/js/lib/Socket.IO-node/support/expresso/deps/jscoverage/js/jsatom.cpp
C++ | 1064 lines | 839 code | 101 blank | 124 comment | 85 complexity | 1363ab9dbc2f9d35f90c607e514bd8c2 MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.1, MPL-2.0-no-copyleft-exception, BSD-3-Clause
1/* -*- 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/* 41 * JS atom table. 42 */ 43#include "jsstddef.h" 44#include <stdlib.h> 45#include <string.h> 46#include "jstypes.h" 47#include "jsutil.h" /* Added by JSIFY */ 48#include "jshash.h" /* Added by JSIFY */ 49#include "jsprf.h" 50#include "jsapi.h" 51#include "jsatom.h" 52#include "jscntxt.h" 53#include "jsversion.h" 54#include "jsgc.h" 55#include "jslock.h" 56#include "jsnum.h" 57#include "jsscan.h" 58#include "jsstr.h" 59 60const char * 61js_AtomToPrintableString(JSContext *cx, JSAtom *atom) 62{ 63 return js_ValueToPrintableString(cx, ATOM_KEY(atom)); 64} 65 66#define JS_PROTO(name,code,init) const char js_##name##_str[] = #name; 67#include "jsproto.tbl" 68#undef JS_PROTO 69 70/* 71 * String constants for common atoms defined in JSAtomState starting from 72 * JSAtomState.emptyAtom until JSAtomState.lazy. 73 * 74 * The elements of the array after the first empty string define strings 75 * corresponding to the two boolean literals, false and true, followed by the 76 * JSType enumerators from jspubtd.h starting with "undefined" for JSTYPE_VOID 77 * (which is pseudo-boolean 2) and continuing as initialized below. The static 78 * asserts check these relations. 79 */ 80JS_STATIC_ASSERT(JSTYPE_LIMIT == 8); 81JS_STATIC_ASSERT(JSVAL_TO_BOOLEAN(JSVAL_VOID) == 2); 82JS_STATIC_ASSERT(JSTYPE_VOID == 0); 83 84const char *const js_common_atom_names[] = { 85 "", /* emptyAtom */ 86 js_false_str, /* booleanAtoms[0] */ 87 js_true_str, /* booleanAtoms[1] */ 88 js_undefined_str, /* typeAtoms[JSTYPE_VOID] */ 89 js_object_str, /* typeAtoms[JSTYPE_OBJECT] */ 90 js_function_str, /* typeAtoms[JSTYPE_FUNCTION] */ 91 "string", /* typeAtoms[JSTYPE_STRING] */ 92 "number", /* typeAtoms[JSTYPE_NUMBER] */ 93 "boolean", /* typeAtoms[JSTYPE_BOOLEAN] */ 94 js_null_str, /* typeAtoms[JSTYPE_NULL] */ 95 "xml", /* typeAtoms[JSTYPE_XML] */ 96 js_null_str, /* nullAtom */ 97 98#define JS_PROTO(name,code,init) js_##name##_str, 99#include "jsproto.tbl" 100#undef JS_PROTO 101 102 js_anonymous_str, /* anonymousAtom */ 103 js_apply_str, /* applyAtom */ 104 js_arguments_str, /* argumentsAtom */ 105 js_arity_str, /* arityAtom */ 106 js_call_str, /* callAtom */ 107 js_callee_str, /* calleeAtom */ 108 js_caller_str, /* callerAtom */ 109 js_class_prototype_str, /* classPrototypeAtom */ 110 js_constructor_str, /* constructorAtom */ 111 js_count_str, /* countAtom */ 112 js_each_str, /* eachAtom */ 113 js_eval_str, /* evalAtom */ 114 js_fileName_str, /* fileNameAtom */ 115 js_get_str, /* getAtom */ 116 js_getter_str, /* getterAtom */ 117 js_index_str, /* indexAtom */ 118 js_input_str, /* inputAtom */ 119 js_iterator_str, /* iteratorAtom */ 120 js_length_str, /* lengthAtom */ 121 js_lineNumber_str, /* lineNumberAtom */ 122 js_message_str, /* messageAtom */ 123 js_name_str, /* nameAtom */ 124 js_next_str, /* nextAtom */ 125 js_noSuchMethod_str, /* noSuchMethodAtom */ 126 js_parent_str, /* parentAtom */ 127 js_proto_str, /* protoAtom */ 128 js_set_str, /* setAtom */ 129 js_setter_str, /* setterAtom */ 130 js_stack_str, /* stackAtom */ 131 js_toLocaleString_str, /* toLocaleStringAtom */ 132 js_toSource_str, /* toSourceAtom */ 133 js_toString_str, /* toStringAtom */ 134 js_valueOf_str, /* valueOfAtom */ 135 js_toJSON_str, /* toJSONAtom */ 136 "(void 0)", /* void0Atom */ 137 138#if JS_HAS_XML_SUPPORT 139 js_etago_str, /* etagoAtom */ 140 js_namespace_str, /* namespaceAtom */ 141 js_ptagc_str, /* ptagcAtom */ 142 js_qualifier_str, /* qualifierAtom */ 143 js_space_str, /* spaceAtom */ 144 js_stago_str, /* stagoAtom */ 145 js_star_str, /* starAtom */ 146 js_starQualifier_str, /* starQualifierAtom */ 147 js_tagc_str, /* tagcAtom */ 148 js_xml_str, /* xmlAtom */ 149#endif 150 151#ifdef NARCISSUS 152 js___call___str, /* __call__Atom */ 153 js___construct___str, /* __construct__Atom */ 154 js___hasInstance___str, /* __hasInstance__Atom */ 155 js_ExecutionContext_str, /* ExecutionContextAtom */ 156 js_current_str, /* currentAtom */ 157#endif 158}; 159 160JS_STATIC_ASSERT(JS_ARRAY_LENGTH(js_common_atom_names) * sizeof(JSAtom *) == 161 LAZY_ATOM_OFFSET_START - ATOM_OFFSET_START); 162 163/* 164 * Interpreter macros called by the trace recorder assume common atom indexes 165 * fit in one byte of immediate operand. 166 */ 167JS_STATIC_ASSERT(JS_ARRAY_LENGTH(js_common_atom_names) < 256); 168 169const size_t js_common_atom_count = JS_ARRAY_LENGTH(js_common_atom_names); 170 171const char js_anonymous_str[] = "anonymous"; 172const char js_apply_str[] = "apply"; 173const char js_arguments_str[] = "arguments"; 174const char js_arity_str[] = "arity"; 175const char js_call_str[] = "call"; 176const char js_callee_str[] = "callee"; 177const char js_caller_str[] = "caller"; 178const char js_class_prototype_str[] = "prototype"; 179const char js_constructor_str[] = "constructor"; 180const char js_count_str[] = "__count__"; 181const char js_each_str[] = "each"; 182const char js_eval_str[] = "eval"; 183const char js_fileName_str[] = "fileName"; 184const char js_get_str[] = "get"; 185const char js_getter_str[] = "getter"; 186const char js_index_str[] = "index"; 187const char js_input_str[] = "input"; 188const char js_iterator_str[] = "__iterator__"; 189const char js_length_str[] = "length"; 190const char js_lineNumber_str[] = "lineNumber"; 191const char js_message_str[] = "message"; 192const char js_name_str[] = "name"; 193const char js_next_str[] = "next"; 194const char js_noSuchMethod_str[] = "__noSuchMethod__"; 195const char js_object_str[] = "object"; 196const char js_parent_str[] = "__parent__"; 197const char js_proto_str[] = "__proto__"; 198const char js_setter_str[] = "setter"; 199const char js_set_str[] = "set"; 200const char js_stack_str[] = "stack"; 201const char js_toSource_str[] = "toSource"; 202const char js_toString_str[] = "toString"; 203const char js_toLocaleString_str[] = "toLocaleString"; 204const char js_undefined_str[] = "undefined"; 205const char js_valueOf_str[] = "valueOf"; 206const char js_toJSON_str[] = "toJSON"; 207 208#if JS_HAS_XML_SUPPORT 209const char js_etago_str[] = "</"; 210const char js_namespace_str[] = "namespace"; 211const char js_ptagc_str[] = "/>"; 212const char js_qualifier_str[] = "::"; 213const char js_space_str[] = " "; 214const char js_stago_str[] = "<"; 215const char js_star_str[] = "*"; 216const char js_starQualifier_str[] = "*::"; 217const char js_tagc_str[] = ">"; 218const char js_xml_str[] = "xml"; 219#endif 220 221#if JS_HAS_GENERATORS 222const char js_close_str[] = "close"; 223const char js_send_str[] = "send"; 224#endif 225 226#ifdef NARCISSUS 227const char js___call___str[] = "__call__"; 228const char js___construct___str[] = "__construct__"; 229const char js___hasInstance___str[] = "__hasInstance__"; 230const char js_ExecutionContext_str[] = "ExecutionContext"; 231const char js_current_str[] = "current"; 232#endif 233 234/* 235 * JSAtomState.doubleAtoms and JSAtomState.stringAtoms hashtable entry. To 236 * support pinned and interned string atoms, we use the lowest bits of the 237 * keyAndFlags field to store ATOM_PINNED and ATOM_INTERNED flags. 238 */ 239typedef struct JSAtomHashEntry { 240 JSDHashEntryHdr hdr; 241 jsuword keyAndFlags; 242} JSAtomHashEntry; 243 244#define ATOM_ENTRY_FLAG_MASK (ATOM_PINNED | ATOM_INTERNED) 245 246JS_STATIC_ASSERT(ATOM_ENTRY_FLAG_MASK < JSVAL_ALIGN); 247 248/* 249 * Helper macros to access and modify JSAtomHashEntry. 