1505962 - Add redirection for rand()

Status: RESOLVED FIXED

(Core Graveyard :: Web Replay, enhancement)

Description

[Brian Hackett [Laid off!]]

Attachment: patch

While in a single threaded context we should be able to control for the random number seed and generate the same sequence of numbers, there are several ways in which we could fail to replay the numbers exactly --- if rand() is called while events are passed through, or if it is called from multiple threads whose accesses aren't synchronized.  The attached patch adds a redirection to ensure that rand() calls always produce the same value.

Comment 1

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/fa47f2e5c1fb
Add redirection for rand(), r=lsmyth.

Comment 2

[Daniel Varga [:dvarga]]

https://hg.mozilla.org/mozilla-central/rev/fa47f2e5c1fb

Comment 3

[Brian Hackett [Laid off!]]

This patch broke Web Replay on 10.13 (and possibly other versions), backing out for now.

https://hg.mozilla.org/integration/mozilla-inbound/rev/c418b8e31eacc847c27c03c4636ce3315c0c7e2f

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/f3cea0fce1e0
Add redirection for rand(), r=lsmyth.

Comment 5

[Brian Hackett [Laid off!]]

It turns out this patch never broke things after all (after backing it out 10.13 was still broken), but the problem was with the CGColorSpaceCreateDeviceGray redirection added by bug 1505922.

Comment 6

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/f3cea0fce1e0