Closed Bug 1254618 Opened 8 years ago Closed 8 years ago
Transaction Stack to use ns Deque rather than std::deque
Using std::deque here causes problems for libc++ builds; TestTXMgr on OSX 10.6 opt times out when libc++'d std::deque is used. Running the test locally shows that the test process consumes gigabytes (!) of memory and is thus reduced to swapping, rather than making any progress. libc++'s std::deque also appears to be slightly slower in said test that even OSX libstdc++'s std::deque. (Admittedly, this test is artificial.) Let's sidestep the slowness of libc++'s std::deque by rewriting nsTransactionStack to use nsDeque rather than std::deque. Not only does this change enable OSX 10.6 tests to pass, it also makes TestTXMgr significantly faster in opt builds: TestTXMgr is anywhere from 25-60% faster (depending on the platform) than when using std::deque from libstdc++ or libc++.
This is a straightforward data structures change that I think anybody could review, but flagging Ehsan for old times' sake in editor/ and because he may be interested in the libc++ issues. (No, I didn't thoroughly investigate what libc++ is doing wrong here, but I will note that this issue of libc++'s std::deque being bad turns up on OSX and Android both.)
Attachment #8727970 - Flags: review?(ehsan)
You need to log in before you can comment on or make changes to this bug.