1 /* 2 3 B G E T 4 5 Buffer allocator 6 7 Designed and implemented in April of 1972 by John Walker, based on the 8 Case Algol OPRO$ algorithm implemented in 1966. 9 10 Reimplemented in 1975 by John Walker for the Interdata 70. 11 Reimplemented in 1977 by John Walker for the Marinchip 9900. 12 Reimplemented in 1982 by Duff Kurland for the Intel 8080. 13 14 Portable C version implemented in September of 1990 by an older, wiser 15 instance of the original implementor. 16 17 Souped up and/or weighed down slightly shortly thereafter by Greg 18 Lutz. 19 20 AMIX edition, including the new compaction call-back option, prepared 21 by John Walker in July of 1992. 22 23 Bug in built-in test program fixed, ANSI compiler warnings eradicated, 24 buffer pool validator implemented, and guaranteed repeatable test 25 added by John Walker in October of 1995. 26 27 This program is in the public domain. 28 29 1. This is the book of the generations of Adam. In the day that God 30 created man, in the likeness of God made he him; 31 2. Male and female created he them; and blessed them, and called 32 their name Adam, in the day when they were created. 33 3. And Adam lived an hundred and thirty years, and begat a son in 34 his own likeness, and after his image; and called his name Seth: 35 4. And the days of Adam after he had begotten Seth were eight 36 hundred years: and he begat sons and daughters: 37 5. And all the days that Adam lived were nine hundred and thirty 38 years: and he died. 39 6. And Seth lived an hundred and five years, and begat Enos: 40 7. And Seth lived after he begat Enos eight hundred and seven years, 41 and begat sons and daughters: 42 8. And all the days of Seth were nine hundred and twelve years: and 43 he died. 44 9. And Enos lived ninety years, and begat Cainan: 45 10. And Enos lived after he begat Cainan eight hundred and fifteen 46 years, and begat sons and daughters: 47 11. And all the days of Enos were nine hundred and five years: and 48 he died. 49 12. And Cainan lived seventy years and begat Mahalaleel: 50 13. And Cainan lived after he begat Mahalaleel eight hundred and 51 forty years, and begat sons and daughters: 52 14. And all the days of Cainan were nine hundred and ten years: and 53 he died. 54 15. And Mahalaleel lived sixty and five years, and begat Jared: 55 16. And Mahalaleel lived after he begat Jared eight hundred and 56 thirty years, and begat sons and daughters: 57 17. And all the days of Mahalaleel were eight hundred ninety and 58 five years: and he died. 59 18. And Jared lived an hundred sixty and two years, and he begat 60 Enoch: 61 19. And Jared lived after he begat Enoch eight hundred years, and 62 begat sons and daughters: 63 20. And all the days of Jared were nine hundred sixty and two years: 64 and he died. 65 21. And Enoch lived sixty and five years, and begat Methuselah: 66 22. And Enoch walked with God after he begat Methuselah three 67 hundred years, and begat sons and daughters: 68 23. And all the days of Enoch were three hundred sixty and five 69 years: 70 24. And Enoch walked with God: and he was not; for God took him. 71 25. And Methuselah lived an hundred eighty and seven years, and 72 begat Lamech. 73 26. And Methuselah lived after he begat Lamech seven hundred eighty 74 and two years, and begat sons and daughters: 75 27. And all the days of Methuselah were nine hundred sixty and nine 76 years: and he died. 77 28. And Lamech lived an hundred eighty and two years, and begat a 78 son: 79 29. And he called his name Noah, saying, This same shall comfort us 80 concerning our work and toil of our hands, because of the ground 81 which the LORD hath cursed. 82 30. And Lamech lived after he begat Noah five hundred ninety and 83 five years, and begat sons and daughters: 84 31. And all the days of Lamech were seven hundred seventy and seven 85 years: and he died. 86 32. And Noah was five hundred years old: and Noah begat Shem, Ham, 87 and Japheth. 88 89 And buffers begat buffers, and links begat links, and buffer pools 90 begat links to chains of buffer pools containing buffers, and lo the 91 buffers and links and pools of buffers and pools of links to chains of 92 pools of buffers were fruitful and they multiplied and the Operating 93 System looked down upon them and said that it was Good. 94 95 96 INTRODUCTION 97 ============ 98 99 BGET is a comprehensive memory allocation package which is easily 100 configured to the needs of an application. BGET is efficient in 101 both the time needed to allocate and release buffers and in the 102 memory overhead required for buffer pool management. It 103 automatically consolidates contiguous space to minimise 104 fragmentation. BGET is configured by compile-time definitions, 105 Major options include: 106 107 * A built-in test program to exercise BGET and 108 demonstrate how the various functions are used. 109 110 * Allocation by either the "first fit" or "best fit" 111 method. 112 113 * Wiping buffers at release time to catch code which 114 references previously released storage. 115 116 * Built-in routines to dump individual buffers or the 117 entire buffer pool. 118 119 * Retrieval of allocation and pool size statistics. 120 121 * Quantisation of buffer sizes to a power of two to 122 satisfy hardware alignment constraints. 123 124 * Automatic pool compaction, growth, and shrinkage by 125 means of call-backs to user defined functions. 126 127 Applications of BGET can range from storage management in 128 ROM-based embedded programs to providing the framework upon which 129 a multitasking system incorporating garbage collection is 130 constructed. BGET incorporates extensive internal consistency 131 checking using the <assert.h> mechanism; all these checks can be 132 turned off by compiling with NDEBUG defined, yielding a version of 133 BGET with minimal size and maximum speed. 134 135 The basic algorithm underlying BGET has withstood the test of 136 time; more than 25 years have passed since the first 137 implementation of this code. And yet, it is substantially more 138 efficient than the native allocation schemes of many operating 139 systems: the Macintosh and Microsoft Windows to name two, on which 140 programs have obtained substantial speed-ups by layering BGET as 141 an application level memory manager atop the underlying system's. 142 143 BGET has been implemented on the largest mainframes and the lowest 144 of microprocessors. It has served as the core for multitasking 145 operating systems, multi-thread applications, embedded software in 146 data network switching processors, and a host of C programs. And 147 while it has accreted flexibility and additional options over the 148 years, it remains fast, memory efficient, portable, and easy to 149 integrate into your program. 