Created attachment 575350 [details] browser testcase (requires extension) To reproduce in a debug browser build: 1. Install https://www.squarefree.com/extensions/domFuzzLite3.xpi 2. XPCOM_MEM_LEAK_LOG=2 ./firefox v.html --> trace-refcnt reports that nsGlobalWindow and more leak To reproduce in the shell using valgrind: 1. Build a spidermonkey shell: a. Create a new directory b. js/src/configure --enable-debug --disable-optimize --enable-valgrind c. make 2. valgrind --leak-check=full --dsymutil=yes ./js -e "gczeal(4); gczeal(0);" --> valgrind reports a significant leak rooted in js::gc::StartVerifyBarriers
Created attachment 575351 [details] shell valgrind output
It worries me that turning on GC debugging makes the GC stop working ;)
Created attachment 608552 [details] [diff] [review] fix I remember fixing the shell problem a while ago, although I can't find the bug. It no longer reproduces. The problem in the browser case was that, even though we set the gczeal back to 0, we were still calling Start/EndVerifyBarriers repeatedly. I had thought that the verifier would stop at the next GC. However, if a GC happens during a verification, it starts a new one after the GC is done. The current patch adds a few places where we EndVerifyBarriers if the zeal is 0. I considered just calling EndVerifyBarriers from SetGCZeal, but I'd rather have this happen from places where we already know that GC is safe. Also, I made sure not to start a verification if we do a CC_FORCED GC, since it relies on the mark bits being correct afterwards.
Comment on attachment 608552 [details] [diff] [review] fix Review of attachment 608552 [details] [diff] [review]: ----------------------------------------------------------------- ::: js/src/jsgc.cpp @@ +3693,5 @@ > } > + ~AutoVerifyBarriers() { > + if (inVerify && reason != gcreason::CC_FORCED && > + cx->runtime->gcZeal() == ZealVerifierValue) > + { There is no reason to store inVerify and reason as they stay the same. Instead store the result of inVerify && reason != gcreason::CC_FORCED in a flag. Also comment here why it is necessary to protect StartVerifyBarriers(cx) with the extra checks.
https://hg.mozilla.org/integration/mozilla-inbound/rev/ca74029146c2
https://hg.mozilla.org/mozilla-central/rev/ca74029146c2
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