gecko/js/public/GCAPI.h
Wes Kocher 3dbc5bd2fa Backed out 7 changesets (bug 935228, bug 936143, bug 935470, bug 933882, bug 934799) for breaking ASAN browser-chrome tests on a CLOSED TREE
Backed out changeset ae6f2151610f (bug 934799)
Backed out changeset 82495f0c5da2 (bug 934799)
Backed out changeset 77be849d81e7 (bug 935228)
Backed out changeset 555e5759fe5f (bug 935470)
Backed out changeset ce4011f33422 (bug 933882)
Backed out changeset e13e98eab890 (bug 936143)
Backed out changeset fb230c191a88 (bug 936143)
2013-11-11 16:53:59 -08:00

350 lines
10 KiB
C++

/* -*- 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 js_GCAPI_h
#define js_GCAPI_h
#include "mozilla/NullPtr.h"
#include "js/HeapAPI.h"
#include "js/RootingAPI.h"
#include "js/Value.h"
namespace JS {
#define GCREASONS(D) \
/* Reasons internal to the JS engine */ \
D(API) \
D(MAYBEGC) \
D(DESTROY_RUNTIME) \
D(DESTROY_CONTEXT) \
D(LAST_DITCH) \
D(TOO_MUCH_MALLOC) \
D(ALLOC_TRIGGER) \
D(DEBUG_GC) \
D(DEBUG_MODE_GC) \
D(TRANSPLANT) \
D(RESET) \
D(OUT_OF_NURSERY) \
D(EVICT_NURSERY) \
D(FULL_STORE_BUFFER) \
\
/* These are reserved for future use. */ \
D(RESERVED0) \
D(RESERVED1) \
D(RESERVED2) \
D(RESERVED3) \
D(RESERVED4) \
D(RESERVED5) \
D(RESERVED6) \
D(RESERVED7) \
D(RESERVED8) \
D(RESERVED9) \
D(RESERVED10) \
D(RESERVED11) \
D(RESERVED12) \
D(RESERVED13) \
D(RESERVED14) \
D(RESERVED15) \
D(RESERVED16) \
D(RESERVED17) \
D(RESERVED18) \
D(RESERVED19) \
\
/* Reasons from Firefox */ \
D(DOM_WINDOW_UTILS) \
D(COMPONENT_UTILS) \
D(MEM_PRESSURE) \
D(CC_WAITING) \
D(CC_FORCED) \
D(LOAD_END) \
D(POST_COMPARTMENT) \
D(PAGE_HIDE) \
D(NSJSCONTEXT_DESTROY) \
D(SET_NEW_DOCUMENT) \
D(SET_DOC_SHELL) \
D(DOM_UTILS) \
D(DOM_IPC) \
D(DOM_WORKER) \
D(INTER_SLICE_GC) \
D(REFRESH_FRAME) \
D(FULL_GC_TIMER) \
D(SHUTDOWN_CC) \
D(FINISH_LARGE_EVALUTE)
namespace gcreason {
/* GCReasons will end up looking like JSGC_MAYBEGC */
enum Reason {
#define MAKE_REASON(name) name,
GCREASONS(MAKE_REASON)
#undef MAKE_REASON
NO_REASON,
NUM_REASONS,
/*
* For telemetry, we want to keep a fixed max bucket size over time so we
* don't have to switch histograms. 100 is conservative; as of this writing
* there are 26. But the cost of extra buckets seems to be low while the
* cost of switching histograms is high.
*/
NUM_TELEMETRY_REASONS = 100
};
} /* namespace gcreason */
extern JS_FRIEND_API(void)
PrepareZoneForGC(Zone *zone);
extern JS_FRIEND_API(void)
PrepareForFullGC(JSRuntime *rt);
extern JS_FRIEND_API(void)
PrepareForIncrementalGC(JSRuntime *rt);
extern JS_FRIEND_API(bool)
IsGCScheduled(JSRuntime *rt);
extern JS_FRIEND_API(void)
SkipZoneForGC(Zone *zone);
/*
* When triggering a GC using one of the functions below, it is first necessary
* to select the compartments to be collected. To do this, you can call
* PrepareZoneForGC on each compartment, or you can call PrepareForFullGC
* to select all compartments. Failing to select any compartment is an error.
