The Tor Browser: js/src/gc/Zone.cpp@6474c204b198 (annotated)

js/src/gc/Zone.cpp@6474c204b198 (annotated)

js/src/gc/Zone.cpp

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
  * vim: set ts=8 sts=4 et sw=4 tw=99:
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "gc/Zone.h"
 #include "jsgc.h"
 #ifdef JS_ION
 #include "jit/BaselineJIT.h"
 #include "jit/Ion.h"
 #include "jit/JitCompartment.h"
 #endif
 #include "vm/Debugger.h"
 #include "vm/Runtime.h"
 #include "jsgcinlines.h"
 using namespace js;
 using namespace js::gc;
 JS::Zone::Zone(JSRuntime *rt)
   : JS::shadow::Zone(rt, &rt->gcMarker),
     allocator(this),
     ionUsingBarriers_(false),
     active(false),
     gcScheduled(false),
     gcState(NoGC),
     gcPreserveCode(false),
     gcBytes(0),
     gcTriggerBytes(0),
     gcHeapGrowthFactor(3.0),
     isSystem(false),
     usedByExclusiveThread(false),
     scheduledForDestruction(false),
     maybeAlive(true),
     gcMallocBytes(0),
     gcMallocGCTriggered(false),
     gcGrayRoots(),
     data(nullptr),
     types(this)
 #ifdef JS_ION
     , jitZone_(nullptr)
 #endif
 {
     /* Ensure that there are no vtables to mess us up here. */
     JS_ASSERT(reinterpret_cast<JS::shadow::Zone *>(this) ==
               static_cast<JS::shadow::Zone *>(this));
     setGCMaxMallocBytes(rt->gcMaxMallocBytes * 0.9);
 }
 Zone::~Zone()
 {
     if (this == runtimeFromMainThread()->systemZone)
         runtimeFromMainThread()->systemZone = nullptr;
 #ifdef JS_ION
     js_delete(jitZone_);
 #endif
 }
 void
 Zone::setNeedsBarrier(bool needs, ShouldUpdateIon updateIon)
 {
 #ifdef JS_ION
     if (updateIon == UpdateIon && needs != ionUsingBarriers_) {
         jit::ToggleBarriers(this, needs);
         ionUsingBarriers_ = needs;
     }
 #endif
     if (needs && runtimeFromMainThread()->isAtomsZone(this))
         JS_ASSERT(!runtimeFromMainThread()->exclusiveThreadsPresent());
     JS_ASSERT_IF(needs, canCollect());
     needsBarrier_ = needs;
 }
 void
 Zone::resetGCMallocBytes()
 {
     gcMallocBytes = ptrdiff_t(gcMaxMallocBytes);
     gcMallocGCTriggered = false;
 }
 void
 Zone::setGCMaxMallocBytes(size_t value)
 {
     /*
      * For compatibility treat any value that exceeds PTRDIFF_T_MAX to
      * mean that value.
      */
     gcMaxMallocBytes = (ptrdiff_t(value) >= 0) ? value : size_t(-1) >> 1;
     resetGCMallocBytes();
 }
 void
 Zone::onTooMuchMalloc()
 {
     if (!gcMallocGCTriggered)
         gcMallocGCTriggered = TriggerZoneGC(this, JS::gcreason::TOO_MUCH_MALLOC);
 }
 void
 Zone::sweep(FreeOp *fop, bool releaseTypes, bool *oom)
 {
     /*
      * Periodically release observed types for all scripts. This is safe to
      * do when there are no frames for the zone on the stack.
      */
     if (active)
         releaseTypes = false;
     {
         gcstats::AutoPhase ap(fop->runtime()->gcStats, gcstats::PHASE_DISCARD_ANALYSIS);
         types.sweep(fop, releaseTypes, oom);
     }
     if (!fop->runtime()->debuggerList.isEmpty())
         sweepBreakpoints(fop);
     active = false;
 }
 void
 Zone::sweepBreakpoints(FreeOp *fop)
 {
     /*
      * Sweep all compartments in a zone at the same time, since there is no way
      * to iterate over the scripts belonging to a single compartment in a zone.
      */
     gcstats::AutoPhase ap1(fop->runtime()->gcStats, gcstats::PHASE_SWEEP_TABLES);
     gcstats::AutoPhase ap2(fop->runtime()->gcStats, gcstats::PHASE_SWEEP_TABLES_BREAKPOINT);
     JS_ASSERT(isGCSweeping());
     for (CellIterUnderGC i(this, FINALIZE_SCRIPT); !i.done(); i.next()) {
         JSScript *script = i.get<JSScript>();
         JS_ASSERT(script->zone()->isGCSweeping());
         if (!script->hasAnyBreakpointsOrStepMode())
             continue;
         bool scriptGone = IsScriptAboutToBeFinalized(&script);
         JS_ASSERT(script == i.get<JSScript>());
