trunk/js/jsgc.h

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Communicator client code, released
 * March 31, 1998.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#ifndef jsgc_h___
#define jsgc_h___
/*
 * JS Garbage Collector.
 */
#include "jsprvtd.h"
#include "jspubtd.h"
#include "jsdhash.h"
#include "jsbit.h"
#include "jsutil.h"

JS_BEGIN_EXTERN_C

#define JSTRACE_XML         3

/*
 * One past the maximum trace kind.
 */
#define JSTRACE_LIMIT       4

/*
 * We use the trace kinds as the types for all GC things except external
 * strings.
 */
#define GCX_OBJECT              JSTRACE_OBJECT      /* JSObject */
#define GCX_DOUBLE              JSTRACE_DOUBLE      /* jsdouble */
#define GCX_STRING              JSTRACE_STRING      /* JSString */
#define GCX_XML                 JSTRACE_XML         /* JSXML */
#define GCX_EXTERNAL_STRING     JSTRACE_LIMIT       /* JSString with external
                                                       chars */
/*
 * The number of defined GC types and the maximum limit for the number of
 * possible GC types.
 */
#define GCX_NTYPES              (GCX_EXTERNAL_STRING + 8)
#define GCX_LIMIT_LOG2         4           /* type index bits */
#define GCX_LIMIT              JS_BIT(GCX_LIMIT_LOG2)

/* GC flag definitions, must fit in 8 bits (type index goes in the low bits). */
#define GCF_TYPEMASK    JS_BITMASK(GCX_LIMIT_LOG2)
#define GCF_MARK        JS_BIT(GCX_LIMIT_LOG2)
#define GCF_FINAL       JS_BIT(GCX_LIMIT_LOG2 + 1)
#define GCF_LOCKSHIFT   (GCX_LIMIT_LOG2 + 2)   /* lock bit shift */
#define GCF_LOCK        JS_BIT(GCF_LOCKSHIFT)   /* lock request bit in API */

/*
 * Get the type of the external string or -1 if the string was not created
 * with JS_NewExternalString.
 */
extern intN
js_GetExternalStringGCType(JSString *str);

extern JS_FRIEND_API(uint32)
js_GetGCThingTraceKind(void *thing);

/*
 * The sole purpose of the function is to preserve public API compatibility
 * in JS_GetStringBytes which takes only single JSString* argument.
 */
JSRuntime*
js_GetGCStringRuntime(JSString *str);

#if 1
/*
 * Since we're forcing a GC from JS_GC anyway, don't bother wasting cycles
 * loading oldval.  XXX remove implied force, fix jsinterp.c's "second arg
 * ignored", etc.
 */
#define GC_POKE(cx, oldval) ((cx)->runtime->gcPoke = JS_TRUE)
#else
#define GC_POKE(cx, oldval) ((cx)->runtime->gcPoke = JSVAL_IS_GCTHING(oldval))
#endif

/*
 * Write barrier macro monitoring property update from oldval to newval in
 * scope->object.
 *
 * Since oldval is used only for the branded scope case, and the oldval actual
 * argument expression is typically not used otherwise by callers, performance
 * benefits if oldval is *not* evaluated into a callsite temporary variable,
 * and instead passed to GC_WRITE_BARRIER for conditional evaluation (we rely
 * on modern compilers to do a good CSE job). Yay, C macros.
 */
#define GC_WRITE_BARRIER(cx,scope,oldval,newval)                              \
    JS_BEGIN_MACRO                                                            \
        if (SCOPE_IS_BRANDED(scope) &&                                        \
            (oldval) != (newval) &&                                           \
            (VALUE_IS_FUNCTION(cx,oldval) || VALUE_IS_FUNCTION(cx,newval))) { \
            js_MakeScopeShapeUnique(cx, scope);                               \
        }                                                                     \
        GC_POKE(cx, oldval);                                                  \
    JS_END_MACRO

extern JSBool
js_InitGC(JSRuntime *rt, uint32 maxbytes);

extern void
js_FinishGC(JSRuntime *rt);

extern intN
js_ChangeExternalStringFinalizer(JSStringFinalizeOp oldop,
                                 JSStringFinalizeOp newop);

extern JSBool
js_AddRoot(JSContext *cx, void *rp, const char *name);

extern JSBool
js_AddRootRT(JSRuntime *rt, void *rp, const char *name);

extern JSBool
js_RemoveRoot(JSRuntime *rt, void *rp);

