114217 2013-04-08 14:13:03 -0700 Web/Plugin process deadlock initializing async plugins 2013-04-11 10:16:59 -0700 1 1 1 Unclassified WebKit WebKit2 528+ (Nightly build) All All RESOLVED INVALID InRadar P2 Normal --- 1 beidson beidson andersca oldest_to_newest 871163 0 beidson 2013-04-08 14:13:03 -0700 Web/Plugin process deadlock initializing async plugins Imagine: -A WebProcess is instantiating a plugin, so it synchronously asks for a new plugin process connection. -Once it gets the connection, it asynchronously asks for a plugin to initialize. -While that one is initializing, it's instantiating another plugin. -It synchronously asks for a new plugin process connection. In this scenario, when the plugin process finishes up the async initialization, it notifies the web process with a synchronous message. So it's synchronously waiting on the WebProcess, and the WebProcess is synchronously waiting on the plugin process. Deadlock. I think this is an easy fix because I don't now why the plugin process notification to the WebProcess is synchronous - the replies are empty. In radar as <rdar://problem/13525232> 871166 1 196954 beidson 2013-04-08 14:15:32 -0700 Created attachment 196954 Patch v1 871176 2 beidson 2013-04-08 14:30:28 -0700 http://trac.webkit.org/changeset/147953 871287 3 beidson 2013-04-08 17:18:24 -0700 This caused platform/mac-wk2/plugins/slow/asynchronous-plugin-initialization-multiple.html to fail. Looking in to it now. 871299 4 beidson 2013-04-08 17:26:34 -0700 Here's what happens in the test: 1 - PluginProcess gets 20 requests to async init. Those 20 messages are queued up. 2 - It starts the first 1, which takes 0.5 seconds 3 - During that time, the WebProcess tells it to destroy all of them. These 20 messages are sync messages, and presumably get queued up behind those 20 in step one. In the working case, those 20 "Destroy" messages are handled immediately after the first plugin is finished initializing, even though there's 19 requests to create waiting. In the failing case, all 20 requests to create are handled before any of the requests to destroy are handled. 