150 151 152 BGET IMPLEMENTATION ASSUMPTIONS 153 =============================== 154 155 BGET is written in as portable a dialect of C as possible. The 156 only fundamental assumption about the underlying hardware 157 architecture is that memory is allocated is a linear array which 158 can be addressed as a vector of C "char" objects. On segmented 159 address space architectures, this generally means that BGET should 160 be used to allocate storage within a single segment (although some 161 compilers simulate linear address spaces on segmented 162 architectures). On segmented architectures, then, BGET buffer 163 pools may not be larger than a segment, but since BGET allows any 164 number of separate buffer pools, there is no limit on the total 165 storage which can be managed, only on the largest individual 166 object which can be allocated. Machines with a linear address 167 architecture, such as the VAX, 680x0, Sparc, MIPS, or the Intel 168 80386 and above in native mode, may use BGET without restriction. 169 170 171 GETTING STARTED WITH BGET 172 ========================= 173 174 Although BGET can be configured in a multitude of fashions, there 175 are three basic ways of working with BGET. The functions 176 mentioned below are documented in the following section. Please 177 excuse the forward references which are made in the interest of 178 providing a roadmap to guide you to the BGET functions you're 179 likely to need. 180 181 Embedded Applications 182 --------------------- 183 184 Embedded applications typically have a fixed area of memory 185 dedicated to buffer allocation (often in a separate RAM address 186 space distinct from the ROM that contains the executable code). 187 To use BGET in such an environment, simply call bpool() with the 188 start address and length of the buffer pool area in RAM, then 189 allocate buffers with bget() and release them with brel(). 190 Embedded applications with very limited RAM but abundant CPU speed 191 may benefit by configuring BGET for BestFit allocation (which is 192 usually not worth it in other environments). 193 194 Malloc() Emulation 195 ------------------ 196 197 If the C library malloc() function is too slow, not present in 198 your development environment (for example, an a native Windows or 199 Macintosh program), or otherwise unsuitable, you can replace it 200 with BGET. Initially define a buffer pool of an appropriate size 201 with bpool()--usually obtained by making a call to the operating 202 system's low-level memory allocator. Then allocate buffers with 203 bget(), bgetz(), and bgetr() (the last two permit the allocation 204 of buffers initialised to zero and [inefficient] re-allocation of 205 existing buffers for compatibility with C library functions). 206 Release buffers by calling brel(). If a buffer allocation request 207 fails, obtain more storage from the underlying operating system, 208 add it to the buffer pool by another call to bpool(), and continue 209 execution. 210 211 Automatic Storage Management 212 ---------------------------- 213 214 You can use BGET as your application's native memory manager and 215 implement automatic storage pool expansion, contraction, and 216 optionally application-specific memory compaction by compiling 217 BGET with the BECtl variable defined, then calling bectl() and 218 supplying functions for storage compaction, acquisition, and 219 release, as well as a standard pool expansion increment. All of 220 these functions are optional (although it doesn't make much sense 221 to provide a release function without an acquisition function, 222 does it?). Once the call-back functions have been defined with 223 bectl(), you simply use bget() and brel() to allocate and release 224 storage as before. You can supply an initial buffer pool with 225 bpool() or rely on automatic allocation to acquire the entire 226 pool. When a call on bget() cannot be satisfied, BGET first 227 checks if a compaction function has been supplied. If so, it is 228 called (with the space required to satisfy the allocation request 229 and a sequence number to allow the compaction routine to be called 230 successively without looping). If the compaction function is able 231 to free any storage (it needn't know whether the storage it freed 232 was adequate) it should return a nonzero value, whereupon BGET 233 will retry the allocation request and, if it fails again, call the 234 compaction function again with the next-higher sequence number. 235 236 If the compaction function returns zero, indicating failure to 237 free space, or no compaction function is defined, BGET next tests 238 whether a non-NULL allocation function was supplied to bectl(). 239 If so, that function is called with an argument indicating how 240 many bytes of additional space are required. This will be the 241 standard pool expansion increment supplied in the call to bectl() 242 unless the original bget() call requested a buffer larger than 243 this; buffers larger than the standard pool block can be managed 244 "off the books" by BGET in this mode. If the allocation function 245 succeeds in obtaining the storage, it returns a pointer to the new 246 block and BGET expands the buffer pool; if it fails, the 247 allocation request fails and returns NULL to the caller. If a 248 non-NULL release function is supplied, expansion blocks which 249 become totally empty are released to the global free pool by 250 passing their addresses to the release function. 251 252 Equipped with appropriate allocation, release, and compaction 253 functions, BGET can be used as part of very sophisticated memory 254 management strategies, including garbage collection. (Note, 255 however, that BGET is *not* a garbage collector by itself, and 256 that developing such a system requires much additional logic and 257 careful design of the application's memory allocation strategy.) 258 259 260 BGET FUNCTION DESCRIPTIONS 261 ========================== 262 263 Functions implemented in this file (some are enabled by certain of 264 the optional settings below): 265 266 void bpool(void *buffer, bufsize len); 267 268 Create a buffer pool of <len> bytes, using the storage starting at 269 <buffer>. You can call bpool() subsequently to contribute 270 additional storage to the overall buffer pool. 271 272 void *bget(bufsize size); 273 274 Allocate a buffer of <size> bytes. The address of the buffer is 275 returned, or NULL if insufficient memory was available to allocate 276 the buffer. 277 278 void *bgetz(bufsize size); 279 280 Allocate a buffer of <size> bytes and clear it to all zeroes. The 281 address of the buffer is returned, or NULL if insufficient memory 282 was available to allocate the buffer. 283 284 void *bgetr(void *buffer, bufsize newsize); 285 286 Reallocate a buffer previously allocated by bget(), changing its 287 size to <newsize> and preserving all existing data. NULL is 288 returned if insufficient memory is available to reallocate the 289 buffer, in which case the original buffer remains intact. 