The Tor Browser: js/src/gc/Marking.h@6474c204b198 (annotated)

js/src/gc/Marking.h@6474c204b198 (annotated)

js/src/gc/Marking.h

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/. */
 #ifndef gc_Marking_h
 #define gc_Marking_h
 #include "gc/Barrier.h"
 class JSAtom;
 class JSLinearString;
 namespace js {
 class ArgumentsObject;
 class ArrayBufferObject;
 class ArrayBufferViewObject;
 class SharedArrayBufferObject;
 class BaseShape;
 class DebugScopeObject;
 struct GCMarker;
 class GlobalObject;
 class LazyScript;
 class ScopeObject;
 class Shape;
 class UnownedBaseShape;
 template<class, typename> class HeapPtr;
 namespace jit {
 class JitCode;
 class IonScript;
 class VMFunction;
 }
 namespace types {
 class Type;
 }
 namespace gc {
 /*** Object Marking ***/
 /*
  * These functions expose marking functionality for all of the different GC
  * thing kinds. For each GC thing, there are several variants. As an example,
  * these are the variants generated for JSObject. They are listed from most to
  * least desirable for use:
  *
  * MarkObject(JSTracer *trc, const HeapPtr<JSObject> &thing, const char *name);
  *     This function should be used for marking JSObjects, in preference to all
  *     others below. Use it when you have HeapPtr<JSObject>, which
  *     automatically implements write barriers.
  *
  * MarkObjectRoot(JSTracer *trc, JSObject *thing, const char *name);
  *     This function is only valid during the root marking phase of GC (i.e.,
  *     when MarkRuntime is on the stack).
  *
  * MarkObjectUnbarriered(JSTracer *trc, JSObject *thing, const char *name);
  *     Like MarkObject, this function can be called at any time. It is more
  *     forgiving, since it doesn't demand a HeapPtr as an argument. Its use
  *     should always be accompanied by a comment explaining how write barriers
  *     are implemented for the given field.
  *
  * Additionally, the functions MarkObjectRange and MarkObjectRootRange are
  * defined for marking arrays of object pointers.
  *
  * The following functions are provided to test whether a GC thing is marked
  * under different circumstances:
  *
  * IsObjectAboutToBeFinalized(JSObject **thing);
  *     This function is indended to be used in code used to sweep GC things.  It
  *     indicates whether the object will will be finialized in the current group
  *     of compartments being swept.  Note that this will return false for any
  *     object not in the group of compartments currently being swept, as even if
  *     it is unmarked it may still become marked before it is swept.
  *
  * IsObjectMarked(JSObject **thing);
  *     This function is indended to be used in rare cases in code used to mark
  *     GC things.  It indicates whether the object is currently marked.
  *
  * UpdateObjectIfRelocated(JSObject **thingp);
  *     In some circumstances -- e.g. optional weak marking -- it is necessary
  *     to look at the pointer before marking it strongly or weakly. In these
  *     cases, the following must be called to update the pointer before use.
  */
 #define DeclMarker(base, type)                                                                    \
 void Mark##base(JSTracer *trc, BarrieredPtr<type> *thing, const char *name);                      \
 void Mark##base##Root(JSTracer *trc, type **thingp, const char *name);                            \
 void Mark##base##Unbarriered(JSTracer *trc, type **thingp, const char *name);                     \
 void Mark##base##Range(JSTracer *trc, size_t len, HeapPtr<type> *thing, const char *name);        \
 void Mark##base##RootRange(JSTracer *trc, size_t len, type **thing, const char *name);            \
 bool Is##base##Marked(type **thingp);                                                             \
 bool Is##base##Marked(BarrieredPtr<type> *thingp);                                                \
