Пример #1
0
void
js_DestroyContext(JSContext *cx, JSGCMode gcmode)
{
    JSRuntime *rt;
    JSBool last;
    JSArgumentFormatMap *map;

    rt = cx->runtime;

    /* Remove cx from context list first. */
    JS_LOCK_RUNTIME(rt);
    JS_ASSERT(rt->state == JSRTS_UP || rt->state == JSRTS_LAUNCHING);
    JS_REMOVE_LINK(&cx->links);
    last = (rt->contextList.next == &rt->contextList);
    if (last)
        rt->state = JSRTS_LANDING;
    JS_UNLOCK_RUNTIME(rt);

    if (last) {
        /* Unpin all pinned atoms before final GC. */
        js_UnpinPinnedAtoms(&rt->atomState);

        /* Unlock and clear GC things held by runtime pointers. */
        js_FinishRuntimeNumberState(cx);
        js_FinishRuntimeStringState(cx);

        /* Clear debugging state to remove GC roots. */
        JS_ClearAllTraps(cx);
        JS_ClearAllWatchPoints(cx);
    }

#if JS_HAS_REGEXPS
    /*
     * Remove more GC roots in regExpStatics, then collect garbage.
     * XXX anti-modularity alert: we rely on the call to js_RemoveRoot within
     * XXX this function call to wait for any racing GC to complete, in the
     * XXX case where JS_DestroyContext is called outside of a request on cx
     */
    js_FreeRegExpStatics(cx, &cx->regExpStatics);
#endif

#ifdef JS_THREADSAFE
    /*
     * Destroying a context implicitly calls JS_EndRequest().  Also, we must
     * end our request here in case we are "last" -- in that event, another
     * js_DestroyContext that was not last might be waiting in the GC for our
     * request to end.  We'll let it run below, just before we do the truly
     * final GC and then free atom state.
     *
     * At this point, cx must be inaccessible to other threads.  It's off the
     * rt->contextList, and it should not be reachable via any object private
     * data structure.
     */
    while (cx->requestDepth != 0)
        JS_EndRequest(cx);
#endif

    if (last) {
        /* Always force, so we wait for any racing GC to finish. */
        js_ForceGC(cx);

        /* Iterate until no finalizer removes a GC root or lock. */
        while (rt->gcPoke)
            js_GC(cx, GC_LAST_CONTEXT);

        /* Try to free atom state, now that no unrooted scripts survive. */
        if (rt->atomState.liveAtoms == 0)
            js_FreeAtomState(cx, &rt->atomState);

        /* Take the runtime down, now that it has no contexts or atoms. */
        JS_LOCK_RUNTIME(rt);
        rt->state = JSRTS_DOWN;
        JS_NOTIFY_ALL_CONDVAR(rt->stateChange);
        JS_UNLOCK_RUNTIME(rt);
    } else {
        if (gcmode == JS_FORCE_GC)
            js_ForceGC(cx);
        else if (gcmode == JS_MAYBE_GC)
            JS_MaybeGC(cx);
    }

    /* Free the stuff hanging off of cx. */
    JS_FinishArenaPool(&cx->stackPool);
    JS_FinishArenaPool(&cx->codePool);
    JS_FinishArenaPool(&cx->notePool);
    JS_FinishArenaPool(&cx->tempPool);
    if (cx->lastMessage)
        free(cx->lastMessage);

    /* Remove any argument formatters. */
    map = cx->argumentFormatMap;
    while (map) {
        JSArgumentFormatMap *temp = map;
        map = map->next;
        JS_free(cx, temp);
    }

    /* Destroy the resolve recursion damper. */
    if (cx->resolvingTable) {
        JS_DHashTableDestroy(cx->resolvingTable);
        cx->resolvingTable = NULL;
    }

    /* Finally, free cx itself. */
    free(cx);
}
Пример #2
0
void
js_DestroyContext(JSContext *cx, JSDestroyContextMode mode)
{
    JSRuntime *rt;
    JSContextCallback cxCallback;
    JSBool last;
    JSArgumentFormatMap *map;
    JSLocalRootStack *lrs;
    JSLocalRootChunk *lrc;

    rt = cx->runtime;

    if (mode != JSDCM_NEW_FAILED) {
        cxCallback = rt->cxCallback;
        if (cxCallback) {
            /*
             * JSCONTEXT_DESTROY callback is not allowed to fail and must
             * return true.
             */
#ifdef DEBUG
            JSBool callbackStatus =
#endif
            cxCallback(cx, JSCONTEXT_DESTROY);
            JS_ASSERT(callbackStatus);
        }
    }