#ifdef DEBUG
extern void
js_DumpNamedRoots(JSRuntime *rt,
                  void (*dump)(const char *name, void *rp, void *data),
                  void *data);
#endif

extern uint32
js_MapGCRoots(JSRuntime *rt, JSGCRootMapFun map, void *data);

/* Table of pointers with count valid members. */
typedef struct JSPtrTable {
    size_t      count;
    void        **array;
} JSPtrTable;

extern JSBool
js_RegisterCloseableIterator(JSContext *cx, JSObject *obj);

/*
 * The private JSGCThing struct, which describes a gcFreeList element.
 */
struct JSGCThing {
    JSGCThing   *next;
    uint8       *flagp;
};

#define GC_NBYTES_MAX           (10 * sizeof(JSGCThing))
#define GC_NUM_FREELISTS        (GC_NBYTES_MAX / sizeof(JSGCThing))
#define GC_FREELIST_NBYTES(i)   (((i) + 1) * sizeof(JSGCThing))
#define GC_FREELIST_INDEX(n)    (((n) / sizeof(JSGCThing)) - 1)

/*
 * Allocates a new GC thing of the given size. After a successful allocation
 * the caller must fully initialize the thing before calling any function that
 * can potentially trigger GC. This will ensure that GC tracing never sees junk
 * values stored in the partially initialized thing.
 */
extern void *
js_NewGCThing(JSContext *cx, uintN flags, size_t nbytes);

/*
 * Allocate a new double jsval and store the result in *vp. vp must be a root.
 * The function does not copy the result into any weak root.
 */
extern JSBool
js_NewDoubleInRootedValue(JSContext *cx, jsdouble d, jsval *vp);

/*
 * Return a pointer to a new GC-allocated and weakly-rooted jsdouble number,
 * or null when the allocation fails.
 */
extern jsdouble *
js_NewWeaklyRootedDouble(JSContext *cx, jsdouble d);

#ifdef JS_TRACER
extern JSBool
js_ReserveObjects(JSContext *cx, size_t nobjects);
#endif

extern JSBool
js_LockGCThingRT(JSRuntime *rt, void *thing);

extern JSBool
js_UnlockGCThingRT(JSRuntime *rt, void *thing);

extern JSBool
js_IsAboutToBeFinalized(JSContext *cx, void *thing);

/*
 * Macro to test if a traversal is the marking phase of GC to avoid exposing
 * ScriptFilenameEntry to traversal implementations.
 */
#define IS_GC_MARKING_TRACER(trc) ((trc)->callback == NULL)

#if JS_HAS_XML_SUPPORT
# define JS_IS_VALID_TRACE_KIND(kind) ((uint32)(kind) < JSTRACE_LIMIT)
#else
# define JS_IS_VALID_TRACE_KIND(kind) ((uint32)(kind) <= JSTRACE_STRING)
#endif

/*
 * Trace jsval when JSVAL_IS_OBJECT(v) can be an arbitrary GC thing casted as
 * JSVAL_OBJECT and js_GetGCThingTraceKind has to be used to find the real
 * type behind v.
 */
extern void
js_CallValueTracerIfGCThing(JSTracer *trc, jsval v);

extern void
js_TraceStackFrame(JSTracer *trc, JSStackFrame *fp);

extern JS_REQUIRES_STACK void
js_TraceRuntime(JSTracer *trc, JSBool allAtoms);

extern JS_REQUIRES_STACK JS_FRIEND_API(void)
js_TraceContext(JSTracer *trc, JSContext *acx);

/*
 * Schedule the GC call at a later safe point.
 */
#ifndef JS_THREADSAFE
# define js_TriggerGC(cx, gcLocked)    js_TriggerGC (cx)
#endif

extern void
js_TriggerGC(JSContext *cx, JSBool gcLocked);