290 291 void brel(void *buf); 292 293 Return the buffer <buf>, previously allocated by bget(), to the 294 free space pool. 295 296 void bectl(int (*compact)(bufsize sizereq, int sequence), 297 void *(*acquire)(bufsize size), 298 void (*release)(void *buf), 299 bufsize pool_incr); 300 301 Expansion control: specify functions through which the package may 302 compact storage (or take other appropriate action) when an 303 allocation request fails, and optionally automatically acquire 304 storage for expansion blocks when necessary, and release such 305 blocks when they become empty. If <compact> is non-NULL, whenever 306 a buffer allocation request fails, the <compact> function will be 307 called with arguments specifying the number of bytes (total buffer 308 size, including header overhead) required to satisfy the 309 allocation request, and a sequence number indicating the number of 310 consecutive calls on <compact> attempting to satisfy this 311 allocation request. The sequence number is 1 for the first call 312 on <compact> for a given allocation request, and increments on 313 subsequent calls, permitting the <compact> function to take 314 increasingly dire measures in an attempt to free up storage. If 315 the <compact> function returns a nonzero value, the allocation 316 attempt is re-tried. If <compact> returns 0 (as it must if it 317 isn't able to release any space or add storage to the buffer 318 pool), the allocation request fails, which can trigger automatic 319 pool expansion if the <acquire> argument is non-NULL. At the time 320 the <compact> function is called, the state of the buffer 321 allocator is identical to that at the moment the allocation 322 request was made; consequently, the <compact> function may call 323 brel(), bpool(), bstats(), and/or directly manipulate the buffer 324 pool in any manner which would be valid were the application in 325 control. This does not, however, relieve the <compact> function 326 of the need to ensure that whatever actions it takes do not change 327 things underneath the application that made the allocation 328 request. For example, a <compact> function that released a buffer 329 in the process of being reallocated with bgetr() would lead to 330 disaster. Implementing a safe and effective <compact> mechanism 331 requires careful design of an application's memory architecture, 332 and cannot generally be easily retrofitted into existing code. 333 334 If <acquire> is non-NULL, that function will be called whenever an 335 allocation request fails. If the <acquire> function succeeds in 336 allocating the requested space and returns a pointer to the new 337 area, allocation will proceed using the expanded buffer pool. If 338 <acquire> cannot obtain the requested space, it should return NULL 339 and the entire allocation process will fail. <pool_incr> 340 specifies the normal expansion block size. Providing an <acquire> 341 function will cause subsequent bget() requests for buffers too 342 large to be managed in the linked-block scheme (in other words, 343 larger than <pool_incr> minus the buffer overhead) to be satisfied 344 directly by calls to the <acquire> function. Automatic release of 345 empty pool blocks will occur only if all pool blocks in the system 346 are the size given by <pool_incr>. 347 348 void bstats(bufsize *curalloc, bufsize *totfree, 349 bufsize *maxfree, long *nget, long *nrel); 350 351 The amount of space currently allocated is stored into the 352 variable pointed to by <curalloc>. The total free space (sum of 353 all free blocks in the pool) is stored into the variable pointed 354 to by <totfree>, and the size of the largest single block in the 355 free space pool is stored into the variable pointed to by 356 <maxfree>. The variables pointed to by <nget> and <nrel> are 357 filled, respectively, with the number of successful (non-NULL 358 return) bget() calls and the number of brel() calls. 359 360 void bstatse(bufsize *pool_incr, long *npool, 361 long *npget, long *nprel, 362 long *ndget, long *ndrel); 363 364 Extended statistics: The expansion block size will be stored into 365 the variable pointed to by <pool_incr>, or the negative thereof if 366 automatic expansion block releases are disabled. The number of 367 currently active pool blocks will be stored into the variable 368 pointed to by <npool>. The variables pointed to by <npget> and 369 <nprel> will be filled with, respectively, the number of expansion 370 block acquisitions and releases which have occurred. The 371 variables pointed to by <ndget> and <ndrel> will be filled with 372 the number of bget() and brel() calls, respectively, managed 373 through blocks directly allocated by the acquisition and release 374 functions. 375 376 void bufdump(void *buf); 377 378 The buffer pointed to by <buf> is dumped on standard output. 379 380 void bpoold(void *pool, int dumpalloc, int dumpfree); 381 382 All buffers in the buffer pool <pool>, previously initialised by a 383 call on bpool(), are listed in ascending memory address order. If 384 <dumpalloc> is nonzero, the contents of allocated buffers are 385 dumped; if <dumpfree> is nonzero, the contents of free blocks are 386 dumped. 387 388 int bpoolv(void *pool); 389 390 The named buffer pool, previously initialised by a call on 391 bpool(), is validated for bad pointers, overwritten data, etc. If 392 compiled with NDEBUG not defined, any error generates an assertion 393 failure. Otherwise 1 is returned if the pool is valid, 0 if an 394 error is found. 395 396 397 BGET CONFIGURATION 398 ================== 399 */ 400 401 /* 402 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED 403 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 404 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 405 * IN NO EVENT SHALL ST BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 406 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 407 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 408 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 409 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 410 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 411 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 412 */ 413 414 /* #define BGET_ENABLE_ALL_OPTIONS */ 415 #ifdef BGET_ENABLE_OPTION 416 #define TestProg 20000 /* Generate built-in test program 417 if defined. The value specifies 418 how many buffer allocation attempts 419 the test program should make. */ 420 421 #define SizeQuant 4 /* Buffer allocation size quantum: 422 all buffers allocated are a 423 multiple of this size. This 424 MUST be a power of two. */ 425 426 #define BufDump 1 /* Define this symbol to enable the 427 bpoold() function which dumps the 428 buffers in a buffer pool. */ 429 430 #define BufValid 1 /* Define this symbol to enable the 431 bpoolv() function for validating 432 a buffer pool. */ 433 434 #define DumpData 1 /* Define this symbol to enable the 435 bufdump() function which allows 436 dumping the contents of an allocated 437 or free buffer. */ 438 439 #define BufStats 1 /* Define this symbol to enable the 440 bstats() function which calculates 441 the total free space in the buffer 442 pool, the largest available 443 buffer, and the total space 444 currently allocated. */ 445 446 #define FreeWipe 1 /* Wipe free buffers to a guaranteed 447 pattern of garbage to trip up 448 miscreants who attempt to use 449 pointers into released buffers. */ 450 451 #define BestFit 1 /* Use a best fit algorithm when 452 searching for space for an 453 allocation request. This uses 454 memory more efficiently, but 455 allocation will be much slower. */ 456 457 #define BECtl 1 /* Define this symbol to enable the 458 bectl() function for automatic 459 