Source:SLASH'EM 0.0.7E7F2/alloc.c
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Below is the full text to alloc.c from the source code of SLASH'EM 0.0.7E7F2. To link to a particular line, write [[SLASH'EM 0.0.7E7F2/alloc.c#line123]], for example.
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1. /* SCCS Id: @(#)alloc.c 3.4 1995/10/04 */ 2. /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */ 3. /* NetHack may be freely redistributed. See license for details. */ 4. 5. /* to get the malloc() prototype from system.h */ 6. #define ALLOC_C /* comment line for pre-compiled headers */ 7. /* since this file is also used in auxiliary programs, don't include all the 8. * function declarations for all of nethack 9. */ 10. #define EXTERN_H /* comment line for pre-compiled headers */ 11. #include "config.h" 12. 13. /* [Ali] 14. * There are a number of preprocessor symbols which affect how this 15. * file is compiled: 16. * 17. * NHALLOC_DLL When set this causes the alloc module to build as a stand-alone 18. * allocator (which can either be used in object form for use 19. * with utility programs or combined with panic.o to form a DLL 20. * for dynamic linking with the game - this last allows for the 21. * possibility of 3rd party libraries to allocate memory via the 22. * module and thus be represented in the heap monitoring). 23. * 24. * Global symbols defined: malloc, calloc etc. 25. * monitor_heap_push, monitor_heap_pop etc. 26. * 27. * Warning: The version of panic defined in panic.o does _not_ 28. * attempt to save the game. nhalloc.dll should therefore only be 29. * used for testing. 30. * 31. * WIZARD When set this causes the definition of the fmt_ptr function. 32. * 33. * MONITOR_HEAP When set this causes the alloc module to define the nhalloc and 34. * nhfree functions (which can then be used by the alloc and free 35. * macros). This allows some basic monitoring of the heap for 36. * memory leaks by dumping the heap to a log file on exit. 37. * 38. * Note: This symbol also causes fmt_ptr to be defined. 39. * 40. * Note: If the INTERNAL_MALLOC symbol is also defined, then 41. * nhalloc and nhfree will use the monitor_heap_ functions to 42. * store information about where the memory was allocated from. 43. * Unless compiling on the WIN32 platform, this will also cause 44. * the definition of the monitor_heap_ functions, the trivial 45. * allocator and a standard front end (malloc and friends). 46. * On the WIN32 platform, the monitor_heap_ and standard allocator 47. * functions are left as external references. 48. */ 49. 50. /* to get the definitons of ENOMEM and errno */ 51. #if defined(NHALLOC_DLL) || defined(MONITOR_HEAP) && defined(INTERNAL_MALLOC) 52. #include <stdlib.h> 53. #include <errno.h> 54. #ifdef WIN32 55. #include <win32api.h> 56. #endif 57. #endif 58. 59. #ifdef NHALLOC_DLL 60. #undef free 61. #else /* NHALLOC_DLL */ 62. #if defined(MONITOR_HEAP) || defined(WIZARD) 63. char *FDECL(fmt_ptr, (const genericptr,char *)); 64. #endif 65. 66. #ifdef MONITOR_HEAP 67. #undef alloc 68. #undef free 69. extern void FDECL(free,(genericptr_t)); 70. static void NDECL(heapmon_init); 71. 72. static FILE *heaplog = 0; 73. static boolean tried_heaplog = FALSE; 74. #endif 75. 