Merge branch 'ported-moebius'

Remove GCZeal code from Spidermonkey.
This resolves #8

1 files changed, 0 insertions, 414 deletions

diff --git a/js/src/gc/Verifier.cpp b/js/src/gc/Verifier.cpp
index dd4031606..3ebbbb4f6 100644
--- a/js/src/gc/Verifier.cpp
+++ b/js/src/gc/Verifier.cpp
@@ -26,420 +26,6 @@
 using namespace js;
 using namespace js::gc;
 
-#ifdef JS_GC_ZEAL
-
-/*
- * Write barrier verification
- *
- * The next few functions are for write barrier verification.
- *
- * The VerifyBarriers function is a shorthand. It checks if a verification phase
- * is currently running. If not, it starts one. Otherwise, it ends the current
- * phase and starts a new one.
- *
- * The user can adjust the frequency of verifications, which causes
- * VerifyBarriers to be a no-op all but one out of N calls. However, if the
- * |always| parameter is true, it starts a new phase no matter what.
- *
- * Pre-Barrier Verifier:
- *   When StartVerifyBarriers is called, a snapshot is taken of all objects in
- *   the GC heap and saved in an explicit graph data structure. Later,
- *   EndVerifyBarriers traverses the heap again. Any pointer values that were in
- *   the snapshot and are no longer found must be marked; otherwise an assertion
- *   triggers. Note that we must not GC in between starting and finishing a
- *   verification phase.
- */
-
-struct EdgeValue
-{
-    void* thing;
-    JS::TraceKind kind;
-    const char* label;
-};
-
-struct VerifyNode
-{
-    void* thing;
-    JS::TraceKind kind;
-    uint32_t count;
-    EdgeValue edges[1];
-};
-
-typedef HashMap<void*, VerifyNode*, DefaultHasher<void*>, SystemAllocPolicy> NodeMap;
-
-/*
- * The verifier data structures are simple. The entire graph is stored in a
- * single block of memory. At the beginning is a VerifyNode for the root
- * node. It is followed by a sequence of EdgeValues--the exact number is given
- * in the node. After the edges come more nodes and their edges.
- *
- * The edgeptr and term fields are used to allocate out of the block of memory
- * for the graph. If we run out of memory (i.e., if edgeptr goes beyond term),
- * we just abandon the verification.
- *
- * The nodemap field is a hashtable that maps from the address of the GC thing
- * to the VerifyNode that represents it.
- */
-class js::VerifyPreTracer final : public JS::CallbackTracer
-{
-    JS::AutoDisableGenerationalGC noggc;
-
-    void onChild(const JS::GCCellPtr& thing) override;
-
-  public:
-    /* The gcNumber when the verification began. */
-    uint64_t number;
-
-    /* This counts up to gcZealFrequency to decide whether to verify. */
-    int count;
-
-    /* This graph represents the initial GC "snapshot". */
-    VerifyNode* curnode;
-    VerifyNode* root;
-    char* edgeptr;
-    char* term;
-    NodeMap nodemap;
-
-    explicit VerifyPreTracer(JSRuntime* rt)
-      : JS::CallbackTracer(rt), noggc(rt), number(rt->gc.gcNumber()), count(0), curnode(nullptr),
-        root(nullptr), edgeptr(nullptr), term(nullptr)
-    {}
-
-    ~VerifyPreTracer() {
-        js_free(root);
-    }
-};
-
-/*
- * This function builds up the heap snapshot by adding edges to the current
- * node.
- */
-void
-VerifyPreTracer::onChild(const JS::GCCellPtr& thing)
-{
-    MOZ_ASSERT(!IsInsideNursery(thing.asCell()));
-
-    // Skip things in other runtimes.
-    if (thing.asCell()->asTenured().runtimeFromAnyThread() != runtime())
-        return;
-
-    edgeptr += sizeof(EdgeValue);
-    if (edgeptr >= term) {
-        edgeptr = term;
-        return;
-    }
-
-    VerifyNode* node = curnode;
-    uint32_t i = node->count;
-
-    node->edges[i].thing = thing.asCell();
-    node->edges[i].kind = thing.kind();
-    node->edges[i].label = contextName();
-    node->count++;
-}
-
-static VerifyNode*
-MakeNode(VerifyPreTracer* trc, void* thing, JS::TraceKind kind)
-{
-    NodeMap::AddPtr p = trc->nodemap.lookupForAdd(thing);
-    if (!p) {
-        VerifyNode* node = (VerifyNode*)trc->edgeptr;
-        trc->edgeptr += sizeof(VerifyNode) - sizeof(EdgeValue);
-        if (trc->edgeptr >= trc->term) {
-            trc->edgeptr = trc->term;