pool space control. */ 460 #endif 461 462 #include <stdio.h> 463 #include <stdbool.h> 464 465 #ifdef lint 466 #define NDEBUG /* Exits in asserts confuse lint */ 467 /* LINTLIBRARY */ /* Don't complain about def, no ref */ 468 extern char *sprintf(); /* Sun includes don't define sprintf */ 469 #endif 470 471 #include <assert.h> 472 #include <memory.h> 473 474 #ifdef BufDump /* BufDump implies DumpData */ 475 #ifndef DumpData 476 #define DumpData 1 477 #endif 478 #endif 479 480 #ifdef DumpData 481 #include <ctype.h> 482 #endif 483 484 #ifdef __KERNEL__ 485 #ifdef CFG_CORE_BGET_BESTFIT 486 #define BestFit 1 487 #endif 488 #endif 489 490 /* Declare the interface, including the requested buffer size type, 491 bufsize. */ 492 493 #include "bget.h" 494 495 #define MemSize int /* Type for size arguments to memxxx() 496 functions such as memcmp(). */ 497 498 /* Queue links */ 499 500 struct qlinks { 501 struct bfhead *flink; /* Forward link */ 502 struct bfhead *blink; /* Backward link */ 503 }; 504 505 /* Header in allocated and free buffers */ 506 507 struct bhead { 508 bufsize prevfree; /* Relative link back to previous 509 free buffer in memory or 0 if 510 previous buffer is allocated. */ 511 bufsize bsize; /* Buffer size: positive if free, 512 negative if allocated. */ 513 }; 514 #define BH(p) ((struct bhead *) (p)) 515 516 /* Header in directly allocated buffers (by acqfcn) */ 517 518 struct bdhead { 519 bufsize tsize; /* Total size, including overhead */ 520 bufsize offs; /* Offset from allocated buffer */ 521 struct bhead bh; /* Common header */ 522 }; 523 #define BDH(p) ((struct bdhead *) (p)) 524 525 /* Header in free buffers */ 526 527 struct bfhead { 528 struct bhead bh; /* Common allocated/free header */ 529 struct qlinks ql; /* Links on free list */ 530 }; 531 #define BFH(p) ((struct bfhead *) (p)) 532 533 /* Poolset definition */ 534 struct bpoolset { 535 struct bfhead freelist; 536 #ifdef BufStats 537 bufsize totalloc; /* Total space currently allocated */ 538 long numget; /* Number of bget() calls */ 539 long numrel; /* Number of brel() calls */ 540 #ifdef BECtl 541 long numpblk; /* Number of pool blocks */ 542 long numpget; /* Number of block gets and rels */ 543 long numprel; 544 long numdget; /* Number of direct gets and rels */ 545 long numdrel; 546 #endif /* BECtl */ 547 #endif /* BufStats */ 548 549 #ifdef BECtl 550 /* Automatic expansion block management functions */ 551 552 int (*compfcn) _((bufsize sizereq, int sequence)); 553 void *(*acqfcn) _((bufsize size)); 554 void (*relfcn) _((void *buf)); 555 556 bufsize exp_incr; /* Expansion block size */ 557 bufsize pool_len; /* 0: no bpool calls have been made 558 -1: not all pool blocks are 559 the same size 560 >0: (common) block size for all 561 bpool calls made so far 562 */ 563 #endif 564 }; 565 566 /* Minimum allocation quantum: */ 567 568 #define QLSize (sizeof(struct qlinks)) 569 #define SizeQ ((SizeQuant > QLSize) ? SizeQuant : QLSize) 570 571 #define V (void) /* To denote unwanted returned values */ 572 573 /* End sentinel: value placed in bsize field of dummy block delimiting 574 end of pool block. The most negative number which will fit in a 575 bufsize, defined in a way that the compiler will accept. */ 576 577 #define ESent ((bufsize) (-(((1L << (sizeof(bufsize) * 8 - 2)) - 1) * 2) - 2)) 578 579 static bufsize buf_get_pos(struct bfhead *bf, bufsize align, bufsize hdr_size, 580 bufsize size) 581 { 582 unsigned long buf = 0; 583 bufsize pos = 0; 584 585 if (bf->bh.bsize < size) 586 return -1; 587 588 /* 589 * plus sizeof(struct bhead) and hdr_size since buf will follow just 590 * after a struct bhead and an eventual extra header. 591 */ 592 buf = (unsigned long)bf + bf->bh.bsize - size + sizeof(struct bhead) + 593 hdr_size; 594 buf &= ~(align - 1); 595 pos = buf - (unsigned long)bf - sizeof(struct bhead) - hdr_size; 596 597 if (pos == 0) /* exact match */ 598 return pos; 599 if (pos >= SizeQ + sizeof(struct bhead)) /* room for an empty buffer */ 600 return pos; 601 602 return -1; 603 } 604 605 /* BGET -- Allocate a buffer. */ 606 607 void *bget(requested_align, hdr_size, requested_size, poolset) 608 bufsize requested_align; 609 bufsize hdr_size; 610 bufsize requested_size; 611 struct bpoolset *poolset; 612 { 613 bufsize align = requested_align; 614 bufsize size = requested_size; 615 bufsize pos; 616 struct bfhead *b; 617 #ifdef BestFit 618 struct bfhead *best; 619 #endif 620 void *buf; 621 #ifdef BECtl 622 int compactseq = 0; 623 #endif 624 625 assert(size > 0); 626 COMPILE_TIME_ASSERT(BGET_HDR_QUANTUM == SizeQ); 627 628 if (align < 0 || (align > 0 && !IS_POWER_OF_TWO((unsigned long)align))) 629 return NULL; 630 if (hdr_size % BGET_HDR_QUANTUM != 0) 631 return NULL; 632 633 if (size < SizeQ) { /* Need at least room for the */ 634 size = SizeQ; /* queue links. */ 635 } 636 if (align < SizeQ) 637 align = SizeQ; 638 #ifdef SizeQuant 639 #if SizeQuant > 1 640 if (ADD_OVERFLOW(size, SizeQuant - 1, &size)) 641 return NULL; 642 643 size = ROUNDDOWN(size, SizeQuant); 644 #endif 645 #endif 646 647 /* Add overhead in allocated buffer to size required. */ 648 if (ADD_OVERFLOW(size, sizeof(struct bhead), &size)) 649 return NULL; 650 if (ADD_OVERFLOW(size, hdr_size, &size)) 651 return NULL; 652 653 #ifdef BECtl 654 /* If a compact function was provided in the call to bectl(), wrap 655 a loop around the allocation process to allow compaction to 656 intervene in case we don't find a suitable buffer in the chain. */ 657 658 while (1) { 659 #endif 660 b = poolset->freelist.ql.flink; 661 #ifdef BestFit 662 best = &poolset->freelist; 663 #endif 664 665 666 /* Scan the free list searching for the first buffer big enough 667 to hold the requested size buffer. */ 668 669 #ifdef BestFit 670 while (b != &poolset->freelist) { 671 assert(b->bh.prevfree == 0); 672 pos = buf_get_pos(b, align, hdr_size, size); 673 if (pos >= 0) { 674 if ((best == &poolset->freelist) || 675 (b->bh.bsize < best->bh.bsize)) { 676 best = b; 677 } 678 } 679 b = b->ql.flink; /* Link to next buffer */ 680 } 681 b = best; 682 #endif /* BestFit */ 683 684 while (b != &poolset->freelist) { 685 pos = buf_get_pos(b, align, hdr_size, size); 686 if (pos >= 0) { 687 struct bhead *b_alloc = BH((char *)b + pos); 688 struct bhead *b_next = BH((char *)b + b->bh.bsize); 689 690 assert(b_next->prevfree == b->bh.bsize); 691 692 /* 693 * Zero the back pointer in the next buffer in memory 694 * to indicate that this buffer is allocated. 695 */ 696 b_next->prevfree = 0; 697 698 assert(b->ql.blink->ql.flink == b); 699 assert(b->ql.flink->ql.blink == b); 700 701 if (pos == 0) { 702 /* 703 * Need to allocate from the beginning of this free block. 704 * Unlink the block and mark it as allocated. 705 */ 706 b->ql.blink->ql.flink = b->ql.flink; 707 b->ql.flink->ql.blink = b->ql.blink; 708 709 /* Negate size to mark buffer allocated. */ 710 b->bh.bsize = -b->bh.bsize; 711 } else { 712 /* 713 * Carve out the memory allocation from the end of this 714 * free block. Negative size to mark buffer allocated. 