193569 2019-01-18 05:41:36 -0800 [GLIB] Remote Inspector: no data displayed 2019-02-05 08:03:35 -0800 1 1 1 Unclassified WebKit WebKitGTK WebKit Nightly Build PC Linux RESOLVED FIXED P2 Normal --- 1 s.ungureanu webkit-unassigned bburg bugs-noreply cgarcia ews-watchlist hi joepeck keith_miller mark.lam mcatanzaro msaboff saam t.bernard webkit-bug-importer oldest_to_newest 1495807 0 s.ungureanu 2019-01-18 05:41:36 -0800 Overview: After the 2.23.2(and 2.23.3) webkit gtk releases, remote inspector is not working anymore. The remote inspector attaches to a debugged minibrowser but doesn't display any data in any of the remote inspector's tabs. Moreover, the debugged minibrowser hangs even after the debugging session is ended. Reproduction steps: 1. Run MiniBrowser and load a web page. 2. Attach the remote inspector in order to debug the minibrowser session. Expected result: Remote debugger attaches to the running minibrowser and retrieves inspector data. Actual result: No data is displayed in any of the tabs. The minibrowser session hangs after remote debugging is closed. Build date and hardware: Built on 17th January 2019, using webkitgtk 2.23.2 and 2.23.3 on Ubuntu 18.04.1 TLS Build parameters: cmake -DPORT=GTK -DENABLE_OPENGL=ON -DENABLE_GLES2=ON -DENABLE_MINIBROWSER=ON -DCMAKE_BUILD_TYPE=Release -DENABLE_WEBGL=ON -DENABLE_ENCRYPTED_MEDIA=ON -DENABLE_MEDIA_SOURCE=ON -GNinja .. Run command: WEBKIT_INSPECTOR_SERVER=0.0.0.0:12345 ./bin/MiniBrowser 1495818 1 cgarcia 2019-01-18 06:36:41 -0800 This is because the target is in a deadlock in the main thread: Thread 1 (Thread 0x7fa2e998e9c0 (LWP 32133)): #0 futex_wait_cancelable (private=0, expected=0, futex_word=0x7fa2e81fb964) at ../sysdeps/unix/sysv/linux/futex-internal.h:88 #1 __pthread_cond_wait_common (abstime=0x0, mutex=0x7fa2e81fb910, cond=0x7fa2e81fb938) at pthread_cond_wait.c:502 #2 __pthread_cond_wait (cond=0x7fa2e81fb938, mutex=0x7fa2e81fb910) at pthread_cond_wait.c:655 #3 0x00007fa2f145326b in WTF::ThreadCondition::timedWait(WTF::Mutex&, WTF::WallTime) () from /home/cgarcia/src/git/gnome/WebKit/WebKitBuild/Release/lib/libjavascriptcoregtk-4.0.so.18 #4 0x00007fa2f13f145b in WTF::ParkingLot::parkConditionallyImpl(void const*, WTF::ScopedLambda<bool ()> const&, WTF::ScopedLambda<void ()> const&, WTF::TimeWithDynamicClockType const&) () from /home/cgarcia/src/git/gnome/WebKit/WebKitBuild/Release/lib/libjavascriptcoregtk-4.0.so.18 #5 0x00007fa2f13e5aae in WTF::LockAlgorithm<unsigned char, (unsigned char)1, (unsigned