/*
 * Kinds of js_GC invocation.
 */
typedef enum JSGCInvocationKind {
    /* Normal invocation. */
    GC_NORMAL           = 0,

    /*
     * Called from js_DestroyContext for last JSContext in a JSRuntime, when
     * it is imperative that rt->gcPoke gets cleared early in js_GC.
     */
    GC_LAST_CONTEXT     = 1,

    /*
     * Flag bit telling js_GC that the caller has already acquired rt->gcLock.
     * Currently, this flag is set for the invocation kinds that also preserve
     * atoms and weak roots, so we don't need another bit for GC_KEEP_ATOMS.
     */
    GC_LOCK_HELD        = 0x10,
    GC_KEEP_ATOMS       = GC_LOCK_HELD,

    /*
     * Called from js_SetProtoOrParent with a request to set an object's proto
     * or parent slot inserted on rt->setSlotRequests.
     */
    GC_SET_SLOT_REQUEST = GC_LOCK_HELD | 1,

    /*
     * Called from js_NewGCThing as a last-ditch GC attempt. See comments in
     * jsgc.c just before js_GC's definition for details.
     */
    GC_LAST_DITCH       = GC_LOCK_HELD | 2
} JSGCInvocationKind;

extern void
js_GC(JSContext *cx, JSGCInvocationKind gckind);

/* Call this after succesful malloc of memory for GC-related things. */
extern void
js_UpdateMallocCounter(JSContext *cx, size_t nbytes);

typedef struct JSGCArenaInfo JSGCArenaInfo;
typedef struct JSGCArenaList JSGCArenaList;
typedef struct JSGCChunkInfo JSGCChunkInfo;

struct JSGCArenaList {
    JSGCArenaInfo   *last;          /* last allocated GC arena */
    uint16          lastCount;      /* number of allocated things in the last
                                       arena */
    uint16          thingSize;      /* size of things to allocate on this list
                                     */
    JSGCThing       *freeList;      /* list of free GC things */
};

typedef union JSGCDoubleCell JSGCDoubleCell;

union JSGCDoubleCell {
    double          number;
    JSGCDoubleCell  *link;
};

typedef struct JSGCDoubleArenaList {
    JSGCArenaInfo   *first;             /* first allocated GC arena */
    jsbitmap        *nextDoubleFlags;   /* bitmask with flags to check for free
                                           things */
} JSGCDoubleArenaList;

typedef struct JSGCFreeListSet JSGCFreeListSet;

struct JSGCFreeListSet {
    JSGCThing           *array[GC_NUM_FREELISTS];
    JSGCFreeListSet     *link;
};

extern const JSGCFreeListSet js_GCEmptyFreeListSet;

extern void
js_RevokeGCLocalFreeLists(JSContext *cx);

extern void
js_DestroyScriptsToGC(JSContext *cx, JSThreadData *data);

struct JSWeakRoots {
    /* Most recently created things by type, members of the GC's root set. */
    void            *newborn[GCX_NTYPES];

    /* Atom root for the last-looked-up atom on this context. */
    jsval           lastAtom;

    /* Root for the result of the most recent js_InternalInvoke call. */
    jsval           lastInternalResult;
};

#define JS_CLEAR_WEAK_ROOTS(wr) (memset((wr), 0, sizeof(JSWeakRoots)))

/*
 * Increase runtime->gcBytes by sz bytes to account for an allocation outside
 * the GC that will be freed only after the GC is run. The function may run
 * the last ditch GC to ensure that gcBytes does not exceed gcMaxBytes. It will
 * fail if the latter is not possible.
 *
 * This function requires that runtime->gcLock is held on entry. On successful
 * return the lock is still held and on failure it will be released with
 * the error reported.
 */
extern JSBool
js_AddAsGCBytes(JSContext *cx, size_t sz);

extern void
js_RemoveAsGCBytes(JSRuntime* rt, size_t sz);