250 */ 251#define TO_ATOM_ENTRY(hdr) ((JSAtomHashEntry *) hdr) 252#define ATOM_ENTRY_KEY(entry) \ 253 ((void *)((entry)->keyAndFlags & ~ATOM_ENTRY_FLAG_MASK)) 254#define ATOM_ENTRY_FLAGS(entry) \ 255 ((uintN)((entry)->keyAndFlags & ATOM_ENTRY_FLAG_MASK)) 256#define INIT_ATOM_ENTRY(entry, key) \ 257 ((void)((entry)->keyAndFlags = (jsuword)(key))) 258#define ADD_ATOM_ENTRY_FLAGS(entry, flags) \ 259 ((void)((entry)->keyAndFlags |= (jsuword)(flags))) 260#define CLEAR_ATOM_ENTRY_FLAGS(entry, flags) \ 261 ((void)((entry)->keyAndFlags &= ~(jsuword)(flags))) 262 263static JSDHashNumber 264HashDouble(JSDHashTable *table, const void *key); 265 266static JSBool 267MatchDouble(JSDHashTable *table, const JSDHashEntryHdr *hdr, const void *key); 268 269static JSDHashNumber 270HashString(JSDHashTable *table, const void *key); 271 272static JSBool 273MatchString(JSDHashTable *table, const JSDHashEntryHdr *hdr, const void *key); 274 275static const JSDHashTableOps DoubleHashOps = { 276 JS_DHashAllocTable, 277 JS_DHashFreeTable, 278 HashDouble, 279 MatchDouble, 280 JS_DHashMoveEntryStub, 281 JS_DHashClearEntryStub, 282 JS_DHashFinalizeStub, 283 NULL 284}; 285 286static const JSDHashTableOps StringHashOps = { 287 JS_DHashAllocTable, 288 JS_DHashFreeTable, 289 HashString, 290 MatchString, 291 JS_DHashMoveEntryStub, 292 JS_DHashClearEntryStub, 293 JS_DHashFinalizeStub, 294 NULL 295}; 296 297#define IS_DOUBLE_TABLE(table) ((table)->ops == &DoubleHashOps) 298#define IS_STRING_TABLE(table) ((table)->ops == &StringHashOps) 299 300#define IS_INITIALIZED_STATE(state) IS_DOUBLE_TABLE(&(state)->doubleAtoms) 301 302static JSDHashNumber 303HashDouble(JSDHashTable *table, const void *key) 304{ 305 jsdouble d; 306 307 JS_ASSERT(IS_DOUBLE_TABLE(table)); 308 d = *(jsdouble *)key; 309 return JSDOUBLE_HI32(d) ^ JSDOUBLE_LO32(d); 310} 311 312static JSDHashNumber 313HashString(JSDHashTable *table, const void *key) 314{ 315 JS_ASSERT(IS_STRING_TABLE(table)); 316 return js_HashString((JSString *)key); 317} 318 319static JSBool 320MatchDouble(JSDHashTable *table, const JSDHashEntryHdr *hdr, const void *key) 321{ 322 JSAtomHashEntry *entry = TO_ATOM_ENTRY(hdr); 323 jsdouble d1, d2; 324 325 JS_ASSERT(IS_DOUBLE_TABLE(table)); 326 if (entry->keyAndFlags == 0) { 327 /* See comments in MatchString. */ 328 return JS_FALSE; 329 } 330 331 d1 = *(jsdouble *)ATOM_ENTRY_KEY(entry); 332 d2 = *(jsdouble *)key; 333 if (JSDOUBLE_IS_NaN(d1)) 334 return JSDOUBLE_IS_NaN(d2); 335#if defined(XP_WIN) 336 /* XXX MSVC miscompiles such that (NaN == 0) */ 337 if (JSDOUBLE_IS_NaN(d2)) 338 return JS_FALSE; 339#endif 340 return d1 == d2; 341} 342 343static JSBool 344MatchString(JSDHashTable *table, const JSDHashEntryHdr *hdr, const void *key) 345{ 346 JSAtomHashEntry *entry = TO_ATOM_ENTRY(hdr); 347 348 JS_ASSERT(IS_STRING_TABLE(table)); 349 if (entry->keyAndFlags == 0) { 350 /* 351 * This happens when js_AtomizeString adds a new hash entry and 352 * releases the lock but before it takes the lock the second time to 353 * initialize keyAndFlags for the entry. 354 * 355 * We always return false for such entries so JS_DHashTableOperate 356 * never finds them. We clean them during GC's sweep phase. 357 * 358 * It means that with a contested lock or when GC is triggered outside 359 * the lock we may end up adding two entries, but this is a price for 360 * simpler code. 361 */ 362 return JS_FALSE; 363 } 364 return js_EqualStrings((JSString *)ATOM_ENTRY_KEY(entry), (JSString *)key); 365} 366 367/* 368 * For a browser build from 2007-08-09 after the browser starts up there are 369 * just 55 double atoms, but over 15000 string atoms. Not to penalize more 370 * economical embeddings allocating too much memory initially we initialize 371 * atomized strings with just 1K entries. 