76. long *FDECL(alloc,(unsigned int)); 77. extern void VDECL(panic, (const char *,...)) PRINTF_F(1,2); 78. 79. 80. long * 81. alloc(lth) 82. register unsigned int lth; 83. { 84. #ifdef LINT 85. /* 86. * a ridiculous definition, suppressing 87. * "possible pointer alignment problem" for (long *) malloc() 88. * from lint 89. */ 90. long dummy = ftell(stderr); 91. 92. if(lth) dummy = 0; /* make sure arg is used */ 93. return(&dummy); 94. #else 95. register genericptr_t ptr; 96. 97. ptr = malloc(lth); 98. #ifndef MONITOR_HEAP 99. if (!ptr) panic("Memory allocation failure; cannot get %u bytes", lth); 100. #endif 101. return((long *) ptr); 102. #endif 103. } 104. 105. 106. #if defined(MONITOR_HEAP) || defined(WIZARD) 107. 108. # if defined(MICRO) || defined(WIN32) 109. /* we actually want to know which systems have an ANSI run-time library 110. * to know which support the new %p format for printing pointers. 111. * due to the presence of things like gcc, NHSTDC is not a good test. 112. * so we assume microcomputers have all converted to ANSI and bigger 113. * computers which may have older libraries give reasonable results with 114. * the cast. 115. */ 116. # define MONITOR_PTR_FMT 117. # endif 118. 119. # ifdef MONITOR_PTR_FMT 120. # define PTR_FMT "%p" 121. # define PTR_TYP genericptr_t 122. # else 123. # define PTR_FMT "%06lx" 124. # define PTR_TYP unsigned long 125. # endif 126. 127. /* format a pointer for display purposes; caller supplies the result buffer */ 128. char * 129. fmt_ptr(ptr, buf) 130. const genericptr ptr; 131. char *buf; 132. { 133. Sprintf(buf, PTR_FMT, (PTR_TYP)ptr); 134. return buf; 135. } 136. 137. #endif /* MONITOR_HEAP || WIZARD */ 138. #endif /* !NHALLOC_DLL */ 139. 140. #if defined(MONITOR_HEAP) && !defined(NHALLOC_DLL) 141. 142. /* If ${NH_HEAPLOG} is defined and we can create a file by that name, 143. then we'll log the allocation and release information to that file. */ 144. static void 145. heapmon_init() 146. { 147. char *logname = getenv("NH_HEAPLOG"); 148. 149. if (logname && *logname) 150. heaplog = fopen(logname, "w"); 151. tried_heaplog = TRUE; 152. } 153. 154. long * 155. nhalloc(lth, file, line) 156. unsigned int lth; 157. const char *file; 158. int line; 159. { 160. long *ptr; 161. char ptr_address[20]; 162. 163. #ifdef INTERNAL_MALLOC 164. monitor_heap_push(file, line); 165. #endif 166. ptr = alloc(lth); 167. #ifdef INTERNAL_MALLOC 168. (void)monitor_heap_pop(file, line, 0); 169. #endif 170. if (!tried_heaplog) heapmon_init(); 171. if (heaplog) 172. (void) fprintf(heaplog, "+%5u %s %4d %s\n", lth, 173. fmt_ptr((genericptr_t)ptr, ptr_address), 174. line, file); 175. /* potential panic in alloc() was deferred til here */ 176. if (!ptr) panic("Cannot get %u bytes, line %d of %s", 177. lth, line, file); 178. 179. return ptr; 180. } 181. 182. void 183. nhfree(ptr, file, line) 184. genericptr_t ptr; 185. const char *file; 186. int line; 187. { 188. char ptr_address[20]; 189. 190. if (!tried_heaplog) heapmon_init(); 191. if (heaplog) 192. (void) fprintf(heaplog, "- %s %4d %s\n", 193. fmt_ptr((genericptr_t)ptr, ptr_address), 194. line, file); 195. 196. free(ptr); 197. } 198. #endif /* MONITOR_HEAP && !NHALLOC_DLL */ 199. 