#ifdef DEBUG_notme
#define JS_GCMETER 1
#endif

#ifdef JS_GCMETER

typedef struct JSGCArenaStats {
    uint32  alloc;          /* allocation attempts */
    uint32  localalloc;     /* allocations from local lists */
    uint32  retry;          /* allocation retries after running the GC */
    uint32  fail;           /* allocation failures */
    uint32  nthings;        /* live GC things */
    uint32  maxthings;      /* maximum of live GC cells */
    double  totalthings;    /* live GC things the GC scanned so far */
    uint32  narenas;        /* number of arena in list before the GC */
    uint32  newarenas;      /* new arenas allocated before the last GC */
    uint32  livearenas;     /* number of live arenas after the last GC */
    uint32  maxarenas;      /* maximum of allocated arenas */
    uint32  totalarenas;    /* total number of arenas with live things that
                               GC scanned so far */
} JSGCArenaStats;

typedef struct JSGCStats {
    uint32  finalfail;  /* finalizer calls allocator failures */
    uint32  lockborn;   /* things born locked */
    uint32  lock;       /* valid lock calls */
    uint32  unlock;     /* valid unlock calls */
    uint32  depth;      /* mark tail recursion depth */
    uint32  maxdepth;   /* maximum mark tail recursion depth */
    uint32  cdepth;     /* mark recursion depth of C functions */
    uint32  maxcdepth;  /* maximum mark recursion depth of C functions */
    uint32  untraced;   /* number of times tracing of GC thing's children were
                           delayed due to a low C stack */
#ifdef DEBUG
    uint32  maxuntraced;/* maximum number of things with children to trace
                           later */
#endif
    uint32  maxlevel;   /* maximum GC nesting (indirect recursion) level */
    uint32  poke;       /* number of potentially useful GC calls */
    uint32  afree;      /* thing arenas freed so far */
    uint32  stackseg;   /* total extraordinary stack segments scanned */
    uint32  segslots;   /* total stack segment jsval slots scanned */
    uint32  nclose;     /* number of objects with close hooks */
    uint32  maxnclose;  /* max number of objects with close hooks */
    uint32  closelater; /* number of close hooks scheduled to run */
    uint32  maxcloselater; /* max number of close hooks scheduled to run */

    JSGCArenaStats  arenaStats[GC_NUM_FREELISTS];
    JSGCArenaStats  doubleArenaStats;
} JSGCStats;

extern JS_FRIEND_API(void)
js_DumpGCStats(JSRuntime *rt, FILE *fp);