char)2, WTF::EmptyLockHooks<unsigned char> >::lockSlow(WTF::Atomic<unsigned char>&) () from /home/cgarcia/src/git/gnome/WebKit/WebKitBuild/Release/lib/libjavascriptcoregtk-4.0.so.18 #6 0x00007fa2f0ecb3aa in Inspector::RemoteInspector::sendMessageToRemote(unsigned int, WTF::String const&) () from /home/cgarcia/src/git/gnome/WebKit/WebKitBuild/Release/lib/libjavascriptcoregtk-4.0.so.18 #7 0x00007fa2f0e5cd10 in Inspector::FrontendRouter::sendEvent(WTF::String const&) const () from /home/cgarcia/src/git/gnome/WebKit/WebKitBuild/Release/lib/libjavascriptcoregtk-4.0.so.18 #8 0x00007fa2f0e83f91 in Inspector::TargetFrontendDispatcher::targetCreated(WTF::RefPtr<Inspector::Protocol::Target::TargetInfo, WTF::DumbPtrTraits<Inspector::Protocol::Target::TargetInfo> >) () from /home/cgarcia/src/git/gnome/WebKit/WebKitBuild/Release/lib/libjavascriptcoregtk-4.0.so.18 #9 0x00007fa2f0ebe158 in Inspector::InspectorTargetAgent::connectToTargets() () from /home/cgarcia/src/git/gnome/WebKit/WebKitBuild/Release/lib/libjavascriptcoregtk-4.0.so.18 --Type <RET> for more, q to quit, c to continue without paging-- #10 0x00007fa2f0e5c323 in Inspector::AgentRegistry::didCreateFrontendAndBackend(Inspector::FrontendRouter*, Inspector::BackendDispatcher*) () from /home/cgarcia/src/git/gnome/WebKit/WebKitBuild/Release/lib/libjavascriptcoregtk-4.0.so.18 #11 0x00007fa2f4678f51 in WebKit::WebPageInspectorController::connectFrontend(Inspector::FrontendChannel&, bool, bool) () from /home/cgarcia/src/git/gnome/WebKit/WebKitBuild/Release/lib/libwebkit2gtk-4.0.so.37 #12 0x00007fa2f0ece081 in Inspector::RemoteConnectionToTarget::setup(bool, bool) () from /home/cgarcia/src/git/gnome/WebKit/WebKitBuild/Release/lib/libjavascriptcoregtk-4.0.so.18 #13 0x00007fa2f0ece25c in Inspector::RemoteInspector::setup(unsigned int) () from /home/cgarcia/src/git/gnome/WebKit/WebKitBuild/Release/lib/libjavascriptcoregtk-4.0.so.18 #14 0x00007fa2f0ece2dd in Inspector::RemoteInspector::receivedSetupMessage(unsigned int) () from /home/cgarcia/src/git/gnome/WebKit/WebKitBuild/Release/lib/libjavascriptcoregtk-4.0.so.18 #15 0x00007fa2f0ece385 in Inspector::RemoteInspector::{lambda(_GDBusConnection*, char const*, char const*, char const*, char const*, _GVariant*, _GDBusMethodInvocation*, void*)#1}::_FUN(_GDBusConnection*, char const*, char const*, char const*, char const*, _GVariant*, _GDBusMethodInvocation*, void*) () from /home/cgarcia/src/git/gnome/WebKit/WebKitBuild/Release/lib/libjavascriptcoregtk-4.0.so.18 #16 0x00007fa2f2078fe9 in