557776 - js_InitTitle: initialise title->lock properly

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Julian Seward [:jseward]]

jslock.cpp: js_InitTitle(JSContext *cx, JSTitle *title) initialises
title->lock by memsetting it to zero: PodZero(&title->lock).  This
isn't the official way to do it and gives two problems:

* js_FinishTitle does properly finalise it by calling js_FinishLock.
  As a result, runtime thread checking tools that try to pair up
  lock initialisations and finalisations by watching js_InitLock and
  js_FinishLock report floods of errors about finalisation of a lock
  which was never initialised.

* from reading js_InitLock, PodZero-ing the lock to initialise it is
  only correct in the case "#ifndef NSPR_LOCK".  It's not obviously
  correct when NSPR_LOCK is defined.

Comment 1

[Julian Seward [:jseward]]

Attachment: proposed fix

Comment 2

[Jason Orendorff [:jorendorff]]

Comment on attachment 437532 [details] [diff] [review]
proposed fix

Yes, this is an obvious bug.

Comment 3

[Jason Orendorff [:jorendorff]]

http://hg.mozilla.org/tracemonkey/rev/5343df124795

Comment 4

[Robert Sayre]

http://hg.mozilla.org/mozilla-central/rev/5343df124795