#endif /* JS_GCMETER */

JS_END_EXTERN_C

#endif /* jsgc_h___ */
1	siliconforks	332	/* -- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 --
2			*
3			* *** BEGIN LICENSE BLOCK ***
4			* Version: MPL 1.1/GPL 2.0/LGPL 2.1
5			*
6			* The contents of this file are subject to the Mozilla Public License Version
7			* 1.1 (the "License"); you may not use this file except in compliance with
8			* the License. You may obtain a copy of the License at
9			* http://www.mozilla.org/MPL/
10			*
11			* Software distributed under the License is distributed on an "AS IS" basis,
12			* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
13			* for the specific language governing rights and limitations under the
14			* License.
15			*
16			* The Original Code is Mozilla Communicator client code, released
17			* March 31, 1998.
18			*
19			* The Initial Developer of the Original Code is
20			* Netscape Communications Corporation.
21			* Portions created by the Initial Developer are Copyright (C) 1998
22			* the Initial Developer. All Rights Reserved.
23			*
24			* Contributor(s):
25			*
26			* Alternatively, the contents of this file may be used under the terms of
27			* either of the GNU General Public License Version 2 or later (the "GPL"),
28			* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
29			* in which case the provisions of the GPL or the LGPL are applicable instead
30			* of those above. If you wish to allow use of your version of this file only
31			* under the terms of either the GPL or the LGPL, and not to allow others to
32			* use your version of this file under the terms of the MPL, indicate your
33			* decision by deleting the provisions above and replace them with the notice
34			* and other provisions required by the GPL or the LGPL. If you do not delete
35			* the provisions above, a recipient may use your version of this file under
36			* the terms of any one of the MPL, the GPL or the LGPL.
37			*
38			* *** END LICENSE BLOCK *** */
39
40			#ifndef jsgc_h___
41			#define jsgc_h___
42			/*
43			* JS Garbage Collector.
44			*/
45			#include "jsprvtd.h"
46			#include "jspubtd.h"
47			#include "jsdhash.h"
48			#include "jsbit.h"
49			#include "jsutil.h"
50
51			JS_BEGIN_EXTERN_C
52
53			#define JSTRACE_XML 3
54
55			/*
56			* One past the maximum trace kind.
57			*/
58			#define JSTRACE_LIMIT 4
59
60			/*
61			* We use the trace kinds as the types for all GC things except external
62			* strings.
63			*/
64			#define GCX_OBJECT JSTRACE_OBJECT /* JSObject */
65			#define GCX_DOUBLE JSTRACE_DOUBLE /* jsdouble */
66			#define GCX_STRING JSTRACE_STRING /* JSString */
67			#define GCX_XML JSTRACE_XML /* JSXML */
68			#define GCX_EXTERNAL_STRING JSTRACE_LIMIT /* JSString with external
69			chars */
70			/*
71	siliconforks	460	* The number of defined GC types and the maximum limit for the number of
72			* possible GC types.
73	siliconforks	332	*/
74			#define GCX_NTYPES (GCX_EXTERNAL_STRING + 8)
75			#define GCX_LIMIT_LOG2 4 /* type index bits */
76			#define GCX_LIMIT JS_BIT(GCX_LIMIT_LOG2)
77
78			/* GC flag definitions, must fit in 8 bits (type index goes in the low bits). */
79			#define GCF_TYPEMASK JS_BITMASK(GCX_LIMIT_LOG2)
80			#define GCF_MARK JS_BIT(GCX_LIMIT_LOG2)
81			#define GCF_FINAL JS_BIT(GCX_LIMIT_LOG2 + 1)
82			#define GCF_LOCKSHIFT (GCX_LIMIT_LOG2 + 2) /* lock bit shift */
83			#define GCF_LOCK JS_BIT(GCF_LOCKSHIFT) /* lock request bit in API */
84
85			/*
86			* Get the type of the external string or -1 if the string was not created
87			* with JS_NewExternalString.
88			*/
89			extern intN
90			js_GetExternalStringGCType(JSString *str);
91
92			extern JS_FRIEND_API(uint32)
93			js_GetGCThingTraceKind(void *thing);
94
95			/*
96			* The sole purpose of the function is to preserve public API compatibility
97			* in JS_GetStringBytes which takes only single JSString* argument.
98			*/
