/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* 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/. */
/* Shadow definition of |JS::Zone| innards. Do not use this directly! */
#ifndef js_shadow_Zone_h
#define js_shadow_Zone_h
#include "mozilla/Assertions.h" // MOZ_ASSERT
#include "mozilla/Atomics.h"
#include <stdint.h>
// uint8_t, uint32_t
#include "jspubtd.h" // js::CurrentThreadCanAccessRuntime
#include "jstypes.h" // js::Bit
struct JS_PUBLIC_API JSRuntime;
class JS_PUBLIC_API JSTracer;
namespace JS {
namespace shadow {
struct Zone {
enum GCState : uint32_t {
NoGC = 0,
Prepare,
MarkBlackOnly,
MarkBlackAndGray,
Sweep,
Finished,
Compact,
VerifyPreBarriers,
Limit
};
using BarrierState = mozilla::Atomic<uint32_t, mozilla::Relaxed>;
enum Kind : uint8_t { NormalZone, AtomsZone, SystemZone };
protected:
JSRuntime*
const runtime_;
JSTracer*
const barrierTracer_;
// A pointer to the JSRuntime's |gcMarker|.
BarrierState needsIncrementalBarrier_;
GCState gcState_ = NoGC;
const Kind kind_;
Zone(JSRuntime* runtime, JSTracer* barrierTracerArg, Kind kind)
: runtime_(runtime), barrierTracer_(barrierTracerArg), kind_(kind) {
MOZ_ASSERT(!needsIncrementalBarrier());
}
public:
bool needsIncrementalBarrier()
const {
return needsIncrementalBarrier_; }
JSTracer* barrierTracer() {
MOZ_ASSERT(needsIncrementalBarrier_);
MOZ_ASSERT(js::CurrentThreadCanAccessRuntime(runtime_));
return barrierTracer_;
}
JSRuntime* runtimeFromMainThread()
const {
MOZ_ASSERT(js::CurrentThreadCanAccessRuntime(runtime_));
return runtime_;
}
// Note: Unrestricted access to the zone's runtime from an arbitrary
// thread can easily lead to races. Use this method very carefully.
JSRuntime* runtimeFromAnyThread()
const {
return runtime_; }
GCState gcState()
const {
return GCState(uint32_t(gcState_)); }
static constexpr uint32_t gcStateMask(GCState state) {
static_assert(uint32_t(Limit) < 32);
return js::Bit(state);
}
bool hasAnyGCState(uint32_t stateMask)
const {
return js::Bit(gcState_) & stateMask;
}
bool wasGCStarted()
const {
return gcState() != NoGC; }
bool isGCPreparing()
const {
return gcState() == Prepare; }
bool isGCMarkingBlackOnly()
const {
return gcState() == MarkBlackOnly; }
bool isGCMarkingBlackAndGray()
const {
return gcState() == MarkBlackAndGray; }
bool isGCSweeping()
const {
return gcState() == Sweep; }
bool isGCFinished()
const {
return gcState() == Finished; }
bool isGCCompacting()
const {
return gcState() == Compact; }
bool isGCMarking()
const {
return hasAnyGCState(gcStateMask(MarkBlackOnly) |
gcStateMask(MarkBlackAndGray));
}
bool isGCMarkingOrSweeping()
const {
return hasAnyGCState(gcStateMask(MarkBlackOnly) |
gcStateMask(MarkBlackAndGray) | gcStateMask(Sweep));
}
bool isGCMarkingOrVerifyingPreBarriers()
const {
return hasAnyGCState(gcStateMask(MarkBlackOnly) |
gcStateMask(MarkBlackAndGray) |
gcStateMask(VerifyPreBarriers));
}
bool isGCSweepingOrCompacting()
const {
return hasAnyGCState(gcStateMask(Sweep) | gcStateMask(Compact));
}
bool isVerifyingPreBarriers()
const {
return gcState() == VerifyPreBarriers; }
bool isAtomsZone()
const {
return kind_ == AtomsZone; }
bool isSystemZone()
const {
return kind_ == SystemZone; }
static shadow::Zone* from(JS::Zone* zone) {
return reinterpret_cast<shadow::Zone*>(zone);
}
static const shadow::Zone* from(
const JS::Zone* zone) {
return reinterpret_cast<
const shadow::Zone*>(zone);
}
};
}
// namespace shadow
}
// namespace JS
#endif // js_shadow_Zone_h
