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 uint64_t free2_sum; /* Sum of size^2 of each free chunk */ 541 #ifdef BECtl 542 long numpblk; /* Number of pool blocks */ 543 long numpget; /* Number of block gets and rels */ 544 long numprel; 545 long numdget; /* Number of direct gets and rels */ 546 long numdrel; 547 #endif /* BECtl */ 548 #endif /* BufStats */ 549 550 #ifdef BECtl 551 /* Automatic expansion block management functions */ 552 553 int (*compfcn) _((bufsize sizereq, int sequence)); 554 void *(*acqfcn) _((bufsize size)); 555 void (*relfcn) _((void *buf)); 556 557 bufsize exp_incr; /* Expansion block size */ 558 bufsize pool_len; /* 0: no bpool calls have been made 559 -1: not all pool blocks are 560 the same size 561 >0: (common) block size for all 562 bpool calls made so far 563 */ 564 #endif 565 }; 566 567 /* Minimum allocation quantum: */ 568 569 #define QLSize (sizeof(struct qlinks)) 570 #define SizeQ ((SizeQuant > QLSize) ? SizeQuant : QLSize) 571 572 #define V (void) /* To denote unwanted returned values */ 573 574 /* End sentinel: value placed in bsize field of dummy block delimiting 575 end of pool block. The most negative number which will fit in a 576 bufsize, defined in a way that the compiler will accept. */ 577 578 #define ESent ((bufsize) (-(((1L << (sizeof(bufsize) * 8 - 2)) - 1) * 2) - 2)) 579 580 static bufsize buf_get_pos(struct bfhead *bf, bufsize align, bufsize hdr_size, 581 bufsize size) 582 { 583 unsigned long buf = 0; 584 bufsize pos = 0; 585 586 if (bf->bh.bsize < size) 587 return -1; 588 589 /* 590 * plus sizeof(struct bhead) and hdr_size since buf will follow just 591 * after a struct bhead and an eventual extra header. 592 */ 593 buf = (unsigned long)bf + bf->bh.bsize - size + sizeof(struct bhead) + 594 hdr_size; 595 buf &= ~(align - 1); 596 pos = buf - (unsigned long)bf - sizeof(struct bhead) - hdr_size; 597 598 if (pos == 0) /* exact match */ 599 return pos; 600 if (pos >= SizeQ + sizeof(struct bhead)) /* room for an empty buffer */ 601 return pos; 602 603 return -1; 604 } 605 606 static uint64_t __maybe_unused get_free2_sum(struct bpoolset *poolset) 607 { 608 struct bfhead *b = poolset->freelist.ql.flink; 609 uint64_t free2_sum = 0; 610 uint64_t bs = 0; 611 612 while (b != &poolset->freelist) { 613 bs = b->bh.bsize; 614 free2_sum += bs * bs; 615 b = b->ql.flink; /* Link to next buffer */ 616 } 617 618 return free2_sum; 619 } 620 621 /* 622 * update_free2_sum() - cumulative update of the free^2 sum 623 * @poolset: The addressed poolset 624 * @rem_sz: Size of a removed free block, 0 if unused 625 * @rem_sz2: Size of one more removed free block, 0 if unused 626 * @add_sz: Size of an added free block, 0 if unused 627 * 628 * As free blocks are removed, added, or merged the sum of the size ^ 2 of 629 * all free blocks needs to be updated. The most complicated case is where 630 * two free blocks are merged into one free block, both the old sizes must be 631 * supplied and the new size. 632 */ 633 static void update_free2_sum(struct bpoolset *poolset __maybe_unused, 634 uint64_t rem_sz __maybe_unused, 635 uint64_t rem_sz2 __maybe_unused, 636 uint64_t add_sz __maybe_unused) 637 { 638 #ifdef BufStats 639 uint64_t r2 = rem_sz * rem_sz + rem_sz2 * rem_sz2; 640 uint64_t a2 = add_sz * add_sz; 641 uint64_t f2s __maybe_unused = get_free2_sum(poolset); 642 643 assert(f2s == poolset->free2_sum - r2 + a2); 644 assert(poolset->free2_sum >= r2); 645 poolset->free2_sum -= r2; 646 poolset->free2_sum += a2; 647 #endif 648 } 649 650 /* BGET -- Allocate a buffer. */ 651 652 void *bget(requested_align, hdr_size, requested_size, poolset) 653 bufsize requested_align; 654 bufsize hdr_size; 655 bufsize requested_size; 656 struct bpoolset *poolset; 657 { 658 bufsize align = requested_align; 659 bufsize size = requested_size; 660 bufsize pos; 661 struct bfhead *b; 662 #ifdef BestFit 663 struct bfhead *best; 664 #endif 665 void *buf; 666 #ifdef BECtl 667 int compactseq = 0; 668 #endif 669 670 assert(size > 0); 671 COMPILE_TIME_ASSERT(BGET_HDR_QUANTUM == SizeQ); 672 673 if (align < 0 || (align > 0 && !IS_POWER_OF_TWO((unsigned long)align))) 674 return NULL; 675 if (hdr_size % BGET_HDR_QUANTUM != 0) 676 return NULL; 677 678 if (size < SizeQ) { /* Need at least room for the */ 679 size = SizeQ; /* queue links. */ 680 } 681 if (align < SizeQ) 682 align = SizeQ; 683 #ifdef SizeQuant 684 #if SizeQuant > 1 685 if (ADD_OVERFLOW(size, SizeQuant - 1, &size)) 686 return NULL; 687 688 size = ROUNDDOWN(size, SizeQuant); 689 #endif 