99			JSRuntime*
100			js_GetGCStringRuntime(JSString *str);
101
102			#if 1
103			/*
104			* Since we're forcing a GC from JS_GC anyway, don't bother wasting cycles
105			* loading oldval. XXX remove implied force, fix jsinterp.c's "second arg
106			* ignored", etc.
107			*/
108			#define GC_POKE(cx, oldval) ((cx)->runtime->gcPoke = JS_TRUE)
109			#else
110			#define GC_POKE(cx, oldval) ((cx)->runtime->gcPoke = JSVAL_IS_GCTHING(oldval))
111			#endif
112
113			/*
114			* Write barrier macro monitoring property update from oldval to newval in
115			* scope->object.
116			*
117			* Since oldval is used only for the branded scope case, and the oldval actual
118			* argument expression is typically not used otherwise by callers, performance
119			* benefits if oldval is not evaluated into a callsite temporary variable,
120			* and instead passed to GC_WRITE_BARRIER for conditional evaluation (we rely
121			* on modern compilers to do a good CSE job). Yay, C macros.
122			*/
123			#define GC_WRITE_BARRIER(cx,scope,oldval,newval) \
124			JS_BEGIN_MACRO \
125			if (SCOPE_IS_BRANDED(scope) && \
126			(oldval) != (newval) && \
127			(VALUE_IS_FUNCTION(cx,oldval) \|\| VALUE_IS_FUNCTION(cx,newval))) { \
128	siliconforks	460	js_MakeScopeShapeUnique(cx, scope); \
129	siliconforks	332	} \
130			GC_POKE(cx, oldval); \
131			JS_END_MACRO
132
133			extern JSBool
134			js_InitGC(JSRuntime *rt, uint32 maxbytes);
135
136			extern void
137			js_FinishGC(JSRuntime *rt);
138
139			extern intN
140			js_ChangeExternalStringFinalizer(JSStringFinalizeOp oldop,
141			JSStringFinalizeOp newop);
142
143			extern JSBool
144			js_AddRoot(JSContext cx, void rp, const char *name);
145
146			extern JSBool
147			js_AddRootRT(JSRuntime rt, void rp, const char *name);
148
149			extern JSBool
150			js_RemoveRoot(JSRuntime rt, void rp);
151
152			#ifdef DEBUG
153			extern void
154			js_DumpNamedRoots(JSRuntime *rt,
155			void (dump)(const char name, void rp, void data),
156			void *data);
157			#endif
158
159			extern uint32
160			js_MapGCRoots(JSRuntime rt, JSGCRootMapFun map, void data);
161
162			/* Table of pointers with count valid members. */
163			typedef struct JSPtrTable {
164			size_t count;
165			void **array;
166			} JSPtrTable;
167
168			extern JSBool
169			js_RegisterCloseableIterator(JSContext cx, JSObject obj);
170
171			/*
172			* The private JSGCThing struct, which describes a gcFreeList element.
173			*/
174			struct JSGCThing {
175			JSGCThing *next;
176			uint8 *flagp;
177			};
178
179			#define GC_NBYTES_MAX (10 * sizeof(JSGCThing))
180			#define GC_NUM_FREELISTS (GC_NBYTES_MAX / sizeof(JSGCThing))
181			#define GC_FREELIST_NBYTES(i) (((i) + 1) * sizeof(JSGCThing))
182			#define GC_FREELIST_INDEX(n) (((n) / sizeof(JSGCThing)) - 1)
183
184			/*
185			* Allocates a new GC thing of the given size. After a successful allocation
186			* the caller must fully initialize the thing before calling any function that
187			* can potentially trigger GC. This will ensure that GC tracing never sees junk
188			* values stored in the partially initialized thing.
189			*/
190			extern void *
191			js_NewGCThing(JSContext *cx, uintN flags, size_t nbytes);
192
193			/*
194			* Allocate a new double jsval and store the result in *vp. vp must be a root.
195			* The function does not copy the result into any weak root.
196			*/
197			extern JSBool
198			js_NewDoubleInRootedValue(JSContext cx, jsdouble d, jsval vp);
199
200			/*
201			* Return a pointer to a new GC-allocated and weakly-rooted jsdouble number,
202			* or null when the allocation fails.
203			*/
204			extern jsdouble *
205			js_NewWeaklyRootedDouble(JSContext *cx, jsdouble d);
206
207	siliconforks	460	#ifdef JS_TRACER
208	siliconforks	332	extern JSBool
209	siliconforks	460	js_ReserveObjects(JSContext *cx, size_t nobjects);
210			#endif
211
212			extern JSBool
