/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- * vim: set ts=8 sw=4 et tw=78: * * ***** 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 jscntxt_h___ #define jscntxt_h___ /* * JS execution context. */ #include "jsarena.h" /* Added by JSIFY */ #include "jsclist.h" #include "jslong.h" #include "jsatom.h" #include "jsversion.h" #include "jsdhash.h" #include "jsgc.h" #include "jsinterp.h" #include "jsobj.h" #include "jsprvtd.h" #include "jspubtd.h" #include "jsregexp.h" #include "jsutil.h" JS_BEGIN_EXTERN_C /* * js_GetSrcNote cache to avoid O(n^2) growth in finding a source note for a * given pc in a script. We use the script->code pointer to tag the cache, * instead of the script address itself, so that source notes are always found * by offset from the bytecode with which they were generated. */ typedef struct JSGSNCache { jsbytecode *code; JSDHashTable table; #ifdef JS_GSNMETER uint32 hits; uint32 misses; uint32 fills; uint32 clears; # define GSN_CACHE_METER(cache,cnt) (++(cache)->cnt) #else # define GSN_CACHE_METER(cache,cnt) /* nothing */ #endif } JSGSNCache; #define GSN_CACHE_CLEAR(cache) \ JS_BEGIN_MACRO \ (cache)->code = NULL; \ if ((cache)->table.ops) { \ JS_DHashTableFinish(&(cache)->table); \ (cache)->table.ops = NULL; \ } \ GSN_CACHE_METER(cache, clears); \ JS_END_MACRO /* These helper macros take a cx as parameter and operate on its GSN cache. */ #define JS_CLEAR_GSN_CACHE(cx) GSN_CACHE_CLEAR(&JS_GSN_CACHE(cx)) #define JS_METER_GSN_CACHE(cx,cnt) GSN_CACHE_METER(&JS_GSN_CACHE(cx), cnt) #ifdef __cplusplus namespace nanojit { class Fragment; class Fragmento; class LirBuffer; } class TraceRecorder; extern "C++" { template class Queue; } typedef Queue SlotList; # define CLS(T) T* #else # define CLS(T) void* #endif #define FRAGMENT_TABLE_SIZE 512 struct VMFragment; /* * Trace monitor. Every JSThread (if JS_THREADSAFE) or JSRuntime (if not * JS_THREADSAFE) has an associated trace monitor that keeps track of loop * frequencies for all JavaScript code loaded into that runtime. */ typedef struct JSTraceMonitor { /* * Flag set when running (or recording) JIT-compiled code. This prevents * both interpreter activation and last-ditch garbage collection when up * against our runtime's memory limits. This flag also suppresses calls to * JS_ReportOutOfMemory when failing due to runtime limits. */ JSBool onTrace; CLS(nanojit::LirBuffer) lirbuf; CLS(nanojit::Fragmento) fragmento; CLS(TraceRecorder) recorder; uint32 globalShape; CLS(SlotList) globalSlots; jsval *reservedDoublePool; jsval *reservedDoublePoolPtr; struct VMFragment* vmfragments[FRAGMENT_TABLE_SIZE]; /* * reservedObjects is a linked list (via fslots[0]) of preallocated JSObjects. * The JIT uses this to ensure that leaving a trace tree can't fail. */ JSObject *reservedObjects; JSBool useReservedObjects; /* Fragmento for the regular expression compiler. This is logically * a distinct compiler but needs to be managed in exactly the same * way as the real tracing Fragmento. */ CLS(nanojit::LirBuffer) reLirBuf; CLS(nanojit::Fragmento) reFragmento; /* Keep a list of recorders we need to abort on cache flush. */ CLS(TraceRecorder) abortStack; } JSTraceMonitor; #ifdef JS_TRACER # define JS_ON_TRACE(cx) (JS_TRACE_MONITOR(cx).onTrace) #else # define JS_ON_TRACE(cx) JS_FALSE #endif #ifdef DEBUG # define JS_EVAL_CACHE_METERING 1 #endif /* Number of potentially reusable scriptsToGC to search for the eval cache. */ #ifndef JS_EVAL_CACHE_SHIFT # define JS_EVAL_CACHE_SHIFT 6 #endif #define JS_EVAL_CACHE_SIZE JS_BIT(JS_EVAL_CACHE_SHIFT) #ifdef JS_EVAL_CACHE_METERING # define EVAL_CACHE_METER_LIST(_) _(probe), _(hit), _(step), _(noscope) # define ID(x) x /* Have to typedef this for LiveConnect C code, which includes us. */ typedef struct JSEvalCacheMeter { uint64 EVAL_CACHE_METER_LIST(ID); } JSEvalCacheMeter; # undef ID # define DECLARE_EVAL_CACHE_METER JSEvalCacheMeter evalCacheMeter; #else # define DECLARE_EVAL_CACHE_METER /* nothing */ #endif #ifdef JS_THREADSAFE /* * Structure uniquely representing a thread. It holds thread-private data * that can be accessed without a global lock. */ struct JSThread { /* Linked list of all contexts active on this thread. */ JSCList contextList; /* Opaque thread-id, from NSPR's PR_GetCurrentThread(). */ jsword id; /* * Thread-local version of JSRuntime.gcMallocBytes to avoid taking * locks on each JS_malloc. */ uint32 gcMallocBytes; /* * Store the GSN cache in struct JSThread, not struct JSContext, both to * save space and to simplify cleanup in js_GC. Any embedding (Firefox * or another Gecko application) that uses many contexts per thread is * unlikely to interleave js_GetSrcNote-intensive loops in the decompiler * among two or more contexts running script in one thread. */ JSGSNCache gsnCache; /* Property cache for faster call/get/set invocation. */ JSPropertyCache propertyCache; #ifdef JS_TRACER /* Trace-tree JIT recorder/interpreter