call_in_idle_cb (user_data=<optimized out>) at ../gio/gdbusconnection.c:4847 #17 0x00007fa2f1e63588 in g_main_dispatch (context=0x55f1f3a5b150) at ../glib/gmain.c:3190 #18 g_main_context_dispatch (context=context@entry=0x55f1f3a5b150) at ../glib/gmain.c:3855 #19 0x00007fa2f1e63948 in g_main_context_iterate (context=0x55f1f3a5b150, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../glib/gmain.c:3928 #20 0x00007fa2f1e63c32 in g_main_loop_run (loop=0x55f1f40fd470) at ../glib/gmain.c:4124 #21 0x00007fa2f267f155 in gtk_main () at gtkmain.c:1323 #22 0x000055f1f1acf914 in main () See: #12 0x00007fa2f0ece081 in Inspector::RemoteConnectionToTarget::setup(bool, bool) () Here we take the remote inspector mutex that is still locked when: #6 0x00007fa2f0ecb3aa in Inspector::RemoteInspector::sendMessageToRemote(unsigned int, WTF::String const&) () is called. This doesn't happen in cocoa inspector because RemoteConnectionToTarget::setup() calls RemoteInspectionTarget::connect() asynchronously, so the remote inspector mutex is no longer locked. In the GLib case I think we can get rid of the mutex when receiving DBus messages, because they are dispatched to the main thread by GDBus. 1496558 2 359682 cgarcia 2019-01-21 02:56:47 -0800 Created attachment 359682 Patch 1496659 3 359682 mcatanzaro 2019-01-21 14:41:23 -0800 Comment on attachment 359682 Patch r=me. Moving the lock to the smaller scope is safer anyway. 1496660 4 359682 mcatanzaro 2019-01-21 14:42:09 -0800 Comment on attachment 359682 Patch And thanks for this bug report, Serban. We would surely have released 2.24 with this broken had you not reported it. 1497264 5 cgarcia 2019-01-23 02:13:02 -0800 Committed r240330: <https://trac.webkit.org/changeset/240330> 359682 2019-01-21 02:56:47 -0800 2019-01-21 14:42:09 -0800 Patch wk-remote-inspector-deadlock.diff text/plain 2354 cgarcia ZGlmZiAtLWdpdCBhL1NvdXJjZS9KYXZhU2NyaXB0Q29yZS9DaGFuZ2VMb2cgYi9Tb3VyY2UvSmF2 YVNjcmlwdENvcmUvQ2hhbmdlTG9nCmluZGV4IGRiYzdkNDZhZDE4Li43YjRmYzVkM2MxYiAxMDA2 NDQKLS0tIGEvU291cmNlL0phdmFTY3JpcHRDb3JlL0NoYW5nZUxvZworKysgYi9Tb3VyY2UvSmF2 YVNjcmlwdENvcmUvQ2hhbmdlTG9nCkBAIC0xLDMgKzEsMTcgQEAKKzIwMTktMDEtMjEgIENhcmxv cyBHYXJjaWEgQ2FtcG9zICA8Y2dhcmNpYUBpZ2FsaWEuY29tPgorCisgICAgICAgIFtHTElCXSBS ZW1vdGUgSW5zcGVjdG9yOiBubyBkYXRhIGRpc3BsYXllZAorICAgICAgICBodHRwczovL2J1Z3Mu d2Via2l0Lm9yZy9zaG93X2J1Zy5jZ2k/aWQ9MTkzNTY5CisKKyAgICAgICAgUmV2aWV3ZWQgYnkg Tk9CT0RZIChPT1BTISkuCisKKyAgICAgICAgUmVsZWFzZSB0aGUgcmVtb3RlIGluc3BlY3RvciBt dXRleCBiZWZvcmUgdXNpbmcgUmVtb3RlQ29ubmVjdGlvblRvVGFyZ2V0IGluIFJlbW90ZUluc3Bl