213	siliconforks	332	js_LockGCThingRT(JSRuntime rt, void thing);
214
215			extern JSBool
216			js_UnlockGCThingRT(JSRuntime rt, void thing);
217
218			extern JSBool
219			js_IsAboutToBeFinalized(JSContext cx, void thing);
220
221			/*
222			* Macro to test if a traversal is the marking phase of GC to avoid exposing
223			* ScriptFilenameEntry to traversal implementations.
224			*/
225			#define IS_GC_MARKING_TRACER(trc) ((trc)->callback == NULL)
226
227			#if JS_HAS_XML_SUPPORT
228			# define JS_IS_VALID_TRACE_KIND(kind) ((uint32)(kind) < JSTRACE_LIMIT)
229			#else
230			# define JS_IS_VALID_TRACE_KIND(kind) ((uint32)(kind) <= JSTRACE_STRING)
231			#endif
232
233			/*
234			* Trace jsval when JSVAL_IS_OBJECT(v) can be an arbitrary GC thing casted as
235			* JSVAL_OBJECT and js_GetGCThingTraceKind has to be used to find the real
236			* type behind v.
237			*/
238			extern void
239			js_CallValueTracerIfGCThing(JSTracer *trc, jsval v);
240
241			extern void
242			js_TraceStackFrame(JSTracer trc, JSStackFrame fp);
243
244	siliconforks	460	extern JS_REQUIRES_STACK void
245	siliconforks	332	js_TraceRuntime(JSTracer *trc, JSBool allAtoms);
246
247	siliconforks	460	extern JS_REQUIRES_STACK JS_FRIEND_API(void)
248	siliconforks	332	js_TraceContext(JSTracer trc, JSContext acx);
249
250			/*
251	siliconforks	460	* Schedule the GC call at a later safe point.
252			*/
253			#ifndef JS_THREADSAFE
254			# define js_TriggerGC(cx, gcLocked) js_TriggerGC (cx)
255			#endif
256
257			extern void
258			js_TriggerGC(JSContext *cx, JSBool gcLocked);
259
260			/*
261	siliconforks	332	* Kinds of js_GC invocation.
262			*/
263			typedef enum JSGCInvocationKind {
264			/* Normal invocation. */
265			GC_NORMAL = 0,
266
267			/*
268			* Called from js_DestroyContext for last JSContext in a JSRuntime, when
269			* it is imperative that rt->gcPoke gets cleared early in js_GC.
270			*/
271			GC_LAST_CONTEXT = 1,
272
273			/*
274			* Flag bit telling js_GC that the caller has already acquired rt->gcLock.
275			* Currently, this flag is set for the invocation kinds that also preserve
276			* atoms and weak roots, so we don't need another bit for GC_KEEP_ATOMS.
277			*/
278			GC_LOCK_HELD = 0x10,
279			GC_KEEP_ATOMS = GC_LOCK_HELD,
280
281			/*
282			* Called from js_SetProtoOrParent with a request to set an object's proto
283			* or parent slot inserted on rt->setSlotRequests.
284			*/
285			GC_SET_SLOT_REQUEST = GC_LOCK_HELD \| 1,
286
287			/*
288			* Called from js_NewGCThing as a last-ditch GC attempt. See comments in
289			* jsgc.c just before js_GC's definition for details.
290			*/
291			GC_LAST_DITCH = GC_LOCK_HELD \| 2
292			} JSGCInvocationKind;
293
294			extern void
295			js_GC(JSContext *cx, JSGCInvocationKind gckind);
296
297			/* Call this after succesful malloc of memory for GC-related things. */
298			extern void
299			js_UpdateMallocCounter(JSContext *cx, size_t nbytes);
300
301			typedef struct JSGCArenaInfo JSGCArenaInfo;
302			typedef struct JSGCArenaList JSGCArenaList;
303			typedef struct JSGCChunkInfo JSGCChunkInfo;
304
305			struct JSGCArenaList {
306			JSGCArenaInfo last; / last allocated GC arena */
307			uint16 lastCount; /* number of allocated things in the last
308			arena */
309			uint16 thingSize; /* size of things to allocate on this list
310			*/
311			JSGCThing freeList; / list of free GC things */
312			};
313
314			typedef union JSGCDoubleCell JSGCDoubleCell;
315
316			union JSGCDoubleCell {
317			double number;
318			JSGCDoubleCell *link;
319			};
320
321			typedef struct JSGCDoubleArenaList {
322			JSGCArenaInfo first; / first allocated GC arena */
323			jsbitmap nextDoubleFlags; / bitmask with flags to check for free
324			things */
325			} JSGCDoubleArenaList;
326
327			typedef struct JSGCFreeListSet JSGCFreeListSet;
328
329			struct JSGCFreeListSet {
330			JSGCThing *array[GC_NUM_FREELISTS];
331			JSGCFreeListSet *link;
332			};