state. */ JSTraceMonitor traceMonitor; #endif /* Lock-free hashed lists of scripts created by eval to garbage-collect. */ JSScript *scriptsToGC[JS_EVAL_CACHE_SIZE]; DECLARE_EVAL_CACHE_METER }; #define JS_CACHE_LOCUS(cx) ((cx)->thread) extern void js_ThreadDestructorCB(void *ptr); extern JSBool js_SetContextThread(JSContext *cx); extern void js_ClearContextThread(JSContext *cx); extern JSThread * js_GetCurrentThread(JSRuntime *rt); #endif /* JS_THREADSAFE */ typedef enum JSDestroyContextMode { JSDCM_NO_GC, JSDCM_MAYBE_GC, JSDCM_FORCE_GC, JSDCM_NEW_FAILED } JSDestroyContextMode; typedef enum JSRuntimeState { JSRTS_DOWN, JSRTS_LAUNCHING, JSRTS_UP, JSRTS_LANDING } JSRuntimeState; typedef enum JSBuiltinFunctionId { JSBUILTIN_ObjectToIterator, JSBUILTIN_CallIteratorNext, JSBUILTIN_LIMIT } JSBuiltinFunctionId; typedef struct JSPropertyTreeEntry { JSDHashEntryHdr hdr; JSScopeProperty *child; } JSPropertyTreeEntry; typedef struct JSSetSlotRequest JSSetSlotRequest; struct JSSetSlotRequest { JSObject *obj; /* object containing slot to set */ JSObject *pobj; /* new proto or parent reference */ uint16 slot; /* which to set, proto or parent */ uint16 errnum; /* JSMSG_NO_ERROR or error result */ JSSetSlotRequest *next; /* next request in GC worklist */ }; struct JSRuntime { /* Runtime state, synchronized by the stateChange/gcLock condvar/lock. */ JSRuntimeState state; /* Context create/destroy callback. */ JSContextCallback cxCallback; /* Garbage collector state, used by jsgc.c. */ JSGCChunkInfo *gcChunkList; JSGCArenaList gcArenaList[GC_NUM_FREELISTS]; JSGCDoubleArenaList gcDoubleArenaList; JSGCFreeListSet *gcFreeListsPool; JSDHashTable gcRootsHash; JSDHashTable *gcLocksHash; jsrefcount gcKeepAtoms; uint32 gcBytes; uint32 gcLastBytes; uint32 gcMaxBytes; uint32 gcMaxMallocBytes; uint32 gcEmptyArenaPoolLifespan; uint32 gcLevel; uint32 gcNumber; JSTracer *gcMarkingTracer; uint32 gcTriggerFactor; /* * NB: do not pack another flag here by claiming gcPadding unless the new * flag is written only by the GC thread. Atomic updates to packed bytes * are not guaranteed, so stores issued by one thread may be lost due to * unsynchronized read-modify-write cycles on other threads. */ JSPackedBool gcPoke; JSPackedBool gcRunning; uint16 gcPadding; #ifdef JS_GC_ZEAL jsrefcount gcZeal; #endif JSGCCallback gcCallback; uint32 gcMallocBytes; JSGCArenaInfo *gcUntracedArenaStackTop; #ifdef DEBUG size_t gcTraceLaterCount; #endif /* * Table for tracking iterators to ensure that we close iterator's state * before finalizing the iterable object. */ JSPtrTable gcIteratorTable; /* * The trace operation and its data argument to trace embedding-specific * GC roots. */ JSTraceDataOp gcExtraRootsTraceOp; void *gcExtraRootsData; /* * Used to serialize cycle checks when setting __proto__ or __parent__ by * requesting the GC handle the required cycle detection. If the GC hasn't * been poked, it won't scan for garbage. This member is protected by * rt->gcLock. */ JSSetSlotRequest *setSlotRequests; /* Random number generator state, used by jsmath.c. */ JSBool rngInitialized; int64 rngMultiplier; int64 rngAddend; int64 rngMask; int64 rngSeed; jsdouble rngDscale; /* Well-known numbers held for use by this runtime's contexts. */ jsdouble *jsNaN; jsdouble *jsNegativeInfinity; jsdouble *jsPositiveInfinity; #ifdef JS_THREADSAFE JSLock *deflatedStringCacheLock; #endif JSHashTable *deflatedStringCache; #ifdef DEBUG uint32 deflatedStringCacheBytes; #endif /* * Empty and unit-length strings held for use by this runtime's contexts. * The unitStrings array and its elements are created on demand. */ JSString *emptyString; JSString **unitStrings; /* * Builtin functions, lazily created and held for use by the trace recorder. * * This field would be #ifdef JS_TRACER, but XPConnect is compiled without * -DJS_TRACER and includes this header. */ JSObject *builtinFunctions[JSBUILTIN_LIMIT]; /* List of active contexts sharing this runtime; protected by gcLock. */ JSCList contextList; /* Per runtime debug hooks -- see jsprvtd.h and jsdbgapi.h. */ JSDebugHooks globalDebugHooks; /* More debugging state, see jsdbgapi.c. */ JSCList trapList; JSCList watchPointList; /* Client opaque pointers */ void *data; #ifdef JS_THREADSAFE /* These combine to interlock the GC and new requests. */ PRLock *gcLock; PRCondVar *gcDone; PRCondVar *requestDone; uint32 requestCount; JSThread *gcThread; /* Lock and owning thread pointer for JS_LOCK_RUNTIME. */ PRLock *rtLock; #ifdef DEBUG jsword rtLockOwner; #endif /* Used to synchronize down/up state change; protected by gcLock. */ PRCondVar *stateChange; /* * State for sharing single-threaded titles, once a second thread tries to * lock a title. The titleSharingDone condvar is protected by rt->gcLock * to minimize number of locks taken in JS_EndRequest. * * The titleSharingTodo linked list is likewise "global" per runtime, not * one-list-per-context, to