subr_blist.c revision 69781
1 2/* 3 * BLIST.C - Bitmap allocator/deallocator, using a radix tree with hinting 4 * 5 * (c)Copyright 1998, Matthew Dillon. Terms for use and redistribution 6 * are covered by the BSD Copyright as found in /usr/src/COPYRIGHT. 7 * 8 * This module implements a general bitmap allocator/deallocator. The 9 * allocator eats around 2 bits per 'block'. The module does not 10 * try to interpret the meaning of a 'block' other then to return 11 * SWAPBLK_NONE on an allocation failure. 12 * 13 * A radix tree is used to maintain the bitmap. Two radix constants are 14 * involved: One for the bitmaps contained in the leaf nodes (typically 15 * 32), and one for the meta nodes (typically 16). Both meta and leaf 16 * nodes have a hint field. This field gives us a hint as to the largest 17 * free contiguous range of blocks under the node. It may contain a 18 * value that is too high, but will never contain a value that is too 19 * low. When the radix tree is searched, allocation failures in subtrees 20 * update the hint. 21 * 22 * The radix tree also implements two collapsed states for meta nodes: 23 * the ALL-ALLOCATED state and the ALL-FREE state. If a meta node is 24 * in either of these two states, all information contained underneath 25 * the node is considered stale. These states are used to optimize 26 * allocation and freeing operations. 27 * 28 * The hinting greatly increases code efficiency for allocations while 29 * the general radix structure optimizes both allocations and frees. The 30 * radix tree should be able to operate well no matter how much 31 * fragmentation there is and no matter how large a bitmap is used. 32 * 33 * Unlike the rlist code, the blist code wires all necessary memory at 34 * creation time. Neither allocations nor frees require interaction with 35 * the memory subsystem. In contrast, the rlist code may allocate memory 36 * on an rlist_free() call. The non-blocking features of the blist code 37 * are used to great advantage in the swap code (vm/nswap_pager.c). The 38 * rlist code uses a little less overall memory then the blist code (but 39 * due to swap interleaving not all that much less), but the blist code 40 * scales much, much better. 41 * 42 * LAYOUT: The radix tree is layed out recursively using a 43 * linear array. Each meta node is immediately followed (layed out 44 * sequentially in memory) by BLIST_META_RADIX lower level nodes. This 45 * is a recursive structure but one that can be easily scanned through 46 * a very simple 'skip' calculation. In order to support large radixes, 47 * portions of the tree may reside outside our memory allocation. We 48 * handle this with an early-termination optimization (when bighint is 49 * set to -1) on the scan. The memory allocation is only large enough 50 * to cover the number of blocks requested at creation time even if it 51 * must be encompassed in larger root-node radix. 52 * 53 * NOTE: the allocator cannot currently allocate more then 54 * BLIST_BMAP_RADIX blocks per call. It will panic with 'allocation too 55 * large' if you try. This is an area that could use improvement. The 56 * radix is large enough that this restriction does not effect the swap 57 * system, though. Currently only the allocation code is effected by 58 * this algorithmic unfeature. The freeing code can handle arbitrary 59 * ranges. 60 * 61 * This code can be compiled stand-alone for debugging. 