*/
extern JS_FRIEND_API(void)
GCForReason(JSRuntime *rt, gcreason::Reason reason);
extern JS_FRIEND_API(void)
ShrinkingGC(JSRuntime *rt, gcreason::Reason reason);
extern JS_FRIEND_API(void)
ShrinkGCBuffers(JSRuntime *rt);
extern JS_FRIEND_API(void)
IncrementalGC(JSRuntime *rt, gcreason::Reason reason, int64_t millis = 0);
extern JS_FRIEND_API(void)
FinishIncrementalGC(JSRuntime *rt, gcreason::Reason reason);
enum GCProgress {
/*
* During non-incremental GC, the GC is bracketed by JSGC_CYCLE_BEGIN/END
* callbacks. During an incremental GC, the sequence of callbacks is as
* follows:
* JSGC_CYCLE_BEGIN, JSGC_SLICE_END (first slice)
* JSGC_SLICE_BEGIN, JSGC_SLICE_END (second slice)
* ...
* JSGC_SLICE_BEGIN, JSGC_CYCLE_END (last slice)
*/
GC_CYCLE_BEGIN,
GC_SLICE_BEGIN,
GC_SLICE_END,
GC_CYCLE_END
};
struct JS_FRIEND_API(GCDescription) {
bool isCompartment_;
GCDescription(bool isCompartment)
: isCompartment_(isCompartment) {}
jschar *formatMessage(JSRuntime *rt) const;
jschar *formatJSON(JSRuntime *rt, uint64_t timestamp) const;
};
typedef void
(* GCSliceCallback)(JSRuntime *rt, GCProgress progress, const GCDescription &desc);
extern JS_FRIEND_API(GCSliceCallback)
SetGCSliceCallback(JSRuntime *rt, GCSliceCallback callback);
/*
* Signals a good place to do an incremental slice, because the browser is
* drawing a frame.
*/
extern JS_FRIEND_API(void)
NotifyDidPaint(JSRuntime *rt);
extern JS_FRIEND_API(bool)
IsIncrementalGCEnabled(JSRuntime *rt);
JS_FRIEND_API(bool)
IsIncrementalGCInProgress(JSRuntime *rt);
extern JS_FRIEND_API(void)
DisableIncrementalGC(JSRuntime *rt);
extern JS_FRIEND_API(void)
DisableGenerationalGC(JSRuntime *rt);
extern JS_FRIEND_API(void)
EnableGenerationalGC(JSRuntime *rt);
extern JS_FRIEND_API(bool)
IsIncrementalBarrierNeeded(JSRuntime *rt);
extern JS_FRIEND_API(bool)
IsIncrementalBarrierNeeded(JSContext *cx);
extern JS_FRIEND_API(void)
IncrementalReferenceBarrier(void *ptr, JSGCTraceKind kind);
extern JS_FRIEND_API(void)
IncrementalValueBarrier(const Value &v);
extern JS_FRIEND_API(void)
IncrementalObjectBarrier(JSObject *obj);
extern JS_FRIEND_API(void)
PokeGC(JSRuntime *rt);
/* Was the most recent GC run incrementally? */
extern JS_FRIEND_API(bool)
WasIncrementalGC(JSRuntime *rt);
extern JS_FRIEND_API(size_t)
GetGCNumber();
class JS_PUBLIC_API(AutoAssertNoGC)
{
#ifdef DEBUG
JSRuntime *runtime;
size_t gcNumber;
public:
AutoAssertNoGC();
AutoAssertNoGC(JSRuntime *rt);
~AutoAssertNoGC();
#else
public:
/* Prevent unreferenced local warnings in opt builds. */
AutoAssertNoGC() {}
AutoAssertNoGC(JSRuntime *) {}
#endif
};
class JS_PUBLIC_API(ObjectPtr)
{
Heap<JSObject *> value;
public:
ObjectPtr() : value(nullptr) {}
ObjectPtr(JSObject *obj) : value(obj) {}
/* Always call finalize before the destructor. */