-            return nullptr;
-        }
-
-        node->thing = thing;
-        node->count = 0;
-        node->kind = kind;
-        if (!trc->nodemap.add(p, thing, node)) {
-            trc->edgeptr = trc->term;
-            return nullptr;
-        }
-
-        return node;
-    }
-    return nullptr;
-}
-
-static VerifyNode*
-NextNode(VerifyNode* node)
-{
-    if (node->count == 0)
-        return (VerifyNode*)((char*)node + sizeof(VerifyNode) - sizeof(EdgeValue));
-    else
-        return (VerifyNode*)((char*)node + sizeof(VerifyNode) +
-                             sizeof(EdgeValue)*(node->count - 1));
-}
-
-void
-gc::GCRuntime::startVerifyPreBarriers()
-{
-    if (verifyPreData || isIncrementalGCInProgress())
-        return;
-
-    if (IsIncrementalGCUnsafe(rt) != AbortReason::None)
-        return;
-
-    number++;
-
-    VerifyPreTracer* trc = js_new<VerifyPreTracer>(rt);
-    if (!trc)
-        return;
-
-    AutoPrepareForTracing prep(rt->contextFromMainThread(), WithAtoms);
-
-    for (auto chunk = allNonEmptyChunks(); !chunk.done(); chunk.next())
-        chunk->bitmap.clear();
-
-    gcstats::AutoPhase ap(stats, gcstats::PHASE_TRACE_HEAP);
-
-    const size_t size = 64 * 1024 * 1024;
-    trc->root = (VerifyNode*)js_malloc(size);
-    if (!trc->root)
-        goto oom;
-    trc->edgeptr = (char*)trc->root;
-    trc->term = trc->edgeptr + size;
-
-    if (!trc->nodemap.init())
-        goto oom;
-
-    /* Create the root node. */
-    trc->curnode = MakeNode(trc, nullptr, JS::TraceKind(0));
-
-    incrementalState = State::MarkRoots;
-
-    /* Make all the roots be edges emanating from the root node. */
-    traceRuntime(trc, prep.session().lock);
-
-    VerifyNode* node;
-    node = trc->curnode;
-    if (trc->edgeptr == trc->term)
-        goto oom;
-
-    /* For each edge, make a node for it if one doesn't already exist. */
-    while ((char*)node < trc->edgeptr) {
-        for (uint32_t i = 0; i < node->count; i++) {
-            EdgeValue& e = node->edges[i];
-            VerifyNode* child = MakeNode(trc, e.thing, e.kind);
-            if (child) {
-                trc->curnode = child;
-                js::TraceChildren(trc, e.thing, e.kind);
-            }
-            if (trc->edgeptr == trc->term)
-                goto oom;
-        }
-
-        node = NextNode(node);
-    }
-
-    verifyPreData = trc;
-    incrementalState = State::Mark;
-    marker.start();
-
-    for (ZonesIter zone(rt, WithAtoms); !zone.done(); zone.next()) {
-        PurgeJITCaches(zone);
-        if (!zone->usedByExclusiveThread) {
-            zone->setNeedsIncrementalBarrier(true, Zone::UpdateJit);
-            zone->arenas.purge();
-        }
-    }
-
-    return;
-
-oom:
-    incrementalState = State::NotActive;
-    js_delete(trc);
-    verifyPreData = nullptr;
-}
-
-static bool
-IsMarkedOrAllocated(TenuredCell* cell)
-{
-    return cell->isMarked() || cell->arena()->allocatedDuringIncremental;
-}
-
-struct CheckEdgeTracer : public JS::CallbackTracer {
-    VerifyNode* node;
-    explicit CheckEdgeTracer(JSRuntime* rt) : JS::CallbackTracer(rt), node(nullptr) {}
-    void onChild(const JS::GCCellPtr& thing) override;
-};
-
-static const uint32_t MAX_VERIFIER_EDGES = 1000;
-
-/*
- * This function is called by EndVerifyBarriers for every heap edge. If the edge
- * already existed in the original snapshot, we "cancel it out" by overwriting
- * it with nullptr. EndVerifyBarriers later asserts that the remaining
- * non-nullptr edges (i.e., the ones from the original snapshot that must have
- * been modified) must point to marked objects.
- */
-void
-CheckEdgeTracer::onChild(const JS::GCCellPtr& thing)
-{
-    // Skip things in other runtimes.
-    if (thing.asCell()->asTenured().runtimeFromAnyThread() != runtime())
-        return;
-
-    /* Avoid n^2 behavior. */
-    if (node->count > MAX_VERIFIER_EDGES)
-        return;
-
-    for (uint32_t i = 0; i < node->count; i++) {
-        if (node->edges[i].thing == thing.asCell()) {
-            MOZ_ASSERT(node->edges[i].kind == thing.kind());
-            node->edges[i].thing = nullptr;