62 * 63 * $FreeBSD: head/sys/kern/subr_blist.c 69781 2000-12-08 21:51:06Z dwmalone $ 64 */ 65 66#ifdef _KERNEL 67 68#include <sys/param.h> 69#include <sys/systm.h> 70#include <sys/lock.h> 71#include <sys/kernel.h> 72#include <sys/blist.h> 73#include <sys/malloc.h> 74#include <vm/vm.h> 75#include <vm/vm_object.h> 76#include <vm/vm_kern.h> 77#include <vm/vm_extern.h> 78#include <vm/vm_page.h> 79 80#else 81 82#ifndef BLIST_NO_DEBUG 83#define BLIST_DEBUG 84#endif 85 86#define SWAPBLK_NONE ((daddr_t)-1) 87 88#include <sys/types.h> 89#include <stdio.h> 90#include <string.h> 91#include <stdlib.h> 92#include <stdarg.h> 93 94#define malloc(a,b,c) malloc(a) 95#define free(a,b) free(a) 96 97typedef unsigned int u_daddr_t; 98 99#include <sys/blist.h> 100 101void panic(const char *ctl, ...); 102 103#endif 104 105/* 106 * static support functions 107 */ 108 109static daddr_t blst_leaf_alloc(blmeta_t *scan, daddr_t blk, int count); 110static daddr_t blst_meta_alloc(blmeta_t *scan, daddr_t blk, 111 daddr_t count, daddr_t radix, int skip); 112static void blst_leaf_free(blmeta_t *scan, daddr_t relblk, int count); 113static void blst_meta_free(blmeta_t *scan, daddr_t freeBlk, daddr_t count, 114 daddr_t radix, int skip, daddr_t blk); 115static void blst_copy(blmeta_t *scan, daddr_t blk, daddr_t radix, 116 daddr_t skip, blist_t dest, daddr_t count); 117static daddr_t blst_radix_init(blmeta_t *scan, daddr_t radix, 118 int skip, daddr_t count); 119#ifndef _KERNEL 120static void blst_radix_print(blmeta_t *scan, daddr_t blk, 121 daddr_t radix, int skip, int tab); 122#endif 123 124#ifdef _KERNEL 125static MALLOC_DEFINE(M_SWAP, "SWAP", "Swap space"); 126#endif 127 128/* 129 * blist_create() - create a blist capable of handling up to the specified 130 * number of blocks 131 * 132 * blocks must be greater then 0 133 * 134 * The smallest blist consists of a single leaf node capable of 135 * managing BLIST_BMAP_RADIX blocks. 136 */ 137 138blist_t 139blist_create(daddr_t blocks) 140{ 141 blist_t bl; 142 int radix; 143 int skip = 0; 144 145 /* 146 * Calculate radix and skip field used for scanning. 147 */ 148 radix = BLIST_BMAP_RADIX; 149 150 while (radix < blocks) { 151 radix <<= BLIST_META_RADIX_SHIFT; 152 skip = (skip + 1) << BLIST_META_RADIX_SHIFT; 153 } 154 155 bl = malloc(sizeof(struct blist), M_SWAP, M_WAITOK | M_ZERO); 156 157 bl->bl_blocks = blocks; 158 bl->bl_radix = radix; 159 bl->bl_skip = skip; 160 bl->bl_rootblks = 1 + 161 blst_radix_init(NULL, bl->bl_radix, bl->bl_skip, blocks); 162 bl->bl_root = malloc(sizeof(blmeta_t) * bl->bl_rootblks, M_SWAP, M_WAITOK); 163 164#if defined(BLIST_DEBUG) 165 printf( 166 "BLIST representing %d blocks (%d MB of swap)" 167 ", requiring %dK of ram\n", 168 bl->bl_blocks, 169 bl->bl_blocks * 4 / 1024, 170 (bl->bl_rootblks * sizeof(blmeta_t) + 1023) / 1024 171 ); 172 printf("BLIST raw radix tree contains %d records\n", bl->bl_rootblks); 173#endif 174 blst_radix_init(bl->bl_root, bl->bl_radix, bl->bl_skip, blocks); 175 176 return(bl); 177} 178 179void 180blist_destroy(blist_t bl) 181{ 182 free(bl->bl_root, M_SWAP); 183 free(bl, M_SWAP); 184} 185 186/* 187 * blist_alloc() - reserve space in the block bitmap. Return the base 188 * of a contiguous region or SWAPBLK_NONE if space could 189 * not be allocated. 190 */ 191 192daddr_t 193blist_alloc(blist_t bl, daddr_t count) 194{ 195 daddr_t blk = SWAPBLK_NONE; 196 197 if (bl) { 198 if (bl->bl_radix == BLIST_BMAP_RADIX) 199 blk = blst_leaf_alloc(bl->bl_root, 0, count); 200 else 201 blk = blst_meta_alloc(bl->bl_root, 0, count, bl->bl_radix, bl->bl_skip); 202 if (blk != SWAPBLK_NONE) 203 bl->bl_free -= count; 204 } 205 return(blk); 206} 207 208/* 209 * blist_free() - free up space in the block bitmap. Return the base 210 * of a contiguous region. Panic if an inconsistancy is 211 * found. 