Diff
Modified: branches/safari-603-branch/JSTests/ChangeLog (210633 => 210634)
--- branches/safari-603-branch/JSTests/ChangeLog 2017-01-12 16:44:36 UTC (rev 210633)
+++ branches/safari-603-branch/JSTests/ChangeLog 2017-01-12 16:44:41 UTC (rev 210634)
@@ -1,3 +1,17 @@
+2017-01-11 Matthew Hanson <[email protected]>
+
+ Merge r210451. rdar://problem/29909812
+
+ 2016-12-30 Filip Pizlo <[email protected]>
+
+ DeferGC::~DeferGC should be super cheap
+ https://bugs.webkit.org/show_bug.cgi?id=166626
+
+ Reviewed by Saam Barati.
+
+ * stress/slow-path-generator-updating-current-node-dfg.js:
+ * stress/unshift-array-storage.js:
+
2017-01-10 Matthew Hanson <[email protected]>
Rollout r210336. rdar://problem/29912353
Modified: branches/safari-603-branch/JSTests/stress/slow-path-generator-updating-current-node-dfg.js (210633 => 210634)
--- branches/safari-603-branch/JSTests/stress/slow-path-generator-updating-current-node-dfg.js 2017-01-12 16:44:36 UTC (rev 210633)
+++ branches/safari-603-branch/JSTests/stress/slow-path-generator-updating-current-node-dfg.js 2017-01-12 16:44:41 UTC (rev 210634)
@@ -1,4 +1,7 @@
-//@ runFTLNoCJIT("--deferGCShouldCollectWithProbability=true", "--deferGCProbability=1.0")
+// FIXME: Bring back something like the deferGC probability mode.
+// https://bugs.webkit.org/show_bug.cgi?id=166627
+//@ skip
+// //@ runFTLNoCJIT("--deferGCShouldCollectWithProbability=true", "--deferGCProbability=1.0")
function foo(a) {
return a.push(25);
Modified: branches/safari-603-branch/JSTests/stress/unshift-array-storage.js (210633 => 210634)
--- branches/safari-603-branch/JSTests/stress/unshift-array-storage.js 2017-01-12 16:44:36 UTC (rev 210633)
+++ branches/safari-603-branch/JSTests/stress/unshift-array-storage.js 2017-01-12 16:44:41 UTC (rev 210634)
@@ -1,4 +1,7 @@
-//@ runFTLNoCJIT("--scribbleFreeCells=true", "--deferGCShouldCollectWithProbability=true", "--deferGCProbability=1")
+// FIXME: Bring back something like the deferGC probability mode.
+// https://bugs.webkit.org/show_bug.cgi?id=166627
+//@ skip
+// //@ runFTLNoCJIT("--scribbleFreeCells=true", "--deferGCShouldCollectWithProbability=true", "--deferGCProbability=1")
// Create some array storage.
var array = [];
Modified: branches/safari-603-branch/Source/_javascript_Core/ChangeLog (210633 => 210634)
--- branches/safari-603-branch/Source/_javascript_Core/ChangeLog 2017-01-12 16:44:36 UTC (rev 210633)
+++ branches/safari-603-branch/Source/_javascript_Core/ChangeLog 2017-01-12 16:44:41 UTC (rev 210634)
@@ -1,5 +1,52 @@
2017-01-11 Matthew Hanson <[email protected]>
+ Merge r210451. rdar://problem/29909812
+
+ 2016-12-30 Filip Pizlo <[email protected]>
+
+ DeferGC::~DeferGC should be super cheap
+ https://bugs.webkit.org/show_bug.cgi?id=166626
+
+ Reviewed by Saam Barati.
+
+ Right now, ~DeferGC requires running the collector's full collectIfNecessaryOrDefer()
+ hook, which is super big. Normally, that hook would only be called from GC slow paths,
+ so it ought to be possible to add complex logic to it. It benefits the GC algorithm to
+ make that code smart, not necessarily fast.