372 */ 373#define JS_STRING_HASH_COUNT 1024 374#define JS_DOUBLE_HASH_COUNT 64 375 376JSBool 377js_InitAtomState(JSRuntime *rt) 378{ 379 JSAtomState *state = &rt->atomState; 380 381 /* 382 * The caller must zero the state before calling this function. 383 */ 384 JS_ASSERT(!state->stringAtoms.ops); 385 JS_ASSERT(!state->doubleAtoms.ops); 386 387 if (!JS_DHashTableInit(&state->stringAtoms, &StringHashOps, 388 NULL, sizeof(JSAtomHashEntry), 389 JS_DHASH_DEFAULT_CAPACITY(JS_STRING_HASH_COUNT))) { 390 state->stringAtoms.ops = NULL; 391 return JS_FALSE; 392 } 393 JS_ASSERT(IS_STRING_TABLE(&state->stringAtoms)); 394 395 if (!JS_DHashTableInit(&state->doubleAtoms, &DoubleHashOps, 396 NULL, sizeof(JSAtomHashEntry), 397 JS_DHASH_DEFAULT_CAPACITY(JS_DOUBLE_HASH_COUNT))) { 398 state->doubleAtoms.ops = NULL; 399 JS_DHashTableFinish(&state->stringAtoms); 400 state->stringAtoms.ops = NULL; 401 return JS_FALSE; 402 } 403 JS_ASSERT(IS_DOUBLE_TABLE(&state->doubleAtoms)); 404 405#ifdef JS_THREADSAFE 406 js_InitLock(&state->lock); 407#endif 408 JS_ASSERT(IS_INITIALIZED_STATE(state)); 409 return JS_TRUE; 410} 411 412static JSDHashOperator 413js_string_uninterner(JSDHashTable *table, JSDHashEntryHdr *hdr, 414 uint32 number, void *arg) 415{ 416 JSAtomHashEntry *entry = TO_ATOM_ENTRY(hdr); 417 JSRuntime *rt = (JSRuntime *)arg; 418 JSString *str; 419 420 /* 421 * Any string entry that remains at this point must be initialized, as the 422 * last GC should clean any uninitialized ones. 423 */ 424 JS_ASSERT(IS_STRING_TABLE(table)); 425 JS_ASSERT(entry->keyAndFlags != 0); 426 str = (JSString *)ATOM_ENTRY_KEY(entry); 427 428 /* Pass null as context. */ 429 js_FinalizeStringRT(rt, str, js_GetExternalStringGCType(str), NULL); 430 return JS_DHASH_NEXT; 431} 432 433void 434js_FinishAtomState(JSRuntime *rt) 435{ 436 JSAtomState *state = &rt->atomState; 437 438 if (!IS_INITIALIZED_STATE(state)) { 439 /* 440 * We are called with uninitialized state when JS_NewRuntime fails and 441 * calls JS_DestroyRuntime on a partially initialized runtime. 442 */ 443 return; 444 } 445 446 JS_DHashTableEnumerate(&state->stringAtoms, js_string_uninterner, rt); 447 JS_DHashTableFinish(&state->stringAtoms); 448 JS_DHashTableFinish(&state->doubleAtoms); 449 450#ifdef JS_THREADSAFE 451 js_FinishLock(&state->lock); 452#endif 453#ifdef DEBUG 454 memset(state, JS_FREE_PATTERN, sizeof *state); 455#endif 456} 457 458JSBool 459js_InitCommonAtoms(JSContext *cx) 460{ 461 JSAtomState *state = &cx->runtime->atomState; 462 uintN i; 463 JSAtom **atoms; 464 465 atoms = COMMON_ATOMS_START(state); 466 for (i = 0; i < JS_ARRAY_LENGTH(js_common_atom_names); i++, atoms++) { 467 *atoms = js_Atomize(cx, js_common_atom_names[i], 468 strlen(js_common_atom_names[i]), ATOM_PINNED); 469 if (!*atoms) 470 return JS_FALSE; 471 } 472 JS_ASSERT((uint8 *)atoms - (uint8 *)state == LAZY_ATOM_OFFSET_START); 473 memset(atoms, 0, ATOM_OFFSET_LIMIT - LAZY_ATOM_OFFSET_START); 474 475 return JS_TRUE; 476} 477 478static JSDHashOperator 479js_atom_unpinner(JSDHashTable *table, JSDHashEntryHdr *hdr, 480 uint32 number, void *arg) 481{ 482 JS_ASSERT(IS_STRING_TABLE(table)); 483 CLEAR_ATOM_ENTRY_FLAGS(TO_ATOM_ENTRY(hdr), ATOM_PINNED); 484 return JS_DHASH_NEXT; 485} 486 487void 488js_FinishCommonAtoms(JSContext *cx) 489{ 490 JSAtomState *state = &cx->runtime->atomState; 491 492 JS_DHashTableEnumerate(&state->stringAtoms, js_atom_unpinner, NULL); 493#ifdef DEBUG 494 memset(COMMON_ATOMS_START(state), JS_FREE_PATTERN, 495 ATOM_OFFSET_LIMIT - ATOM_OFFSET_START); 496#endif 497} 498 499static JSDHashOperator 500js_locked_atom_tracer(JSDHashTable *table, JSDHashEntryHdr *hdr, 501 uint32 number, void *arg) 502{ 503 JSAtomHashEntry *entry = TO_ATOM_ENTRY(hdr); 504 JSTracer *trc = (JSTracer *)arg; 505 506 if (entry->keyAndFlags == 0) { 507 /* Ignore uninitialized entries