715 */ 716 b_alloc->bsize = -(b->bh.bsize - pos); 717 b_alloc->prevfree = pos; 718 b->bh.bsize = pos; 719 } 720 721 assert(b_alloc->bsize < 0); 722 /* 723 * At this point is b_alloc pointing to the allocated 724 * buffer and b_next at the buffer following. b might be a 725 * free block or a used block now. 726 */ 727 if (-b_alloc->bsize - size > SizeQ + sizeof(struct bhead)) { 728 /* 729 * b_alloc has too much unused memory at the 730 * end we need to split the block and register that 731 * last part as free. 732 */ 733 b = BFH((char *)b_alloc + size); 734 b->bh.bsize = -b_alloc->bsize - size; 735 b->bh.prevfree = 0; 736 b_alloc->bsize += b->bh.bsize; 737 738 assert(poolset->freelist.ql.blink->ql.flink == 739 &poolset->freelist); 740 assert(poolset->freelist.ql.flink->ql.blink == 741 &poolset->freelist); 742 b->ql.flink = &poolset->freelist; 743 b->ql.blink = poolset->freelist.ql.blink; 744 poolset->freelist.ql.blink = b; 745 b->ql.blink->ql.flink = b; 746 747 assert(BH((char *)b + b->bh.bsize) == b_next); 748 b_next->prevfree = b->bh.bsize; 749 } 750 751 #ifdef BufStats 752 poolset->totalloc -= b_alloc->bsize; 753 poolset->numget++; /* Increment number of bget() calls */ 754 #endif 755 buf = (char *)b_alloc + sizeof(struct bhead); 756 tag_asan_alloced(buf, size); 757 return buf; 758 } 759 b = b->ql.flink; /* Link to next buffer */ 760 } 761 #ifdef BECtl 762 763 /* We failed to find a buffer. If there's a compact function 764 defined, notify it of the size requested. If it returns 765 TRUE, try the allocation again. */ 766 767 if ((poolset->compfcn == NULL) || 768 (!(poolset->compfcn)(size, ++compactseq))) { 769 break; 770 } 771 } 772 773 /* No buffer available with requested size free. */ 774 775 /* Don't give up yet -- look in the reserve supply. */ 776 777 if (poolset->acqfcn != NULL) { 778 if (size > exp_incr - sizeof(struct bfhead) - align) { 779 780 /* Request is too large to fit in a single expansion 781 block. Try to satisy it by a direct buffer acquisition. */ 782 char *p; 783 784 size += sizeof(struct bdhead) - sizeof(struct bhead); 785 if (align > QLSize) 786 size += align; 787 p = poolset->acqfcn(size); 788 if (p != NULL) { 789 struct bdhead *bdh; 790 791 if (align <= QLSize) { 792 bdh = BDH(p); 793 buf = bdh + 1; 794 } else { 795 unsigned long tp = (unsigned long)p; 796 797 tp += sizeof(*bdh) + hdr_size + align; 798 tp &= ~(align - 1); 799 tp -= hdr_size; 800 buf = (void *)tp; 801 bdh = BDH((char *)buf - sizeof(*bdh)); 802 } 803 804 /* Mark the buffer special by setting the size field 805 of its header to zero. */ 806 bdh->bh.bsize = 0; 807 bdh->bh.prevfree = 0; 808 bdh->tsize = size; 809 bdh->offs = (unsigned long)bdh - (unsigned long)p; 810 #ifdef BufStats 811 poolset->totalloc += size; 812 poolset->numget++; /* Increment number of bget() calls */ 813 poolset->numdget++; /* Direct bget() call count */ 814 #endif 815 tag_asan_alloced(buf, size); 816 return buf; 817 } 818 819 } else { 820 821 /* Try to obtain a new expansion block */ 822 823 void *newpool; 824 825 if ((newpool = poolset->acqfcn((bufsize) exp_incr)) != NULL) { 826 bpool(newpool, exp_incr, poolset); 827 buf = bget(align, hdr_size, requested_size, pool); /* This can't, I say, can't 828 get into a loop. */ 829 return buf; 830 } 831 } 832 } 833 834 /* Still no buffer available */ 835 836 #endif /* BECtl */ 837 838 return NULL; 839 } 840 841 /* BGETZ -- Allocate a buffer and clear its contents to zero. We clear 842 the entire contents of the buffer to zero, not just the 843 region requested by the caller. */ 844 845 void *bgetz(align, hdr_size, size, poolset) 846 bufsize align; 847 bufsize hdr_size; 848 bufsize size; 849 struct bpoolset *poolset; 850 { 851 char *buf = (char *) bget(align, hdr_size, size, poolset); 852 853 if (buf != NULL) { 854 struct bhead *b; 855 bufsize rsize; 856 857 b = BH(buf - sizeof(struct bhead)); 858 rsize = -(b->bsize); 859 if (rsize == 0) { 860 struct bdhead *bd; 861 862 bd = BDH(buf - sizeof(struct bdhead)); 863 rsize = bd->tsize - sizeof(struct bdhead) - bd->offs; 864 } else { 865 rsize -= sizeof(struct bhead); 866 } 867 assert(rsize >= size); 868 V memset_unchecked(buf, 0, (MemSize) rsize); 869 } 870 return ((void *) buf); 871 } 872 873 /* BGETR -- Reallocate a buffer. This is a minimal implementation, 874 simply in terms of brel() and bget(). It could be 875 enhanced to allow the buffer to grow into adjacent free 876 blocks and to avoid moving data unnecessarily. */ 877 878 void *bgetr(buf, align, hdr_size, size, poolset) 879 void *buf; 880 bufsize align; 881 bufsize hdr_size; 882 bufsize size; 883 struct bpoolset *poolset; 884 { 885 void *nbuf; 886 bufsize osize; /* Old size of buffer */ 887 struct bhead *b; 888 889 if ((nbuf = bget(align, hdr_size, size, poolset)) == NULL) { /* Acquire new buffer */ 890 return NULL; 891 } 892 if (buf == NULL) { 893 return nbuf; 894 } 895 b = BH(((char *) buf) - sizeof(struct bhead)); 896 osize = -b->bsize; 897 #ifdef BECtl 898 if (osize == 0) { 899 /* Buffer acquired directly through acqfcn. */ 900 struct bdhead *bd; 901 902 bd = BDH(((char *) buf) - sizeof(struct bdhead)); 903 osize = bd->tsize - sizeof(struct bdhead) - bd->offs; 904 } else 905 #endif 906 osize -= sizeof(struct bhead); 907 assert(osize > 0); 908 V memcpy((char *) nbuf, (char *) buf, /* Copy the data */ 909 (MemSize) ((size < osize) ? size : osize)); 910 #ifndef __KERNEL__ 911 /* User space reallocations are always zeroed */ 912 if (size > osize) 913 V memset((char *) nbuf + osize, 0, size - osize); 914 #endif 915 brel(buf, poolset, false /* !wipe */); 916 return nbuf; 917 } 918 919 /* BREL -- Release a buffer. */ 920 921 void brel(buf, poolset, wipe) 922 void *buf; 923 struct bpoolset *poolset; 924 int wipe; 925 { 926 struct bfhead *b, *bn; 927 bufsize bs; 928 929 b = BFH(((char *) buf) - sizeof(struct bhead)); 930 #ifdef BufStats 931 poolset->numrel++; /* Increment number of brel() calls */ 932 #endif 933 assert(buf != NULL); 934 935 #ifdef FreeWipe 936 wipe = true; 937 #endif 938 #ifdef BECtl 939 if (b->bh.bsize == 0) { /* Directly-acquired buffer? */ 940 struct bdhead *bdh; 941 942 bdh = BDH(((char *) buf) - sizeof(struct bdhead)); 943 assert(b->bh.prevfree == 0); 944 #ifdef BufStats 945 poolset->totalloc -= bdh->tsize; 946 assert(poolset->totalloc >= 0); 947 poolset->numdrel++; /* Number of direct releases */ 948 #endif /* BufStats */ 949 if (wipe) { 950 V memset_unchecked((char *) buf, 0x55, 951 (MemSize) (bdh->tsize - 952 sizeof(struct bdhead))); 953 } 954 bs = bdh->tsize - sizeof(struct bdhead); 955 assert(poolset->relfcn != NULL); 956 poolset->relfcn((char *)buf - sizeof(struct bdhead) - bdh->offs); /* Release it directly. */ 957 tag_asan_free(buf, bs); 958 return; 959 } 960 #endif /* BECtl */ 961 962 /* Buffer size must be negative, indicating that the buffer is 963 allocated. */ 964 965 if (b->bh.bsize >= 0) { 966 bn = NULL; 967 } 968 assert(b->bh.bsize < 0); 969 bs = -b->bh.bsize; 970 971 /* Back pointer in next buffer must be zero, indicating the 972 same thing: */ 973 974 assert(BH((char *) b - b->bh.bsize)->prevfree == 0); 975 976 #ifdef BufStats 977 poolset->totalloc += b->bh.bsize; 978 assert(poolset->totalloc >= 0); 979 #endif 980 981 /* If the back link is nonzero, the previous buffer is free. */ 982 983 if (b->bh.prevfree != 0) { 984 985 /* The previous buffer is