+
+ The right thing for it to do is to have ~DeferGC check a boolean to see if
+ collectIfNecessaryOrDefer() had previously deferred anything, and only call it if that
+ is true. That's what this patch does.
+
+ Unfortunately, this means that we lose the collectAccordingToDeferGCProbability mode,
+ which we used for two tests. Since I could only see two tests that used this mode, I
+ felt that it was better to enhance the GC than to keep the tests. I filed bug 166627 to
+ bring back something like that mode.
+
+ Although this patch does make some paths faster, its real goal is to ensure that bug
+ 165963 can add more logic to collectIfNecessaryOrDefer() without introducing a big
+ regression. Until then, I wouldn't be surprised if this patch was a progression, but I'm
+ not betting on it.
+
+ * heap/Heap.cpp:
+ (JSC::Heap::collectIfNecessaryOrDefer):
+ (JSC::Heap::decrementDeferralDepthAndGCIfNeededSlow):
+ (JSC::Heap::canCollect): Deleted.
+ (JSC::Heap::shouldCollectHeuristic): Deleted.
+ (JSC::Heap::shouldCollect): Deleted.
+ (JSC::Heap::collectAccordingToDeferGCProbability): Deleted.
+ (JSC::Heap::decrementDeferralDepthAndGCIfNeeded): Deleted.
+ * heap/Heap.h:
+ * heap/HeapInlines.h:
+ (JSC::Heap::incrementDeferralDepth):
+ (JSC::Heap::decrementDeferralDepth):
+ (JSC::Heap::decrementDeferralDepthAndGCIfNeeded):
+ (JSC::Heap::mayNeedToStop):
+ (JSC::Heap::stopIfNecessary):
+ * runtime/Options.h:
+
+2017-01-11 Matthew Hanson <[email protected]>
+
Merge r210398. rdar://problem/29229439
2017-01-05 Filip Pizlo <[email protected]>
Modified: branches/safari-603-branch/Source/_javascript_Core/heap/Heap.cpp (210633 => 210634)
--- branches/safari-603-branch/Source/_javascript_Core/heap/Heap.cpp 2017-01-12 16:44:36 UTC (rev 210633)
+++ branches/safari-603-branch/Source/_javascript_Core/heap/Heap.cpp 2017-01-12 16:44:41 UTC (rev 210634)
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2003-2009, 2011, 2013-2016 Apple Inc. All rights reserved.
+ * Copyright (C) 2003-2017 Apple Inc. All rights reserved.
* Copyright (C) 2007 Eric Seidel <[email protected]>
*
* This library is free software; you can redistribute it and/or
@@ -2023,29 +2023,6 @@
addToRememberedSet(from);
}
-bool Heap::canCollect()
-{
- if (isDeferred())
- return false;
- if (!m_isSafeToCollect)
- return false;
- if (mutatorState() == MutatorState::HelpingGC)
- return false;
- return true;
-}
-
-bool Heap::shouldCollectHeuristic()
-{
- if (Options::gcMaxHeapSize())
- return m_bytesAllocatedThisCycle > Options::gcMaxHeapSize();
- return m_bytesAllocatedThisCycle > m_maxEdenSize;
-}
-
-bool Heap::shouldCollect()
-{
- return canCollect() && shouldCollectHeuristic();
-}
-
bool Heap::isCurrentThreadBusy()
{
return mayBeGCThread() || mutatorState() != MutatorState::Running;
@@ -2077,49 +2054,55 @@
bool Heap::collectIfNecessaryOrDefer(GCDeferralContext* deferralContext)
{
- if (!canCollect())
+ ASSERT(!DisallowGC::isGCDisallowedOnCurrentThread());
+
+ if (!m_isSafeToCollect)
return false;
+ if (mutatorState() == MutatorState::HelpingGC)
