. So... at this point
// we know that any and all wrappers that might have been
// referencing the protos in the dying list are themselves dead.
// So, we can safely delete all the protos in the list.
self->mDyingWrappedNativeProtoMap->
Enumerate(DyingProtoKiller, nsnull);
// mThreadRunningGC indicates that GC is running.
// Clear it and notify waiters.
{ // scoped lock
XPCAutoLock lock(self->GetMapLock());
NS_ASSERTION(self->mThreadRunningGC == PR_GetCurrentThread(), "bad state");
self->mThreadRunningGC = nsnull;
xpc_NotifyAll(self->GetMapLock());
}
break;
}
case JSGC_END:
{
// NOTE that this event happens outside of the gc lock in
// the js engine. So this could be simultaneous with the
// events above.
// Do any deferred released of native objects.
nsVoidArray* array = &self->mNativesToReleaseArray;
#ifdef XPC_TRACK_DEFERRED_RELEASES
printf("XPC - Begin deferred Release of %d nsISupports pointers\n",
array->Count());
#endif
while(1)
{
nsISupports* obj;
{
PRInt32 count = array->Count();
if(!count)
{
array->Compact();
break;
}
obj = reinterpret_cast<nsISupports*>
(array->ElementAt(count-1));
array->RemoveElementAt(count-1);
}
NS_RELEASE(obj);
}
#ifdef XPC_TRACK_DEFERRED_RELEASES
printf("XPC - End deferred Releases\n");
#endif
break;
}
default:
break;
}
}
// always chain to old GCCallback if non-null.
return gOldJSGCCallback ? gOldJSGCCallback(cx, status) : JS_TRUE;
}