333
334			extern const JSGCFreeListSet js_GCEmptyFreeListSet;
335
336			extern void
337			js_RevokeGCLocalFreeLists(JSContext *cx);
338
339	siliconforks	460	extern void
340			js_DestroyScriptsToGC(JSContext cx, JSThreadData data);
341
342	siliconforks	332	struct JSWeakRoots {
343			/* Most recently created things by type, members of the GC's root set. */
344			void *newborn[GCX_NTYPES];
345
346			/* Atom root for the last-looked-up atom on this context. */
347			jsval lastAtom;
348
349			/* Root for the result of the most recent js_InternalInvoke call. */
350			jsval lastInternalResult;
351			};
352
353			#define JS_CLEAR_WEAK_ROOTS(wr) (memset((wr), 0, sizeof(JSWeakRoots)))
354
355			/*
356			* Increase runtime->gcBytes by sz bytes to account for an allocation outside
357			* the GC that will be freed only after the GC is run. The function may run
358			* the last ditch GC to ensure that gcBytes does not exceed gcMaxBytes. It will
359			* fail if the latter is not possible.
360			*
361			* This function requires that runtime->gcLock is held on entry. On successful
362			* return the lock is still held and on failure it will be released with
363			* the error reported.
364			*/
365			extern JSBool
366			js_AddAsGCBytes(JSContext *cx, size_t sz);
367
368			extern void
369			js_RemoveAsGCBytes(JSRuntime* rt, size_t sz);
370
371			#ifdef DEBUG_notme
372			#define JS_GCMETER 1
373			#endif
374
375			#ifdef JS_GCMETER
376
377			typedef struct JSGCArenaStats {
378			uint32 alloc; /* allocation attempts */
379			uint32 localalloc; /* allocations from local lists */
380			uint32 retry; /* allocation retries after running the GC */
381			uint32 fail; /* allocation failures */
382			uint32 nthings; /* live GC things */
383			uint32 maxthings; /* maximum of live GC cells */
384			double totalthings; /* live GC things the GC scanned so far */
385			uint32 narenas; /* number of arena in list before the GC */
386			uint32 newarenas; /* new arenas allocated before the last GC */
387			uint32 livearenas; /* number of live arenas after the last GC */
388			uint32 maxarenas; /* maximum of allocated arenas */
389			uint32 totalarenas; /* total number of arenas with live things that
390			GC scanned so far */
391			} JSGCArenaStats;
392
393			typedef struct JSGCStats {
394			uint32 finalfail; /* finalizer calls allocator failures */
395			uint32 lockborn; /* things born locked */
396			uint32 lock; /* valid lock calls */
397			uint32 unlock; /* valid unlock calls */
398			uint32 depth; /* mark tail recursion depth */
399			uint32 maxdepth; /* maximum mark tail recursion depth */
400			uint32 cdepth; /* mark recursion depth of C functions */
401			uint32 maxcdepth; /* maximum mark recursion depth of C functions */
402			uint32 untraced; /* number of times tracing of GC thing's children were
403			delayed due to a low C stack */
404			#ifdef DEBUG
405			uint32 maxuntraced;/* maximum number of things with children to trace
406			later */
407			#endif
408			uint32 maxlevel; /* maximum GC nesting (indirect recursion) level */
409			uint32 poke; /* number of potentially useful GC calls */
410			uint32 afree; /* thing arenas freed so far */
411			uint32 stackseg; /* total extraordinary stack segments scanned */
412			uint32 segslots; /* total stack segment jsval slots scanned */
413			uint32 nclose; /* number of objects with close hooks */
414			uint32 maxnclose; /* max number of objects with close hooks */
415			uint32 closelater; /* number of close hooks scheduled to run */
416			uint32 maxcloselater; /* max number of close hooks scheduled to run */
417
418			JSGCArenaStats arenaStats[GC_NUM_FREELISTS];
419			JSGCArenaStats doubleArenaStats;
420			} JSGCStats;
421
422			extern JS_FRIEND_API(void)
423			js_DumpGCStats(JSRuntime rt, FILE fp);
424
425			#endif /* JS_GCMETER */
426
427			JS_END_EXTERN_C
428
429			#endif /* jsgc_h___ */