free. Consolidate this buffer with it 986 by adding the length of this buffer to the previous free 987 buffer. Note that we subtract the size in the buffer being 988 released, since it's negative to indicate that the buffer is 989 allocated. */ 990 991 register bufsize size = b->bh.bsize; 992 993 /* Make the previous buffer the one we're working on. */ 994 assert(BH((char *) b - b->bh.prevfree)->bsize == b->bh.prevfree); 995 b = BFH(((char *) b) - b->bh.prevfree); 996 b->bh.bsize -= size; 997 } else { 998 999 /* The previous buffer isn't allocated. Insert this buffer 1000 on the free list as an isolated free block. */ 1001 1002 assert(poolset->freelist.ql.blink->ql.flink == &poolset->freelist); 1003 assert(poolset->freelist.ql.flink->ql.blink == &poolset->freelist); 1004 b->ql.flink = &poolset->freelist; 1005 b->ql.blink = poolset->freelist.ql.blink; 1006 poolset->freelist.ql.blink = b; 1007 b->ql.blink->ql.flink = b; 1008 b->bh.bsize = -b->bh.bsize; 1009 } 1010 1011 /* Now we look at the next buffer in memory, located by advancing from 1012 the start of this buffer by its size, to see if that buffer is 1013 free. If it is, we combine this buffer with the next one in 1014 memory, dechaining the second buffer from the free list. */ 1015 1016 bn = BFH(((char *) b) + b->bh.bsize); 1017 if (bn->bh.bsize > 0) { 1018 1019 /* The buffer is free. Remove it from the free list and add 1020 its size to that of our buffer. */ 1021 1022 assert(BH((char *) bn + bn->bh.bsize)->prevfree == bn->bh.bsize); 1023 assert(bn->ql.blink->ql.flink == bn); 1024 assert(bn->ql.flink->ql.blink == bn); 1025 bn->ql.blink->ql.flink = bn->ql.flink; 1026 bn->ql.flink->ql.blink = bn->ql.blink; 1027 b->bh.bsize += bn->bh.bsize; 1028 1029 /* Finally, advance to the buffer that follows the newly 1030 consolidated free block. We must set its backpointer to the 1031 head of the consolidated free block. We know the next block 1032 must be an allocated block because the process of recombination 1033 guarantees that two free blocks will never be contiguous in 1034 memory. */ 1035 1036 bn = BFH(((char *) b) + b->bh.bsize); 1037 } 1038 if (wipe) { 1039 V memset_unchecked(((char *) b) + sizeof(struct bfhead), 0x55, 1040 (MemSize) (b->bh.bsize - sizeof(struct bfhead))); 1041 } 1042 assert(bn->bh.bsize < 0); 1043 1044 /* The next buffer is allocated. Set the backpointer in it to point 1045 to this buffer; the previous free buffer in memory. */ 1046 1047 bn->bh.prevfree = b->bh.bsize; 1048 1049 #ifdef BECtl 1050 1051 /* If a block-release function is defined, and this free buffer 1052 constitutes the entire block, release it. Note that pool_len 1053 is defined in such a way that the test will fail unless all 1054 pool blocks are the same size. */ 1055 1056 if (poolset->relfcn != NULL && 1057 ((bufsize) b->bh.bsize) == (pool_len - sizeof(struct bhead))) { 1058 1059 assert(b->bh.prevfree == 0); 1060 assert(BH((char *) b + b->bh.bsize)->bsize == ESent); 1061 assert(BH((char *) b + b->bh.bsize)->prevfree == b->bh.bsize); 1062 /* Unlink the buffer from the free list */ 1063 b->ql.blink->ql.flink = b->ql.flink; 1064 b->ql.flink->ql.blink = b->ql.blink; 1065 1066 poolset->relfcn(b); 1067 #ifdef BufStats 1068 poolset->numprel++; /* Nr of expansion block releases */ 1069 poolset->numpblk--; /* Total number of blocks */ 1070 assert(numpblk == numpget - numprel); 1071 #endif /* BufStats */ 1072 } 1073 #endif /* BECtl */ 1074 tag_asan_free(buf, bs); 1075 } 1076 1077 #ifdef BECtl 1078 1079 /* BECTL -- Establish automatic pool expansion control */ 1080 1081 void bectl(compact, acquire, release, pool_incr, poolset) 1082 int (*compact) _((bufsize sizereq, int sequence)); 1083 void *(*acquire) _((bufsize size)); 1084 void (*release) _((void *buf)); 1085 bufsize pool_incr; 1086 struct bpoolset *poolset; 1087 { 1088 poolset->compfcn = compact; 1089 poolset->acqfcn = acquire; 1090 poolset->relfcn = release; 1091 poolset->exp_incr = pool_incr; 1092 } 1093 #endif 1094 1095 /* BPOOL -- Add a region of memory to the buffer pool. */ 1096 1097 void bpool(buf, len, poolset) 1098 void *buf; 1099 bufsize len; 1100 struct bpoolset *poolset; 1101 { 1102 struct bfhead *b = BFH(buf); 1103 struct bhead *bn; 1104 1105 #ifdef SizeQuant 1106 len &= ~(SizeQuant - 1); 1107 #endif 1108 #ifdef BECtl 1109 if (poolset->pool_len == 0) { 1110 pool_len = len; 1111 } else if (len != poolset->pool_len) { 1112 poolset->pool_len = -1; 1113 } 1114 #ifdef BufStats 1115 poolset->numpget++; /* Number of block acquisitions */ 1116 poolset->numpblk++; /* Number of blocks total */ 1117 assert(poolset->numpblk == poolset->numpget - poolset->numprel); 1118 #endif /* BufStats */ 1119 #endif /* BECtl */ 1120 1121 /* Since the block is initially occupied by a single free buffer, 1122 it had better not be (much) larger than the largest buffer 1123 whose size we can store in bhead.bsize. */ 1124 1125 assert(len - sizeof(struct bhead) <= -((bufsize) ESent + 1)); 1126 1127 /* Clear the backpointer at the start of the block to indicate that 1128 there is no free block prior to this one. That blocks 1129 recombination when the first block in memory is released. */ 1130 1131 b->bh.prevfree = 0; 1132 1133 /* Chain the new block to the free list. */ 1134 1135 assert(poolset->freelist.ql.blink->ql.flink == &poolset->freelist); 1136 assert(poolset->freelist.ql.flink->ql.blink == &poolset->freelist); 1137 b->ql.flink = &poolset->freelist; 1138 b->ql.blink = poolset->freelist.ql.blink; 1139 poolset->freelist.ql.blink = b; 1140 b->ql.blink->ql.flink = b; 1141 1142 /* Create a dummy allocated buffer at the end of the pool. This dummy 1143 buffer is seen when a buffer at the end of the pool is released and 1144 blocks recombination of the last buffer with the dummy buffer at 1145 the end. The length in the dummy buffer is set to the largest 1146 negative number to denote the end of the pool for diagnostic 1147 routines (this specific value is not counted on by the actual 1148 allocation and release functions). */ 1149 1150 len -= sizeof(struct bhead); 1151 b->bh.bsize = (bufsize) len; 1152 #ifdef FreeWipe 1153 V memset_unchecked(((char *) b) + sizeof(struct bfhead), 0x55, 1154 (MemSize) (len - sizeof(struct bfhead))); 1155 #endif 1156 bn = BH(((char *) b) + len); 1157 bn->prevfree = (bufsize) len; 1158 /* Definition of ESent assumes two's complement! */ 1159 assert((~0) == -1); 1160 bn->bsize = ESent; 1161 } 1162 1163 #ifdef BufStats 1164 1165 /* BSTATS -- Return buffer allocation free space statistics. */ 1166 1167 void bstats(curalloc, totfree, maxfree, nget, nrel, poolset) 1168 bufsize *curalloc, *totfree, *maxfree; 1169 long *nget, *nrel; 1170 struct bpoolset *poolset; 1171 { 1172 struct bfhead *b = poolset->freelist.ql.flink; 1173 1174 *nget = poolset->numget; 1175 *nrel = poolset->numrel; 1176 *curalloc = poolset->totalloc; 1177 *totfree = 0; 1178 *maxfree = -1; 1179 while (b != &poolset->freelist) { 1180 assert(b->bh.bsize > 0); 1181 *totfree += b->bh.bsize; 1182 if (b->bh.bsize > *maxfree) { 1183 *maxfree = b->bh.bsize; 1184 } 1185 b = b->ql.flink; /* Link to next buffer */ 1186 } 1187 } 1188 1189 #ifdef BECtl 1190 1191 /* BSTATSE -- Return extended statistics */ 1192 1193 void bstatse(pool_incr, npool, npget, nprel, ndget, ndrel, poolset) 1194 bufsize *pool_incr; 1195 long *npool, *npget, *nprel, *ndget, *ndrel; 1196 struct bpoolset *poolset; 1197 { 1198 *pool_incr = (poolset->pool_len < 0) ? 