690 #endif 691 692 /* Add overhead in allocated buffer to size required. */ 693 if (ADD_OVERFLOW(size, sizeof(struct bhead), &size)) 694 return NULL; 695 if (ADD_OVERFLOW(size, hdr_size, &size)) 696 return NULL; 697 698 #ifdef BECtl 699 /* If a compact function was provided in the call to bectl(), wrap 700 a loop around the allocation process to allow compaction to 701 intervene in case we don't find a suitable buffer in the chain. */ 702 703 while (1) { 704 #endif 705 b = poolset->freelist.ql.flink; 706 #ifdef BestFit 707 best = &poolset->freelist; 708 #endif 709 710 711 /* Scan the free list searching for the first buffer big enough 712 to hold the requested size buffer. */ 713 714 #ifdef BestFit 715 while (b != &poolset->freelist) { 716 assert(b->bh.prevfree == 0); 717 pos = buf_get_pos(b, align, hdr_size, size); 718 if (pos >= 0) { 719 if ((best == &poolset->freelist) || 720 (b->bh.bsize < best->bh.bsize)) { 721 best = b; 722 } 723 } 724 b = b->ql.flink; /* Link to next buffer */ 725 } 726 b = best; 727 #endif /* BestFit */ 728 729 while (b != &poolset->freelist) { 730 pos = buf_get_pos(b, align, hdr_size, size); 731 if (pos >= 0) { 732 struct bhead *b_alloc = BH((char *)b + pos); 733 struct bhead *b_next = BH((char *)b + b->bh.bsize); 734 bufsize rem_sz = b->bh.bsize; 735 bufsize add_sz = pos; 736 737 assert(b_next->prevfree == b->bh.bsize); 738 739 /* 740 * Zero the back pointer in the next buffer in memory 741 * to indicate that this buffer is allocated. 742 */ 743 b_next->prevfree = 0; 744 745 assert(b->ql.blink->ql.flink == b); 746 assert(b->ql.flink->ql.blink == b); 747 748 if (pos == 0) { 749 /* 750 * Need to allocate from the beginning of this free block. 751 * Unlink the block and mark it as allocated. 752 */ 753 b->ql.blink->ql.flink = b->ql.flink; 754 b->ql.flink->ql.blink = b->ql.blink; 755 756 /* Negate size to mark buffer allocated. */ 757 b->bh.bsize = -b->bh.bsize; 758 } else { 759 /* 760 * Carve out the memory allocation from the end of this 761 * free block. Negative size to mark buffer allocated. 762 */ 763 b_alloc->bsize = -(b->bh.bsize - pos); 764 b_alloc->prevfree = pos; 765 b->bh.bsize = pos; 766 } 767 update_free2_sum(poolset, rem_sz, 0, add_sz); 768 769 assert(b_alloc->bsize < 0); 770 /* 771 * At this point is b_alloc pointing to the allocated 772 * buffer and b_next at the buffer following. b might be a 773 * free block or a used block now. 774 */ 775 if (-b_alloc->bsize - size > SizeQ + sizeof(struct bhead)) { 776 /* 777 * b_alloc has too much unused memory at the 778 * end we need to split the block and register that 779 * last part as free. 780 */ 781 b = BFH((char *)b_alloc + size); 782 b->bh.bsize = -b_alloc->bsize - size; 783 b->bh.prevfree = 0; 784 b_alloc->bsize += b->bh.bsize; 785 786 assert(poolset->freelist.ql.blink->ql.flink == 787 &poolset->freelist); 788 assert(poolset->freelist.ql.flink->ql.blink == 789 &poolset->freelist); 790 b->ql.flink = &poolset->freelist; 791 b->ql.blink = poolset->freelist.ql.blink; 792 poolset->freelist.ql.blink = b; 793 b->ql.blink->ql.flink = b; 794 795 assert(BH((char *)b + b->bh.bsize) == b_next); 796 b_next->prevfree = b->bh.bsize; 797 update_free2_sum(poolset, 0, 0, b->bh.bsize); 798 } 799 800 #ifdef BufStats 801 poolset->totalloc -= b_alloc->bsize; 802 poolset->numget++; /* Increment number of bget() calls */ 803 #endif 804 buf = (char *)b_alloc + sizeof(struct bhead); 805 return buf; 806 } 807 b = b->ql.flink; /* Link to next buffer */ 808 } 809 #ifdef BECtl 810 811 /* We failed to find a buffer. If there's a compact function 812 defined, notify it of the size requested. If it returns 813 TRUE, try the allocation again. */ 814 815 if ((poolset->compfcn == NULL) || 816 (!(poolset->compfcn)(size, ++compactseq))) { 817 break; 818 } 819 } 820 821 /* No buffer available with requested size free. */ 822 823 /* Don't give up yet -- look in the reserve supply. */ 824 825 if (poolset->acqfcn != NULL) { 826 if (size > exp_incr - sizeof(struct bfhead) - align) { 827 828 /* Request is too large to fit in a single expansion 829 block. Try to satisy it by a direct buffer acquisition. */ 830 char *p; 831 832 size += sizeof(struct bdhead) - sizeof(struct bhead); 833 if (align > QLSize) 834 size += align; 835 p = poolset->acqfcn(size); 836 if (p != NULL) { 837 struct bdhead *bdh; 838 839 if (align <= QLSize) { 840 bdh = BDH(p); 841 buf = bdh + 1; 842 } else { 843 unsigned long tp = (unsigned long)p; 844 845 tp += sizeof(*bdh) + hdr_size + align; 846 tp &= ~(align - 1); 847 