Bug 149095 – jsc-layout-tests.yaml/js/script-tests/dfg-dead-variable-on-exit.js.layout-ftl occasionally times out in debug

• Component: JavaScriptCore
• Status: NEW

[Filip Pizlo]

It looks like this:

jsc-layout-tests.yaml/js/script-tests/dfg-dead-variable-on-exit.js.layout-ftl: This tests that if a variable is dead on OSR exit, it will at least contain a valid JS value.
jsc-layout-tests.yaml/js/script-tests/dfg-dead-variable-on-exit.js.layout-ftl: 
jsc-layout-tests.yaml/js/script-tests/dfg-dead-variable-on-exit.js.layout-ftl: On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
jsc-layout-tests.yaml/js/script-tests/dfg-dead-variable-on-exit.js.layout-ftl: 
jsc-layout-tests.yaml/js/script-tests/dfg-dead-variable-on-exit.js.layout-ftl: 
jsc-layout-tests.yaml/js/script-tests/dfg-dead-variable-on-exit.js.layout-ftl: Timed out after 339.000000 seconds!
jsc-layout-tests.yaml/js/script-tests/dfg-dead-variable-on-exit.js.layout-ftl: 1   0x1065d7e40 WTFCrash
jsc-layout-tests.yaml/js/script-tests/dfg-dead-variable-on-exit.js.layout-ftl: 2   0x105a1b1ce timeoutThreadMain(void*)
jsc-layout-tests.yaml/js/script-tests/dfg-dead-variable-on-exit.js.layout-ftl: 3   0x106640a79 WTF::createThread(void (*)(void*), void*, char const*)::$_0::operator()() const
jsc-layout-tests.yaml/js/script-tests/dfg-dead-variable-on-exit.js.layout-ftl: 4   0x106640a4c std::__1::__function::__func<WTF::createThread(void (*)(void*), void*, char const*)::$_0, std::__1::allocator<WTF::createThread(void (*)(void*), void*, char const*)::$_0>, void ()>::operator()()
jsc-layout-tests.yaml/js/script-tests/dfg-dead-variable-on-exit.js.layout-ftl: 5   0x1060a307a std::__1::function<void ()>::operator()() const
jsc-layout-tests.yaml/js/script-tests/dfg-dead-variable-on-exit.js.layout-ftl: 6   0x10663f89e WTF::threadEntryPoint(void*)
jsc-layout-tests.yaml/js/script-tests/dfg-dead-variable-on-exit.js.layout-ftl: 7   0x106641011 WTF::wtfThreadEntryPoint(void*)
jsc-layout-tests.yaml/js/script-tests/dfg-dead-variable-on-exit.js.layout-ftl: 8   0x7fff86dee05a _pthread_body
jsc-layout-tests.yaml/js/script-tests/dfg-dead-variable-on-exit.js.layout-ftl: 9   0x7fff86dedfd7 _pthread_body
jsc-layout-tests.yaml/js/script-tests/dfg-dead-variable-on-exit.js.layout-ftl: 10  0x7fff86deb3ed thread_start
jsc-layout-tests.yaml/js/script-tests/dfg-dead-variable-on-exit.js.layout-ftl: test_script_22195: line 2: 49168 Segmentation fault: 11  "$@" ../../../../.vm/JavaScriptCore.framework/Resources/jsc --useFTLJIT\=false --enableFunctionDotArguments\=true --testTheFTL\=true --useFTLJIT\=true --ftlCrashesIfCantInitializeLLVM\=true resources/standalone-pre.js dfg-dead-variable-on-exit.js resources/standalone-post.js
jsc-layout-tests.yaml/js/script-tests/dfg-dead-variable-on-exit.js.layout-ftl: ERROR: Unexpected exit code: 139
FAIL: jsc-layout-tests.yaml/js/script-tests/dfg-dead-variable-on-exit.js.layout-ftl

[Alexey Proskuryakov]

This is still happening.

[Radar WebKit Bug Importer]

<rdar://problem/22904432>

[Csaba Osztrogonác]

*** Bug 149744 has been marked as a duplicate of this bug. ***

[Csaba Osztrogonác]

I checked the bot history, and we noticed this failure first time on r189621:
https://build.webkit.org/builders/Apple%20Yosemite%20Debug%20JSC%20%28Tests%29/builds/3192

relevant JSC changes before this change:
- https://trac.webkit.org/changeset/189620
- https://trac.webkit.org/changeset/189616
- https://trac.webkit.org/changeset/189596
- https://trac.webkit.org/changeset/189586