1199 -poolset->exp_incr : poolset->exp_incr; 1200 *npool = poolset->numpblk; 1201 *npget = poolset->numpget; 1202 *nprel = poolset->numprel; 1203 *ndget = poolset->numdget; 1204 *ndrel = poolset->numdrel; 1205 } 1206 #endif /* BECtl */ 1207 #endif /* BufStats */ 1208 1209 #ifdef DumpData 1210 1211 /* BUFDUMP -- Dump the data in a buffer. This is called with the user 1212 data pointer, and backs up to the buffer header. It will 1213 dump either a free block or an allocated one. */ 1214 1215 void bufdump(buf) 1216 void *buf; 1217 { 1218 struct bfhead *b; 1219 unsigned char *bdump; 1220 bufsize bdlen; 1221 1222 b = BFH(((char *) buf) - sizeof(struct bhead)); 1223 assert(b->bh.bsize != 0); 1224 if (b->bh.bsize < 0) { 1225 bdump = (unsigned char *) buf; 1226 bdlen = (-b->bh.bsize) - sizeof(struct bhead); 1227 } else { 1228 bdump = (unsigned char *) (((char *) b) + sizeof(struct bfhead)); 1229 bdlen = b->bh.bsize - sizeof(struct bfhead); 1230 } 1231 1232 while (bdlen > 0) { 1233 int i, dupes = 0; 1234 bufsize l = bdlen; 1235 char bhex[50], bascii[20]; 1236 1237 if (l > 16) { 1238 l = 16; 1239 } 1240 1241 for (i = 0; i < l; i++) { 1242 V snprintf(bhex + i * 3, sizeof(bhex) - i * 3, "%02X ", 1243 bdump[i]); 1244 bascii[i] = isprint(bdump[i]) ? bdump[i] : ' '; 1245 } 1246 bascii[i] = 0; 1247 V printf("%-48s %s\n", bhex, bascii); 1248 bdump += l; 1249 bdlen -= l; 1250 while ((bdlen > 16) && (memcmp((char *) (bdump - 16), 1251 (char *) bdump, 16) == 0)) { 1252 dupes++; 1253 bdump += 16; 1254 bdlen -= 16; 1255 } 1256 if (dupes > 1) { 1257 V printf( 1258 " (%d lines [%d bytes] identical to above line skipped)\n", 1259 dupes, dupes * 16); 1260 } else if (dupes == 1) { 1261 bdump -= 16; 1262 bdlen += 16; 1263 } 1264 } 1265 } 1266 #endif 1267 1268 #ifdef BufDump 1269 1270 /* BPOOLD -- Dump a buffer pool. The buffer headers are always listed. 1271 If DUMPALLOC is nonzero, the contents of allocated buffers 1272 are dumped. If DUMPFREE is nonzero, free blocks are 1273 dumped as well. If FreeWipe checking is enabled, free 1274 blocks which have been clobbered will always be dumped. */ 1275 1276 void bpoold(buf, dumpalloc, dumpfree) 1277 void *buf; 1278 int dumpalloc, dumpfree; 1279 { 1280 struct bfhead *b = BFH(buf); 1281 1282 while (b->bh.bsize != ESent) { 1283 bufsize bs = b->bh.bsize; 1284 1285 if (bs < 0) { 1286 bs = -bs; 1287 V printf("Allocated buffer: size %6ld bytes.\n", (long) bs); 1288 if (dumpalloc) { 1289 bufdump((void *) (((char *) b) + sizeof(struct bhead))); 1290 } 1291 } else { 1292 char *lerr = ""; 1293 1294 assert(bs > 0); 1295 if ((b->ql.blink->ql.flink != b) || 1296 (b->ql.flink->ql.blink != b)) { 1297 lerr = " (Bad free list links)"; 1298 } 1299 V printf("Free block: size %6ld bytes.%s\n", 1300 (long) bs, lerr); 1301 #ifdef FreeWipe 1302 lerr = ((char *) b) + sizeof(struct bfhead); 1303 if ((bs > sizeof(struct bfhead)) && ((*lerr != 0x55) || 1304 (memcmp(lerr, lerr + 1, 1305 (MemSize) (bs - (sizeof(struct bfhead) + 1))) != 0))) { 1306 V printf( 1307 "(Contents of above free block have been overstored.)\n"); 1308 bufdump((void *) (((char *) b) + sizeof(struct bhead))); 1309 } else 1310 #endif 1311 if (dumpfree) { 1312 bufdump((void *) (((char *) b) + sizeof(struct bhead))); 1313 } 1314 } 1315 b = BFH(((char *) b) + bs); 1316 } 1317 } 1318 #endif /* BufDump */ 1319 1320 #ifdef BufValid 1321 1322 /* BPOOLV -- Validate a buffer pool. If NDEBUG isn't defined, 1323 any error generates an assertion failure. */ 1324 1325 int bpoolv(buf) 1326 void *buf; 1327 { 1328 struct bfhead *b = BFH(buf); 1329 1330 while (b->bh.bsize != ESent) { 1331 bufsize bs = b->bh.bsize; 1332 1333 if (bs < 0) { 1334 bs = -bs; 1335 } else { 1336 const char *lerr = ""; 1337 1338 assert(bs > 0); 1339 if (bs <= 0) { 1340 return 0; 1341 } 1342 if ((b->ql.blink->ql.flink != b) || 1343 (b->ql.flink->ql.blink != b)) { 1344 V printf("Free block: size %6ld bytes. (Bad free list links)\n", 1345 (long) bs); 1346 assert(0); 1347 return 0; 1348 } 1349 #ifdef FreeWipe 1350 lerr = ((char *) b) + sizeof(struct bfhead); 1351 if ((bs > sizeof(struct bfhead)) && ((*lerr != 0x55) || 1352 (memcmp(lerr, lerr + 1, 1353 (MemSize) (bs - (sizeof(struct bfhead) + 1))) != 0))) { 1354 V printf( 1355 "(Contents of above free block have been overstored.)\n"); 1356 bufdump((void *) (((char *) b) + sizeof(struct bhead))); 1357 assert(0); 1358 return 0; 1359 } 1360 #endif 1361 } 1362 b = BFH(((char *) b) + bs); 1363 } 1364 return 1; 1365 } 1366 #endif /* BufValid */ 1367 1368 /***********************\ 1369 * * 1370 * Built-in test program * 1371 * * 1372 \***********************/ 1373 1374 #if !defined(__KERNEL__) && !defined(__LDELF__) && defined(CFG_TA_BGET_TEST) 1375 1376 #define TestProg 20000 1377 1378 #ifdef BECtl 1379 #define PoolSize 300000 /* Test buffer pool size */ 1380 #else 1381 #define PoolSize 50000 /* Test buffer pool size */ 1382 #endif 1383 #define ExpIncr 32768 /* Test expansion block size */ 1384 #define CompactTries 10 /* Maximum tries at compacting */ 1385 1386 #define dumpAlloc 0 /* Dump allocated buffers ? */ 1387 #define dumpFree 0 /* Dump free buffers ? */ 1388 1389 static char *bchain = NULL; /* Our private buffer chain */ 1390 static char *bp = NULL; /* Our initial buffer pool */ 1391 1392 #ifdef UsingFloat 1393 #include <math.h> 1394 #endif 1395 1396 static unsigned long int next = 1; 1397 1398 static void *(*mymalloc)(size_t size); 1399 static void (*myfree)(void *ptr); 1400 1401 static struct bpoolset mypoolset = { 1402 .freelist = { 1403 .bh = { 0, 0}, 1404 .ql = { &mypoolset.freelist, &mypoolset.freelist}, 1405 } 1406 }; 1407 1408 /* Return next random integer */ 1409 1410 static int myrand(void) 1411 { 1412 next = next * 1103515245L + 12345; 1413 return (unsigned int) (next / 65536L) % 32768L; 1414 } 1415 1416 /* Set seed for random generator */ 1417 1418 static void mysrand(unsigned int seed) 1419 { 1420 next = seed; 1421 } 1422 1423 /* STATS -- Edit statistics returned by bstats() or bstatse(). */ 1424 1425 static void stats(const char *when __maybe_unused, 1426 struct bpoolset *poolset __maybe_unused) 1427 { 1428 #ifdef BufStats 1429 bufsize cural, totfree, maxfree; 1430 long nget, nfree; 1431 #endif 1432 #ifdef BECtl 1433 bufsize pincr; 1434 long totblocks, npget, nprel, ndget, ndrel; 1435 #endif 1436 1437 #ifdef BufStats 1438 bstats(&cural, &totfree, &maxfree, &nget, &nfree, poolset); 1439 V printf( 1440 "%s: %ld gets, %ld releases. %ld in use, %ld free, largest = %ld\n", 1441 when, nget, nfree, (long) cural, (long) totfree, (long) maxfree); 1442 #endif 1443 #ifdef BECtl 1444 bstatse(&pincr, &totblocks, &npget, &nprel, &ndget, &ndrel, poolset); 1445 V printf( 1446 " Blocks: size = %ld, %ld (%ld bytes) in use, %ld gets, %ld frees\n", 1447 (long)pincr, totblocks, pincr * totblocks, npget, nprel); 1448 V printf(" %ld direct gets, %ld direct frees\n", ndget, ndrel); 1449 #endif /* BECtl */ 1450 } 1451 1452 #ifdef BECtl 1453 static int protect = 0; /* Disable compaction during bgetr() */ 1454 1455 /* BCOMPACT -- Compaction call-back function. */ 1456 1457 static int bcompact(bsize, seq) 1458 bufsize bsize; 1459 int seq; 1460 { 1461 #ifdef CompactTries 1462 char *bc = bchain; 1463 int i = myrand() & 0x3; 1464 1465 #ifdef COMPACTRACE 1466 V printf("Compaction requested. %ld bytes needed, sequence %d.