+ return false;
+ if (!Options::useGC())
+ return false;
- if (deferralContext) {
- deferralContext->m_shouldGC |=
- !!(m_worldState.load() & (shouldStopBit | needFinalizeBit | gcDidJITBit));
- } else
- stopIfNecessary();
+ if (mayNeedToStop()) {
+ if (deferralContext)
+ deferralContext->m_shouldGC = true;
+ else if (isDeferred())
+ m_didDeferGCWork = true;
+ else
+ stopIfNecessary();
+ }
- if (!shouldCollectHeuristic())
- return false;
+ if (UNLIKELY(Options::gcMaxHeapSize())) {
+ if (m_bytesAllocatedThisCycle <= Options::gcMaxHeapSize())
+ return false;
+ } else {
+ if (m_bytesAllocatedThisCycle <= m_maxEdenSize)
+ return false;
+ }
if (deferralContext)
deferralContext->m_shouldGC = true;
+ else if (isDeferred())
+ m_didDeferGCWork = true;
else
collectAsync();
return true;
}
-void Heap::collectAccordingToDeferGCProbability()
+void Heap::decrementDeferralDepthAndGCIfNeededSlow()
{
- if (isDeferred() || !m_isSafeToCollect || collectionScope() || mutatorState() == MutatorState::HelpingGC)
+ // Can't do anything if we're still deferred.
+ if (m_deferralDepth)
return;
-
- if (randomNumber() < Options::deferGCProbability()) {
- collectAsync();
- return;
- }
-
- // If our coin flip told us not to GC, we still might GC,
- // but we GC according to our memory pressure markers.
+
+ ASSERT(!isDeferred());
+
+ m_didDeferGCWork = false;
+ // FIXME: Bring back something like the DeferGCProbability mode.
+ // https://bugs.webkit.org/show_bug.cgi?id=166627
collectIfNecessaryOrDefer();
}
-void Heap::decrementDeferralDepthAndGCIfNeeded()
-{
- decrementDeferralDepth();
- if (UNLIKELY(Options::deferGCShouldCollectWithProbability()))
- collectAccordingToDeferGCProbability();
- else
- collectIfNecessaryOrDefer();
-}
-
void Heap::registerWeakGCMap(void* weakGCMap, std::function<void()> pruningCallback)
{
m_weakGCMaps.add(weakGCMap, WTFMove(pruningCallback));
Modified: branches/safari-603-branch/Source/_javascript_Core/heap/Heap.h (210633 => 210634)
--- branches/safari-603-branch/Source/_javascript_Core/heap/Heap.h 2017-01-12 16:44:36 UTC (rev 210633)
+++ branches/safari-603-branch/Source/_javascript_Core/heap/Heap.h 2017-01-12 16:44:41 UTC (rev 210634)
@@ -1,7 +1,7 @@
/*
* Copyright (C) 1999-2000 Harri Porten ([email protected])
* Copyright (C) 2001 Peter Kelly ([email protected])
- * Copyright (C) 2003-2009, 2013-2016 Apple Inc. All rights reserved.
+ * Copyright (C) 2003-2017 Apple Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
@@ -185,9 +185,7 @@
JS_EXPORT_PRIVATE void collectAllGarbageIfNotDoneRecently();
JS_EXPORT_PRIVATE void collectAllGarbage();
- bool canCollect();
bool shouldCollectHeuristic();
- bool shouldCollect();
// Queue up a collection. Returns immediately. This will not queue a collection if a collection
// of equal or greater strength exists. Full collections are stronger than std::nullopt collections
@@ -204,7 +202,6 @@
JS_EXPORT_PRIVATE void collectSync(std::optional<CollectionScope> = std::nullopt);
bool collectIfNecessaryOrDefer(GCDeferralContext* = nullptr); // Returns true if it did collect.