871305 5 beidson 2013-04-08 17:38:08 -0700 Skipped in r147968 while I explore this. 871306 6 beidson 2013-04-08 17:38:33 -0700 Reopening - the failure shows the patch broke the async plugin feature. 873282 7 beidson 2013-04-10 15:57:46 -0700 This probably wasn't necessary, and we should roll it out. 873969 8 beidson 2013-04-11 10:16:59 -0700 Rolled out in http://trac.webkit.org/changeset/148214 196954 2013-04-08 14:15:32 -0700 2013-04-08 14:16:53 -0700 Patch v1 patch text/plain 2806 beidson ZGlmZiAtLWdpdCBhL1NvdXJjZS9XZWJLaXQyL0NoYW5nZUxvZyBiL1NvdXJjZS9XZWJLaXQyL0No YW5nZUxvZwppbmRleCA4YTEwNWU3Li40MmI5NDFjIDEwMDY0NAotLS0gYS9Tb3VyY2UvV2ViS2l0 Mi9DaGFuZ2VMb2cKKysrIGIvU291cmNlL1dlYktpdDIvQ2hhbmdlTG9nCkBAIC0xLDMgKzEsMTYg QEAKKzIwMTMtMDQtMDggIEJyYWR5IEVpZHNvbiAgPGJlaWRzb25AYXBwbGUuY29tPgorCisgICAg ICAgIFdlYi9QbHVnaW4gcHJvY2VzcyBkZWFkbG9jayBpbml0aWFsaXppbmcgYXN5bmMgcGx1Z2lu cy4KKyAgICAgICAgPHJkYXI6Ly9wcm9ibGVtLzEzNTI1MjMyPiBhbmQgaHR0cHM6Ly9idWdzLndl YmtpdC5vcmcvc2hvd19idWcuY2dpP2lkPTExNDIxNworCisgICAgICAgIFJldmlld2VkIGJ5IE5P Qk9EWSAoT09QUyEpLgorCisgICAgICAgVGhlICJBc3luYyBpbml0aWFsaXphdGlvbiBjb21wbGV0 ZSIgbWVzc2FnZXMgcHJvYmFibHkgZG9uJ3QgaGF2ZSB0byBiZSBzeW5jaHJvbm91cy4KKworICAg ICAgICAqIFBsdWdpblByb2Nlc3MvV2ViUHJvY2Vzc0Nvbm5lY3Rpb24uY3BwOgorICAgICAgICAo V2ViS2l0OjpXZWJQcm9jZXNzQ29ubmVjdGlvbjo6Y3JlYXRlUGx1Z2luQXN5bmNocm9ub3VzbHkp OiBOb3RpZnkgb2YgaW5pdGlhbGl6YXRpb24gc3VjY2Vzcy9mYWlsdXJlIGFzeW5jaHJvbm91c2x5 LgorICAgICAgICAqIFdlYlByb2Nlc3MvUGx1Z2lucy9QbHVnaW5Qcm94eS5tZXNzYWdlcy5pbjog CisKIDIwMTMtMDQtMDggIE1pa2hhaWwgUG96ZG55YWtvdiAgPG1pa2hhaWwucG96ZG55YWtvdkBp bnRlbC5jb20+CiAKICAgICAgICAgW1dLMl1bRUZMXSBXZWJWaWV3OiBBZGQgY2FsbGJhY2tzIHRv IHRoZSBXS1ZpZXdDbGllbnQgdG8gcmVtb3ZlIGRpcmVjdCBhY2Nlc3MgdG8gcGFnZSB2aWV3cG9y dCBjb250cm9sbGVyCmRpZmYgLS1naXQgYS9Tb3VyY2UvV2ViS2l0Mi9QbHVnaW5Qcm9jZXNzL1dl YlByb2Nlc3NDb25uZWN0aW9uLmNwcCBiL1NvdXJjZS9XZWJLaXQyL1BsdWdpblByb2Nlc3MvV2Vi UHJvY2Vzc0Nvbm5lY3Rpb24uY3BwCmluZGV4IGFjMmE5OTUuLjE0MTI2ZGMgMTAwNjQ0Ci0tLSBh L1NvdXJjZS9XZWJLaXQyL1BsdWdpblByb2Nlc3MvV2ViUHJvY2Vzc0Nvbm5lY3Rpb24uY3BwCisr KyBiL1NvdXJjZS9XZWJLaXQyL1BsdWdpblByb2Nlc3MvV2ViUHJvY2Vzc0Nvbm5lY3Rpb24uY3Bw CkBAIC0yOTIsMTEgKzI5MiwxMSBAQCB2b2lkIFdlYlByb2Nlc3NDb25uZWN0aW9uOjpjcmVhdGVQ bHVnaW5Bc3luY2hyb25vdXNseShjb25zdCBQbHVnaW5DcmVhdGlvblBhcmFtZQogCiAgICAgLy8g T3RoZXJ3aXNlLCBzZW5kIHRoZSBhc3luY2hyb25vdXMgcmVzdWx0cyBub3cuCiAgICAgaWYgKCFy ZXN1bHQpIHsKLSAgICAgICAgbV9jb25uZWN0aW9uLT5zZW5kU3luYyhNZXNzYWdlczo6UGx1Z2lu UHJveHk6OkRpZEZhaWxUb0NyZWF0ZVBsdWdpbigpLCBNZXNzYWdlczo6UGx1Z2luUHJveHk6OkRp ZEZhaWxUb0NyZWF0ZVBsdWdpbjo6UmVwbHkoKSwgY3JlYXRpb25QYXJhbWV0ZXJzLnBsdWdpbklu c3RhbmNlSUQpOworICAgICAgICBtX2Nvbm5lY3Rpb24tPnNlbmQoTWVzc2FnZXM6OlBsdWdpblBy b3h5OjpEaWRGYWlsVG9DcmVhdGVQbHVnaW4oKSwgY3JlYXRpb25QYXJhbWV0ZXJzLnBsdWdpbklu c3RhbmNlSUQpOwogICAgICAgICByZXR1cm47CiAgICAgfQogCi0gICAgbV9jb25uZWN0aW9uLT5z ZW5kU3luYyhNZXNzYWdlczo6UGx1Z2luUHJveHk6OkRpZENyZWF0ZVBsdWdpbih3YW50c1doZWVs RXZlbnRzLCByZW1vdGVMYXllckNsaWVudElEKSwgTWVzc2FnZXM6OlBsdWdpblByb3h5OjpEaWRD cmVhdGVQbHVnaW46OlJlcGx5KCksIGNyZWF0aW9uUGFyYW1ldGVycy5wbHVnaW5JbnN0YW5jZUlE KTsKKyAgICBtX2Nvbm5lY3Rpb24tPnNlbmQoTWVzc2FnZXM6OlBsdWdpblByb3h5OjpEaWRDcmVh dGVQbHVnaW4od2FudHNXaGVlbEV2ZW50cywgcmVtb3RlTGF5ZXJDbGllbnRJRCksIGNyZWF0aW9u UGFyYW1ldGVycy5wbHVnaW5JbnN0YW5jZUlEKTsKIH0KIAogfSAvLyBuYW1lc3BhY2UgV2ViS2l0 CmRpZmYgLS1naXQgYS9Tb3VyY2UvV2ViS2l0Mi9XZWJQcm9jZXNzL1BsdWdpbnMvUGx1Z2luUHJv eHkubWVzc2FnZXMuaW4gYi9Tb3VyY2UvV2ViS2l0Mi9XZWJQcm9jZXNzL1BsdWdpbnMvUGx1Z2lu UHJveHkubWVzc2FnZXMuaW4KaW5kZXggMjExYTI1OS4uNjczMjA2YSAxMDA2NDQKLS0tIGEvU291 cmNlL1dlYktpdDIvV2ViUHJvY2Vzcy9QbHVnaW5zL1BsdWdpblByb3h5Lm1lc3NhZ2VzLmluCisr KyBiL1NvdXJjZS9XZWJLaXQyL1dlYlByb2Nlc3MvUGx1Z2lucy9QbHVnaW5Qcm94eS5tZXNzYWdl cy5pbgpAQCAtNzYsMTAgKzc2LDEwIEBAIG1lc3NhZ2VzIC0+IFBsdWdpblByb3h5IExlZ2FjeVJl Y2VpdmVyIHsKICNlbmRpZgogCiAgICAgIyBUZWxscyB0aGUgV2ViUHJvY2VzcyB0aGF0IHRoZSBw bHVnLWluIHdhcyBzdWNjZXNzZnVsbHkgaW5pdGlhbGl6ZWQgYXN5bmNocm9ub3VzbHkKLSAgICBE aWRDcmVhdGVQbHVnaW4oYm9vbCB3YW50c1doZWVsRXZlbnRzLCB1aW50MzJfdCByZW1vdGVMYXll ckNsaWVudElEKSAtPiAoKQorICAgIERpZENyZWF0ZVBsdWdpbihib29sIHdhbnRzV2hlZWxFdmVu dHMsIHVpbnQzMl90IHJlbW90ZUxheWVyQ2xpZW50SUQpCiAgICAgCiAgICAgIyBUZWxscyB0aGUg V2ViUHJvY2VzcyB0aGF0IHRoZSBwbHVnLWluIGZhaWxlZCB0byBpbml0aWFsaXplLgotICAgIERp ZEZhaWxUb0NyZWF0ZVBsdWdpbigpIC0+ICgpCisgICAgRGlkRmFpbFRvQ3JlYXRlUGx1Z2luKCkK IH0KIAogI2VuZGlmCg==