/* -*- 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/. */
#ifndef jscompartment_h
#define jscompartment_h
#include "mozilla/MemoryReporting.h"
#include "builtin/TypedObject.h"
#include "gc/Zone.h"
#include "vm/GlobalObject.h"
#include "vm/PIC.h"
#include "vm/SavedStacks.h"
namespace js {
namespace jit {
class JitCompartment;
}
namespace gc {
template<class Node> class ComponentFinder;
}
struct NativeIterator;
/*
* A single-entry cache for some base-10 double-to-string conversions. This
* helps date-format-xparb.js. It also avoids skewing the results for
* v8-splay.js when measured by the SunSpider harness, where the splay tree
* initialization (which includes many repeated double-to-string conversions)
* is erroneously included in the measurement; see bug 562553.
*/
class DtoaCache {
double d;
int base;
JSFlatString* s; // if s==nullptr, d and base are not valid
public:
DtoaCache() : s(nullptr) {}
void purge() { s = nullptr; }
JSFlatString* lookup(int base, double d) {
return this->s && base == this->base && d == this->d ? this->s : nullptr;
}
void cache(int base, double d, JSFlatString* s) {
this->base = base;
this->d = d;
this->s = s;
}
};
/* If HashNumber grows, need to change WrapperHasher. */
JS_STATIC_ASSERT(sizeof(HashNumber) == 4);
struct CrossCompartmentKey
{
enum Kind {
ObjectWrapper,
StringWrapper,
DebuggerScript,
DebuggerSource,
DebuggerObject,
DebuggerEnvironment
};
Kind kind;
JSObject* debugger;
js::gc::Cell* wrapped;
CrossCompartmentKey()
: kind(ObjectWrapper), debugger(nullptr), wrapped(nullptr) {}
CrossCompartmentKey(JSObject* wrapped)
: kind(ObjectWrapper), debugger(nullptr), wrapped(wrapped) {}
CrossCompartmentKey(JSString* wrapped)
: kind(StringWrapper), debugger(nullptr), wrapped(wrapped) {}
CrossCompartmentKey(Value wrapped)
: kind(wrapped.isString() ? StringWrapper : ObjectWrapper),
debugger(nullptr),
wrapped((js::gc::Cell*)wrapped.toGCThing()) {}
CrossCompartmentKey(const RootedValue& wrapped)
: kind(wrapped.get().isString() ? StringWrapper : ObjectWrapper),
debugger(nullptr),
wrapped((js::gc::Cell*)wrapped.get().toGCThing()) {}
CrossCompartmentKey(Kind kind, JSObject* dbg, js::gc::Cell* wrapped)
: kind(kind), debugger(dbg), wrapped(wrapped) {}
};
struct WrapperHasher : public DefaultHasher<CrossCompartmentKey>
{
static HashNumber hash(const CrossCompartmentKey& key) {
JS_ASSERT(!IsPoisonedPtr(key.wrapped));
return uint32_t(uintptr_t(key.wrapped)) | uint32_t(key.kind);
}
static bool match(const CrossCompartmentKey& l, const CrossCompartmentKey& k) {
return l.kind == k.kind && l.debugger == k.debugger && l.wrapped == k.wrapped;
}
};
typedef HashMap<CrossCompartmentKey, ReadBarrieredValue,
WrapperHasher, SystemAllocPolicy> WrapperMap;
} /* namespace js */
namespace JS {
struct TypeInferenceSizes;
}
namespace js {
class AutoDebugModeInvalidation;
class DebugScopes;
class WeakMapBase;
}
struct JSCompartment
{
JS::CompartmentOptions options_;
private:
JS::Zone* zone_;
JSRuntime* runtime_;
public:
JSPrincipals* principals;
bool isSystem;
bool isSelfHosting;
bool marked;
#ifdef DEBUG
bool firedOnNewGlobalObject;
#endif
void mark() { marked = true; }
private:
friend struct JSRuntime;
friend struct JSContext;
friend class js::ExclusiveContext;
js::ReadBarriered<js::GlobalObject> global_;
unsigned enterCompartmentDepth;
public:
void enter() { enterCompartmentDepth++; }
void leave() { enterCompartmentDepth--; }
bool hasBeenEntered() { return !!enterCompartmentDepth; }
JS::Zone* zone() { return zone_; }
const JS::Zone* zone() const { return zone_; }
JS::CompartmentOptions& options() { return options_; }
const JS::CompartmentOptions& options() const { return options_; }
JSRuntime* runtimeFromMainThread() {
JS_ASSERT(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_;
}
/*
* Nb: global_ might be nullptr, if (a) it's the atoms compartment, or
* (b) the compartment's global has been collected. The latter can happen
* if e.g. a string in a compartment is rooted but no object is, and thus
* the global isn't rooted, and thus the global can be finalized while the
* compartment lives on.
