1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/js/src/gc/Zone.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,269 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
1.5 + * vim: set ts=8 sts=4 et sw=4 tw=99:
1.6 + * This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#include "gc/Zone.h"
1.11 +
1.12 +#include "jsgc.h"
1.13 +
1.14 +#ifdef JS_ION
1.15 +#include "jit/BaselineJIT.h"
1.16 +#include "jit/Ion.h"
1.17 +#include "jit/JitCompartment.h"
1.18 +#endif
1.19 +#include "vm/Debugger.h"
1.20 +#include "vm/Runtime.h"
1.21 +
1.22 +#include "jsgcinlines.h"
1.23 +
1.24 +using namespace js;
1.25 +using namespace js::gc;
1.26 +
1.27 +JS::Zone::Zone(JSRuntime *rt)
1.28 + : JS::shadow::Zone(rt, &rt->gcMarker),
1.29 + allocator(this),
1.30 + ionUsingBarriers_(false),
1.31 + active(false),
1.32 + gcScheduled(false),
1.33 + gcState(NoGC),
1.34 + gcPreserveCode(false),
1.35 + gcBytes(0),
1.36 + gcTriggerBytes(0),
1.37 + gcHeapGrowthFactor(3.0),
1.38 + isSystem(false),
1.39 + usedByExclusiveThread(false),
1.40 + scheduledForDestruction(false),
1.41 + maybeAlive(true),
1.42 + gcMallocBytes(0),
1.43 + gcMallocGCTriggered(false),
1.44 + gcGrayRoots(),
1.45 + data(nullptr),
1.46 + types(this)
1.47 +#ifdef JS_ION
1.48 + , jitZone_(nullptr)
1.49 +#endif
1.50 +{
1.51 + /* Ensure that there are no vtables to mess us up here. */
1.52 + JS_ASSERT(reinterpret_cast<JS::shadow::Zone *>(this) ==
1.53 + static_cast<JS::shadow::Zone *>(this));
1.54 +
1.55 + setGCMaxMallocBytes(rt->gcMaxMallocBytes * 0.9);
1.56 +}
1.57 +
1.58 +Zone::~Zone()
1.59 +{
1.60 + if (this == runtimeFromMainThread()->systemZone)
1.61 + runtimeFromMainThread()->systemZone = nullptr;
1.62 +
1.63 +#ifdef JS_ION
1.64 + js_delete(jitZone_);
1.65 +#endif
1.66 +}
1.67 +
1.68 +void
1.69 +Zone::setNeedsBarrier(bool needs, ShouldUpdateIon updateIon)
1.70 +{
1.71 +#ifdef JS_ION
1.72 + if (updateIon == UpdateIon && needs != ionUsingBarriers_) {
1.73 + jit::ToggleBarriers(this, needs);
1.74 + ionUsingBarriers_ = needs;
1.75 + }
1.76 +#endif
1.77 +
1.78 + if (needs && runtimeFromMainThread()->isAtomsZone(this))
1.79 + JS_ASSERT(!runtimeFromMainThread()->exclusiveThreadsPresent());
1.80 +
1.81 + JS_ASSERT_IF(needs, canCollect());
1.82 + needsBarrier_ = needs;
1.83 +}
1.84 +
1.85 +void
1.86 +Zone::resetGCMallocBytes()
1.87 +{
1.88 + gcMallocBytes = ptrdiff_t(gcMaxMallocBytes);
1.89 + gcMallocGCTriggered = false;
1.90 +}
1.91 +
1.92 +void
1.93 +Zone::setGCMaxMallocBytes(size_t value)
1.94 +{
1.95 + /*
1.96 + * For compatibility treat any value that exceeds PTRDIFF_T_MAX to
1.97 + * mean that value.
1.98 + */
1.99 + gcMaxMallocBytes = (ptrdiff_t(value) >= 0) ? value : size_t(-1) >> 1;
1.100 + resetGCMallocBytes();
1.101 +}
1.102 +
1.103 +void
1.104 +Zone::onTooMuchMalloc()
1.105 +{
1.106 + if (!gcMallocGCTriggered)
1.107 + gcMallocGCTriggered = TriggerZoneGC(this, JS::gcreason::TOO_MUCH_MALLOC);
1.108 +}
1.109 +
1.110 +void
1.111 +Zone::sweep(FreeOp *fop, bool releaseTypes, bool *oom)
1.112 +{
1.113 + /*
1.114 + * Periodically release observed types for all scripts. This is safe to
1.115 + * do when there are no frames for the zone on the stack.
1.116 + */
1.117 + if (active)
1.118 + releaseTypes = false;
1.119 +
1.120 + {
1.121 + gcstats::AutoPhase ap(fop->runtime()->gcStats, gcstats::PHASE_DISCARD_ANALYSIS);
1.122 + types.sweep(fop, releaseTypes, oom);
1.123 + }
1.124 +
1.125 + if (!fop->runtime()->debuggerList.isEmpty())
1.126 + sweepBreakpoints(fop);
1.127 +
1.128 + active = false;
1.129 +}
1.130 +
1.131 +void
1.132 +Zone::sweepBreakpoints(FreeOp *fop)
1.133 +{
1.134 + /*
1.135 + * Sweep all compartments in a zone at the same time, since there is no way
1.136 + * to iterate over the scripts belonging to a single compartment in a zone.