tp -= hdr_size; 848 buf = (void *)tp; 849 bdh = BDH((char *)buf - sizeof(*bdh)); 850 } 851 852 /* Mark the buffer special by setting the size field 853 of its header to zero. */ 854 bdh->bh.bsize = 0; 855 bdh->bh.prevfree = 0; 856 bdh->tsize = size; 857 bdh->offs = (unsigned long)bdh - (unsigned long)p; 858 #ifdef BufStats 859 poolset->totalloc += size; 860 poolset->numget++; /* Increment number of bget() calls */ 861 poolset->numdget++; /* Direct bget() call count */ 862 #endif 863 return buf; 864 } 865 866 } else { 867 868 /* Try to obtain a new expansion block */ 869 870 void *newpool; 871 872 if ((newpool = poolset->acqfcn((bufsize) exp_incr)) != NULL) { 873 bpool(newpool, exp_incr, poolset); 874 buf = bget(align, hdr_size, requested_size, pool); /* This can't, I say, can't 875 get into a loop. */ 876 return buf; 877 } 878 } 879 } 880 881 /* Still no buffer available */ 882 883 #endif /* BECtl */ 884 885 return NULL; 886 } 887 888 /* BGETZ -- Allocate a buffer and clear its contents to zero. We clear 889 the entire contents of the buffer to zero, not just the 890 region requested by the caller. */ 891 892 void *bgetz(align, hdr_size, size, poolset) 893 bufsize align; 894 bufsize hdr_size; 895 bufsize size; 896 struct bpoolset *poolset; 897 { 898 char *buf = (char *) bget(align, hdr_size, size, poolset); 899 900 if (buf != NULL) { 901 struct bhead *b; 902 bufsize rsize; 903 904 b = BH(buf - sizeof(struct bhead)); 905 rsize = -(b->bsize); 906 if (rsize == 0) { 907 struct bdhead *bd; 908 909 bd = BDH(buf - sizeof(struct bdhead)); 910 rsize = bd->tsize - sizeof(struct bdhead) - bd->offs; 911 } else { 912 rsize -= sizeof(struct bhead); 913 } 914 assert(rsize >= size); 915 V memset_unchecked(buf, 0, (MemSize) rsize); 916 } 917 return ((void *) buf); 918 } 919 920 /* BGETR -- Reallocate a buffer. This is a minimal implementation, 921 simply in terms of brel() and bget(). It could be 922 enhanced to allow the buffer to grow into adjacent free 923 blocks and to avoid moving data unnecessarily. */ 924 925 void *bgetr(buf, align, hdr_size, size, poolset) 926 void *buf; 927 bufsize align; 928 bufsize hdr_size; 929 bufsize size; 930 struct bpoolset *poolset; 931 { 932 void *nbuf; 933 bufsize osize; /* Old size of buffer */ 934 struct bhead *b; 935 936 if ((nbuf = bget(align, hdr_size, size, poolset)) == NULL) { /* Acquire new buffer */ 937 return NULL; 938 } 939 if (buf == NULL) { 940 return nbuf; 941 } 942 b = BH(((char *) buf) - sizeof(struct bhead)); 943 osize = -b->bsize; 944 #ifdef BECtl 945 if (osize == 0) { 946 /* Buffer acquired directly through acqfcn. */ 947 struct bdhead *bd; 948 949 bd = BDH(((char *) buf) - sizeof(struct bdhead)); 950 osize = bd->tsize - sizeof(struct bdhead) - bd->offs; 951 } else 952 #endif 953 osize -= sizeof(struct bhead); 954 assert(osize > 0); 955 V memcpy_unchecked((char *) nbuf, (char *) buf, /* Copy the data */ 956 (MemSize) ((size < osize) ? size : osize)); 957 #ifndef __KERNEL__ 958 /* User space reallocations are always zeroed */ 959 if (size > osize) 960 V memset_unchecked((char *) nbuf + osize, 0, size - osize); 961 #endif 962 brel(buf, poolset, false /* !wipe */); 963 return nbuf; 964 } 965 966 /* BREL -- Release a buffer. */ 967 968 void brel(buf, poolset, wipe) 969 void *buf; 970 struct bpoolset *poolset; 971 int wipe; 972 { 973 struct bfhead *b, *bn; 974 char *wipe_start; 975 bufsize wipe_size; 976 bufsize add_sz; 977 bufsize rem_sz; 978 bufsize rem_sz2; 979 980 b = BFH(((char *) buf) - sizeof(struct bhead)); 981 #ifdef BufStats 982 poolset->numrel++; /* Increment number of brel() calls */ 983 #endif 984 assert(buf != NULL); 985 986 #ifdef FreeWipe 987 wipe = true; 988 #endif 989 #ifdef BECtl 990 if (b->bh.bsize == 0) { /* Directly-acquired buffer? */ 991 struct bdhead *bdh; 992 993 bdh = BDH(((char *) buf) - sizeof(struct bdhead)); 994 assert(b->bh.prevfree == 0); 995 #ifdef BufStats 996 poolset->totalloc -= bdh->tsize; 997 assert(poolset->totalloc >= 0); 998 poolset->numdrel++; /* Number of direct releases */ 999 #endif /* BufStats */ 1000 if (wipe) { 1001 V memset_unchecked((char *) buf, 0x55, 1002 (MemSize) (bdh->tsize - 1003 sizeof(struct bdhead))); 1004 } 1005 assert(poolset->relfcn != NULL); 1006 poolset->relfcn((char *)buf - sizeof(struct bdhead) - bdh->offs); /* Release it directly. */ 1007 return; 1008 } 1009 #endif /* BECtl */ 1010 1011 /* Buffer size must be negative, indicating that the buffer is 1012 allocated. */ 1013 1014 if (b->bh.bsize >= 0) { 1015 bn = NULL; 1016 } 1017 