-            return;
-        }
-    }
-}
-
-void
-js::gc::AssertSafeToSkipBarrier(TenuredCell* thing)
-{
-    Zone* zone = thing->zoneFromAnyThread();
-    MOZ_ASSERT(!zone->needsIncrementalBarrier() || zone->isAtomsZone());
-}
-
-static bool
-IsMarkedOrAllocated(const EdgeValue& edge)
-{
-    if (!edge.thing || IsMarkedOrAllocated(TenuredCell::fromPointer(edge.thing)))
-        return true;
-
-    // Permanent atoms and well-known symbols aren't marked during graph traversal.
-    if (edge.kind == JS::TraceKind::String && static_cast<JSString*>(edge.thing)->isPermanentAtom())
-        return true;
-    if (edge.kind == JS::TraceKind::Symbol && static_cast<JS::Symbol*>(edge.thing)->isWellKnownSymbol())
-        return true;
-
-    return false;
-}
-
-void
-gc::GCRuntime::endVerifyPreBarriers()
-{
-    VerifyPreTracer* trc = verifyPreData;
-
-    if (!trc)
-        return;
-
-    MOZ_ASSERT(!JS::IsGenerationalGCEnabled(rt));
-
-    AutoPrepareForTracing prep(rt->contextFromMainThread(), SkipAtoms);
-
-    bool compartmentCreated = false;
-
-    /* We need to disable barriers before tracing, which may invoke barriers. */
-    for (ZonesIter zone(rt, WithAtoms); !zone.done(); zone.next()) {
-        if (!zone->needsIncrementalBarrier())
-            compartmentCreated = true;
-
-        zone->setNeedsIncrementalBarrier(false, Zone::UpdateJit);
-        PurgeJITCaches(zone);
-    }
-
-    /*
-     * We need to bump gcNumber so that the methodjit knows that jitcode has
-     * been discarded.
-     */
-    MOZ_ASSERT(trc->number == number);
-    number++;
-
-    verifyPreData = nullptr;
-    incrementalState = State::NotActive;
-
-    if (!compartmentCreated && IsIncrementalGCUnsafe(rt) == AbortReason::None) {
-        CheckEdgeTracer cetrc(rt);
-
-        /* Start after the roots. */
-        VerifyNode* node = NextNode(trc->root);
-        while ((char*)node < trc->edgeptr) {
-            cetrc.node = node;
-            js::TraceChildren(&cetrc, node->thing, node->kind);
-
-            if (node->count <= MAX_VERIFIER_EDGES) {
-                for (uint32_t i = 0; i < node->count; i++) {
-                    EdgeValue& edge = node->edges[i];
-                    if (!IsMarkedOrAllocated(edge)) {
-                        char msgbuf[1024];
-                        SprintfLiteral(msgbuf,
-                                       "[barrier verifier] Unmarked edge: %s %p '%s' edge to %s %p",
-                                       JS::GCTraceKindToAscii(node->kind), node->thing,
-                                       edge.label,
-                                       JS::GCTraceKindToAscii(edge.kind), edge.thing);
-                        MOZ_ReportAssertionFailure(msgbuf, __FILE__, __LINE__);
-                        MOZ_CRASH();
-                    }
-                }
-            }
-
-            node = NextNode(node);
-        }
-    }
-
-    marker.reset();
-    marker.stop();
-
-    js_delete(trc);
-}
-
-/*** Barrier Verifier Scheduling ***/
-
-void
-gc::GCRuntime::verifyPreBarriers()
-{
-    if (verifyPreData)
-        endVerifyPreBarriers();
-    else
-        startVerifyPreBarriers();
-}
-
-void
-gc::VerifyBarriers(JSRuntime* rt, VerifierType type)
-{
-    if (type == PreBarrierVerifier)
-        rt->gc.verifyPreBarriers();
-}
-
-void
-gc::GCRuntime::maybeVerifyPreBarriers(bool always)
-{
-    if (!hasZealMode(ZealMode::VerifierPre))
-        return;
-
-    if (rt->mainThread.suppressGC)
-        return;
-
-    if (verifyPreData) {
-        if (++verifyPreData->count < zealFrequency && !always)
-            return;
-
-        endVerifyPreBarriers();
-    }
-
-    startVerifyPreBarriers();
-}
-
-void
-js::gc::MaybeVerifyBarriers(JSContext* cx, bool always)
-{
-    GCRuntime* gc = &cx->runtime()->gc;
-    gc->maybeVerifyPreBarriers(always);
-}
-
-void
-js::gc::GCRuntime::finishVerifier()
-{
-    if (verifyPreData) {
-        js_delete(verifyPreData);
-        verifyPreData = nullptr;
-    }
-}
-
-#endif /* JS_GC_ZEAL */
-
 #ifdef JSGC_HASH_TABLE_CHECKS
 
 class CheckHeapTracer : public JS::CallbackTracer