 bool Is##base##AboutToBeFinalized(type **thingp);                                                 \
 bool Is##base##AboutToBeFinalized(BarrieredPtr<type> *thingp);                                    \
 type *Update##base##IfRelocated(JSRuntime *rt, BarrieredPtr<type> *thingp);                       \
 type *Update##base##IfRelocated(JSRuntime *rt, type **thingp);
 DeclMarker(BaseShape, BaseShape)
 DeclMarker(BaseShape, UnownedBaseShape)
 DeclMarker(JitCode, jit::JitCode)
 DeclMarker(Object, ArgumentsObject)
 DeclMarker(Object, ArrayBufferObject)
 DeclMarker(Object, ArrayBufferViewObject)
 DeclMarker(Object, SharedArrayBufferObject)
 DeclMarker(Object, DebugScopeObject)
 DeclMarker(Object, GlobalObject)
 DeclMarker(Object, JSObject)
 DeclMarker(Object, JSFunction)
 DeclMarker(Object, ScopeObject)
 DeclMarker(Script, JSScript)
 DeclMarker(LazyScript, LazyScript)
 DeclMarker(Shape, Shape)
 DeclMarker(String, JSAtom)
 DeclMarker(String, JSString)
 DeclMarker(String, JSFlatString)
 DeclMarker(String, JSLinearString)
 DeclMarker(String, PropertyName)
 DeclMarker(TypeObject, types::TypeObject)
 #undef DeclMarker
 void
 MarkPermanentAtom(JSTracer *trc, JSAtom *atom, const char *name);
 /* Return true if the pointer is nullptr, or if it is a tagged pointer to
  * nullptr.
  */
 MOZ_ALWAYS_INLINE bool
 IsNullTaggedPointer(void *p)
 {
     return uintptr_t(p) < 32;
 }
 /*** Externally Typed Marking ***/
 /*
  * Note: this must only be called by the GC and only when we are tracing through
  * MarkRoots. It is explicitly for ConservativeStackMarking and should go away
  * after we transition to exact rooting.
  */
 void
 MarkKind(JSTracer *trc, void **thingp, JSGCTraceKind kind);
 void
 MarkGCThingRoot(JSTracer *trc, void **thingp, const char *name);
 void
 MarkGCThingUnbarriered(JSTracer *trc, void **thingp, const char *name);
 /*** ID Marking ***/
 void
 MarkId(JSTracer *trc, BarrieredId *id, const char *name);
 void
 MarkIdRoot(JSTracer *trc, jsid *id, const char *name);
 void
 MarkIdUnbarriered(JSTracer *trc, jsid *id, const char *name);
 void
 MarkIdRange(JSTracer *trc, size_t len, HeapId *vec, const char *name);
 void
 MarkIdRootRange(JSTracer *trc, size_t len, jsid *vec, const char *name);
 /*** Value Marking ***/
 void
 MarkValue(JSTracer *trc, BarrieredValue *v, const char *name);
 void
 MarkValueRange(JSTracer *trc, size_t len, BarrieredValue *vec, const char *name);
 inline void
 MarkValueRange(JSTracer *trc, HeapValue *begin, HeapValue *end, const char *name)
 {
     return MarkValueRange(trc, end - begin, begin, name);
 }
 void
 MarkValueRoot(JSTracer *trc, Value *v, const char *name);
 void
 MarkThingOrValueUnbarriered(JSTracer *trc, uintptr_t *word, const char *name);
 void
 MarkValueRootRange(JSTracer *trc, size_t len, Value *vec, const char *name);
 inline void
 MarkValueRootRange(JSTracer *trc, Value *begin, Value *end, const char *name)
 {
     MarkValueRootRange(trc, end - begin, begin, name);
 }
 void
 MarkTypeRoot(JSTracer *trc, types::Type *v, const char *name);
 bool
 IsValueMarked(Value *v);
 bool
 IsValueAboutToBeFinalized(Value *v);
 /*** Slot Marking ***/
 bool
 IsSlotMarked(HeapSlot *s);
 void
 MarkSlot(JSTracer *trc, HeapSlot *s, const char *name);
 void
 MarkArraySlots(JSTracer *trc, size_t len, HeapSlot *vec, const char *name);
 void
 MarkObjectSlots(JSTracer *trc, JSObject *obj, uint32_t start, uint32_t nslots);
 void
 MarkCrossCompartmentObjectUnbarriered(JSTracer *trc, JSObject *src, JSObject **dst_obj,
                                       const char *name);
 void
 MarkCrossCompartmentScriptUnbarriered(JSTracer *trc, JSObject *src, JSScript **dst_script,
                                       const char *name);
 /*
  * Mark a value that may be in a different compartment from the compartment
  * being GC'd. (Although it won't be marked if it's in the wrong compartment.)
  */
 void
