1544777 - [socket process] Assertion failure: mOnStartRequestCalled (OnStartRequest should be called before OnStopRequest)

Status: RESOLVED FIXED

(Core :: Networking, defect, P2)

Description

[Kershaw Chang [:kershaw]]

I've noticed this assertion when running this test [1].
Here are the steps for causing this assertion.

1. A sync XHR is created in OnStartRequest at [2].
2. Since it's a sync XHR, SpinEventLoopUntil is called here [3].
3. We never have a chance to set mOnStartRequestCalled to true at [4].
4. nsHttpChannel::OnStopRequest is called since HttpTransactionParent receives the IPC from socket process.

[1] https://searchfox.org/mozilla-central/rev/1b2636e8517aa48422ed516affe4d28cb7fa220a/netwerk/test/unit/test_reentrancy.js
[2] https://searchfox.org/mozilla-central/rev/1b2636e8517aa48422ed516affe4d28cb7fa220a/netwerk/test/unit/test_reentrancy.js#51
[3] https://searchfox.org/mozilla-central/rev/1b2636e8517aa48422ed516affe4d28cb7fa220a/dom/xhr/XMLHttpRequestMainThread.cpp#2910
[4] https://searchfox.org/mozilla-central/rev/1b2636e8517aa48422ed516affe4d28cb7fa220a/netwerk/protocol/http/nsHttpChannel.cpp#1829

Comment 1

[Kershaw Chang [:kershaw]]

Attachment: Bug 1544777 - Queue runnables if OnStartRequest is not finished

Comment 2

[Dragana Damjanovic [:dragana]]

can you explain why is it working without the socket process?

Comment 3

[Kershaw Chang [:kershaw]]

(In reply to Dragana Damjanovic [:dragana] from comment #2)

can you explain why is it working without the socket process?

Because OnStartRequest is called at [1]. The |nsInputStreamPump::mState| is always STATE_START until |mListener->OnStartRequest| returns. This means that ODA and OnStopRequest will not called.

When socket process is enabled, RecvOnDataAvailable and RecvOnStopRequest are actually events dispatched from IPC thread and could be executed from [2].

[1] https://searchfox.org/mozilla-central/rev/d33d470140ce3f9426af523eaa8ecfa83476c806/netwerk/base/nsInputStreamPump.cpp#487
[2] https://searchfox.org/mozilla-central/rev/d33d470140ce3f9426af523eaa8ecfa83476c806/xpcom/threads/nsThreadUtils.h#348

Comment 4

[Kershaw Chang [:kershaw]]

https://hg.mozilla.org/projects/larch/rev/5ef1879ba19b9a64273b98bf6a602977d5d556ca