during tracing. */ 508 return JS_DHASH_NEXT; 509 } 510 JS_SET_TRACING_INDEX(trc, "locked_atom", (size_t)number); 511 JS_CallTracer(trc, ATOM_ENTRY_KEY(entry), 512 IS_STRING_TABLE(table) ? JSTRACE_STRING : JSTRACE_DOUBLE); 513 return JS_DHASH_NEXT; 514} 515 516static JSDHashOperator 517js_pinned_atom_tracer(JSDHashTable *table, JSDHashEntryHdr *hdr, 518 uint32 number, void *arg) 519{ 520 JSAtomHashEntry *entry = TO_ATOM_ENTRY(hdr); 521 JSTracer *trc = (JSTracer *)arg; 522 uintN flags = ATOM_ENTRY_FLAGS(entry); 523 524 JS_ASSERT(IS_STRING_TABLE(table)); 525 if (flags & (ATOM_PINNED | ATOM_INTERNED)) { 526 JS_SET_TRACING_INDEX(trc, 527 flags & ATOM_PINNED 528 ? "pinned_atom" 529 : "interned_atom", 530 (size_t)number); 531 JS_CallTracer(trc, ATOM_ENTRY_KEY(entry), JSTRACE_STRING); 532 } 533 return JS_DHASH_NEXT; 534} 535 536void 537js_TraceAtomState(JSTracer *trc, JSBool allAtoms) 538{ 539 JSAtomState *state; 540 541 state = &trc->context->runtime->atomState; 542 if (allAtoms) { 543 JS_DHashTableEnumerate(&state->doubleAtoms, js_locked_atom_tracer, trc); 544 JS_DHashTableEnumerate(&state->stringAtoms, js_locked_atom_tracer, trc); 545 } else { 546 JS_DHashTableEnumerate(&state->stringAtoms, js_pinned_atom_tracer, trc); 547 } 548} 549 550static JSDHashOperator 551js_atom_sweeper(JSDHashTable *table, JSDHashEntryHdr *hdr, 552 uint32 number, void *arg) 553{ 554 JSAtomHashEntry *entry = TO_ATOM_ENTRY(hdr); 555 JSContext *cx = (JSContext *)arg; 556 557 /* Remove uninitialized entries. */ 558 if (entry->keyAndFlags == 0) 559 return JS_DHASH_REMOVE; 560 561 if (ATOM_ENTRY_FLAGS(entry) & (ATOM_PINNED | ATOM_INTERNED)) { 562 /* Pinned or interned key cannot be finalized. */ 563 JS_ASSERT(!js_IsAboutToBeFinalized(cx, ATOM_ENTRY_KEY(entry))); 564 } else if (js_IsAboutToBeFinalized(cx, ATOM_ENTRY_KEY(entry))) { 565 /* Remove entries with things about to be GC'ed. */ 566 return JS_DHASH_REMOVE; 567 } 568 return JS_DHASH_NEXT; 569} 570 571void 572js_SweepAtomState(JSContext *cx) 573{ 574 JSAtomState *state = &cx->runtime->atomState; 575 576 JS_DHashTableEnumerate(&state->doubleAtoms, js_atom_sweeper, cx); 577 JS_DHashTableEnumerate(&state->stringAtoms, js_atom_sweeper, cx); 578 579 /* 580 * Optimize for simplicity and mutate table generation numbers even if the 581 * sweeper has not removed any entries. 582 */ 583 state->doubleAtoms.generation++; 584 state->stringAtoms.generation++; 585} 586 587JSAtom * 588js_AtomizeDouble(JSContext *cx, jsdouble d) 589{ 590 JSAtomState *state; 591 JSDHashTable *table; 592 JSAtomHashEntry *entry; 593 uint32 gen; 594 jsdouble *key; 595 jsval v; 596 597 state = &cx->runtime->atomState; 598 table = &state->doubleAtoms; 599 600 JS_LOCK(cx, &state->lock); 601 entry = TO_ATOM_ENTRY(JS_DHashTableOperate(table, &d, JS_DHASH_ADD)); 602 if (!entry) 603 goto failed_hash_add; 604 if (entry->keyAndFlags == 0) { 605 gen = ++table->generation; 606 JS_UNLOCK(cx, &state->lock); 607 608 key = js_NewWeaklyRootedDouble(cx, d); 609 if (!key) 610 return NULL; 611 612 JS_LOCK(cx, &state->lock); 613 if (table->generation == gen) { 614 JS_ASSERT(entry->keyAndFlags == 0); 615 } else { 616 entry = TO_ATOM_ENTRY(JS_DHashTableOperate(table, key, 617 JS_DHASH_ADD)); 618 if (!entry) 619 goto failed_hash_add; 620 if (entry->keyAndFlags != 0) 621 goto finish; 622 ++table->generation; 623 } 624 INIT_ATOM_ENTRY(entry, key); 625 } 626 627 finish: 628 v = DOUBLE_TO_JSVAL((jsdouble *)ATOM_ENTRY_KEY(entry)); 629 cx->weakRoots.lastAtom = v; 630 JS_UNLOCK(cx, &state->lock); 631 632 return (JSAtom *)v; 633 634 failed_hash_add: 635 JS_UNLOCK(cx, &state->lock); 636 JS_ReportOutOfMemory(cx); 637 return NULL; 638} 639 640JSAtom * 641js_AtomizeString(JSContext *cx, JSString *str, uintN flags) 642{ 643 jsval v; 644 JSAtomState *state; 645 JSDHashTable *table; 646 JSAtomHashEntry *entry; 647 JSString *key; 648 uint32 gen; 649 650 JS_ASSERT(!