    /* Remove cx from context list first. */
    JS_LOCK_GC(rt);
    JS_ASSERT(rt->state == JSRTS_UP || rt->state == JSRTS_LAUNCHING);
    JS_REMOVE_LINK(&cx->links);
    last = (rt->contextList.next == &rt->contextList);
    if (last)
        rt->state = JSRTS_LANDING;
    JS_UNLOCK_GC(rt);

    if (last) {
#ifdef JS_THREADSAFE
        /*
         * If cx is not in a request already, begin one now so that we wait
         * for any racing GC started on a not-last context to finish, before
         * we plow ahead and unpin atoms.  Note that even though we begin a
         * request here if necessary, we end all requests on cx below before
         * forcing a final GC.  This lets any not-last context destruction
         * racing in another thread try to force or maybe run the GC, but by
         * that point, rt->state will not be JSRTS_UP, and that GC attempt
         * will return early.
         */
        if (cx->requestDepth == 0)
            JS_BeginRequest(cx);
#endif

        /* Unpin all pinned atoms before final GC. */
        js_UnpinPinnedAtoms(&rt->atomState);

        /* Unlock and clear GC things held by runtime pointers. */
        js_FinishRuntimeNumberState(cx);
        js_FinishRuntimeStringState(cx);

        /* Clear debugging state to remove GC roots. */
        JS_ClearAllTraps(cx);
        JS_ClearAllWatchPoints(cx);
    }

    /*
     * Remove more GC roots in regExpStatics, then collect garbage.
     * XXX anti-modularity alert: we rely on the call to js_RemoveRoot within
     * XXX this function call to wait for any racing GC to complete, in the
     * XXX case where JS_DestroyContext is called outside of a request on cx
     */
    js_FreeRegExpStatics(cx, &cx->regExpStatics);

#ifdef JS_THREADSAFE
    /*
     * Destroying a context implicitly calls JS_EndRequest().  Also, we must
     * end our request here in case we are "last" -- in that event, another
     * js_DestroyContext that was not last might be waiting in the GC for our
     * request to end.  We'll let it run below, just before we do the truly
     * final GC and then free atom state.
     *
     * At this point, cx must be inaccessible to other threads.  It's off the
     * rt->contextList, and it should not be reachable via any object private
     * data structure.
     */
    while (cx->requestDepth != 0)
        JS_EndRequest(cx);
#endif

    if (last) {
        /* Always force, so we wait for any racing GC to finish. */
        js_ForceGC(cx, GC_LAST_CONTEXT);

        /* Iterate until no JSGC_END-status callback creates more garbage. */
        while (rt->gcPoke)
            js_GC(cx, GC_LAST_CONTEXT);

        /* Try to free atom state, now that no unrooted scripts survive. */
        if (rt->atomState.liveAtoms == 0)
            js_FreeAtomState(cx, &rt->atomState);

        /* Also free the script filename table if it exists and is empty. */
        if (rt->scriptFilenameTable && rt->scriptFilenameTable->nentries == 0)
            js_FinishRuntimeScriptState(rt);

        /*
         * Free the deflated string cache, but only after the last GC has
         * collected all unleaked strings.
         */
        js_FinishDeflatedStringCache(rt);

        /* Take the runtime down, now that it has no contexts or atoms. */
        JS_LOCK_GC(rt);
        rt->state = JSRTS_DOWN;
        JS_NOTIFY_ALL_CONDVAR(rt->stateChange);
        JS_UNLOCK_GC(rt);
    } else {
        if (mode == JSDCM_FORCE_GC)
            js_ForceGC(cx, 0);
        else if (mode == JSDCM_MAYBE_GC)
            JS_MaybeGC(cx);
    }

    /* Free the stuff hanging off of cx. */
    JS_FinishArenaPool(&cx->stackPool);
    JS_FinishArenaPool(&cx->tempPool);
    if (cx->lastMessage)
        free(cx->lastMessage);

    /* Remove any argument formatters. */
    map = cx->argumentFormatMap;
    while (map) {
        JSArgumentFormatMap *temp = map;
        map = map->next;
        JS_free(cx, temp);
    }

    /* Destroy the resolve recursion damper. */
    if (cx->resolvingTable) {
        JS_DHashTableDestroy(cx->resolvingTable);
        cx->resolvingTable = NULL;
    }

    lrs = cx->localRootStack;
    if (lrs) {
        while ((lrc = lrs->topChunk) != &lrs->firstChunk) {
            lrs->topChunk = lrc->down;
            JS_free(cx, lrc);
        }
        JS_free(cx, lrs);
    }

#ifdef JS_THREADSAFE
    js_ClearContextThread(cx);
#endif

    /* Finally, free cx itself. */
    free(cx);
}