assert(b->bh.bsize < 0); 1018 1019 /* Back pointer in next buffer must be zero, indicating the 1020 same thing: */ 1021 1022 assert(BH((char *) b - b->bh.bsize)->prevfree == 0); 1023 1024 #ifdef BufStats 1025 poolset->totalloc += b->bh.bsize; 1026 assert(poolset->totalloc >= 0); 1027 #endif 1028 1029 /* If the back link is nonzero, the previous buffer is free. */ 1030 1031 if (b->bh.prevfree != 0) { 1032 1033 /* The previous buffer is free. Consolidate this buffer with it 1034 by adding the length of this buffer to the previous free 1035 buffer. Note that we subtract the size in the buffer being 1036 released, since it's negative to indicate that the buffer is 1037 allocated. */ 1038 1039 register bufsize size = b->bh.bsize; 1040 1041 /* Only wipe the current buffer, including bfhead. */ 1042 wipe_start = (char *)b; 1043 wipe_size = -size; 1044 1045 /* Make the previous buffer the one we're working on. */ 1046 assert(BH((char *) b - b->bh.prevfree)->bsize == b->bh.prevfree); 1047 b = BFH(((char *) b) - b->bh.prevfree); 1048 rem_sz = b->bh.bsize; 1049 b->bh.bsize -= size; 1050 add_sz = b->bh.bsize; 1051 update_free2_sum(poolset, rem_sz, 0, add_sz); 1052 } else { 1053 1054 /* The previous buffer isn't allocated. Insert this buffer 1055 on the free list as an isolated free block. */ 1056 1057 assert(poolset->freelist.ql.blink->ql.flink == &poolset->freelist); 1058 assert(poolset->freelist.ql.flink->ql.blink == &poolset->freelist); 1059 b->ql.flink = &poolset->freelist; 1060 b->ql.blink = poolset->freelist.ql.blink; 1061 poolset->freelist.ql.blink = b; 1062 b->ql.blink->ql.flink = b; 1063 b->bh.bsize = -b->bh.bsize; 1064 update_free2_sum(poolset, 0, 0, b->bh.bsize); 1065 1066 wipe_start = (char *)b + sizeof(struct bfhead); 1067 wipe_size = b->bh.bsize - sizeof(struct bfhead); 1068 } 1069 1070 /* Now we look at the next buffer in memory, located by advancing from 1071 the start of this buffer by its size, to see if that buffer is 1072 free. If it is, we combine this buffer with the next one in 1073 memory, dechaining the second buffer from the free list. */ 1074 1075 bn = BFH(((char *) b) + b->bh.bsize); 1076 if (bn->bh.bsize > 0) { 1077 1078 /* The buffer is free. Remove it from the free list and add 1079 its size to that of our buffer. */ 1080 1081 assert(BH((char *) bn + bn->bh.bsize)->prevfree == bn->bh.bsize); 1082 assert(bn->ql.blink->ql.flink == bn); 1083 assert(bn->ql.flink->ql.blink == bn); 1084 bn->ql.blink->ql.flink = bn->ql.flink; 1085 bn->ql.flink->ql.blink = bn->ql.blink; 1086 rem_sz = b->bh.bsize; 1087 rem_sz2 = bn->bh.bsize; 1088 b->bh.bsize += bn->bh.bsize; 1089 add_sz = b->bh.bsize; 1090 update_free2_sum(poolset, rem_sz, rem_sz2, add_sz); 1091 1092 /* Finally, advance to the buffer that follows the newly 1093 consolidated free block. We must set its backpointer to the 1094 head of the consolidated free block. We know the next block 1095 must be an allocated block because the process of recombination 1096 guarantees that two free blocks will never be contiguous in 1097 memory. */ 1098 1099 bn = BFH(((char *) b) + b->bh.bsize); 1100 /* Only bfhead of next buffer needs to be wiped */ 1101 wipe_size += sizeof(struct bfhead); 1102 } 1103 if (wipe) { 1104 V memset_unchecked(wipe_start, 0x55, wipe_size); 1105 } 1106 assert(bn->bh.bsize < 0); 1107 1108 /* The next buffer is allocated. Set the backpointer in it to point 1109 to this buffer; the previous free buffer in memory. */ 1110 1111 bn->bh.prevfree = b->bh.bsize; 1112 1113 #ifdef BECtl 1114 1115 /* If a block-release function is defined, and this free buffer 1116 constitutes the entire block, release it. Note that pool_len 1117 is defined in such a way that the test will fail unless all 1118 pool blocks are the same size. */ 1119 1120 if (poolset->relfcn != NULL && 1121 ((bufsize) b->bh.bsize) == (pool_len - sizeof(struct bhead))) { 1122 1123 assert(b->bh.prevfree == 0); 1124 assert(BH((char *) b + b->bh.bsize)->bsize == ESent); 1125 assert(BH((char *) b + b->bh.bsize)->prevfree == b->bh.bsize); 1126 /* Unlink the buffer from the free list */ 1127 b->ql.blink->ql.flink = b->ql.flink; 1128 b->ql.flink->ql.blink = b->ql.blink; 1129 1130 poolset->relfcn(b); 1131 #ifdef BufStats 1132 poolset->numprel++; /* Nr of expansion block releases */ 1133 poolset->numpblk--; /* Total number of blocks */ 1134 assert(numpblk == numpget - numprel); 1135 #endif /* BufStats */ 1136 } 1137 #endif /* BECtl */ 1138 } 1139 1140 #ifdef BECtl 1141 1142 /* BECTL -- Establish automatic pool expansion