(flags & ~(ATOM_PINNED|ATOM_INTERNED|ATOM_TMPSTR|ATOM_NOCOPY))); 651 JS_ASSERT_IF(flags & ATOM_NOCOPY, flags & ATOM_TMPSTR); 652 653 state = &cx->runtime->atomState; 654 table = &state->stringAtoms; 655 656 JS_LOCK(cx, &state->lock); 657 entry = TO_ATOM_ENTRY(JS_DHashTableOperate(table, str, JS_DHASH_ADD)); 658 if (!entry) 659 goto failed_hash_add; 660 if (entry->keyAndFlags != 0) { 661 key = (JSString *)ATOM_ENTRY_KEY(entry); 662 } else { 663 /* 664 * We created a new hashtable entry. Unless str is already allocated 665 * from the GC heap and flat, we have to release state->lock as 666 * string construction is a complex operation. For example, it can 667 * trigger GC which may rehash the table and make the entry invalid. 668 */ 669 ++table->generation; 670 if (!(flags & ATOM_TMPSTR) && JSSTRING_IS_FLAT(str)) { 671 JSFLATSTR_CLEAR_MUTABLE(str); 672 key = str; 673 } else { 674 gen = table->generation; 675 JS_UNLOCK(cx, &state->lock); 676 677 if (flags & ATOM_TMPSTR) { 678 if (flags & ATOM_NOCOPY) { 679 key = js_NewString(cx, JSFLATSTR_CHARS(str), 680 JSFLATSTR_LENGTH(str)); 681 if (!key) 682 return NULL; 683 684 /* Finish handing off chars to the GC'ed key string. */ 685 str->u.chars = NULL; 686 } else { 687 key = js_NewStringCopyN(cx, JSFLATSTR_CHARS(str), 688 JSFLATSTR_LENGTH(str)); 689 if (!key) 690 return NULL; 691 } 692 } else { 693 JS_ASSERT(JSSTRING_IS_DEPENDENT(str)); 694 if (!js_UndependString(cx, str)) 695 return NULL; 696 key = str; 697 } 698 699 JS_LOCK(cx, &state->lock); 700 if (table->generation == gen) { 701 JS_ASSERT(entry->keyAndFlags == 0); 702 } else { 703 entry = TO_ATOM_ENTRY(JS_DHashTableOperate(table, key, 704 JS_DHASH_ADD)); 705 if (!entry) 706 goto failed_hash_add; 707 if (entry->keyAndFlags != 0) { 708 key = (JSString *)ATOM_ENTRY_KEY(entry); 709 goto finish; 710 } 711 ++table->generation; 712 } 713 } 714 INIT_ATOM_ENTRY(entry, key); 715 JSFLATSTR_SET_ATOMIZED(key); 716 } 717 718 finish: 719 ADD_ATOM_ENTRY_FLAGS(entry, flags & (ATOM_PINNED | ATOM_INTERNED)); 720 JS_ASSERT(JSSTRING_IS_ATOMIZED(key)); 721 v = STRING_TO_JSVAL(key); 722 cx->weakRoots.lastAtom = v; 723 JS_UNLOCK(cx, &state->lock); 724 return (JSAtom *)v; 725 726 failed_hash_add: 727 JS_UNLOCK(cx, &state->lock); 728 JS_ReportOutOfMemory(cx); 729 return NULL; 730} 731 732JSAtom * 733js_Atomize(JSContext *cx, const char *bytes, size_t length, uintN flags) 734{ 735 jschar *chars; 736 JSString str; 737 JSAtom *atom; 738 739 /* 740 * Avoiding the malloc in js_InflateString on shorter strings saves us 741 * over 20,000 malloc calls on mozilla browser startup. This compares to 742 * only 131 calls where the string is longer than a 31 char (net) buffer. 743 * The vast majority of atomized strings are already in the hashtable. So 744 * js_AtomizeString rarely has to copy the temp string we make. 745 */ 746#define ATOMIZE_BUF_MAX 32 747 jschar inflated[ATOMIZE_BUF_MAX]; 748 size_t inflatedLength = ATOMIZE_BUF_MAX - 1; 749 750 if (length < ATOMIZE_BUF_MAX) { 751 js_InflateStringToBuffer(cx, bytes, length, inflated, &inflatedLength); 752 inflated[inflatedLength] = 0; 753 chars = inflated; 754 } else { 755 inflatedLength = length; 756 chars = js_InflateString(cx, bytes, &inflatedLength); 757 if (!chars) 758 return NULL; 759 flags |= ATOM_NOCOPY; 760 } 761 762 JSFLATSTR_INIT(&str, (jschar *)chars, inflatedLength); 763 atom = js_AtomizeString(cx, &str, ATOM_TMPSTR | flags); 764 if (chars != inflated && str.u.chars) 765 JS_free(cx, chars); 766 return atom; 767} 768 769JSAtom * 770js_AtomizeChars(JSContext *cx, const jschar *chars, size_t length, uintN flags) 771{ 772 JSString str; 773 774 JSFLATSTR_INIT(&str, (jschar *)chars, length); 775 return js_AtomizeString(cx, &str, ATOM_TMPSTR | flags); 776} 777 778JSAtom * 