*
* In contrast, JSObject::global() is infallible because marking a JSObject
* always marks its global as well.
* TODO: add infallible JSScript::global()
*/
inline js::GlobalObject* maybeGlobal() const;
inline void initGlobal(js::GlobalObject& global);
public:
/*
* Moves all data from the allocator |workerAllocator|, which was
* in use by a parallel worker, into the compartment's main
* allocator. This is used at the end of a parallel section.
*/
void adoptWorkerAllocator(js::Allocator* workerAllocator);
bool activeAnalysis;
/* Type information about the scripts and objects in this compartment. */
js::types::TypeCompartment types;
void* data;
private:
js::ObjectMetadataCallback objectMetadataCallback;
js::SavedStacks savedStacks_;
js::WrapperMap crossCompartmentWrappers;
public:
/* Last time at which an animation was played for a global in this compartment. */
int64_t lastAnimationTime;
js::RegExpCompartment regExps;
/*
* For generational GC, record whether a write barrier has added this
* compartment's global to the store buffer since the last minor GC.
*
* This is used to avoid adding it to the store buffer on every write, which
* can quickly fill the buffer and also cause performance problems.
*/
bool globalWriteBarriered;
public:
void addSizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf,
size_t* tiAllocationSiteTables,
size_t* tiArrayTypeTables,
size_t* tiObjectTypeTables,
size_t* compartmentObject,
size_t* shapesCompartmentTables,
size_t* crossCompartmentWrappers,
size_t* regexpCompartment,
size_t* debuggeesSet,
size_t* savedStacksSet);
/*
* Shared scope property tree, and arena-pool for allocating its nodes.
*/
js::PropertyTree propertyTree;
/* Set of all unowned base shapes in the compartment. */
js::BaseShapeSet baseShapes;
void sweepBaseShapeTable();
/* Set of initial shapes in the compartment. */
js::InitialShapeSet initialShapes;
void sweepInitialShapeTable();
/* Set of default 'new' or lazy types in the compartment. */
js::types::TypeObjectWithNewScriptSet newTypeObjects;
js::types::TypeObjectWithNewScriptSet lazyTypeObjects;
void sweepNewTypeObjectTable(js::types::TypeObjectWithNewScriptSet& table);
#if defined(JSGC_GENERATIONAL) && defined(JS_GC_ZEAL)
void checkNewTypeObjectTableAfterMovingGC();
void checkInitialShapesTableAfterMovingGC();
void checkWrapperMapAfterMovingGC();
#endif
/*
* Hash table of all manually call site-cloned functions from within
* self-hosted code. Cloning according to call site provides extra
* sensitivity for type specialization and inlining.
*/
js::CallsiteCloneTable callsiteClones;
void sweepCallsiteClones();
/*
* Lazily initialized script source object to use for scripts cloned
* from the self-hosting global.
*/
js::ReadBarriered<js::ScriptSourceObject> selfHostingScriptSource;
/* During GC, stores the index of this compartment in rt->compartments. */
unsigned gcIndex;
/*
* During GC, stores the head of a list of incoming pointers from gray cells.
*
* The objects in the list are either cross-compartment wrappers, or
* debugger wrapper objects. The list link is either in the second extra
* slot for the former, or a special slot for the latter.