 MarkCrossCompartmentSlot(JSTracer *trc, JSObject *src, HeapSlot *dst_slot, const char *name);
 /*** Special Cases ***/
 /*
  * The unioned HeapPtr stored in script->globalObj needs special treatment to
  * typecheck correctly.
  */
 void
 MarkObject(JSTracer *trc, HeapPtr<GlobalObject, JSScript *> *thingp, const char *name);
 /*
  * MarkChildren<JSObject> is exposed solely for preWriteBarrier on
  * JSObject::TradeGuts. It should not be considered external interface.
  */
 void
 MarkChildren(JSTracer *trc, JSObject *obj);
 /*
  * Trace through the shape and any shapes it contains to mark
  * non-shape children. This is exposed to the JS API as
  * JS_TraceShapeCycleCollectorChildren.
  */
 void
 MarkCycleCollectorChildren(JSTracer *trc, Shape *shape);
 void
 PushArena(GCMarker *gcmarker, ArenaHeader *aheader);
 /*** Generic ***/
 /*
  * The Mark() functions interface should only be used by code that must be
  * templated.  Other uses should use the more specific, type-named functions.
  */
 inline void
 Mark(JSTracer *trc, BarrieredValue *v, const char *name)
 {
     MarkValue(trc, v, name);
 }
 inline void
 Mark(JSTracer *trc, BarrieredPtrObject *o, const char *name)
 {
     MarkObject(trc, o, name);
 }
 inline void
 Mark(JSTracer *trc, BarrieredPtrScript *o, const char *name)
 {
     MarkScript(trc, o, name);
 }
 inline void
 Mark(JSTracer *trc, HeapPtr<jit::JitCode> *code, const char *name)
 {
     MarkJitCode(trc, code, name);
 }
 /* For use by WeakMap's HashKeyRef instantiation. */
 inline void
 Mark(JSTracer *trc, JSObject **objp, const char *name)
 {
     MarkObjectUnbarriered(trc, objp, name);
 }
 /* For use by Debugger::WeakMap's proxiedScopes HashKeyRef instantiation. */
 inline void
 Mark(JSTracer *trc, ScopeObject **obj, const char *name)
 {
     MarkObjectUnbarriered(trc, obj, name);
 }
 bool
 IsCellMarked(Cell **thingp);
 bool
 IsCellAboutToBeFinalized(Cell **thing);
 inline bool
 IsMarked(BarrieredValue *v)
 {
     if (!v->isMarkable())
         return true;
     return IsValueMarked(v->unsafeGet());
 }
 inline bool
 IsMarked(BarrieredPtrObject *objp)
 {
     return IsObjectMarked(objp);
 }
 inline bool
 IsMarked(BarrieredPtrScript *scriptp)
 {
     return IsScriptMarked(scriptp);
 }
 inline bool
 IsAboutToBeFinalized(BarrieredValue *v)
 {
     if (!v->isMarkable())
         return false;
     return IsValueAboutToBeFinalized(v->unsafeGet());
 }
 inline bool
 IsAboutToBeFinalized(BarrieredPtrObject *objp)
 {
     return IsObjectAboutToBeFinalized(objp);
 }
 inline bool
 IsAboutToBeFinalized(BarrieredPtrScript *scriptp)
 {
     return IsScriptAboutToBeFinalized(scriptp);
 }
 #ifdef JS_ION
 /* Nonsense to get WeakCache to work with new Marking semantics. */
 inline bool
 IsAboutToBeFinalized(const js::jit::VMFunction **vmfunc)
 {
     /*
      * Preserves entries in the WeakCache<VMFunction, JitCode>
      * iff the JitCode has been marked.
      */
     return true;
 }
 inline bool
 IsAboutToBeFinalized(ReadBarriered<js::jit::JitCode> code)
 {
     return IsJitCodeAboutToBeFinalized(code.unsafeGet());
 }
 #endif
 inline Cell *
 ToMarkable(const Value &v)
 {
     if (v.isMarkable())
         return (Cell *)v.toGCThing();
     return nullptr;
 }
 inline Cell *
 ToMarkable(Cell *cell)
 {
     return cell;
 }
 inline JSGCTraceKind
 TraceKind(const Value &v)
 {
     JS_ASSERT(v.isMarkable());
     if (v.isObject())
         return JSTRACE_OBJECT;
     return JSTRACE_STRING;
 }
 inline JSGCTraceKind
 TraceKind(JSObject *obj)
 {
     return JSTRACE_OBJECT;
 }
 inline JSGCTraceKind
 TraceKind(JSScript *script)
 {
     return JSTRACE_SCRIPT;
 }
 inline JSGCTraceKind
 TraceKind(LazyScript *lazy)
 {
     return JSTRACE_LAZY_SCRIPT;
 }
 } /* namespace gc */
 void
 TraceChildren(JSTracer *trc, void *thing, JSGCTraceKind kind);
 } /* namespace js */
 #endif /* gc_Marking_h */

The Tor Browser / annotate

js/src/gc/Marking.h@6474c204b198 (annotated)

js/src/gc/Marking.h