Y3Rvcjo6c2V0dXAoKSB0byBhdm9pZCBhCisgICAgICAgIGRlYWRsb2NrLgorCisgICAgICAgICog aW5zcGVjdG9yL3JlbW90ZS9nbGliL1JlbW90ZUluc3BlY3RvckdsaWIuY3BwOgorICAgICAgICAo SW5zcGVjdG9yOjpSZW1vdGVJbnNwZWN0b3I6OnJlY2VpdmVkU2V0dXBNZXNzYWdlKToKKyAgICAg ICAgKEluc3BlY3Rvcjo6UmVtb3RlSW5zcGVjdG9yOjpzZXR1cCk6CisKIDIwMTktMDEtMjAgIFNh YW0gQmFyYXRpICA8c2JhcmF0aUBhcHBsZS5jb20+CiAKICAgICAgICAgREZHOiBXaGVuIGlubGlu aW5nIERhdGFWaWV3IHNldCogaW50cmluc2ljcyB3ZSBuZWVkIHRvIHNldCB1bmRlZmluZWQgYXMg b3VyIHJlc3VsdApkaWZmIC0tZ2l0IGEvU291cmNlL0phdmFTY3JpcHRDb3JlL2luc3BlY3Rvci9y ZW1vdGUvZ2xpYi9SZW1vdGVJbnNwZWN0b3JHbGliLmNwcCBiL1NvdXJjZS9KYXZhU2NyaXB0Q29y ZS9pbnNwZWN0b3IvcmVtb3RlL2dsaWIvUmVtb3RlSW5zcGVjdG9yR2xpYi5jcHAKaW5kZXggMWQw MGEzMDQ1MDMuLmI3MzQ1NWE0MGNjIDEwMDY0NAotLS0gYS9Tb3VyY2UvSmF2YVNjcmlwdENvcmUv aW5zcGVjdG9yL3JlbW90ZS9nbGliL1JlbW90ZUluc3BlY3RvckdsaWIuY3BwCisrKyBiL1NvdXJj ZS9KYXZhU2NyaXB0Q29yZS9pbnNwZWN0b3IvcmVtb3RlL2dsaWIvUmVtb3RlSW5zcGVjdG9yR2xp Yi5jcHAKQEAgLTI5Myw3ICsyOTMsNiBAQCB2b2lkIFJlbW90ZUluc3BlY3Rvcjo6cmVjZWl2ZWRH ZXRUYXJnZXRMaXN0TWVzc2FnZSgpCiAKIHZvaWQgUmVtb3RlSW5zcGVjdG9yOjpyZWNlaXZlZFNl dHVwTWVzc2FnZSh1bnNpZ25lZCB0YXJnZXRJZGVudGlmaWVyKQogewotICAgIHN0ZDo6bG9ja19n dWFyZDxMb2NrPiBsb2NrKG1fbXV0ZXgpOwogICAgIHNldHVwKHRhcmdldElkZW50aWZpZXIpOwog fQogCkBAIC0zMjgsOSArMzI3LDEzIEBAIHZvaWQgUmVtb3RlSW5zcGVjdG9yOjpyZWNlaXZlZENs b3NlTWVzc2FnZSh1bnNpZ25lZCB0YXJnZXRJZGVudGlmaWVyKQogCiB2b2lkIFJlbW90ZUluc3Bl Y3Rvcjo6c2V0dXAodW5zaWduZWQgdGFyZ2V0SWRlbnRpZmllcikKIHsKLSAgICBSZW1vdGVDb250 cm9sbGFibGVUYXJnZXQqIHRhcmdldCA9IG1fdGFyZ2V0TWFwLmdldCh0YXJnZXRJZGVudGlmaWVy KTsKLSAgICBpZiAoIXRhcmdldCkKLSAgICAgICAgcmV0dXJuOworICAgIFJlbW90ZUNvbnRyb2xs YWJsZVRhcmdldCogdGFyZ2V0OworICAgIHsKKyAgICAgICAgc3RkOjpsb2NrX2d1YXJkPExvY2s+ IGxvY2sobV9tdXRleCk7CisgICAgICAgIHRhcmdldCA9IG1fdGFyZ2V0TWFwLmdldCh0YXJnZXRJ ZGVudGlmaWVyKTsKKyAgICAgICAgaWYgKCF0YXJnZXQpCisgICAgICAgICAgICByZXR1cm47Cisg ICAgfQogCiAgICAgYXV0byBjb25uZWN0aW9uVG9UYXJnZXQgPSBhZG9wdFJlZigqbmV3IFJlbW90 ZUNvbm5lY3Rpb25Ub1RhcmdldCgqdGFyZ2V0KSk7CiAgICAgQVNTRVJUKGlzPFJlbW90ZUluc3Bl Y3Rpb25UYXJnZXQ+KHRhcmdldCkgfHwgaXM8UmVtb3RlQXV0b21hdGlvblRhcmdldD4odGFyZ2V0 KSk7CkBAIC0zMzgsNiArMzQxLDggQEAgdm9pZCBSZW1vdGVJbnNwZWN0b3I6OnNldHVwKHVuc2ln bmVkIHRhcmdldElkZW50aWZpZXIpCiAgICAgICAgIGNvbm5lY3Rpb25Ub1RhcmdldC0+Y2xvc2Uo KTsKICAgICAgICAgcmV0dXJuOwogICAgIH0KKworICAgIHN0ZDo6bG9ja19ndWFyZDxMb2NrPiBs b2NrKG1fbXV0ZXgpOwogICAgIG1fdGFyZ2V0Q29ubmVjdGlvbk1hcC5zZXQodGFyZ2V0SWRlbnRp ZmllciwgV1RGTW92ZShjb25uZWN0aW9uVG9UYXJnZXQpKTsKIAogICAgIHVwZGF0ZUhhc0FjdGl2 ZURlYnVnU2Vzc2lvbigpOwo=