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
buf_get_pos(struct bfhead * bf,bufsize align,bufsize hdr_size,bufsize size)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
bget(requested_align,hdr_size,requested_size,poolset)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
bgetz(align,hdr_size,size,poolset)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
bgetr(buf,align,hdr_size,size,poolset)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
brel(buf,poolset,wipe)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
bpool(buf,len,poolset)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
bstats(curalloc,totfree,maxfree,nget,nrel,poolset)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
bstatse(pool_incr,npool,npget,nprel,ndget,ndrel,poolset)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
bufdump(buf)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
bpoold(buf,dumpalloc,dumpfree)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
bpoolv(buf)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
myrand(void)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
mysrand(unsigned int seed)1418 static void mysrand(unsigned int seed)
1419 {
1420 next = seed;
1421 }
1422
1423 /* STATS -- Edit statistics returned by bstats() or bstatse(). */
1424
stats(const char * when __maybe_unused,struct bpoolset * poolset __maybe_unused)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
bcompact(bsize,seq)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
bexpand(size)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
bshrink(buf)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
blimit(bufsize bs)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
bget_main_test(void * (* malloc_func)(size_t),void (* free_func)(void *))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