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Performance:Leak Tools: Difference between revisions
→Debugging leaks that go through XPConnect
(→Debugging leaks that go through XPConnect: another bug number) |
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One of the most common ways one could leak a JS root is by leaking an nsXPCWrappedJS object. This is the wrapper object in the reverse direction -- when a JS object is used to implement an XPCOM interface and be used transparently by native code. The nsXPCWrappedJS object creates a GC root that exists as long as the wrapper does. The wrapper itself is just a normal reference-counted object, so a leaked nsXPCWrappedJS can be debugged using the normal refcount-balancer tools. | One of the most common ways one could leak a JS root is by leaking an nsXPCWrappedJS object. This is the wrapper object in the reverse direction -- when a JS object is used to implement an XPCOM interface and be used transparently by native code. The nsXPCWrappedJS object creates a GC root that exists as long as the wrapper does. The wrapper itself is just a normal reference-counted object, so a leaked nsXPCWrappedJS can be debugged using the normal refcount-balancer tools. | ||
If you really need to debug leaks that involve JS objects closely, you can get detailed printouts of the paths JS uses to mark objects when it is determining the set of live objects by using the functions added in {{bug|378261}} and {{bug|378255}}. (More documentation of this replacement for GC_MARK_DEBUG, the old way of doing it, would be useful.) | If you really need to debug leaks that involve JS objects closely, you can get detailed printouts of the paths JS uses to mark objects when it is determining the set of live objects by using the functions added in {{bug|378261}} and {{bug|378255}}. (More documentation of this replacement for GC_MARK_DEBUG, the old way of doing it, would be useful. It may just involve setting the XPC_SHUTDOWN_HEAP_DUMP environment variable to a file name, but I haven't tested that.) | ||
= Leak statistics on tinderbox = | = Leak statistics on tinderbox = | ||