control */ 1143 1144 void bectl(compact, acquire, release, pool_incr, poolset) 1145 int (*compact) _((bufsize sizereq, int sequence)); 1146 void *(*acquire) _((bufsize size)); 1147 void (*release) _((void *buf)); 1148 bufsize pool_incr; 1149 struct bpoolset *poolset; 1150 { 1151 poolset->compfcn = compact; 1152 poolset->acqfcn = acquire; 1153 poolset->relfcn = release; 1154 poolset->exp_incr = pool_incr; 1155 } 1156 #endif 1157 1158 /* BPOOL -- Add a region of memory to the buffer pool. */ 1159 1160 void bpool(buf, len, poolset) 1161 void *buf; 1162 bufsize len; 1163 struct bpoolset *poolset; 1164 { 1165 struct bfhead *b = BFH(buf); 1166 struct bhead *bn; 1167 1168 #ifdef SizeQuant 1169 len &= ~(SizeQuant - 1); 1170 #endif 1171 #ifdef BECtl 1172 if (poolset->pool_len == 0) { 1173 pool_len = len; 1174 } else if (len != poolset->pool_len) { 1175 poolset->pool_len = -1; 1176 } 1177 #ifdef BufStats 1178 poolset->numpget++; /* Number of block acquisitions */ 1179 poolset->numpblk++; /* Number of blocks total */ 1180 assert(poolset->numpblk == poolset->numpget - poolset->numprel); 1181 #endif /* BufStats */ 1182 #endif /* BECtl */ 1183 1184 /* Since the block is initially occupied by a single free buffer, 1185 it had better not be (much) larger than the largest buffer 1186 whose size we can store in bhead.bsize. */ 1187 1188 assert(len - sizeof(struct bhead) <= -((bufsize) ESent + 1)); 1189 1190 /* Clear the backpointer at the start of the block to indicate that 1191 there is no free block prior to this one. That blocks 1192 recombination when the first block in memory is released. */ 1193 1194 b->bh.prevfree = 0; 1195 1196 /* Chain the new block to the free list. */ 1197 1198 assert(poolset->freelist.ql.blink->ql.flink == &poolset->freelist); 1199 assert(poolset->freelist.ql.flink->ql.blink == &poolset->freelist); 1200 b->ql.flink = &poolset->freelist; 1201 b->ql.blink = poolset->freelist.ql.blink; 1202 poolset->freelist.ql.blink = b; 1203 b->ql.blink->ql.flink = b; 1204 1205 /* Create a dummy allocated buffer at the end of the pool. This dummy 1206 buffer is seen when a buffer at the end of the pool is released and 1207 blocks recombination of the last buffer with the dummy buffer at 1208 the end. The length in the dummy buffer is set to the largest 1209 negative number to denote the end of the pool for diagnostic 1210 routines (this specific value is not counted on by the actual 1211 allocation and release functions). */ 1212 1213 len -= sizeof(struct bhead); 1214 b->bh.bsize = (bufsize) len; 1215 update_free2_sum(poolset, 0, 0, b->bh.bsize); 1216 #ifdef FreeWipe 1217 V memset_unchecked(((char *) b) + sizeof(struct bfhead), 0x55, 1218 (MemSize) (len - sizeof(struct bfhead))); 1219 #endif 1220 bn = BH(((char *) b) + len); 1221 bn->prevfree = (bufsize) len; 1222 /* Definition of ESent assumes two's complement! */ 1223 assert((~0) == -1); 1224 bn->bsize = ESent; 1225 } 1226 1227 #ifdef BufStats 1228 1229 /* BSTATS -- Return buffer allocation free space statistics. */ 1230 1231 void bstats(curalloc, totfree, maxfree, nget, nrel, poolset) 1232 bufsize *curalloc, *totfree, *maxfree; 1233 long *nget, *nrel; 1234 struct bpoolset *poolset; 1235 { 1236 struct bfhead *b = poolset->freelist.ql.flink; 1237 1238 *nget = poolset->numget; 1239 *nrel = poolset->numrel; 1240 *curalloc = poolset->totalloc; 1241 *totfree = 0; 1242 *maxfree = -1; 1243 while (b != &poolset->freelist) { 1244 assert(b->bh.bsize > 0); 1245 *totfree += b->bh.bsize; 1246 if (b->bh.bsize > *maxfree) { 1247 *maxfree = b->bh.bsize; 1248 } 1249 b = b->ql.flink; /* Link to next buffer */ 1250 } 1251 } 1252 1253 #ifdef BECtl 1254 1255 /* BSTATSE -- Return extended statistics */ 1256 1257 void bstatse(pool_incr, npool, npget, nprel, ndget, ndrel, poolset) 1258 bufsize *pool_incr; 1259 long *npool, *npget, *nprel, *ndget, *ndrel; 1260 struct bpoolset *poolset; 1261 { 1262 *pool_incr = (poolset->pool_len < 0) ? 