200. /* 201. * Under Win32, the trivial allocator and monitor front end are 202. * placed in nhalloc.dll rather than in the main executable. 203. */ 204. 205. #if defined(NHALLOC_DLL) || (defined(INTERNAL_MALLOC) && !defined(WIN32)) 206. /* 207. * [Ali] A trivial malloc implementation. 208. * 209. * Notes: 210. * 211. * If attempting to port to a non-UNIX environment, you will need 212. * a replacement for the sbrk() call. Under UNIX, sbrk() returns 213. * contiguous blocks. If there is no equivalent call in the target 214. * environment, you will either need to make this allocator rather 215. * more intelligent, or just increase PAGESIZE to something huge like 216. * 1Mb to keep the resultant fragmentation under control. 217. * 218. * The alignment implementation is advisory at best; we assume that 219. * if the target enviroment is that bothered by alignment, sbrk() 220. * will return aligned blocks and the compiler will pad the triv_head 221. * structure appropriately. If either of these assumptions is not 222. * correct, the alignment will be relaxed, which is presumably okay. 223. * 224. * This implementation is _very_ vulnerable to memory allocation bugs 225. * in the main code. Don't enable it unless you are confident that 226. * no such bugs exist. 227. */ 228. 229. #define TRIV_ALIGN sizeof(double) 230. #define TRIV_PAGESIZE 4096 231. 232. struct triv_head { 233. size_t triv_size; /* Total block size (excluding header) */ 234. union { 235. struct { 236. size_t nb; /* Number of bytes allocated by user */ 237. void *userdata; 238. } alloc; 239. struct triv_head *next; /* Next free block */ 240. double d; /* Dummy for alignment */ 241. } u; 242. #define triv_nb u.alloc.nb 243. #define triv_userdata u.alloc.userdata 244. #define triv_next u.next /* Free blocks only */ 245. }; 246. 247. static struct triv_head *triv_freelist = NULL; 248. #ifdef WIN32 249. /* 250. * MS-Windows rounds size request up to a system page, so we need to 251. * ensure we always request an exact number of system pages. This 252. * variable holds TRIV_PAGESIZE rounded up accordingly. 253. */ 254. static unsigned int triv_pagesize = 0; 255. #endif 256. 257. #define ROUNDUP(nbytes, align) (((nbytes) + (align) - 1) / (align) * (align)) 258. 259. void *triv_get_userdata(void *p) 260. { 261. struct triv_head *h; 262. if (!p) 263. return p; 264. h = (struct triv_head *)p - 1; 265. return h->triv_userdata; 266. } 267. 268. void triv_set_userdata(void *p, void *d) 269. { 270. struct triv_head *h; 271. if (p) { 272. h = (struct triv_head *)p - 1; 273. h->triv_userdata = d; 274. } 275. } 276. 277. #define IS_CONTIGUOUS(h1,h2) ((h2) == \ 278. (struct triv_head *)((unsigned char *)((h1) + 1) + (h1)->triv_size)) 279. 280. void triv_free(void *p) 281. { 282. struct triv_head *f, *lf, *h; 283. if (!p) 284. return; 285. h = (struct triv_head *)p - 1; 286. /* Find f, the first free block _after_ h in memory */ 287. for (lf = NULL, f = triv_freelist; f; lf = f, f = f->triv_next) 288. if (f > h) 289. break; 290. if (IS_CONTIGUOUS(h, f)) { 291. /* f is contiguous with h; merge them */ 292. h->triv_size += sizeof(struct triv_head) + f->triv_size; 293. h->triv_next = f->triv_next; 294. } 295. else 296. /* f is not contiguous; insert new block */ 297. h->triv_next = f; 298. /* Update pointer from previous block */ 299. if (lf) 300. lf->triv_next = h; 301. else 302. triv_freelist = h; 303. /* Then check last free block _below_ h in memory */ 304. if (lf && IS_CONTIGUOUS(lf, h)) { 305. /* h is contiguous with lf; merge them */ 306. lf->triv_size += sizeof(struct triv_head) + h->triv_size; 307. lf->triv_next = h->triv_next; 308. } 309. } 310. 