conserve space over all contexts, optimizing * for the likely case that titles become shared rarely, and among a very * small set of threads (contexts). */ PRCondVar *titleSharingDone; JSTitle *titleSharingTodo; /* * Magic terminator for the rt->titleSharingTodo linked list, threaded through * title->u.link. This hack allows us to test whether a title is on the list * by asking whether title->u.link is non-null. We use a large, likely bogus * pointer here to distinguish this value from any valid u.count (small int) * value. */ #define NO_TITLE_SHARING_TODO ((JSTitle *) 0xfeedbeef) /* * Lock serializing trapList and watchPointList accesses, and count of all * mutations to trapList and watchPointList made by debugger threads. To * keep the code simple, we define debuggerMutations for the thread-unsafe * case too. */ PRLock *debuggerLock; #endif /* JS_THREADSAFE */ uint32 debuggerMutations; /* * Security callbacks set on the runtime are used by each context unless * an override is set on the context. */ JSSecurityCallbacks *securityCallbacks; /* * Shared scope property tree, and arena-pool for allocating its nodes. * The propertyRemovals counter is incremented for every js_ClearScope, * and for each js_RemoveScopeProperty that frees a slot in an object. * See js_NativeGet and js_NativeSet in jsobj.c. */ JSDHashTable propertyTreeHash; JSScopeProperty *propertyFreeList; JSArenaPool propertyArenaPool; int32 propertyRemovals; /* Script filename table. */ struct JSHashTable *scriptFilenameTable; JSCList scriptFilenamePrefixes; #ifdef JS_THREADSAFE PRLock *scriptFilenameTableLock; #endif /* Number localization, used by jsnum.c */ const char *thousandsSeparator; const char *decimalSeparator; const char *numGrouping; /* * Weak references to lazily-created, well-known XML singletons. * * NB: Singleton objects must be carefully disconnected from the rest of * the object graph usually associated with a JSContext's global object, * including the set of standard class objects. See jsxml.c for details. */ JSObject *anynameObject; JSObject *functionNamespaceObject; /* * A helper list for the GC, so it can mark native iterator states. See * js_TraceNativeEnumerators for details. */ JSNativeEnumerator *nativeEnumerators; #ifndef JS_THREADSAFE /* * For thread-unsafe embeddings, the GSN cache lives in the runtime and * not each context, since we expect it to be filled once when decompiling * a longer script, then hit repeatedly as js_GetSrcNote is called during * the decompiler activation that filled it. */ JSGSNCache gsnCache; /* Property cache for faster call/get/set invocation. */ JSPropertyCache propertyCache; /* Trace-tree JIT recorder/interpreter state. */ JSTraceMonitor traceMonitor; /* Lock-free hashed lists of scripts created by eval to garbage-collect. */ JSScript *scriptsToGC[JS_EVAL_CACHE_SIZE]; DECLARE_EVAL_CACHE_METER #define JS_CACHE_LOCUS(cx) ((cx)->runtime) #endif /* * Object shape (property cache structural type) identifier generator. * * Type 0 stands for the empty scope, and must not be regenerated due to * uint32 wrap-around. Since we use atomic pre-increment, the initial * value for the first typed non-empty scope will be 1. * * The GC compresses live types, minimizing rt->shapeGen in the process. * If this counter overflows into SHAPE_OVERFLOW_BIT (in jsinterp.h), the * GC will disable property caches for all threads, to avoid aliasing two * different types. Updated by js_GenerateShape (in jsinterp.c). */ uint32 shapeGen; /* Literal table maintained by jsatom.c functions. */ JSAtomState atomState; /* * Cache of reusable JSNativeEnumerators mapped by shape identifiers (as * stored in scope->shape). This cache is nulled by the GC and protected * by gcLock. */ #define NATIVE_ENUM_CACHE_LOG2 8 #define NATIVE_ENUM_CACHE_MASK JS_BITMASK(NATIVE_ENUM_CACHE_LOG2) #define NATIVE_ENUM_CACHE_SIZE JS_BIT(NATIVE_ENUM_CACHE_LOG2) #define NATIVE_ENUM_CACHE_HASH(shape) \ ((((shape) >> NATIVE_ENUM_CACHE_LOG2) ^ (shape)) & NATIVE_ENUM_CACHE_MASK) jsuword nativeEnumCache[NATIVE_ENUM_CACHE_SIZE]; /* * Runtime-wide flag set to true when any Array prototype has an indexed * property defined on it, creating a hazard for code reading or writing * over a hole from a dense Array instance that is not prepared to look up * the proto chain (the writing case must involve a check for a read-only * element, which cannot be shadowed). */ JSBool anyArrayProtoHasElement; /* * Various metering fields are defined at the end of JSRuntime. In this * way there is no need to recompile all the code that refers to other * fields of JSRuntime after enabling the corresponding metering macro. */ #ifdef JS_DUMP_ENUM_CACHE_STATS int32 nativeEnumProbes; int32 nativeEnumMisses; # define ENUM_CACHE_METER(name) JS_ATOMIC_INCREMENT(&cx->runtime->name) #else # define ENUM_CACHE_METER(name) ((void) 0) #endif #ifdef JS_DUMP_LOOP_STATS /* Loop statistics, to trigger trace