\n", 1467 (long) bsize, seq); 1468 #endif 1469 1470 if (protect || (seq > CompactTries)) { 1471 #ifdef COMPACTRACE 1472 V printf("Compaction gave up.\n"); 1473 #endif 1474 return 0; 1475 } 1476 1477 /* Based on a random cast, release a random buffer in the list 1478 of allocated buffers. */ 1479 1480 while (i > 0 && bc != NULL) { 1481 bc = *((char **) bc); 1482 i--; 1483 } 1484 if (bc != NULL) { 1485 char *fb; 1486 1487 fb = *((char **) bc); 1488 if (fb != NULL) { 1489 *((char **) bc) = *((char **) fb); 1490 brel((void *) fb); 1491 return 1; 1492 } 1493 } 1494 1495 #ifdef COMPACTRACE 1496 V printf("Compaction bailed out.\n"); 1497 #endif 1498 #endif /* CompactTries */ 1499 return 0; 1500 } 1501 1502 /* BEXPAND -- Expand pool call-back function. */ 1503 1504 static void *bexpand(size) 1505 bufsize size; 1506 { 1507 void *np = NULL; 1508 bufsize cural, totfree, maxfree; 1509 long nget, nfree; 1510 1511 /* Don't expand beyond the total allocated size given by PoolSize. */ 1512 1513 bstats(&cural, &totfree, &maxfree, &nget, &nfree); 1514 1515 if (cural < PoolSize) { 1516 np = (void *) mymalloc((unsigned) size); 1517 } 1518 #ifdef EXPTRACE 1519 V printf("Expand pool by %ld -- %s.\n", (long) size, 1520 np == NULL ? "failed" : "succeeded"); 1521 #endif 1522 return np; 1523 } 1524 1525 /* BSHRINK -- Shrink buffer pool call-back function. */ 1526 1527 static void bshrink(buf) 1528 void *buf; 1529 { 1530 if (((char *) buf) == bp) { 1531 #ifdef EXPTRACE 1532 V printf("Initial pool released.\n"); 1533 #endif 1534 bp = NULL; 1535 } 1536 #ifdef EXPTRACE 1537 V printf("Shrink pool.\n"); 1538 #endif 1539 myfree((char *) buf); 1540 } 1541 1542 #endif /* BECtl */ 1543 1544 /* Restrict buffer requests to those large enough to contain our pointer and 1545 small enough for the CPU architecture. */ 1546 1547 static bufsize blimit(bufsize bs) 1548 { 1549 if (bs < sizeof(char *)) { 1550 bs = sizeof(char *); 1551 } 1552 1553 /* This is written out in this ugly fashion because the 1554 cool expression in sizeof(int) that auto-configured 1555 to any length int befuddled some compilers. */ 1556 1557 if (sizeof(int) == 2) { 1558 if (bs > 32767) { 1559 bs = 32767; 1560 } 1561 } else { 1562 if (bs > 200000) { 1563 bs = 200000; 1564 } 1565 } 1566 return bs; 1567 } 1568 1569 int bget_main_test(void *(*malloc_func)(size_t), void (*free_func)(void *)) 1570 { 1571 int i; 1572 #ifdef UsingFloat 1573 double x; 1574 #endif 1575 1576 mymalloc = malloc_func; 1577 myfree = free_func; 1578 1579 /* Seed the random number generator. If Repeatable is defined, we 1580 always use the same seed. Otherwise, we seed from the clock to 1581 shake things up from run to run. */ 1582 1583 mysrand(1234); 1584 1585 /* Compute x such that pow(x, p) ranges between 1 and 4*ExpIncr as 1586 p ranges from 0 to ExpIncr-1, with a concentration in the lower 1587 numbers. */ 1588 1589 #ifdef UsingFloat 1590 x = 4.0 * ExpIncr; 1591 x = log(x); 1592 x = exp(log(4.0 * ExpIncr) / (ExpIncr - 1.0)); 1593 #endif 1594 1595 #ifdef BECtl 1596 bectl(bcompact, bexpand, bshrink, (bufsize) ExpIncr, &mypoolset); 1597 bp = mymalloc(ExpIncr); 1598 assert(bp != NULL); 1599 bpool((void *) bp, (bufsize) ExpIncr); 1600 #else 1601 bp = mymalloc(PoolSize); 1602 assert(bp != NULL); 1603 bpool((void *) bp, (bufsize) PoolSize, &mypoolset); 1604 #endif 1605 1606 stats("Create pool", &mypoolset); 1607 #ifdef BufValid 1608 V bpoolv((void *) bp); 1609 #endif 1610 #ifdef BufDump 1611 bpoold((void *) bp, dumpAlloc, dumpFree); 1612 #endif 1613 1614 for (i = 0; i < TestProg; i++) { 1615 char *cb; 1616 #ifdef UsingFloat 1617 bufsize bs = pow(x, (double) (myrand() & (ExpIncr - 1))); 1618 #else 1619 bufsize bs = (myrand() & (ExpIncr * 4 - 1)) / (1 << (myrand() & 0x7)); 1620 #endif 1621 bufsize align = 0; 1622 bufsize hdr_size = 0; 1623 1624 switch (rand() & 0x3) { 1625 case 1: 1626 align = 32; 1627 break; 1628 case 2: 1629 align = 64; 1630 break; 1631 case 3: 1632 align = 128; 1633 break; 1634 default: 1635 break; 1636 } 1637 1638 hdr_size = (rand() & 0x3) * BGET_HDR_QUANTUM; 1639 1640 assert(bs <= (((bufsize) 4) * ExpIncr)); 1641 bs = blimit(bs); 1642 if (myrand() & 0x400) { 1643 cb = (char *) bgetz(align, hdr_size, bs, &mypoolset); 1644 } else { 1645 cb = (char *) bget(align, hdr_size, bs, &mypoolset); 1646 } 1647 if (cb == NULL) { 1648 #ifdef EasyOut 1649 break; 1650 #else 1651 char *bc = bchain; 1652 1653 if (bc != NULL) { 1654 char *fb; 1655 1656 fb = *((char **) bc); 1657 if (fb != NULL) { 1658 *((char **) bc) = *((char **) fb); 1659 brel((void *) fb, &mypoolset, true/*wipe*/); 1660 } 1661 } 1662 continue; 1663 #endif 1664 } 1665 assert(!align || !(((unsigned long)cb + hdr_size) & (align - 1))); 1666 *((char **) cb) = (char *) bchain; 1667 bchain = cb; 1668 1669 /* Based on a random cast, release a random buffer in the list 1670 of allocated buffers. */ 1671 1672 if ((myrand() & 0x10) == 0) { 1673 char *bc = bchain; 1674 int j = myrand() & 0x3; 1675 1676 while (j > 0 && bc != NULL) { 1677 bc = *((char **) bc); 1678 j--; 1679 } 1680 if (bc != NULL) { 1681 char *fb; 1682 1683 fb = *((char **) bc); 1684 if (fb != NULL) { 1685 *((char **) bc) = *((char **) fb); 1686 brel((void *) fb, &mypoolset, true/*wipe*/); 1687 } 1688 } 1689 } 1690 1691 /* Based on a random cast, reallocate a random buffer in the list 1692 to a random size */ 1693 1694 if ((myrand() & 0x20) == 0) { 1695 char *bc = bchain; 1696 int j = myrand() & 0x3; 1697 1698 while (j > 0 && bc != NULL) { 1699 bc = *((char **) bc); 1700 j--; 1701 } 1702 if (bc != NULL) { 1703 char *fb; 1704 1705 fb = *((char **) bc); 1706 if (fb != NULL) { 1707 char *newb; 1708 1709 #ifdef UsingFloat 1710 bs = pow(x, (double) (myrand() & (ExpIncr - 1))); 1711 #else 1712 bs = (rand() & (ExpIncr * 4 - 1)) / (1 << (rand() & 0x7)); 1713 #endif 1714 bs = blimit(bs); 1715 #ifdef BECtl 1716 protect = 1; /* Protect against compaction */ 1717 #endif 1718 newb = (char *) bgetr((void *) fb, align, hdr_size, bs, &mypoolset); 1719 #ifdef BECtl 1720 protect = 0; 1721 #endif 1722 if (newb != NULL) { 1723 assert(!align || !(((unsigned long)newb + hdr_size) & 1724 (align - 1))); 1725 *((char **) bc) = newb; 1726 } 1727 } 1728 } 1729 } 1730 } 1731 stats("\nAfter allocation", &mypoolset); 1732 if (bp != NULL) { 1733 #ifdef BufValid 1734 V bpoolv((void *) bp); 1735 #endif 1736 #ifdef BufDump 1737 bpoold((void *) bp, dumpAlloc, dumpFree); 1738 #endif 1739 } 1740 1741 while (bchain != NULL) { 1742 char *buf = bchain; 1743 1744 bchain = *((char **) buf); 1745 brel((void *) buf, &mypoolset, true/*wipe*/); 1746 } 1747 stats("\nAfter release", &mypoolset); 1748 #ifndef BECtl 1749 if (bp != NULL) { 1750 #ifdef BufValid 1751 V bpoolv((void *) bp); 1752 #endif 1753 #ifdef BufDump 1754 bpoold((void *) bp, dumpAlloc, dumpFree); 1755 #endif 1756 } 1757 #endif 1758 1759 return 0; 1760 } 1761 #endif 1762