311. void *triv_malloc(size_t nb) 312. { 313. struct triv_head *f, *lf, *nf; 314. size_t size = ROUNDUP(nb, TRIV_ALIGN); 315. size_t pagesize; 316. if (!nb) 317. return NULL; /* _Not_ an error; don't set errno */ 318. for (lf = NULL, f = triv_freelist; f; lf = f, f = f->triv_next) 319. /* Use first block found which is large enough */ 320. if (f->triv_size >= size) { 321. /* Split the free block if there's enough space left over */ 322. if (f->triv_size - size > sizeof(struct triv_head)) { 323. nf = (struct triv_head *)((unsigned char *)(f + 1) + size); 324. nf->triv_size = f->triv_size - size - sizeof(struct triv_head); 325. nf->triv_next = f->triv_next; 326. f->triv_next = nf; 327. f->triv_size = size; 328. } 329. /* Remove block from freelist */ 330. if (lf) 331. lf->triv_next = f->triv_next; 332. else 333. triv_freelist = f->triv_next; 334. /* Initialise header and return */ 335. f->triv_nb = nb; 336. f->triv_userdata = NULL; 337. return f + 1; 338. } 339. /* Get new block */ 340. #ifdef WIN32 341. if (triv_pagesize == 0) { 342. SYSTEM_INFO si; 343. GetSystemInfo(&si); 344. triv_pagesize = ROUNDUP(TRIV_PAGESIZE, si.dwPageSize); 345. } 346. pagesize = ROUNDUP(sizeof(struct triv_head) + size, triv_pagesize); 347. f = VirtualAlloc(NULL, pagesize, MEM_COMMIT, PAGE_READWRITE); 348. #else 349. pagesize = ROUNDUP(sizeof(struct triv_head) + size, TRIV_PAGESIZE); 350. f = sbrk(pagesize); 351. #endif 352. if (!f) { 353. errno = ENOMEM; 354. return f; 355. } 356. /* Initialise header */ 357. f->triv_size = pagesize - sizeof(struct triv_head); 358. f->triv_nb = nb; 359. f->triv_userdata = NULL; 360. /* Split the new block if there's enough space left over */ 361. if (f->triv_size - size > sizeof(struct triv_head)) { 362. nf = (struct triv_head *)((unsigned char *)(f + 1) + size); 363. nf->triv_size = f->triv_size - size - sizeof(struct triv_head); 364. f->triv_size = size; 365. /* And contribute it to the free list */ 366. triv_free(nf + 1); 367. } 368. return f + 1; 369. } 370. 371. void *triv_calloc(size_t nobj, size_t size) 372. { 373. void *p; 374. size_t nb = nobj * size; 375. if (nb / nobj != size) { /* Check overflow */ 376. errno = ENOMEM; 377. return NULL; 378. } 379. p = triv_malloc(nb); 380. if (p) 381. memset(p, 0, nb); 382. return p; 383. } 384. 385. void *triv_realloc(void *p, size_t size) 386. { 387. struct triv_head *h; 388. void *np; 389. if (!size) { 390. triv_free(p); 391. return NULL; 392. } 393. if (!p) 394. return triv_malloc(size); 395. h = (struct triv_head *)p - 1; 396. if (size <= h->triv_size) { 397. h->triv_nb = size; 398. return p; 399. } 400. np = triv_malloc(size); 401. if (np) { 402. memcpy(np, p, h->triv_nb); 403. triv_set_userdata(np, triv_get_userdata(p)); 404. triv_free(p); 405. } 406. return np; 407. } 408. 