recording and compiling. */ JSBasicStats loopStats; #endif #if defined DEBUG || defined JS_DUMP_PROPTREE_STATS /* Function invocation metering. */ jsrefcount inlineCalls; jsrefcount nativeCalls; jsrefcount nonInlineCalls; jsrefcount constructs; /* Title lock and scope property metering. */ jsrefcount claimAttempts; jsrefcount claimedTitles; jsrefcount deadContexts; jsrefcount deadlocksAvoided; jsrefcount liveScopes; jsrefcount sharedTitles; jsrefcount totalScopes; jsrefcount liveScopeProps; jsrefcount liveScopePropsPreSweep; jsrefcount totalScopeProps; jsrefcount livePropTreeNodes; jsrefcount duplicatePropTreeNodes; jsrefcount totalPropTreeNodes; jsrefcount propTreeKidsChunks; jsrefcount middleDeleteFixups; /* String instrumentation. */ jsrefcount liveStrings; jsrefcount totalStrings; jsrefcount liveDependentStrings; jsrefcount totalDependentStrings; jsrefcount badUndependStrings; double lengthSum; double lengthSquaredSum; double strdepLengthSum; double strdepLengthSquaredSum; #endif /* DEBUG || JS_DUMP_PROPTREE_STATS */ #ifdef JS_SCOPE_DEPTH_METER /* * Stats on runtime prototype chain lookups and scope chain depths, i.e., * counts of objects traversed on a chain until the wanted id is found. */ JSBasicStats protoLookupDepthStats; JSBasicStats scopeSearchDepthStats; /* * Stats on compile-time host environment and lexical scope chain lengths * (maximum depths). */ JSBasicStats hostenvScopeDepthStats; JSBasicStats lexicalScopeDepthStats; #endif #ifdef JS_GCMETER JSGCStats gcStats; #endif }; /* Common macros to access thread-local caches in JSThread or JSRuntime. */ #define JS_GSN_CACHE(cx) (JS_CACHE_LOCUS(cx)->gsnCache) #define JS_PROPERTY_CACHE(cx) (JS_CACHE_LOCUS(cx)->propertyCache) #define JS_TRACE_MONITOR(cx) (JS_CACHE_LOCUS(cx)->traceMonitor) #define JS_SCRIPTS_TO_GC(cx) (JS_CACHE_LOCUS(cx)->scriptsToGC) #ifdef JS_EVAL_CACHE_METERING # define EVAL_CACHE_METER(x) (JS_CACHE_LOCUS(cx)->evalCacheMeter.x++) #else # define EVAL_CACHE_METER(x) ((void) 0) #endif #undef DECLARE_EVAL_CACHE_METER #ifdef DEBUG # define JS_RUNTIME_METER(rt, which) JS_ATOMIC_INCREMENT(&(rt)->which) # define JS_RUNTIME_UNMETER(rt, which) JS_ATOMIC_DECREMENT(&(rt)->which) #else # define JS_RUNTIME_METER(rt, which) /* nothing */ # define JS_RUNTIME_UNMETER(rt, which) /* nothing */ #endif #define JS_KEEP_ATOMS(rt) JS_ATOMIC_INCREMENT(&(rt)->gcKeepAtoms); #define JS_UNKEEP_ATOMS(rt) JS_ATOMIC_DECREMENT(&(rt)->gcKeepAtoms); #ifdef JS_ARGUMENT_FORMATTER_DEFINED /* * Linked list mapping format strings for JS_{Convert,Push}Arguments{,VA} to * formatter functions. Elements are sorted in non-increasing format string * length order. */ struct JSArgumentFormatMap { const char *format; size_t length; JSArgumentFormatter formatter; JSArgumentFormatMap *next; }; #endif struct JSStackHeader { uintN nslots; JSStackHeader *down; }; #define JS_STACK_SEGMENT(sh) ((jsval *)(sh) + 2) /* * Key and entry types for the JSContext.resolvingTable hash table, typedef'd * here because all consumers need to see these declarations (and not just the * typedef names, as would be the case for an opaque pointer-to-typedef'd-type * declaration), along with cx->resolvingTable. */ typedef struct JSResolvingKey { JSObject *obj; jsid id; } JSResolvingKey; typedef struct JSResolvingEntry { JSDHashEntryHdr hdr; JSResolvingKey key; uint32 flags; } JSResolvingEntry; #define JSRESFLAG_LOOKUP 0x1 /* resolving id from lookup */ #define JSRESFLAG_WATCH 0x2 /* resolving id from watch */ typedef struct JSLocalRootChunk JSLocalRootChunk; #define JSLRS_CHUNK_SHIFT 8 #define JSLRS_CHUNK_SIZE JS_BIT(JSLRS_CHUNK_SHIFT) #define JSLRS_CHUNK_MASK JS_BITMASK(JSLRS_CHUNK_SHIFT) struct JSLocalRootChunk { jsval roots[JSLRS_CHUNK_SIZE]; JSLocalRootChunk *down; }; typedef struct JSLocalRootStack { uint32 scopeMark; uint32 rootCount; JSLocalRootChunk *topChunk; JSLocalRootChunk firstChunk; } JSLocalRootStack; #define JSLRS_NULL_MARK ((uint32) -1) /* * Macros to push/pop JSTempValueRooter instances to context-linked stack of * temporary GC roots. If you need to protect a result value that flows out of * a C function across several layers of other functions, use the * js_LeaveLocalRootScopeWithResult internal API (see further below) instead. * * The macros also provide a simple way to get a single rooted pointer via * JS_PUSH_TEMP_ROOT_(cx, NULL, &tvr). Then &tvr.u. gives the * necessary pointer. * * JSTempValueRooter.count defines the type of the rooted value referenced by * JSTempValueRooter.u union of type JSTempValueUnion. When count is positive * or zero, u.array points to a vector of jsvals. Otherwise it must be one of * the following constants: */ #define JSTVU_SINGLE (-1) /* u.value or u. is single jsval or GC-thing */ #define JSTVU_TRACE (-2) /* u.trace is a hook to trace a custom * structure */ #define JSTVU_SPROP (-3) /* u.sprop roots property tree node */ #define JSTVU_WEAK_ROOTS (-4) /* u.weakRoots