- void collectAccordingToDeferGCProbability();
void completeAllJITPlans();
@@ -268,7 +265,7 @@
void addReference(JSCell*, ArrayBuffer*);
- bool isDeferred() const { return !!m_deferralDepth || !Options::useGC(); }
+ bool isDeferred() const { return !!m_deferralDepth; }
StructureIDTable& structureIDTable() { return m_structureIDTable; }
@@ -341,6 +338,8 @@
// already be called for you at the right times.
void stopIfNecessary();
+ bool mayNeedToStop();
+
// This is a much stronger kind of stopping of the collector, and it may require waiting for a
// while. This is meant to be a legacy API for clients of collectAllGarbage that expect that there
// is no GC before or after that function call. After calling this, you are free to start GCs
@@ -488,7 +487,8 @@
void incrementDeferralDepth();
void decrementDeferralDepth();
- JS_EXPORT_PRIVATE void decrementDeferralDepthAndGCIfNeeded();
+ void decrementDeferralDepthAndGCIfNeeded();
+ JS_EXPORT_PRIVATE void decrementDeferralDepthAndGCIfNeededSlow();
size_t threadVisitCount();
size_t threadBytesVisited();
@@ -579,6 +579,7 @@
Vector<HeapObserver*> m_observers;
unsigned m_deferralDepth;
+ bool m_didDeferGCWork { false };
std::unique_ptr<HeapVerifier> m_verifier;
Modified: branches/safari-603-branch/Source/_javascript_Core/heap/HeapInlines.h (210633 => 210634)
--- branches/safari-603-branch/Source/_javascript_Core/heap/HeapInlines.h 2017-01-12 16:44:36 UTC (rev 210633)
+++ branches/safari-603-branch/Source/_javascript_Core/heap/HeapInlines.h 2017-01-12 16:44:41 UTC (rev 210634)
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2014-2016 Apple Inc. All rights reserved.
+ * Copyright (C) 2014-2017 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -315,16 +315,47 @@
inline void Heap::incrementDeferralDepth()
{
- RELEASE_ASSERT(m_deferralDepth < 100); // Sanity check to make sure this doesn't get ridiculous.
+ ASSERT(!mayBeGCThread() || m_collectorBelievesThatTheWorldIsStopped);
m_deferralDepth++;
}
inline void Heap::decrementDeferralDepth()
{
- RELEASE_ASSERT(m_deferralDepth >= 1);
+ ASSERT(!mayBeGCThread() || m_collectorBelievesThatTheWorldIsStopped);
m_deferralDepth--;
}
+inline void Heap::decrementDeferralDepthAndGCIfNeeded()
+{
+ ASSERT(!mayBeGCThread() || m_collectorBelievesThatTheWorldIsStopped);
+ m_deferralDepth--;
+
+ if (UNLIKELY(m_didDeferGCWork)) {
+ decrementDeferralDepthAndGCIfNeededSlow();
+
+ // Here are the possible relationships between m_deferralDepth and m_didDeferGCWork.
+ // Note that prior to the call to decrementDeferralDepthAndGCIfNeededSlow,
+ // m_didDeferGCWork had to have been true. Now it can be either false or true. There is
+ // nothing we can reliably assert.
+ //
+ // Possible arrangements of m_didDeferGCWork and !!m_deferralDepth:
+ //
+ // Both false: We popped out of all DeferGCs and we did whatever work was deferred.
+ //
+ // Only m_didDeferGCWork is true: We stopped for GC and the GC did DeferGC. This is
+ // possible because of how we handle the baseline JIT's worklist. It's also perfectly
+ // safe because it only protects reportExtraMemory. We can just ignore this.
+ //
+ // Only !!m_deferralDepth is true: m_didDeferGCWork had been set spuriously. It is only
+ // cleared by decrementDeferralDepthAndGCIfNeededSlow(). So, if we had deferred work but
+ // then decrementDeferralDepth()'d, then we might have the bit set even if we GC'd since
+ // then.
+ //
+ // Both true: We're in a recursive ~DeferGC. We wanted to do something about the
+ // deferred work, but were unable to.