409. /* Monitoring front-end */ 410. 411. struct monitor_id { 412. const char *id; /* Typically file name */ 413. int subid; /* Typically line number */ 414. }; 415. 416. static char *monitor_id_stack_default_id = "<none>"; 417. static int monitor_id_stack_depth = 0; 418. static struct monitor_id *monitor_id_stack = NULL; 419. static size_t monitor_mem_in_use = 0; 420. static boolean monitor_trace = 0; 421. static FILE *monitor_fp = NULL; 422. 423. #define MHF_MARKED 1 424. 425. struct monitor_head { 426. void *p; 427. size_t size; 428. struct monitor_id id; 429. unsigned long flags; 430. struct monitor_head *next, *prev; 431. }; 432. 433. static struct monitor_head *monitor_heap = NULL; 434. 435. void monitor_heap_push(const char *id, int subid) 436. { 437. ++monitor_id_stack_depth; 438. monitor_id_stack = triv_realloc(monitor_id_stack, 439. monitor_id_stack_depth * sizeof (*monitor_id_stack)); 440. if (!monitor_id_stack) 441. panic("monitor_heap_push: not enough memory"); 442. monitor_id_stack[monitor_id_stack_depth - 1].id = id; 443. monitor_id_stack[monitor_id_stack_depth - 1].subid = subid; 444. } 445. 446. /* retval is to make writing macros which use monitor_heap_push/pop easier */ 447. 448. unsigned long monitor_heap_pop(const char *id, int subid, unsigned long retval) 449. { 450. if (!monitor_id_stack_depth) 451. panic("monitor_heap_pop: empty stack"); 452. if (monitor_id_stack[monitor_id_stack_depth - 1].id != id || 453. monitor_id_stack[monitor_id_stack_depth - 1].subid != subid) 454. panic("monitor_heap_pop: mismatch: (%s, %d) != (%s, %d)", 455. monitor_id_stack[monitor_id_stack_depth - 1].id, 456. monitor_id_stack[monitor_id_stack_depth - 1].subid, 457. id, subid); 458. --monitor_id_stack_depth; 459. monitor_id_stack = triv_realloc(monitor_id_stack, 460. monitor_id_stack_depth * sizeof (*monitor_id_stack)); 461. return retval; 462. } 463. 464. void monitor_heap_set_subid(const char *id, int subid) 465. { 466. if (!monitor_id_stack_depth) 467. panic("monitor_heap_set_subid: empty stack"); 468. if (monitor_id_stack[monitor_id_stack_depth - 1].id != id) 469. panic("monitor_heap_set_subid: mismatch: %s != %s", 470. monitor_id_stack[monitor_id_stack_depth - 1].id, id); 471. monitor_id_stack[monitor_id_stack_depth - 1].subid = subid; 472. } 473. 474. size_t monitor_heap_getmem(void) 475. { 476. return monitor_mem_in_use; 477. } 478. 479. boolean monitor_heap_trace(boolean flag) 480. { 481. boolean retval = !!monitor_trace; 482. if (flag) 483. monitor_trace++; 484. else 485. monitor_trace--; 486. return retval; 487. } 488. 489. void monitor_heap_mark(void) 490. { 491. struct monitor_head *m; 492. for(m = monitor_heap; m; m = m->next) 493. m->flags |= MHF_MARKED; 494. } 495. 496. void monitor_heap_release(void) 497. { 498. int first = 1; 499. struct monitor_head *m; 500. if (!monitor_fp) 501. return; 502. for(m = monitor_heap; m; m = m->next) 503. m->flags ^= MHF_MARKED; 504. for(m = monitor_heap; m; m = m->next) 505. if (m->flags & MHF_MARKED) { 506. if (first) { 507. fprintf(monitor_fp, 508. "Blocks allocated but not freed during mark/release:\n"); 509. fprintf(monitor_fp, "Address Size Sub-ID ID\n"); 510. first = 0; 511. } 512. fprintf(monitor_fp, 513. "%-16p%-8lu%-8d%s\n", m->p, m->size, m->id.subid, m->id.id); 514. } 515. } 516. 