points to saved weak roots */ #define JSTVU_PARSE_CONTEXT (-5) /* u.parseContext roots JSParseContext* */ #define JSTVU_SCRIPT (-6) /* u.script roots JSScript* */ /* * Here single JSTVU_SINGLE covers both jsval and pointers to any GC-thing via * reinterpreting the thing as JSVAL_OBJECT. It works because the GC-thing is * aligned on a 0 mod 8 boundary, and object has the 0 jsval tag. So any * GC-thing may be tagged as if it were an object and untagged, if it's then * used only as an opaque pointer until discriminated by other means than tag * bits. This is how, for example, js_GetGCThingTraceKind uses its |thing| * parameter -- it consults GC-thing flags stored separately from the thing to * decide the kind of thing. * * The following checks that this type-punning is possible. */ JS_STATIC_ASSERT(sizeof(JSTempValueUnion) == sizeof(jsval)); JS_STATIC_ASSERT(sizeof(JSTempValueUnion) == sizeof(void *)); #define JS_PUSH_TEMP_ROOT_COMMON(cx,x,tvr,cnt,kind) \ JS_BEGIN_MACRO \ JS_ASSERT((cx)->tempValueRooters != (tvr)); \ (tvr)->count = (cnt); \ (tvr)->u.kind = (x); \ (tvr)->down = (cx)->tempValueRooters; \ (cx)->tempValueRooters = (tvr); \ JS_END_MACRO #define JS_POP_TEMP_ROOT(cx,tvr) \ JS_BEGIN_MACRO \ JS_ASSERT((cx)->tempValueRooters == (tvr)); \ (cx)->tempValueRooters = (tvr)->down; \ JS_END_MACRO #define JS_PUSH_TEMP_ROOT(cx,cnt,arr,tvr) \ JS_BEGIN_MACRO \ JS_ASSERT((int)(cnt) >= 0); \ JS_PUSH_TEMP_ROOT_COMMON(cx, arr, tvr, (ptrdiff_t) (cnt), array); \ JS_END_MACRO #define JS_PUSH_SINGLE_TEMP_ROOT(cx,val,tvr) \ JS_PUSH_TEMP_ROOT_COMMON(cx, val, tvr, JSTVU_SINGLE, value) #define JS_PUSH_TEMP_ROOT_OBJECT(cx,obj,tvr) \ JS_PUSH_TEMP_ROOT_COMMON(cx, obj, tvr, JSTVU_SINGLE, object) #define JS_PUSH_TEMP_ROOT_STRING(cx,str,tvr) \ JS_PUSH_TEMP_ROOT_COMMON(cx, str, tvr, JSTVU_SINGLE, string) #define JS_PUSH_TEMP_ROOT_XML(cx,xml_,tvr) \ JS_PUSH_TEMP_ROOT_COMMON(cx, xml_, tvr, JSTVU_SINGLE, xml) #define JS_PUSH_TEMP_ROOT_TRACE(cx,trace_,tvr) \ JS_PUSH_TEMP_ROOT_COMMON(cx, trace_, tvr, JSTVU_TRACE, trace) #define JS_PUSH_TEMP_ROOT_SPROP(cx,sprop_,tvr) \ JS_PUSH_TEMP_ROOT_COMMON(cx, sprop_, tvr, JSTVU_SPROP, sprop) #define JS_PUSH_TEMP_ROOT_WEAK_COPY(cx,weakRoots_,tvr) \ JS_PUSH_TEMP_ROOT_COMMON(cx, weakRoots_, tvr, JSTVU_WEAK_ROOTS, weakRoots) #define JS_PUSH_TEMP_ROOT_PARSE_CONTEXT(cx,pc,tvr) \ JS_PUSH_TEMP_ROOT_COMMON(cx, pc, tvr, JSTVU_PARSE_CONTEXT, parseContext) #define JS_PUSH_TEMP_ROOT_SCRIPT(cx,script_,tvr) \ JS_PUSH_TEMP_ROOT_COMMON(cx, script_, tvr, JSTVU_SCRIPT, script) #define JSRESOLVE_INFER 0xffff /* infer bits from current bytecode */ struct JSContext { /* * Operation count. It is declared as the first field in the struct to * ensure the fastest possible access. */ volatile int32 operationCount; /* JSRuntime contextList linkage. */ JSCList link; #if JS_HAS_XML_SUPPORT /* * Bit-set formed from binary exponentials of the XML_* tiny-ids defined * for boolean settings in jsxml.c, plus an XSF_CACHE_VALID bit. Together * these act as a cache of the boolean XML.ignore* and XML.prettyPrinting * property values associated with this context's global object. */ uint8 xmlSettingFlags; uint8 padding; #else uint16 padding; #endif /* * Classic Algol "display" static link optimization. */ #define JS_DISPLAY_SIZE 16 JSStackFrame *display[JS_DISPLAY_SIZE]; /* Runtime version control identifier. */ uint16 version; /* Per-context options. */ uint32 options; /* see jsapi.h for JSOPTION_* */ /* Locale specific callbacks for string conversion. */ JSLocaleCallbacks *localeCallbacks; /* * cx->resolvingTable is non-null and non-empty if we are initializing * standard classes lazily, or if we are otherwise recursing indirectly * from js_LookupProperty through a JSClass.resolve hook. It is used to * limit runaway recursion (see jsapi.c and jsobj.c). */ JSDHashTable *resolvingTable; #if JS_HAS_LVALUE_RETURN /* * Secondary return value from native method called on the left-hand side * of an assignment operator. The native should store the object in which * to set a property in *rval, and return the property's id expressed as a * jsval by calling JS_SetCallReturnValue2(cx, idval). */ jsval rval2; JSPackedBool rval2set; #endif /* * True if generating an error, to prevent runaway recursion. * NB: generatingError packs with rval2set, #if JS_HAS_LVALUE_RETURN; * with insideGCMarkCallback and with throwing below. */ JSPackedBool generatingError; /* Flag to indicate that we run inside gcCallback(cx, JSGC_MARK_END). */ JSPackedBool insideGCMarkCallback; /* Exception state -- the exception member is a GC root by definition. */ JSPackedBool throwing; /* is there a pending exception? */ jsval exception; /* most-recently-thrown exception */ /* Limit pointer for checking native stack consumption during recursion. */ jsuword stackLimit; /* Quota on the size of arenas used to compile and execute scripts. */ size_t scriptStackQuota; /* Data shared by threads