779js_GetExistingStringAtom(JSContext *cx, const jschar *chars, size_t length) 780{ 781 JSString str, *str2; 782 JSAtomState *state; 783 JSDHashEntryHdr *hdr; 784 785 JSFLATSTR_INIT(&str, (jschar *)chars, length); 786 state = &cx->runtime->atomState; 787 788 JS_LOCK(cx, &state->lock); 789 hdr = JS_DHashTableOperate(&state->stringAtoms, &str, JS_DHASH_LOOKUP); 790 str2 = JS_DHASH_ENTRY_IS_BUSY(hdr) 791 ? (JSString *)ATOM_ENTRY_KEY(TO_ATOM_ENTRY(hdr)) 792 : NULL; 793 JS_UNLOCK(cx, &state->lock); 794 795 return str2 ? (JSAtom *)STRING_TO_JSVAL(str2) : NULL; 796} 797 798JSBool 799js_AtomizePrimitiveValue(JSContext *cx, jsval v, JSAtom **atomp) 800{ 801 JSAtom *atom; 802 803 if (JSVAL_IS_STRING(v)) { 804 atom = js_AtomizeString(cx, JSVAL_TO_STRING(v), 0); 805 if (!atom) 806 return JS_FALSE; 807 } else if (JSVAL_IS_DOUBLE(v)) { 808 atom = js_AtomizeDouble(cx, *JSVAL_TO_DOUBLE(v)); 809 if (!atom) 810 return JS_FALSE; 811 } else { 812 JS_ASSERT(JSVAL_IS_INT(v) || JSVAL_IS_BOOLEAN(v) || 813 JSVAL_IS_NULL(v) || JSVAL_IS_VOID(v)); 814 atom = (JSAtom *)v; 815 } 816 *atomp = atom; 817 return JS_TRUE; 818} 819 820JSBool 821js_ValueToStringId(JSContext *cx, jsval v, jsid *idp) 822{ 823 JSString *str; 824 JSAtom *atom; 825 826 /* 827 * Optimize for the common case where v is an already-atomized string. The 828 * comment in jsstr.h before the JSSTRING_SET_ATOMIZED macro's definition 829 * explains why this is thread-safe. The extra rooting via lastAtom (which 830 * would otherwise be done in js_js_AtomizeString) ensures the caller that 831 * the resulting id at is least weakly rooted. 832 */ 833 if (JSVAL_IS_STRING(v)) { 834 str = JSVAL_TO_STRING(v); 835 if (JSSTRING_IS_ATOMIZED(str)) { 836 cx->weakRoots.lastAtom = v; 837 *idp = ATOM_TO_JSID((JSAtom *) v); 838 return JS_TRUE; 839 } 840 } else { 841 str = js_ValueToString(cx, v); 842 if (!str) 843 return JS_FALSE; 844 } 845 atom = js_AtomizeString(cx, str, 0); 846 if (!atom) 847 return JS_FALSE; 848 *idp = ATOM_TO_JSID(atom); 849 return JS_TRUE; 850} 851 852#ifdef DEBUG 853 854static JSDHashOperator 855atom_dumper(JSDHashTable *table, JSDHashEntryHdr *hdr, 856 uint32 number, void *arg) 857{ 858 JSAtomHashEntry *entry = TO_ATOM_ENTRY(hdr); 859 FILE *fp = (FILE *)arg; 860 void *key; 861 uintN flags; 862 863 fprintf(fp, "%3u %08x ", number, (uintN)entry->hdr.keyHash); 864 if (entry->keyAndFlags == 0) { 865 fputs("<uninitialized>", fp); 866 } else { 867 key = ATOM_ENTRY_KEY(entry); 868 if (IS_DOUBLE_TABLE(table)) { 869 fprintf(fp, "%.16g", *(jsdouble *)key); 870 } else { 871 JS_ASSERT(IS_STRING_TABLE(table)); 872 js_FileEscapedString(fp, (JSString *)key, '"'); 873 } 874 flags = ATOM_ENTRY_FLAGS(entry); 875 if (flags != 0) { 876 fputs((flags & (ATOM_PINNED | ATOM_INTERNED)) 877 ? " pinned | interned" 878 : (flags & ATOM_PINNED) ? " pinned" : " interned", 879 fp); 880 } 881 } 882 putc('\n', fp); 883 return JS_DHASH_NEXT; 884} 885 886JS_FRIEND_API(void) 887js_DumpAtoms(JSContext *cx, FILE *fp) 888{ 889 JSAtomState *state = &cx->runtime->atomState; 890 891 fprintf(fp, "stringAtoms table contents:\n"); 892 JS_DHashTableEnumerate(&state->stringAtoms, atom_dumper, fp); 893#ifdef JS_DHASHMETER 894 JS_DHashTableDumpMeter(&state->stringAtoms, atom_dumper, fp); 895#endif 896 putc('\n', fp); 897 898 fprintf(fp, "doubleAtoms table contents:\n"); 899 JS_DHashTableEnumerate(&state->doubleAtoms, atom_dumper, fp); 900#ifdef JS_DHASHMETER 901 JS_DHashTableDumpMeter(&state->doubleAtoms, atom_dumper, fp); 902#endif 903 putc('\n', fp); 904} 905 906#endif 907 908static JSHashNumber 909js_hash_atom_ptr(const void *key) 910{ 911 const JSAtom *atom = (const JSAtom *) key; 912 return ATOM_HASH(atom); 913} 914 915static void * 916js_alloc_temp_space(void *priv, size_t size) 917{ 918 JSContext *cx = (JSContext *) priv; 919 void *space; 920 921 