+ }
+}
+
inline HashSet<MarkedArgumentBuffer*>& Heap::markListSet()
{
if (!m_markListSet)
@@ -363,11 +394,15 @@
releaseAccessSlow();
}
+inline bool Heap::mayNeedToStop()
+{
+ return m_worldState.loadRelaxed() != hasAccessBit;
+}
+
inline void Heap::stopIfNecessary()
{
- if (m_worldState.loadRelaxed() == hasAccessBit)
- return;
- stopIfNecessarySlow();
+ if (mayNeedToStop())
+ stopIfNecessarySlow();
}
inline void Heap::writeBarrierOpaqueRoot(void* root)
Modified: branches/safari-603-branch/Source/_javascript_Core/runtime/Options.cpp (210633 => 210634)
--- branches/safari-603-branch/Source/_javascript_Core/runtime/Options.cpp 2017-01-12 16:44:36 UTC (rev 210633)
+++ branches/safari-603-branch/Source/_javascript_Core/runtime/Options.cpp 2017-01-12 16:44:41 UTC (rev 210634)
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2011-2012, 2014-2016 Apple Inc. All rights reserved.
+ * Copyright (C) 2011-2017 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -418,7 +418,6 @@
ASSERT((static_cast<int64_t>(Options::thresholdForOptimizeAfterLongWarmUp()) << Options::reoptimizationRetryCounterMax()) > 0);
ASSERT((static_cast<int64_t>(Options::thresholdForOptimizeAfterLongWarmUp()) << Options::reoptimizationRetryCounterMax()) <= static_cast<int64_t>(std::numeric_limits<int32_t>::max()));
- ASSERT(Options::deferGCProbability() >= 0.0 && Options::deferGCProbability() <= 1.0);
#if ENABLE(LLINT_STATS)
LLInt::Data::loadStats();
Modified: branches/safari-603-branch/Source/_javascript_Core/runtime/Options.h (210633 => 210634)
--- branches/safari-603-branch/Source/_javascript_Core/runtime/Options.h 2017-01-12 16:44:36 UTC (rev 210633)
+++ branches/safari-603-branch/Source/_javascript_Core/runtime/Options.h 2017-01-12 16:44:41 UTC (rev 210634)
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2011-2016 Apple Inc. All rights reserved.
+ * Copyright (C) 2011-2017 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -330,8 +330,6 @@
v(double, minHeapUtilization, 0.8, Normal, nullptr) \
v(double, minMarkedBlockUtilization, 0.9, Normal, nullptr) \
v(unsigned, slowPathAllocsBetweenGCs, 0, Normal, "force a GC on every Nth slow path alloc, where N is specified by this option") \
- v(bool, deferGCShouldCollectWithProbability, false, Normal, "If true, we perform a collection based on flipping a coin according the probability in the 'deferGCProbability' option when DeferGC is destructed.") \
- v(double, deferGCProbability, 1.0, Normal, "Should be a number between 0 and 1. 1 means DeferGC always GCs when it's destructed and GCing is safe. 0.7 means we force GC 70% the time on DeferGC destruction.") \
\
v(double, percentCPUPerMBForFullTimer, 0.0003125, Normal, nullptr) \
v(double, percentCPUPerMBForEdenTimer, 0.0025, Normal, nullptr) \
Modified: branches/safari-603-branch/Source/_javascript_Core/runtime/ScriptExecutable.cpp (210633 => 210634)
--- branches/safari-603-branch/Source/_javascript_Core/runtime/ScriptExecutable.cpp 2017-01-12 16:44:36 UTC (rev 210633)
+++ branches/safari-603-branch/Source/_javascript_Core/runtime/ScriptExecutable.cpp 2017-01-12 16:44:41 UTC (rev 210634)
@@ -77,8 +77,6 @@
void ScriptExecutable::installCode(VM& vm, CodeBlock* genericCodeBlock, CodeType codeType, CodeSpecializationKind kind)
{
- ASSERT(vm.heap.isDeferred());
-
if (genericCodeBlock)
CODEBLOCK_LOG_EVENT(genericCodeBlock, "installCode", ());