         for (unsigned i = 0; i < script->length(); i++) {
             BreakpointSite *site = script->getBreakpointSite(script->offsetToPC(i));
             if (!site)
                 continue;
             Breakpoint *nextbp;
             for (Breakpoint *bp = site->firstBreakpoint(); bp; bp = nextbp) {
                 nextbp = bp->nextInSite();
                 HeapPtrObject& dbgobj = bp->debugger->toJSObjectRef();
                 JS_ASSERT(dbgobj->zone()->isGCSweeping());
                 bool dying = scriptGone || IsObjectAboutToBeFinalized(&dbgobj);
                 JS_ASSERT_IF(!dying, bp->getHandler()->isMarked());
                 if (dying)
                     bp->destroy(fop);
             }
         }
     }
 }
 void
 Zone::discardJitCode(FreeOp *fop)
 {
 #ifdef JS_ION
     if (!jitZone())
         return;
     if (isPreservingCode()) {
         PurgeJITCaches(this);
     } else {
 # ifdef DEBUG
         /* Assert no baseline scripts are marked as active. */
         for (CellIterUnderGC i(this, FINALIZE_SCRIPT); !i.done(); i.next()) {
             JSScript *script = i.get<JSScript>();
             JS_ASSERT_IF(script->hasBaselineScript(), !script->baselineScript()->active());
         }
 # endif
         /* Mark baseline scripts on the stack as active. */
         jit::MarkActiveBaselineScripts(this);
         /* Only mark OSI points if code is being discarded. */
         jit::InvalidateAll(fop, this);
         for (CellIterUnderGC i(this, FINALIZE_SCRIPT); !i.done(); i.next()) {
             JSScript *script = i.get<JSScript>();
             jit::FinishInvalidation<SequentialExecution>(fop, script);
             // Preserve JIT code that have been recently used in
             // parallel. Note that we mark their baseline scripts as active as
             // well to preserve them.
             if (script->hasParallelIonScript()) {
                 if (jit::ShouldPreserveParallelJITCode(runtimeFromMainThread(), script)) {
                     script->parallelIonScript()->purgeCaches();
                     script->baselineScript()->setActive();
                 } else {
                     jit::FinishInvalidation<ParallelExecution>(fop, script);
                 }
             }
             /*
              * Discard baseline script if it's not marked as active. Note that
              * this also resets the active flag.
              */
             jit::FinishDiscardBaselineScript(fop, script);
             /*
              * Use counts for scripts are reset on GC. After discarding code we
              * need to let it warm back up to get information such as which
              * opcodes are setting array holes or accessing getter properties.
              */
             script->resetUseCount();
         }
         jitZone()->optimizedStubSpace()->free();
     }
 #endif
 }
 uint64_t
 Zone::gcNumber()
 {
     // Zones in use by exclusive threads are not collected, and threads using
     // them cannot access the main runtime's gcNumber without racing.
     return usedByExclusiveThread ? 0 : runtimeFromMainThread()->gcNumber;
 }
 #ifdef JS_ION
 js::jit::JitZone *
 Zone::createJitZone(JSContext *cx)
 {
     MOZ_ASSERT(!jitZone_);
     if (!cx->runtime()->getJitRuntime(cx))
         return nullptr;
     jitZone_ = cx->new_<js::jit::JitZone>();
     return jitZone_;
 }
 #endif
 JS::Zone *
 js::ZoneOfObject(const JSObject &obj)
 {
     return obj.zone();
 }
 JS::Zone *
 js::ZoneOfObjectFromAnyThread(const JSObject &obj)
 {
     return obj.zoneFromAnyThread();
 }
 bool
 Zone::hasMarkedCompartments()
 {
     for (CompartmentsInZoneIter comp(this); !comp.done(); comp.next()) {
         if (comp->marked)
             return true;
     }
     return false;
 }

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js/src/gc/Zone.cpp@6474c204b198 (annotated)

js/src/gc/Zone.cpp