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JSTraceOp is the type of the JSClass.trace.


typedef void
(* JSTraceOp)(JSTracer *trc, JSObject *obj);
Name Type Description
trc JSTracer * The tracer visiting obj.
obj JSObject * The object being visited.


JSTraceOp is the function type for trace operation of the class called to enumerate all traceable things reachable from obj's private data structure. For each such thing, a trace implementation must call one of the JS_Call*Tracer variants on the thing.

JSTraceOp implementation can assume that no other threads mutates object state. It must not change state of the object or corresponding native structures. The only exception for this rule is the case when the embedding needs a tight integration with GC. In that case the embedding can check if the traversal is a part of the marking phase through calling JS_IsGCMarkingTracer and apply a special code like emptying caches or marking its native structures.

JSClass hooks

JSClass offers the following hook:

  • The JSClass.trace callback is called to enumerate all traceable things reachable.

See Also

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 Contributors to this page: kscarfone, arai, fscholz, tschneidereit, Jorend
 Last updated by: kscarfone,