*/
JSObject* gcIncomingGrayPointers;
/* During GC, list of live array buffers with >1 view accumulated during tracing. */
js::ArrayBufferVector gcLiveArrayBuffers;
/* Linked list of live weakmaps in this compartment. */
js::WeakMapBase* gcWeakMapList;
private:
enum {
DebugFromC = 1 << 0,
DebugFromJS = 1 << 1,
DebugNeedDelazification = 1 << 2
};
static const unsigned DebugModeFromMask = DebugFromC | DebugFromJS;
unsigned debugModeBits; // see debugMode() below
public:
JSCompartment(JS::Zone* zone, const JS::CompartmentOptions& options);
~JSCompartment();
bool init(JSContext* cx);
/* Mark cross-compartment wrappers. */
void markCrossCompartmentWrappers(JSTracer* trc);
inline bool wrap(JSContext* cx, JS::MutableHandleValue vp,
JS::HandleObject existing = js::NullPtr());
bool wrap(JSContext* cx, JSString** strp);
bool wrap(JSContext* cx, js::HeapPtrString* strp);
bool wrap(JSContext* cx, JS::MutableHandleObject obj,
JS::HandleObject existingArg = js::NullPtr());
bool wrapId(JSContext* cx, jsid* idp);
bool wrap(JSContext* cx, js::PropertyOp* op);
bool wrap(JSContext* cx, js::StrictPropertyOp* op);
bool wrap(JSContext* cx, JS::MutableHandle<js::PropertyDescriptor> desc);
bool wrap(JSContext* cx, js::AutoIdVector& props);
bool putWrapper(JSContext* cx, const js::CrossCompartmentKey& wrapped, const js::Value& wrapper);
js::WrapperMap::Ptr lookupWrapper(const js::Value& wrapped) {
return crossCompartmentWrappers.lookup(wrapped);
}
void removeWrapper(js::WrapperMap::Ptr p) {
crossCompartmentWrappers.remove(p);
}
struct WrapperEnum : public js::WrapperMap::Enum {
WrapperEnum(JSCompartment* c) : js::WrapperMap::Enum(c->crossCompartmentWrappers) {}
};
void trace(JSTracer* trc);
void markRoots(JSTracer* trc);
bool isDiscardingJitCode(JSTracer* trc);
void sweep(js::FreeOp* fop, bool releaseTypes);
void sweepCrossCompartmentWrappers();
void purge();
void clearTables();
bool hasObjectMetadataCallback() const { return objectMetadataCallback; }
void setObjectMetadataCallback(js::ObjectMetadataCallback callback);
bool callObjectMetadataCallback(JSContext* cx, JSObject** obj) const {
return objectMetadataCallback(cx, obj);
}
js::SavedStacks& savedStacks() { return savedStacks_; }
void findOutgoingEdges(js::gc::ComponentFinder<JS::Zone>& finder);
js::DtoaCache dtoaCache;
/* Random number generator state, used by jsmath.cpp. */
uint64_t rngState;
private:
/*
* Weak reference to each global in this compartment that is a debuggee.
* Each global has its own list of debuggers.
*/
js::GlobalObjectSet debuggees;
private:
JSCompartment* thisForCtor() { return this; }
public:
/*
* There are dueling APIs for debug mode. It can be enabled or disabled via
* JS_SetDebugModeForCompartment. It is automatically enabled and disabled
* by Debugger objects. Therefore debugModeBits has the DebugFromC bit set
* if the C API wants debug mode and the DebugFromJS bit set if debuggees
* is non-empty.
*
* When toggling on, DebugNeedDelazification is set to signal that
* Debugger methods which depend on seeing all scripts (like findScripts)
* need to delazify the scripts in the compartment first.
*/
bool debugMode() const {
return !!(debugModeBits & DebugModeFromMask);
}
/* True if any scripts from this compartment are on the JS stack. */
bool hasScriptsOnStack();
/*
* Schedule the compartment to be delazified. Called from
* LazyScript::Create.
*/
void scheduleDelazificationForDebugMode() {
debugModeBits |= DebugNeedDelazification;
}
/*
* If we scheduled delazification for turning on debug mode, delazify all
* scripts.