1.137 + */
1.138 +
1.139 + gcstats::AutoPhase ap1(fop->runtime()->gcStats, gcstats::PHASE_SWEEP_TABLES);
1.140 + gcstats::AutoPhase ap2(fop->runtime()->gcStats, gcstats::PHASE_SWEEP_TABLES_BREAKPOINT);
1.141 +
1.142 + JS_ASSERT(isGCSweeping());
1.143 + for (CellIterUnderGC i(this, FINALIZE_SCRIPT); !i.done(); i.next()) {
1.144 + JSScript *script = i.get<JSScript>();
1.145 + JS_ASSERT(script->zone()->isGCSweeping());
1.146 + if (!script->hasAnyBreakpointsOrStepMode())
1.147 + continue;
1.148 +
1.149 + bool scriptGone = IsScriptAboutToBeFinalized(&script);
1.150 + JS_ASSERT(script == i.get<JSScript>());
1.151 + for (unsigned i = 0; i < script->length(); i++) {
1.152 + BreakpointSite *site = script->getBreakpointSite(script->offsetToPC(i));
1.153 + if (!site)
1.154 + continue;
1.155 +
1.156 + Breakpoint *nextbp;
1.157 + for (Breakpoint *bp = site->firstBreakpoint(); bp; bp = nextbp) {
1.158 + nextbp = bp->nextInSite();
1.159 + HeapPtrObject& dbgobj = bp->debugger->toJSObjectRef();
1.160 + JS_ASSERT(dbgobj->zone()->isGCSweeping());
1.161 + bool dying = scriptGone || IsObjectAboutToBeFinalized(&dbgobj);
1.162 + JS_ASSERT_IF(!dying, bp->getHandler()->isMarked());
1.163 + if (dying)
1.164 + bp->destroy(fop);
1.165 + }
1.166 + }
1.167 + }
1.168 +}
1.169 +
1.170 +void
1.171 +Zone::discardJitCode(FreeOp *fop)
1.172 +{
1.173 +#ifdef JS_ION
1.174 + if (!jitZone())
1.175 + return;
1.176 +
1.177 + if (isPreservingCode()) {
1.178 + PurgeJITCaches(this);
1.179 + } else {
1.180 +
1.181 +# ifdef DEBUG
1.182 + /* Assert no baseline scripts are marked as active. */
1.183 + for (CellIterUnderGC i(this, FINALIZE_SCRIPT); !i.done(); i.next()) {
1.184 + JSScript *script = i.get<JSScript>();
1.185 + JS_ASSERT_IF(script->hasBaselineScript(), !script->baselineScript()->active());
1.186 + }
1.187 +# endif
1.188 +
1.189 + /* Mark baseline scripts on the stack as active. */
1.190 + jit::MarkActiveBaselineScripts(this);
1.191 +
1.192 + /* Only mark OSI points if code is being discarded. */
1.193 + jit::InvalidateAll(fop, this);
1.194 +
1.195 + for (CellIterUnderGC i(this, FINALIZE_SCRIPT); !i.done(); i.next()) {
1.196 + JSScript *script = i.get<JSScript>();
1.197 + jit::FinishInvalidation<SequentialExecution>(fop, script);
1.198 +
1.199 + // Preserve JIT code that have been recently used in
1.200 + // parallel. Note that we mark their baseline scripts as active as
1.201 + // well to preserve them.
1.202 + if (script->hasParallelIonScript()) {
1.203 + if (jit::ShouldPreserveParallelJITCode(runtimeFromMainThread(), script)) {
1.204 + script->parallelIonScript()->purgeCaches();
1.205 + script->baselineScript()->setActive();
1.206 + } else {
1.207 + jit::FinishInvalidation<ParallelExecution>(fop, script);
1.208 + }
1.209 + }
1.210 +
1.211 + /*
1.212 + * Discard baseline script if it's not marked as active. Note that
1.213 + * this also resets the active flag.
1.214 + */
1.215 + jit::FinishDiscardBaselineScript(fop, script);
1.216 +
1.217 + /*
1.218 + * Use counts for scripts are reset on GC. After discarding code we
1.219 + * need to let it warm back up to get information such as which
1.220 + * opcodes are setting array holes or accessing getter properties.
1.221 + */
1.222 + script->resetUseCount();
1.223 + }
1.224 +
1.225 + jitZone()->optimizedStubSpace()->free();
1.226 + }
1.227 +#endif
1.228 +}
1.229 +
1.230 +uint64_t
1.231 +Zone::gcNumber()
1.232 +{
1.233 + // Zones in use by exclusive threads are not collected, and threads using
1.234 + // them cannot access the main runtime's gcNumber without racing.
1.235 + return usedByExclusiveThread ? 0 : runtimeFromMainThread()->gcNumber;
1.236 +}
1.237 +
1.238 +#ifdef JS_ION
1.239 +js::jit::JitZone *
1.240 +Zone::createJitZone(JSContext *cx)
1.241 +{
1.242 + MOZ_ASSERT(!jitZone_);
1.243 +
1.244 + if (!cx->runtime()->getJitRuntime(cx))
1.245 + return nullptr;
1.246 +
1.247 + jitZone_ = cx->new_<js::jit::JitZone>();
1.248 + return jitZone_;
1.249 +}
1.250 +#endif
1.251 +
1.252 +JS::Zone *
1.253 +js::ZoneOfObject(const JSObject &obj)
1.254 +{
1.255 + return obj.zone();
1.256 +}
1.257 +
1.258 +JS::Zone *
1.259 +js::ZoneOfObjectFromAnyThread(const JSObject &obj)
1.260 +{
1.261 + return obj.zoneFromAnyThread();
1.262 +}
1.263 +
1.264 +bool
1.265 +Zone::hasMarkedCompartments()
1.266 +{
1.267 + for (CompartmentsInZoneIter comp(this); !comp.done(); comp.next()) {
1.268 + if (comp->marked)
1.269 + return true;
1.270 + }
1.271 + return false;
1.272 +}