1263 -poolset->exp_incr : poolset->exp_incr; 1264 *npool = poolset->numpblk; 1265 *npget = poolset->numpget; 1266 *nprel = poolset->numprel; 1267 *ndget = poolset->numdget; 1268 *ndrel = poolset->numdrel; 1269 } 1270 #endif /* BECtl */ 1271 #endif /* BufStats */ 1272 1273 #ifdef DumpData 1274 1275 /* BUFDUMP -- Dump the data in a buffer. This is called with the user 1276 data pointer, and backs up to the buffer header. It will 1277 dump either a free block or an allocated one. */ 1278 1279 void bufdump(buf) 1280 void *buf; 1281 { 1282 struct bfhead *b; 1283 unsigned char *bdump; 1284 bufsize bdlen; 1285 1286 b = BFH(((char *) buf) - sizeof(struct bhead)); 1287 assert(b->bh.bsize != 0); 1288 if (b->bh.bsize < 0) { 1289 bdump = (unsigned char *) buf; 1290 bdlen = (-b->bh.bsize) - sizeof(struct bhead); 1291 } else { 1292 bdump = (unsigned char *) (((char *) b) + sizeof(struct bfhead)); 1293 bdlen = b->bh.bsize - sizeof(struct bfhead); 1294 } 1295 1296 while (bdlen > 0) { 1297 int i, dupes = 0; 1298 bufsize l = bdlen; 1299 char bhex[50], bascii[20]; 1300 1301 if (l > 16) { 1302 l = 16; 1303 } 1304 1305 for (i = 0; i < l; i++) { 1306 V snprintf(bhex + i * 3, sizeof(bhex) - i * 3, "%02X ", 1307 bdump[i]); 1308 bascii[i] = isprint(bdump[i]) ? bdump[i] : ' '; 1309 } 1310 bascii[i] = 0; 1311 V printf("%-48s %s\n", bhex, bascii); 1312 bdump += l; 1313 bdlen -= l; 1314 while ((bdlen > 16) && (memcmp((char *) (bdump - 16), 1315 (char *) bdump, 16) == 0)) { 1316 dupes++; 1317 bdump += 16; 1318 bdlen -= 16; 1319 } 1320 if (dupes > 1) { 1321 V printf( 1322 " (%d lines [%d bytes] identical to above line skipped)\n", 1323 dupes, dupes * 16); 1324 } else if (dupes == 1) { 1325 bdump -= 16; 1326 bdlen += 16; 1327 } 1328 } 1329 } 1330 #endif 1331 1332 #ifdef BufDump 1333 1334 /* BPOOLD -- Dump a buffer pool. The buffer headers are always listed. 1335 If DUMPALLOC is nonzero, the contents of allocated buffers 1336 are dumped. If DUMPFREE is nonzero, free blocks are 1337 dumped as well. If FreeWipe checking is enabled, free 1338 blocks which have been clobbered will always be dumped. */ 1339 1340 void bpoold(buf, dumpalloc, dumpfree) 1341 void *buf; 1342 int dumpalloc, dumpfree; 1343 { 1344 struct bfhead *b = BFH(buf); 1345 1346 while (b->bh.bsize != ESent) { 1347 bufsize bs = b->bh.bsize; 1348 1349 if (bs < 0) { 1350 bs = -bs; 1351 V printf("Allocated buffer: size %6ld bytes.\n", (long) bs); 1352 if (dumpalloc) { 1353 bufdump((void *) (((char *) b) + sizeof(struct bhead))); 1354 } 1355 } else { 1356 char *lerr = ""; 1357 1358 assert(bs > 0); 1359 if ((b->ql.blink->ql.flink != b) || 1360 (b->ql.flink->ql.blink != b)) { 1361 lerr = " (Bad free list links)"; 1362 } 1363 V printf("Free block: size %6ld bytes.%s\n", 1364 (long) bs, lerr); 1365 #ifdef FreeWipe 1366 lerr = ((char *) b) + sizeof(struct bfhead); 1367 if ((bs > sizeof(struct bfhead)) && ((*lerr != 0x55) || 1368 (memcmp(lerr, lerr + 1, 1369 (MemSize) (bs - (sizeof(struct bfhead) + 1))) != 0))) { 1370 V printf( 1371 "(Contents of above free block have been overstored.)\n"); 1372 bufdump((void *) (((char *) b) + sizeof(struct bhead))); 1373 } else 1374 #endif 1375 if (dumpfree) { 1376 bufdump((void *) (((char *) b) + sizeof(struct bhead))); 1377 } 1378 } 1379 b = BFH(((char *) b) + bs); 1380 } 1381 } 1382 #endif /* BufDump */ 1383 1384 #ifdef BufValid 1385 1386 /* BPOOLV -- Validate a buffer pool. If NDEBUG isn't defined, 1387 any error generates an assertion failure. */ 1388 1389 int bpoolv(buf) 1390 void *buf; 1391 { 1392 struct bfhead *b = BFH(buf); 1393 1394 while (b->bh.bsize != ESent) { 1395 bufsize bs = b->bh.bsize; 1396 1397 if (bs < 0) { 1398 bs = -bs; 1399 } else { 1400 const char *lerr = ""; 1401 1402 assert(bs > 0); 1403 if (bs <= 0) { 1404 return 0; 1405 } 1406 if ((b->ql.blink->ql.flink != b) || 1407 (b->ql.flink->ql.blink != b)) { 1408 V printf("Free block: size %6ld bytes. (Bad free list links)\n", 1409 (long) bs); 1410 assert(0); 1411 return 0; 1412 } 1413 #ifdef FreeWipe 1414 lerr = ((char *) b) + sizeof(struct bfhead); 1415 if ((bs > sizeof(struct bfhead)) && ((*lerr != 0x55) || 1416 (memcmp(lerr, lerr + 1, 1417 (MemSize) (bs - (sizeof(struct bfhead) + 1))) != 0))) { 1418 V printf( 1419 "(Contents of above free block have been overstored.)\n"); 1420 bufdump((void *) (((char *) b) + sizeof(struct bhead))); 1421 assert(0); 1422 return 0; 1423 } 1424 #endif 1425 } 1426 b = BFH(((char *) b) + bs); 1427 } 1428 return 1; 1429 } 1430 #endif /* BufValid */ 1431 1432 /***********************\ 1433 * * 1434 * Built-in test program * 1435 * * 1436 \***********************/ 1437 1438 #if !defined(__KERNEL__) && !defined(__LDELF__) && defined(CFG_TA_BGET_TEST) 1439 1440 #define TestProg 20000 1441 1442 #ifdef BECtl 1443 #define PoolSize 300000 /* Test buffer pool size */ 1444 #else 1445 #define PoolSize 50000 /* Test buffer pool size */ 1446 #endif 1447 #define ExpIncr 32768 /* Test expansion block size */ 1448 #define CompactTries 10 /* Maximum tries at compacting */ 1449 1450 #define dumpAlloc 0 /* Dump allocated buffers ? */ 1451 #define dumpFree 0 /* Dump free buffers ? */ 1452 1453 static char *bchain = NULL; /* Our private buffer chain */ 1454 static char *bp = NULL; /* Our initial buffer pool */ 1455 1456 #ifdef UsingFloat 1457 #include <math.h> 1458 #endif 1459 1460 static unsigned long int next = 1; 1461 1462 static void *(*mymalloc)(size_t size); 1463 static void (*myfree)(void *ptr); 1464 1465 static struct bpoolset mypoolset = { 1466 .freelist = { 1467 .bh = { 0, 0}, 1468 .ql = { &mypoolset.freelist, &mypoolset.freelist}, 1469 } 1470 }; 1471 1472 /* Return next random integer */ 1473 1474 static int myrand(void) 1475 { 1476 next = next * 1103515245L + 12345; 1477 return (unsigned int) (next / 65536L) % 32768L; 1478 } 1479 1480 /* Set seed for random generator */ 1481 1482 static void mysrand(unsigned int seed) 1483 { 1484 next = seed; 1485 } 1486 1487 /* STATS -- Edit statistics returned by bstats() or bstatse(). */ 1488 1489 static void stats(const char *when __maybe_unused, 1490 struct bpoolset *poolset __maybe_unused) 1491 { 1492 #ifdef BufStats 1493 bufsize cural, totfree, maxfree; 1494 long nget, nfree; 1495 #endif 1496 #ifdef BECtl 1497 bufsize pincr; 1498 long totblocks, npget, nprel, ndget, ndrel; 1499 #endif 1500 1501 #ifdef BufStats 1502 bstats(&cural, &totfree, &maxfree, &nget, &nfree, poolset); 1503 V printf( 1504 "%s: %ld gets, %ld releases. %ld in use, %ld free, largest = %ld\n", 1505 when, nget, nfree, (long) cural, (long) totfree, (long) maxfree); 1506 #endif 1507 #ifdef BECtl 1508 bstatse(&pincr, &totblocks, &npget, &nprel, &ndget, &ndrel, poolset); 1509 V printf( 1510 " Blocks: size = %ld, %ld (%ld bytes) in use, %ld gets, %ld frees\n", 1511 (long)pincr, totblocks, pincr * totblocks, npget, nprel); 1512 V printf(" %ld direct gets, %ld direct frees\n", ndget, ndrel); 1513 #endif /* BECtl */ 1514 } 1515 1516 #ifdef BECtl 1517 static int protect = 0; /* Disable compaction during bgetr() */ 1518 1519 /* BCOMPACT -- Compaction call-back function. */ 1520 1521 static int bcompact(bsize, seq) 1522 bufsize bsize; 1523 int seq; 1524 { 1525 #ifdef CompactTries 1526 char *bc = bchain; 1527 int i = myrand() & 0x3; 1528 1529 #ifdef COMPACTRACE 1530 V printf("Compaction requested. %ld bytes needed, sequence %d.\n", 1531 (long) bsize, seq); 1532 #endif 1533 1534 if (protect || (seq > CompactTries)) { 1535 #ifdef COMPACTRACE 1536 V printf("Compaction gave up.\n"); 1537 #endif 1538 return 0; 1539 } 1540 1541 /* Based on a random cast, release a random buffer in the list 1542 of allocated buffers. */ 1543 1544 while (i > 0 && bc != NULL) { 1545 bc = *((char **) bc); 1546 i--; 1547 } 1548 if (bc != NULL) { 1549 char *fb; 1550 1551 fb = *((char **) bc); 1552 if (fb != NULL) { 1553 *((char **) bc) = *((char **) fb); 1554 brel((void *) fb); 1555 return 1; 1556 } 1557 } 1558 1559 #ifdef COMPACTRACE 1560 V printf("Compaction bailed out.\n"); 1561 #endif 1562 #endif /* CompactTries */ 1563 return 0; 1564 } 1565 1566 /* BEXPAND -- Expand pool call-back function. */ 1567 1568 static void *bexpand(size) 1569 bufsize size; 1570 { 1571 void *np = NULL; 1572 bufsize cural, totfree, maxfree; 1573 long nget, nfree; 1574 1575 /* Don't expand beyond the total allocated size given by PoolSize. */ 1576 1577 bstats(&cural, &totfree, &maxfree, &nget, &nfree); 1578 1579 if (cural < PoolSize) { 1580 np = (void *) mymalloc((unsigned) size); 1581 } 1582 #ifdef EXPTRACE 1583 V printf("Expand pool by %ld -- %s.\n", (long) size, 1584 np == NULL ? "failed" : "succeeded"); 1585 #endif 1586 return np; 1587 } 1588 1589 /* BSHRINK -- Shrink buffer pool call-back function. */ 1590 1591 static void bshrink(buf) 1592 void *buf; 1593 { 1594 if (((char *) buf) == bp) { 1595 #ifdef EXPTRACE 1596 V printf("Initial pool released.\n"); 1597 #endif 1598 bp = NULL; 1599 } 1600 #ifdef EXPTRACE 1601 V printf("Shrink pool.\n"); 1602 #endif 1603 myfree((char *) buf); 1604 } 1605 1606 #endif /* BECtl */ 1607 1608 /* Restrict buffer requests to those large enough to contain our pointer and 1609 small enough for the CPU architecture. */ 1610 1611 static bufsize blimit(bufsize bs) 1612 { 1613 if (bs < sizeof(char *)) { 1614 bs = sizeof(char *); 1615 } 1616 1617 /* This is written out in this ugly fashion because the 1618 cool expression in sizeof(int) that auto-configured 1619 to any length int befuddled some compilers. */ 1620 1621 if (sizeof(int) == 2) { 1622 if (bs > 32767) { 1623 bs = 32767; 1624 } 1625 } else { 1626 if (bs > 200000) { 1627 bs = 200000; 1628 } 1629 } 1630 return bs; 1631 } 1632 1633 int bget_main_test(void *(*malloc_func)(size_t), void (*free_func)(void *)) 1634 { 1635 int i; 1636 #ifdef UsingFloat 1637 double x; 1638 #endif 1639 1640 mymalloc = malloc_func; 1641 myfree = free_func; 1642 1643 /* Seed the random number generator. If Repeatable is defined, we 1644 always use the same seed. Otherwise, we seed from the clock to 1645 shake things up from run to run. */ 1646 1647 mysrand(1234); 1648 1649 /* Compute x such that pow(x, p) ranges between 1 and 4*ExpIncr as 1650 p ranges from 0 to ExpIncr-1, with a concentration in the lower 1651 numbers. */ 1652 1653 #ifdef UsingFloat 1654 x = 4.0 * ExpIncr; 1655 x = log(x); 1656 x = exp(log(4.0 * ExpIncr) / (ExpIncr - 1.0)); 1657 #endif 1658 1659 #ifdef BECtl 1660 bectl(bcompact, bexpand, bshrink, (bufsize) ExpIncr, &mypoolset); 1661 bp = mymalloc(ExpIncr); 1662 assert(bp != NULL); 1663 bpool((void *) bp, (bufsize) ExpIncr); 1664 #else 1665 bp = mymalloc(PoolSize); 1666 assert(bp != NULL); 1667 bpool((void *) bp, (bufsize) PoolSize, &mypoolset); 1668 #endif 1669 1670 stats("Create pool", &mypoolset); 1671 #ifdef BufValid 1672 V bpoolv((void *) bp); 1673 #endif 1674 #ifdef BufDump 1675 bpoold((void *) bp, dumpAlloc, dumpFree); 1676 #endif 1677 1678 for (i = 0; i < TestProg; i++) { 1679 char *cb; 1680 #ifdef UsingFloat 1681 bufsize bs = pow(x, (double) (myrand() & (ExpIncr - 1))); 1682 #else 1683 bufsize bs = (myrand() & (ExpIncr * 4 - 1)) / (1 << (myrand() & 0x7)); 1684 #endif 1685 bufsize align = 0; 1686 bufsize hdr_size = 0; 1687 1688 switch (rand() & 0x3) { 1689 case 1: 1690 align = 32; 1691 break; 1692 case 2: 1693 align = 64; 1694 break; 1695 case 3: 1696 align = 128; 1697 break; 1698 default: 1699 break; 1700 } 1701 1702 hdr_size = (rand() & 0x3) * BGET_HDR_QUANTUM; 1703 1704 assert(bs <= (((bufsize) 4) * ExpIncr)); 1705 bs = blimit(bs); 1706 if (myrand() & 0x400) { 1707 cb = (char *) bgetz(align, hdr_size, bs, &mypoolset); 1708 } else { 1709 cb = (char *) bget(align, hdr_size, bs, &mypoolset); 1710 } 1711 if (cb == NULL) { 1712 #ifdef EasyOut 1713 break; 1714 #else 1715 char *bc = bchain; 1716 1717 if (bc != NULL) { 1718 char *fb; 1719 1720 fb = *((char **) bc); 1721 if (fb != NULL) { 1722 *((char **) bc) = *((char **) fb); 1723 brel((void *) fb, &mypoolset, true/*wipe*/); 1724 } 1725 } 1726 continue; 1727 #endif 1728 } 1729 assert(!align || !(((unsigned long)cb + hdr_size) & (align - 1))); 1730 *((char **) cb) = (char *) bchain; 1731 bchain = cb; 1732 1733 /* Based on a random cast, release a random buffer in the list 1734 of allocated buffers. */ 1735 1736 if ((myrand() & 0x10) == 0) { 1737 char *bc = bchain; 1738 int j = myrand() & 0x3; 1739 1740 while (j > 0 && bc != NULL) { 1741 bc = *((char **) bc); 1742 j--; 1743 } 1744 if (bc != NULL) { 1745 char *fb; 1746 1747 fb = *((char **) bc); 1748 if (fb != NULL) { 1749 *((char **) bc) = *((char **) fb); 1750 brel((void *) fb, &mypoolset, true/*wipe*/); 1751 } 1752 } 1753 } 1754 1755 /* Based on a random cast, reallocate a random buffer in the list 1756 to a random size */ 1757 1758 if ((myrand() & 0x20) == 0) { 1759 char *bc = bchain; 1760 int j = myrand() & 0x3; 1761 1762 while (j > 0 && bc != NULL) { 1763 bc = *((char **) bc); 1764 j--; 1765 } 1766 if (bc != NULL) { 1767 char *fb; 1768 1769 fb = *((char **) bc); 1770 if (fb != NULL) { 1771 char *newb; 1772 1773 #ifdef UsingFloat 1774 bs = pow(x, (double) (myrand() & (ExpIncr - 1))); 1775 #else 1776 bs = (rand() & (ExpIncr * 4 - 1)) / (1 << (rand() & 0x7)); 1777 #endif 1778 bs = blimit(bs); 1779 #ifdef BECtl 1780 protect = 1; /* Protect against compaction */ 1781 #endif 1782 newb = (char *) bgetr((void *) fb, align, hdr_size, bs, &mypoolset); 1783 #ifdef BECtl 1784 protect = 0; 1785 #endif 1786 if (newb != NULL) { 1787 assert(!align || !(((unsigned long)newb + hdr_size) & 1788 (align - 1))); 1789 *((char **) bc) = newb; 1790 } 1791 } 1792 } 1793 } 1794 } 1795 stats("\nAfter allocation", &mypoolset); 1796 if (bp != NULL) { 1797 #ifdef BufValid 1798 V bpoolv((void *) bp); 1799 #endif 1800 #ifdef BufDump 1801 bpoold((void *) bp, dumpAlloc, dumpFree); 1802 #endif 1803 } 1804 1805 while (bchain != NULL) { 1806 char *buf = bchain; 1807 1808 bchain = *((char **) buf); 1809 brel((void *) buf, &mypoolset, true/*wipe*/); 1810 } 1811 stats("\nAfter release", &mypoolset); 1812 #ifndef BECtl 1813 if (bp != NULL) { 1814 #ifdef BufValid 1815 V bpoolv((void *) bp); 1816 #endif 1817 #ifdef BufDump 1818 bpoold((void *) bp, dumpAlloc, dumpFree); 1819 #endif 1820 } 1821 #endif 1822 1823 return 0; 1824 } 1825 #endif 1826