*/
bool ensureDelazifyScriptsForDebugMode(JSContext* cx);
private:
/* This is called only when debugMode() has just toggled. */
bool updateJITForDebugMode(JSContext* maybecx, js::AutoDebugModeInvalidation& invalidate);
public:
js::GlobalObjectSet& getDebuggees() { return debuggees; }
bool addDebuggee(JSContext* cx, js::GlobalObject* global);
bool addDebuggee(JSContext* cx, js::GlobalObject* global,
js::AutoDebugModeInvalidation& invalidate);
bool removeDebuggee(JSContext* cx, js::GlobalObject* global,
js::GlobalObjectSet::Enum* debuggeesEnum = nullptr);
bool removeDebuggee(JSContext* cx, js::GlobalObject* global,
js::AutoDebugModeInvalidation& invalidate,
js::GlobalObjectSet::Enum* debuggeesEnum = nullptr);
void removeDebuggeeUnderGC(js::FreeOp* fop, js::GlobalObject* global,
js::GlobalObjectSet::Enum* debuggeesEnum = nullptr);
void removeDebuggeeUnderGC(js::FreeOp* fop, js::GlobalObject* global,
js::AutoDebugModeInvalidation& invalidate,
js::GlobalObjectSet::Enum* debuggeesEnum = nullptr);
bool setDebugModeFromC(JSContext* cx, bool b,
js::AutoDebugModeInvalidation& invalidate);
void clearBreakpointsIn(js::FreeOp* fop, js::Debugger* dbg, JS::HandleObject handler);
void clearTraps(js::FreeOp* fop);
private:
void sweepBreakpoints(js::FreeOp* fop);
public:
js::WatchpointMap* watchpointMap;
js::ScriptCountsMap* scriptCountsMap;
js::DebugScriptMap* debugScriptMap;
/* Bookkeeping information for debug scope objects. */
js::DebugScopes* debugScopes;
/*
* List of potentially active iterators that may need deleted property
* suppression.
*/
js::NativeIterator* enumerators;
/* Used by memory reporters and invalid otherwise. */
void* compartmentStats;
#ifdef JS_ION
private:
js::jit::JitCompartment* jitCompartment_;
public:
bool ensureJitCompartmentExists(JSContext* cx);
js::jit::JitCompartment* jitCompartment() {
return jitCompartment_;
}
#endif
};
inline bool
JSRuntime::isAtomsZone(JS::Zone* zone)
{
return zone == atomsCompartment_->zone();
}
// For use when changing the debug mode flag on one or more compartments.
// Invalidate and discard JIT code since debug mode breaks JIT assumptions.
//
// AutoDebugModeInvalidation has two modes: compartment or zone
// invalidation. While it is correct to always use compartment invalidation,
// if you know ahead of time you need to invalidate a whole zone, it is faster
// to invalidate the zone.
//
// Compartment invalidation only invalidates scripts belonging to that
// compartment.
//
// Zone invalidation invalidates all scripts belonging to non-special
// (i.e. those with principals) compartments of the zone.
//
// FIXME: Remove entirely once bug 716647 lands.
//
class js::AutoDebugModeInvalidation
{
JSCompartment* comp_;
JS::Zone* zone_;
enum {
NoNeed = 0,
ToggledOn = 1,
ToggledOff = 2
} needInvalidation_;
public:
explicit AutoDebugModeInvalidation(JSCompartment* comp)
: comp_(comp), zone_(nullptr), needInvalidation_(NoNeed)
{ }
explicit AutoDebugModeInvalidation(JS::Zone* zone)
: comp_(nullptr), zone_(zone), needInvalidation_(NoNeed)
{ }
#ifdef JS_ION
~AutoDebugModeInvalidation();
#else
~AutoDebugModeInvalidation() { }
#endif
bool isFor(JSCompartment* comp) {
if (comp_)
return comp == comp_;
return comp->zone() == zone_;
}
void scheduleInvalidation(bool debugMode) {
// If we are scheduling invalidation for multiple compartments, they
// must all agree on the toggle. This is so we can decide if we need
// to invalidate on-stack scripts.
MOZ_ASSERT_IF(needInvalidation_ != NoNeed,
needInvalidation_ == (debugMode ? ToggledOn : ToggledOff));
needInvalidation_ = debugMode ? ToggledOn : ToggledOff;
}
};
namespace js {
inline js::Handle<js::GlobalObject*>
ExclusiveContext::global() const
{
/*
* It's safe to use |unsafeGet()| here because any compartment that is
* on-stack will be marked automatically, so there's no need for a read
* barrier on it. Once the compartment is popped, the handle is no longer
* safe to use.