212 */ 213 214void 215blist_free(blist_t bl, daddr_t blkno, daddr_t count) 216{ 217 if (bl) { 218 if (bl->bl_radix == BLIST_BMAP_RADIX) 219 blst_leaf_free(bl->bl_root, blkno, count); 220 else 221 blst_meta_free(bl->bl_root, blkno, count, bl->bl_radix, bl->bl_skip, 0); 222 bl->bl_free += count; 223 } 224} 225 226/* 227 * blist_resize() - resize an existing radix tree to handle the 228 * specified number of blocks. This will reallocate 229 * the tree and transfer the previous bitmap to the new 230 * one. When extending the tree you can specify whether 231 * the new blocks are to left allocated or freed. 232 */ 233 234void 235blist_resize(blist_t *pbl, daddr_t count, int freenew) 236{ 237 blist_t newbl = blist_create(count); 238 blist_t save = *pbl; 239 240 *pbl = newbl; 241 if (count > save->bl_blocks) 242 count = save->bl_blocks; 243 blst_copy(save->bl_root, 0, save->bl_radix, save->bl_skip, newbl, count); 244 245 /* 246 * If resizing upwards, should we free the new space or not? 247 */ 248 if (freenew && count < newbl->bl_blocks) { 249 blist_free(newbl, count, newbl->bl_blocks - count); 250 } 251 blist_destroy(save); 252} 253 254#ifdef BLIST_DEBUG 255 256/* 257 * blist_print() - dump radix tree 258 */ 259 260void 261blist_print(blist_t bl) 262{ 263 printf("BLIST {\n"); 264 blst_radix_print(bl->bl_root, 0, bl->bl_radix, bl->bl_skip, 4); 265 printf("}\n"); 266} 267 268#endif 269 270/************************************************************************ 271 * ALLOCATION SUPPORT FUNCTIONS * 272 ************************************************************************ 273 * 274 * These support functions do all the actual work. They may seem 275 * rather longish, but that's because I've commented them up. The 276 * actual code is straight forward. 277 * 278 */ 279 280/* 281 * blist_leaf_alloc() - allocate at a leaf in the radix tree (a bitmap). 282 * 283 * This is the core of the allocator and is optimized for the 1 block 284 * and the BLIST_BMAP_RADIX block allocation cases. Other cases are 285 * somewhat slower. The 1 block allocation case is log2 and extremely 286 * quick. 287 */ 288 289static daddr_t 290blst_leaf_alloc( 291 blmeta_t *scan, 292 daddr_t blk, 293 int count 294) { 295 u_daddr_t orig = scan->u.bmu_bitmap; 296 297 if (orig == 0) { 298 /* 299 * Optimize bitmap all-allocated case. Also, count = 1 300 * case assumes at least 1 bit is free in the bitmap, so 301 * we have to take care of this case here. 302 */ 303 scan->bm_bighint = 0; 304 return(SWAPBLK_NONE); 305 } 306 if (count == 1) { 307 /* 308 * Optimized code to allocate one bit out of the bitmap 309 */ 310 u_daddr_t mask; 311 int j = BLIST_BMAP_RADIX/2; 312 int r = 0; 313 314 mask = (u_daddr_t)-1 >> (BLIST_BMAP_RADIX/2); 315 316 while (j) { 317 if ((orig & mask) == 0) { 318 r += j; 319 orig >>= j; 320 } 321 j >>= 1; 322 mask >>= j; 323 } 324 scan->u.bmu_bitmap &= ~(1 << r); 325 return(blk + r); 326 } 327 if (count <= BLIST_BMAP_RADIX) { 328 /* 329 * non-optimized code to allocate N bits out of the bitmap. 330 * The more bits, the faster the code runs. It will run 331 * the slowest allocating 2 bits, but since there aren't any 332 * memory ops in the core loop (or shouldn't be, anyway), 333 * you probably won't notice the difference. 334 */ 335 int j; 336 int n = BLIST_BMAP_RADIX - count; 337 u_daddr_t mask; 338 339 mask = (u_daddr_t)-1 >> n; 340 341 for (j = 0; j <= n; ++j) { 342 if ((orig & mask) == mask) { 343 scan->u.bmu_bitmap &= ~mask; 344 return(blk + j); 345 } 346 mask = (mask << 1); 347 } 348 } 349 /* 350 * We couldn't allocate count in this subtree, update bighint. 