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JS_SetGCZeal 编辑

This article covers features introduced in SpiderMonkey 1.8

Enable GC zeal, a testing and debugging feature that helps find GC-related bugs in JSAPI applications.

Syntax

void
JS_SetGCZeal(JSContext *cx, uint8_t zeal, uint32_t frequency);

Name	Type	Description
`cx`	`JSContext *`	A context. The GC zeal level of the associated `JSRuntime` is set.
`zeal`	`uint8_t`	The desired level of garbage collection.
`frequency`	`uint32_t`	With some zeal levels, a GC is triggered every `frequency` allocations.

Description

JS_SetGCZeal sets the level of additional garbage collection to perform for a runtime, for the purpose of finding or reproducing bugs.

There are several different levels which have different functions:

Zeal level	Description
0	Normal amount of collection. The default: no additional collections are performed.
1	Collect when roots are added or removed.
2	Collect when every `frequency` allocations.
3	Collect on window paints.
4	Verify pre write barriers between instructions.
5	Verify pre write barriers between window paints.
6	Verify stack rooting.
7	Collect the nursery every `frequency` nursery allocations.
8	Incremental GC in two slices: 1) mark roots 2) finish collection.
9	Incremental GC in two slices: 1) mark all 2) new marking and finish.
10	Incremental GC in multiple slices.
11	Verify post write barriers between instructions.
12	Verify post write barriers between paints.
13	Check internal hashtables on minor GC.
14	Perform a shrinking collection every `frequency` allocations.

With GC zeal enabled, GC-related crashes are much easier to reproduce (they happen more reliably) and debug (they happen sooner, closer to the source of the bug). The drawback is that GC zeal can cause JavaScript code to run extremely slowly.

Regularly running your test suite with GC zeal enabled at level 2 is a good practice.

This function is available only in DEBUG builds. To enable this function in an optimized build, define the macro JS_GC_ZEAL building SpiderMonkey.

(In a debug build of Gecko, you can also set the current GC zeal level using the javascript.options.gczeal preference.)

JS_SetGCZeal 编辑

Syntax

Description

See Also

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友情链接

JS_SetGCZeal 编辑

Syntax

Description

See Also

如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

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友情链接

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。