*/
MOZ_ASSERT(compartment_, "Caller needs to enter a compartment first");
return Handle<GlobalObject*>::fromMarkedLocation(compartment_->global_.unsafeGet());
}
class AssertCompartmentUnchanged
{
public:
AssertCompartmentUnchanged(JSContext* cx
MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
: cx(cx), oldCompartment(cx->compartment())
{
MOZ_GUARD_OBJECT_NOTIFIER_INIT;
}
~AssertCompartmentUnchanged() {
JS_ASSERT(cx->compartment() == oldCompartment);
}
protected:
JSContext * const cx;
JSCompartment * const oldCompartment;
MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};
class AutoCompartment
{
ExclusiveContext * const cx_;
JSCompartment * const origin_;
public:
inline AutoCompartment(ExclusiveContext* cx, JSObject* target);
inline AutoCompartment(ExclusiveContext* cx, JSCompartment* target);
inline ~AutoCompartment();
ExclusiveContext* context() const { return cx_; }
JSCompartment* origin() const { return origin_; }
private:
AutoCompartment(const AutoCompartment&) MOZ_DELETE;
AutoCompartment & operator=(const AutoCompartment&) MOZ_DELETE;
};
/*
* Use this to change the behavior of an AutoCompartment slightly on error. If
* the exception happens to be an Error object, copy it to the origin compartment
* instead of wrapping it.
*/
class ErrorCopier
{
mozilla::Maybe<AutoCompartment>& ac;
RootedObject scope;
public:
ErrorCopier(mozilla::Maybe<AutoCompartment>& ac, JSObject* scope)
: ac(ac), scope(ac.ref().context(), scope) {}
~ErrorCopier();
};
/*
* AutoWrapperVector and AutoWrapperRooter can be used to store wrappers that
* are obtained from the cross-compartment map. However, these classes should
* not be used if the wrapper will escape. For example, it should not be stored
* in the heap.
*
* The AutoWrapper rooters are different from other autorooters because their
* wrappers are marked on every GC slice rather than just the first one. If
* there's some wrapper that we want to use temporarily without causing it to be
* marked, we can use these AutoWrapper classes. If we get unlucky and a GC
* slice runs during the code using the wrapper, the GC will mark the wrapper so
* that it doesn't get swept out from under us. Otherwise, the wrapper needn't
* be marked. This is useful in functions like JS_TransplantObject that
* manipulate wrappers in compartments that may no longer be alive.
*/
/*
* This class stores the data for AutoWrapperVector and AutoWrapperRooter. It
* should not be used in any other situations.
*/
struct WrapperValue
{
/*
* We use unsafeGet() in the constructors to avoid invoking a read barrier
* on the wrapper, which may be dead (see the comment about bug 803376 in
* jsgc.cpp regarding this). If there is an incremental GC while the wrapper
* is in use, the AutoWrapper rooter will ensure the wrapper gets marked.
*/
explicit WrapperValue(const WrapperMap::Ptr& ptr)
: value(*ptr->value().unsafeGet())
{}
explicit WrapperValue(const WrapperMap::Enum& e)
: value(*e.front().value().unsafeGet())
{}
Value& get() { return value; }
Value get() const { return value; }
operator const Value&() const { return value; }
JSObject& toObject() const { return value.toObject(); }
private:
Value value;
};
class AutoWrapperVector : public AutoVectorRooter<WrapperValue>
{
public:
explicit AutoWrapperVector(JSContext* cx
MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
: AutoVectorRooter<WrapperValue>(cx, WRAPVECTOR)
{
MOZ_GUARD_OBJECT_NOTIFIER_INIT;
}
MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};
class AutoWrapperRooter : private AutoGCRooter {
public:
AutoWrapperRooter(JSContext* cx, WrapperValue v
MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
: AutoGCRooter(cx, WRAPPER), value(v)
{
MOZ_GUARD_OBJECT_NOTIFIER_INIT;
}
operator JSObject*() const {
return value.get().toObjectOrNull();
}
friend void AutoGCRooter::trace(JSTracer* trc);
private:
WrapperValue value;
MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};
} /* namespace js */
#endif /* jscompartment_h */