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| author | David Teller <dteller@mozilla.com> | 2019-01-28 23:41:20 +0100 |
|---|---|---|
| committer | wolfbeast <mcwerewolf@wolfbeast.com> | 2019-01-28 23:41:20 +0100 |
| commit | 3476c1d60ec29c5497123194acd7a9310b1023d2 (patch) | |
| tree | 4933db7b4bb27893d3511ac21d5d04a11deea6a9 /js/src/jsapi.h | |
| parent | e82fdef9c7bed415d004086740cab57211575511 (diff) | |
| download | UXP-3476c1d60ec29c5497123194acd7a9310b1023d2.tar UXP-3476c1d60ec29c5497123194acd7a9310b1023d2.tar.gz UXP-3476c1d60ec29c5497123194acd7a9310b1023d2.tar.lz UXP-3476c1d60ec29c5497123194acd7a9310b1023d2.tar.xz UXP-3476c1d60ec29c5497123194acd7a9310b1023d2.zip | |
Reduce number of allocations in AutoStopwatch
This patch fixes two related issues.
1. The AutoStopwatch uses a stack-allocated `mozilla::Vector` to
communicate with its callback during each compartment switch.
This vector was designed to allow its contents to be stack-allocated
but they turned out to be accidentally heap-allocated.
2. During each tick, the stopwatch fills a vector `recentGroups_`.
This vector always started with minimal capacity and had to grow
repeatedly as groups were added, causing repeated reallocations.
This patch preallocates `recentGroups_` to have the same capacity as the
previous tick. We expect that this should eventually reach a stable size
that closely matches the actual needs of the process.
Diffstat (limited to 'js/src/jsapi.h')
| -rw-r--r-- | js/src/jsapi.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/js/src/jsapi.h b/js/src/jsapi.h index 0983f034f..799396a0a 100644 --- a/js/src/jsapi.h +++ b/js/src/jsapi.h @@ -6566,7 +6566,7 @@ struct JS_PUBLIC_API(PerformanceGroup) { uint64_t refCount_; }; -using PerformanceGroupVector = mozilla::Vector<RefPtr<js::PerformanceGroup>, 0, SystemAllocPolicy>; +using PerformanceGroupVector = mozilla::Vector<RefPtr<js::PerformanceGroup>, 8, SystemAllocPolicy>; /** * Commit any Performance Monitoring data. |