~ObjectPtr() { JS_ASSERT(!value); }
void finalize(JSRuntime *rt) {
if (IsIncrementalBarrierNeeded(rt))
IncrementalObjectBarrier(value);
value = nullptr;
}
void init(JSObject *obj) { value = obj; }
JSObject *get() const { return value; }
void writeBarrierPre(JSRuntime *rt) {
IncrementalObjectBarrier(value);
}
bool isAboutToBeFinalized();
ObjectPtr &operator=(JSObject *obj) {
IncrementalObjectBarrier(value);
value = obj;
return *this;
}
void trace(JSTracer *trc, const char *name);
JSObject &operator*() const { return *value; }
JSObject *operator->() const { return value; }
operator JSObject *() const { return value; }
};
/*
* Unsets the gray bit for anything reachable from |thing|. |kind| should not be
* JSTRACE_SHAPE. |thing| should be non-null.
*/
extern JS_FRIEND_API(bool)
UnmarkGrayGCThingRecursively(void *thing, JSGCTraceKind kind);
/*
* This should be called when an object that is marked gray is exposed to the JS
* engine (by handing it to running JS code or writing it into live JS
* data). During incremental GC, since the gray bits haven't been computed yet,
* we conservatively mark the object black.
*/
static JS_ALWAYS_INLINE void
ExposeGCThingToActiveJS(void *thing, JSGCTraceKind kind)
{
JS_ASSERT(kind != JSTRACE_SHAPE);
shadow::Runtime *rt = js::gc::GetGCThingRuntime(thing);
#ifdef JSGC_GENERATIONAL
/*
* GC things residing in the nursery cannot be gray: they have no mark bits.
* All live objects in the nursery are moved to tenured at the beginning of
* each GC slice, so the gray marker never sees nursery things.
*/
if (js::gc::IsInsideNursery(rt, thing))
return;
#endif
if (IsIncrementalBarrierNeededOnGCThing(rt, thing, kind))
IncrementalReferenceBarrier(thing, kind);
else if (GCThingIsMarkedGray(thing))
UnmarkGrayGCThingRecursively(thing, kind);
}
static JS_ALWAYS_INLINE void
ExposeValueToActiveJS(const Value &v)
{
if (v.isMarkable())
ExposeGCThingToActiveJS(v.toGCThing(), v.gcKind());
}
static JS_ALWAYS_INLINE void
ExposeObjectToActiveJS(JSObject *obj)
{
ExposeGCThingToActiveJS(obj, JSTRACE_OBJECT);
}
/*
* If a GC is currently marking, mark the object black.
*/
static JS_ALWAYS_INLINE void
MarkGCThingAsLive(JSRuntime *rt_, void *thing, JSGCTraceKind kind)
{
shadow::Runtime *rt = shadow::Runtime::asShadowRuntime(rt_);
#ifdef JSGC_GENERATIONAL
/*
* Any object in the nursery will not be freed during any GC running at that time.
*/
if (js::gc::IsInsideNursery(rt, thing))
return;
#endif
if (IsIncrementalBarrierNeededOnGCThing(rt, thing, kind))
IncrementalReferenceBarrier(thing, kind);
}
static JS_ALWAYS_INLINE void
MarkStringAsLive(Zone *zone, JSString *string)
{
JSRuntime *rt = JS::shadow::Zone::asShadowZone(zone)->runtimeFromMainThread();
MarkGCThingAsLive(rt, string, JSTRACE_STRING);
}
} /* namespace JS */
#endif /* js_GCAPI_h */