JS_ARENA_ALLOCATE(space, &cx->tempPool, size); 922 if (!space) 923 js_ReportOutOfScriptQuota(cx); 924 return space; 925} 926 927static void 928js_free_temp_space(void *priv, void *item) 929{ 930} 931 932static JSHashEntry * 933js_alloc_temp_entry(void *priv, const void *key) 934{ 935 JSContext *cx = (JSContext *) priv; 936 JSAtomListElement *ale; 937 938 JS_ARENA_ALLOCATE_TYPE(ale, JSAtomListElement, &cx->tempPool); 939 if (!ale) { 940 js_ReportOutOfScriptQuota(cx); 941 return NULL; 942 } 943 return &ale->entry; 944} 945 946static void 947js_free_temp_entry(void *priv, JSHashEntry *he, uintN flag) 948{ 949} 950 951static JSHashAllocOps temp_alloc_ops = { 952 js_alloc_temp_space, js_free_temp_space, 953 js_alloc_temp_entry, js_free_temp_entry 954}; 955 956JSAtomListElement * 957js_IndexAtom(JSContext *cx, JSAtom *atom, JSAtomList *al) 958{ 959 JSAtomListElement *ale, *ale2, *next; 960 JSHashEntry **hep; 961 962 ATOM_LIST_LOOKUP(ale, hep, al, atom); 963 if (!ale) { 964 if (al->count < 10) { 965 /* Few enough for linear search, no hash table needed. */ 966 JS_ASSERT(!al->table); 967 ale = (JSAtomListElement *)js_alloc_temp_entry(cx, atom); 968 if (!ale) 969 return NULL; 970 ALE_SET_ATOM(ale, atom); 971 ale->entry.next = al->list; 972 al->list = &ale->entry; 973 } else { 974 /* We want to hash. Have we already made a hash table? */ 975 if (!al->table) { 976 /* No hash table yet, so hep had better be null! */ 977 JS_ASSERT(!hep); 978 al->table = JS_NewHashTable(al->count + 1, js_hash_atom_ptr, 979 JS_CompareValues, JS_CompareValues, 980 &temp_alloc_ops, cx); 981 if (!al->table) 982 return NULL; 983 984 /* 985 * Set ht->nentries explicitly, because we are moving entries 986 * from al to ht, not calling JS_HashTable(Raw|)Add. 987 */ 988 al->table->nentries = al->count; 989 990 /* Insert each ale on al->list into the new hash table. */ 991 for (ale2 = (JSAtomListElement *)al->list; ale2; ale2 = next) { 992 next = ALE_NEXT(ale2); 993 ale2->entry.keyHash = ATOM_HASH(ALE_ATOM(ale2)); 994 hep = JS_HashTableRawLookup(al->table, ale2->entry.keyHash, 995 ale2->entry.key); 996 ale2->entry.next = *hep; 997 *hep = &ale2->entry; 998 } 999 al->list = NULL; 1000 1001 /* Set hep for insertion of atom's ale, immediately below. */ 1002 hep = JS_HashTableRawLookup(al->table, ATOM_HASH(atom), atom); 1003 } 1004 1005 /* Finally, add an entry for atom into the hash bucket at hep. */ 1006 ale = (JSAtomListElement *) 1007 JS_HashTableRawAdd(al->table, hep, ATOM_HASH(atom), atom, 1008 NULL); 1009 if (!ale) 1010 return NULL; 1011 } 1012 1013 ALE_SET_INDEX(ale, al->count++); 1014 } 1015 return ale; 1016} 1017 1018static intN 1019js_map_atom(JSHashEntry *he, intN i, void *arg) 1020{ 1021 JSAtomListElement *ale = (JSAtomListElement *)he; 1022 JSAtom **vector = (JSAtom **) arg; 1023 1024 vector[ALE_INDEX(ale)] = ALE_ATOM(ale); 1025 return HT_ENUMERATE_NEXT; 1026} 1027 1028#ifdef DEBUG 1029static jsrefcount js_atom_map_count; 1030static jsrefcount js_atom_map_hash_table_count; 1031#endif 1032 1033void 1034js_InitAtomMap(JSContext *cx, JSAtomMap *map, JSAtomList *al) 1035{ 1036 JSAtom **vector; 1037 JSAtomListElement *ale; 1038 uint32 count; 1039 1040 /* Map length must already be initialized. */ 1041 JS_ASSERT(al->count == map->length); 1042#ifdef DEBUG 1043 JS_ATOMIC_INCREMENT(&js_atom_map_count); 1044#endif 1045 ale = (JSAtomListElement *)al->list; 1046 if (!ale && !al->table) { 1047 JS_ASSERT(!map->vector); 1048 return; 1049 } 1050 1051 count = al->count; 1052 vector = map->vector; 1053 if (al->table) { 1054#ifdef DEBUG 1055 JS_ATOMIC_INCREMENT(&js_atom_map_hash_table_count); 1056#endif 1057 JS_HashTableEnumerateEntries(al->table, js_map_atom, vector); 1058 } else { 1059 do { 1060 vector[ALE_INDEX(ale)] = ALE_ATOM(ale); 1061 } while ((ale = ALE_NEXT(ale)) != NULL); 1062 } 1063 ATOM_LIST_INIT(al); 1064}