in an address space. */ JSRuntime *runtime; /* Stack arena pool and frame pointer register. */ JSArenaPool stackPool; JS_REQUIRES_STACK JSStackFrame *fp; /* Temporary arena pool used while compiling and decompiling. */ JSArenaPool tempPool; /* Top-level object and pointer to top stack frame's scope chain. */ JSObject *globalObject; /* Storage to root recently allocated GC things and script result. */ JSWeakRoots weakRoots; /* Regular expression class statics (XXX not shared globally). */ JSRegExpStatics regExpStatics; /* State for object and array toSource conversion. */ JSSharpObjectMap sharpObjectMap; /* Argument formatter support for JS_{Convert,Push}Arguments{,VA}. */ JSArgumentFormatMap *argumentFormatMap; /* Last message string and trace file for debugging. */ char *lastMessage; #ifdef DEBUG void *tracefp; #endif /* Per-context optional error reporter. */ JSErrorReporter errorReporter; /* * Flag indicating that operationCallback stores the deprecated branch * callback. */ uint32 branchCallbackWasSet : 1; uint32 operationLimit : 31; JSOperationCallback operationCallback; /* Interpreter activation count. */ uintN interpLevel; /* Client opaque pointers. */ void *data; void *data2; /* GC and thread-safe state. */ JSStackFrame *dormantFrameChain; /* dormant stack frame to scan */ #ifdef JS_THREADSAFE JSThread *thread; jsrefcount requestDepth; /* Same as requestDepth but ignoring JS_SuspendRequest/JS_ResumeRequest */ jsrefcount outstandingRequests; JSTitle *titleToShare; /* weak reference, see jslock.c */ JSTitle *lockedSealedTitle; /* weak ref, for low-cost sealed title locking */ JSCList threadLinks; /* JSThread contextList linkage */ #define CX_FROM_THREAD_LINKS(tl) \ ((JSContext *)((char *)(tl) - offsetof(JSContext, threadLinks))) #endif /* PDL of stack headers describing stack slots not rooted by argv, etc. */ JSStackHeader *stackHeaders; /* Optional stack of heap-allocated scoped local GC roots. */ JSLocalRootStack *localRootStack; /* Stack of thread-stack-allocated temporary GC roots. */ JSTempValueRooter *tempValueRooters; #ifdef JS_THREADSAFE JSGCFreeListSet *gcLocalFreeLists; #endif /* List of pre-allocated doubles. */ JSGCDoubleCell *doubleFreeList; /* Debug hooks associated with the current context. */ JSDebugHooks *debugHooks; /* Security callbacks that override any defined on the runtime. */ JSSecurityCallbacks *securityCallbacks; /* Pinned regexp pool used for regular expressions. */ JSArenaPool regexpPool; /* Stored here to avoid passing it around as a parameter. */ uintN resolveFlags; }; #ifdef JS_THREADSAFE # define JS_THREAD_ID(cx) ((cx)->thread ? (cx)->thread->id : 0) #endif #ifdef __cplusplus static inline JSAtom ** FrameAtomBase(JSContext *cx, JSStackFrame *fp) { return fp->imacpc ? COMMON_ATOMS_START(&cx->runtime->atomState) : fp->script->atomMap.vector; } /* FIXME(bug 332648): Move this into a public header. */ class JSAutoTempValueRooter { public: JSAutoTempValueRooter(JSContext *cx, size_t len, jsval *vec) : mContext(cx) { JS_PUSH_TEMP_ROOT(mContext, len, vec, &mTvr); } JSAutoTempValueRooter(JSContext *cx, jsval v) : mContext(cx) { JS_PUSH_SINGLE_TEMP_ROOT(mContext, v, &mTvr); } JSAutoTempValueRooter(JSContext *cx, JSString *str) : mContext(cx) { JS_PUSH_TEMP_ROOT_STRING(mContext, str, &mTvr); } ~JSAutoTempValueRooter() { JS_POP_TEMP_ROOT(mContext, &mTvr); } protected: JSContext *mContext; private: #ifndef AIX static void *operator new(size_t); static void operator delete(void *, size_t); #endif JSTempValueRooter mTvr; }; class JSAutoResolveFlags { public: JSAutoResolveFlags(JSContext *cx, uintN flags) : mContext(cx), mSaved(cx->resolveFlags) { cx->resolveFlags = flags; } ~JSAutoResolveFlags() { mContext->resolveFlags = mSaved; } private: JSContext *mContext; uintN mSaved; }; #endif /* __cpluscplus */ /* * Slightly more readable macros for testing per-context option settings (also * to hide bitset implementation detail). * * JSOPTION_XML must be handled specially in order to propagate from compile- * to run-time (from cx->options to script->version/cx->version). To do that, * we copy JSOPTION_XML from cx->options into cx->version as JSVERSION_HAS_XML * whenever options are set, and preserve this XML flag across version number * changes done via the JS_SetVersion API. * * But when executing a script or scripted function, the interpreter changes * cx->version, including the XML flag, to script->version. Thus JSOPTION_XML * is a compile-time option that causes a run-time version change during each * activation of the compiled script. That version change has the effect of * changing JS_HAS_XML_OPTION, so that any compiling done via eval enables XML * support. If an XML-enabled script or function calls a non-XML function, * the flag bit will be cleared during the callee's activation. * * Note that JS_SetVersion API calls never pass JSVERSION_HAS_XML or'd into * that API's version parameter. * * Note