517. static void monitor_dump(void) 518. { 519. int first = 1; 520. struct monitor_head *m; 521. FILE *fp; 522. size_t used = 0; 523. if (!monitor_fp) 524. return; 525. monitor_heap_mark(); 526. fprintf(monitor_fp, "Dump of all monitored blocks in heap:\n"); 527. for(m = monitor_heap; m; m = m->next) { 528. if (m->flags & MHF_MARKED) { 529. used += m->size; 530. if (m->id.id == monitor_id_stack_default_id) 531. continue; 532. if (first) { 533. fprintf(monitor_fp, "Address Size Sub-ID ID\n"); 534. first = 0; 535. } 536. fprintf(monitor_fp, 537. "%-16p%-8lu%-8d%s\n", m->p, m->size, m->id.subid, m->id.id); 538. } 539. } 540. if (first) 541. fprintf(monitor_fp, 542. "No monitored blocks in heap with non-default ID.\n"); 543. fprintf(monitor_fp, "Total used space: %lu bytes\n", used); 544. } 545. 546. void *malloc(size_t nb) 547. { 548. static int busy = 0; 549. static int inited = 0; 550. struct monitor_head *m; 551. if (!busy && !(inited&1) && !monitor_id_stack_depth) { 552. inited|=1; 553. monitor_heap_push(monitor_id_stack_default_id, 0); 554. } 555. if (!busy && !(inited&2)) { 556. char *s; 557. inited|=2; 558. atexit(monitor_dump); 559. s = getenv("NH_HEAPDUMP"); 560. monitor_fp = s ? fopen(s, "w"): NULL; 561. } 562. if (!nb) 563. return NULL; 564. busy++; 565. m = triv_malloc(sizeof(*m)); 566. if (!m) { 567. busy--; 568. return m; 569. } 570. m->size = nb; 571. m->flags = 0; 572. m->p = triv_malloc(nb); 573. if (monitor_trace) 574. fprintf(stderr, "malloc(%d) = %p\n", nb, m->p); 575. if (!m->p) { 576. triv_free(m); 577. busy--; 578. return NULL; 579. } 580. monitor_mem_in_use += nb; 581. m->prev = NULL; 582. m->next = monitor_heap; 583. m->id = monitor_id_stack[monitor_id_stack_depth - 1]; 584. if (monitor_heap) 585. monitor_heap->prev = m; 586. monitor_heap = m; 587. triv_set_userdata(m->p, m); 588. busy--; 589. return m->p; 590. } 591. 592. void *calloc(size_t nobj, size_t size) 593. { 594. void *p; 595. size_t nb = nobj * size; 596. if (nb / nobj != size) { /* Check overflow */ 597. errno = ENOMEM; 598. return NULL; 599. } 600. p = malloc(nb); 601. if (p) 602. memset(p, 0, nb); 603. return p; 604. } 605. 606. void *realloc(void *p, size_t size) 607. { 608. struct monitor_head *m; 609. void *np; 610. if (!size) { 611. free(p); 612. return NULL; 613. } 614. if (!p) 615. return malloc(size); 616. m = triv_get_userdata(p); 617. np = triv_realloc(p, size); 618. if (monitor_trace) 619. fprintf(stderr, "realloc(%p, %d) = %p\n", p, size, np); 620. if (np) { 621. monitor_mem_in_use += size - m->size; 622. m->size = size; 623. m->p = np; 624. } 625. return np; 626. } 627. 628. void free(void *p) 629. { 630. struct monitor_head *m; 631. if (p) 632. { 633. if (monitor_trace) 634. fprintf(stderr, "free(%p)\n", p); 635. m = triv_get_userdata(p); 636. monitor_mem_in_use -= m->size; 637. triv_free(p); 638. if (m->prev) 639. m->prev->next = m->next; 640. else 641. monitor_heap = m->next; 642. if (m->next) 643. m->next->prev = m->prev; 644. triv_free(m); 645. } 646. } 647. 648. #endif /* NHALLOC_DLL || INTERNAL_MALLOC && !WIN32 */ 649. 650. /*alloc.c*/