also that script->version must contain this XML option flag in order * for XDR'ed scripts to serialize and deserialize with that option preserved * for detection at run-time. We can't copy other compile-time options into * script->version because that would break backward compatibility (certain * other options, e.g. JSOPTION_VAROBJFIX, are analogous to JSOPTION_XML). */ #define JS_HAS_OPTION(cx,option) (((cx)->options & (option)) != 0) #define JS_HAS_STRICT_OPTION(cx) JS_HAS_OPTION(cx, JSOPTION_STRICT) #define JS_HAS_WERROR_OPTION(cx) JS_HAS_OPTION(cx, JSOPTION_WERROR) #define JS_HAS_COMPILE_N_GO_OPTION(cx) JS_HAS_OPTION(cx, JSOPTION_COMPILE_N_GO) #define JS_HAS_ATLINE_OPTION(cx) JS_HAS_OPTION(cx, JSOPTION_ATLINE) #define JSVERSION_MASK 0x0FFF /* see JSVersion in jspubtd.h */ #define JSVERSION_HAS_XML 0x1000 /* flag induced by XML option */ #define JSVERSION_ANONFUNFIX 0x2000 /* see jsapi.h, the comments for JSOPTION_ANONFUNFIX */ #define JSVERSION_NUMBER(cx) ((JSVersion)((cx)->version & \ JSVERSION_MASK)) #define JS_HAS_XML_OPTION(cx) ((cx)->version & JSVERSION_HAS_XML || \ JSVERSION_NUMBER(cx) >= JSVERSION_1_6) /* * Initialize a library-wide thread private data index, and remember that it * has already been done, so that it happens only once ever. Returns true on * success. */ extern JSBool js_InitThreadPrivateIndex(void (*ptr)(void *)); /* * Clean up thread-private data on the current thread. NSPR automatically * cleans up thread-private data for every thread except the main thread * (see bug 383977) on shutdown. Thus, this function should be called for * exactly those threads that survive JS_ShutDown, including the main thread. */ extern JSBool js_CleanupThreadPrivateData(); /* * Common subroutine of JS_SetVersion and js_SetVersion, to update per-context * data that depends on version. */ extern void js_OnVersionChange(JSContext *cx); /* * Unlike the JS_SetVersion API, this function stores JSVERSION_HAS_XML and * any future non-version-number flags induced by compiler options. */ extern void js_SetVersion(JSContext *cx, JSVersion version); /* * Create and destroy functions for JSContext, which is manually allocated * and exclusively owned. */ extern JSContext * js_NewContext(JSRuntime *rt, size_t stackChunkSize); extern void js_DestroyContext(JSContext *cx, JSDestroyContextMode mode); /* * Return true if cx points to a context in rt->contextList, else return false. * NB: the caller (see jslock.c:ClaimTitle) must hold rt->gcLock. */ extern JSBool js_ValidContextPointer(JSRuntime *rt, JSContext *cx); static JS_INLINE JSContext * js_ContextFromLinkField(JSCList *link) { JS_ASSERT(link); return (JSContext *) ((uint8 *) link - offsetof(JSContext, link)); } /* * If unlocked, acquire and release rt->gcLock around *iterp update; otherwise * the caller must be holding rt->gcLock. */ extern JSContext * js_ContextIterator(JSRuntime *rt, JSBool unlocked, JSContext **iterp); /* * JSClass.resolve and watchpoint recursion damping machinery. */ extern JSBool js_StartResolving(JSContext *cx, JSResolvingKey *key, uint32 flag, JSResolvingEntry **entryp); extern void js_StopResolving(JSContext *cx, JSResolvingKey *key, uint32 flag, JSResolvingEntry *entry, uint32 generation); /* * Local root set management. * * NB: the jsval parameters below may be properly tagged jsvals, or GC-thing * pointers cast to (jsval). This relies on JSObject's tag being zero, but * on the up side it lets us push int-jsval-encoded scopeMark values on the * local root stack. */ extern JSBool js_EnterLocalRootScope(JSContext *cx); #define js_LeaveLocalRootScope(cx) \ js_LeaveLocalRootScopeWithResult(cx, JSVAL_NULL) extern void js_LeaveLocalRootScopeWithResult(JSContext *cx, jsval rval); extern void js_ForgetLocalRoot(JSContext *cx, jsval v); extern int js_PushLocalRoot(JSContext *cx, JSLocalRootStack *lrs, jsval v); extern void js_TraceLocalRoots(JSTracer *trc, JSLocalRootStack *lrs); /* * Report an exception, which is currently realized as a printf-style format * string and its arguments. */ typedef enum JSErrNum { #define MSG_DEF(name, number, count, exception, format) \ name = number, #include "js.msg" #undef MSG_DEF JSErr_Limit } JSErrNum; extern JS_FRIEND_API(const JSErrorFormatString *) js_GetErrorMessage(void *userRef, const char *locale, const uintN errorNumber); #ifdef va_start extern JSBool js_ReportErrorVA(JSContext *cx, uintN flags, const char *format, va_list ap); extern JSBool js_ReportErrorNumberVA(JSContext *cx, uintN flags, JSErrorCallback callback, void *userRef, const uintN errorNumber, JSBool charArgs, va_list ap); extern JSBool js_ExpandErrorArguments(JSContext *cx, JSErrorCallback callback, void *userRef, const uintN errorNumber, char **message, JSErrorReport *reportp, JSBool *warningp, JSBool charArgs, va_list ap); #endif extern void js_ReportOutOfMemory(JSContext *cx); /* * Report that cx->scriptStackQuota is exhausted. */ extern void js_ReportOutOfScriptQuota(JSContext *cx); extern void js_ReportOverRecursed(JSContext *cx); extern void js_ReportAllocationOverflow(JSContext *cx); #define JS_CHECK_RECURSION(cx, onerror) \ JS_BEGIN_MACRO \ int stackDummy_; \ \ if (!JS_CHECK_STACK_SIZE(cx, stackDummy_)) { \ js_ReportOverRecursed(cx); \ onerror; \ } \ JS_END_MACRO /* * Report an exception using a previously composed JSErrorReport. * XXXbe remove from "friend" API */ extern JS_FRIEND_API(void) js_ReportErrorAgain(JSContext *cx, const char *message, JSErrorReport *report); extern void js_ReportIsNotDefined(JSContext *cx, const char *name); /* * Report an attempt to access the property of a null or undefined value (v). */ extern JSBool js_ReportIsNullOrUndefined(JSContext *cx, intN spindex, jsval v, JSString *fallback); extern void js_ReportMissingArg(JSContext *cx, jsval *vp, uintN arg); /* * Report error using js_DecompileValueGenerator(cx, spindex, v, fallback) as * the first argument for the error message. If the error message has less * then 3 arguments, use null for arg1 or arg2. */ extern JSBool js_ReportValueErrorFlags(JSContext *cx, uintN flags, const uintN errorNumber, intN spindex, jsval v, JSString *fallback, const char *arg1, const char *arg2); #define js_ReportValueError(cx,errorNumber,spindex,v,fallback) \ ((void)js_ReportValueErrorFlags(cx, JSREPORT_ERROR, errorNumber, \ spindex, v, fallback, NULL, NULL)) #define js_ReportValueError2(cx,errorNumber,spindex,v,fallback,arg1) \ ((void)js_ReportValueErrorFlags(cx, JSREPORT_ERROR, errorNumber, \ spindex, v, fallback, arg1, NULL)) #define js_ReportValueError3(cx,errorNumber,spindex,v,fallback,arg1,arg2) \ ((void)js_ReportValueErrorFlags(cx, JSREPORT_ERROR, errorNumber, \ spindex, v, fallback, arg1, arg2)) extern JSErrorFormatString js_ErrorFormatString[JSErr_Limit]; /* * See JS_SetThreadStackLimit in jsapi.c, where we check that the stack grows * in the expected direction. On Unix-y systems, JS_STACK_GROWTH_DIRECTION is * computed on the build host by jscpucfg.c and written into jsautocfg.h. The * macro is hardcoded in jscpucfg.h on Windows and Mac systems (for historical * reasons pre-dating autoconf usage). */ #if JS_STACK_GROWTH_DIRECTION > 0 # define JS_CHECK_STACK_SIZE(cx, lval) ((jsuword)&(lval) < (cx)->stackLimit) #else # define JS_CHECK_STACK_SIZE(cx, lval) ((jsuword)&(lval) > (cx)->stackLimit) #endif /* * Update the operation counter according to the given weight and call the * operation callback when we reach the operation limit. To make this * frequently executed macro faster we decrease the counter from * JSContext.operationLimit and compare against zero to check the limit. * * This macro can run the full GC. Return true if it is OK to continue and * false otherwise. */ #define JS_CHECK_OPERATION_LIMIT(cx, weight) \ (JS_CHECK_OPERATION_WEIGHT(weight), \ (((cx)->operationCount -= (weight)) > 0 || js_ResetOperationCount(cx))) /* * A version of JS_CHECK_OPERATION_LIMIT that just updates the operation count * without calling the operation callback or any other API. This macro resets * the count to 0 when it becomes negative to prevent a wrap-around when the * macro is called repeatably. */ #define JS_COUNT_OPERATION(cx, weight) \ ((void)(JS_CHECK_OPERATION_WEIGHT(weight), \ (cx)->operationCount = ((cx)->operationCount > 0) \ ? (cx)->operationCount - (weight) \ : 0)) /* * The implementation of the above macros assumes that subtracting weights * twice from a positive number does not wrap-around INT32_MIN. */ #define JS_CHECK_OPERATION_WEIGHT(weight) \ (JS_ASSERT((uint32) (weight) > 0), \ JS_ASSERT((uint32) (weight) < JS_BIT(30))) /* Relative operations weights. */ #define JSOW_JUMP 1 #define JSOW_ALLOCATION 100 #define JSOW_LOOKUP_PROPERTY 5 #define JSOW_GET_PROPERTY 10 #define JSOW_SET_PROPERTY 20 #define JSOW_NEW_PROPERTY 200 #define JSOW_DELETE_PROPERTY 30 #define JSOW_ENTER_SHARP JS_OPERATION_WEIGHT_BASE #define JSOW_SCRIPT_JUMP JS_OPERATION_WEIGHT_BASE /* * Reset the operation count and call the operation callback assuming that the * operation limit is reached. */ extern JSBool js_ResetOperationCount(JSContext *cx); static JS_INLINE void js_InitOperationLimit(JSContext *cx) { /* * Set the limit to 1 + max to detect if JS_SetOperationLimit() was ever * called. */ cx->operationCount = (int32) JS_MAX_OPERATION_LIMIT + 1; cx->operationLimit = JS_MAX_OPERATION_LIMIT + 1; } static JS_INLINE JSBool js_HasOperationLimit(JSContext *cx) { return cx->operationLimit <= JS_MAX_OPERATION_LIMIT; } /* * Get the current cx->fp, first lazily instantiating stack frames if needed. * (Do not access cx->fp directly except in JS_REQUIRES_STACK code.) * * Defined in jstracer.cpp if JS_TRACER is defined. */ extern JS_FORCES_STACK JSStackFrame * js_GetTopStackFrame(JSContext *cx); extern JSStackFrame * js_GetScriptedCaller(JSContext *cx, JSStackFrame *fp); JS_END_EXTERN_C #endif /* jscntxt_h___ */