351 */ 352 scan->bm_bighint = count - 1; 353 return(SWAPBLK_NONE); 354} 355 356/* 357 * blist_meta_alloc() - allocate at a meta in the radix tree. 358 * 359 * Attempt to allocate at a meta node. If we can't, we update 360 * bighint and return a failure. Updating bighint optimize future 361 * calls that hit this node. We have to check for our collapse cases 362 * and we have a few optimizations strewn in as well. 363 */ 364 365static daddr_t 366blst_meta_alloc( 367 blmeta_t *scan, 368 daddr_t blk, 369 daddr_t count, 370 daddr_t radix, 371 int skip 372) { 373 int i; 374 int next_skip = (skip >> BLIST_META_RADIX_SHIFT); 375 376 if (scan->u.bmu_avail == 0) { 377 /* 378 * ALL-ALLOCATED special case 379 */ 380 scan->bm_bighint = count; 381 return(SWAPBLK_NONE); 382 } 383 384 if (scan->u.bmu_avail == radix) { 385 radix >>= BLIST_META_RADIX_SHIFT; 386 387 /* 388 * ALL-FREE special case, initialize uninitialize 389 * sublevel. 390 */ 391 for (i = 1; i <= skip; i += next_skip) { 392 if (scan[i].bm_bighint == (daddr_t)-1) 393 break; 394 if (next_skip == 1) { 395 scan[i].u.bmu_bitmap = (u_daddr_t)-1; 396 scan[i].bm_bighint = BLIST_BMAP_RADIX; 397 } else { 398 scan[i].bm_bighint = radix; 399 scan[i].u.bmu_avail = radix; 400 } 401 } 402 } else { 403 radix >>= BLIST_META_RADIX_SHIFT; 404 } 405 406 for (i = 1; i <= skip; i += next_skip) { 407 if (count <= scan[i].bm_bighint) { 408 /* 409 * count fits in object 410 */ 411 daddr_t r; 412 if (next_skip == 1) { 413 r = blst_leaf_alloc(&scan[i], blk, count); 414 } else { 415 r = blst_meta_alloc(&scan[i], blk, count, radix, next_skip - 1); 416 } 417 if (r != SWAPBLK_NONE) { 418 scan->u.bmu_avail -= count; 419 if (scan->bm_bighint > scan->u.bmu_avail) 420 scan->bm_bighint = scan->u.bmu_avail; 421 return(r); 422 } 423 } else if (scan[i].bm_bighint == (daddr_t)-1) { 424 /* 425 * Terminator 426 */ 427 break; 428 } else if (count > radix) { 429 /* 430 * count does not fit in object even if it were 431 * complete free. 432 */ 433 panic("blist_meta_alloc: allocation too large"); 434 } 435 blk += radix; 436 } 437 438 /* 439 * We couldn't allocate count in this subtree, update bighint. 440 */ 441 if (scan->bm_bighint >= count) 442 scan->bm_bighint = count - 1; 443 return(SWAPBLK_NONE); 444} 445 446/* 447 * BLST_LEAF_FREE() - free allocated block from leaf bitmap 448 * 449 */ 450 451static void 452blst_leaf_free( 453 blmeta_t *scan, 454 daddr_t blk, 455 int count 456) { 457 /* 458 * free some data in this bitmap 459 * 460 * e.g. 461 * 0000111111111110000 462 * \_________/\__/ 463 * v n 464 */ 465 int n = blk & (BLIST_BMAP_RADIX - 1); 466 u_daddr_t mask; 467 468 mask = ((u_daddr_t)-1 << n) & 469 ((u_daddr_t)-1 >> (BLIST_BMAP_RADIX - count - n)); 470 471 if (scan->u.bmu_bitmap & mask) 472 panic("blst_radix_free: freeing free block"); 473 scan->u.bmu_bitmap |= mask; 474 475 /* 476 * We could probably do a better job here. We are required to make 477 * bighint at least as large as the biggest contiguous block of 478 * data. If we just shoehorn it, a little extra overhead will 479 * be incured on the next allocation (but only that one typically). 480 */ 481 scan->bm_bighint = BLIST_BMAP_RADIX; 482} 483 484/* 485 * BLST_META_FREE() - free allocated blocks from radix tree meta info 486 * 487 * This support routine frees a range of blocks from the bitmap. 488 * The range must be entirely enclosed by this radix node. If a 489 * meta node, we break the range down recursively to free blocks 490 * in subnodes (which means that this code can free an arbitrary 491 * range whereas the allocation code cannot allocate an arbitrary 492 * range). 493 */ 494 495static void 496blst_meta_free( 497 blmeta_t *scan, 498 daddr_t freeBlk, 499 daddr_t count, 500 daddr_t radix, 501 int skip, 502 daddr_t blk 503) { 504 int i; 505 int next_skip = (skip >> BLIST_META_RADIX_SHIFT); 506 507#if 0 508 printf("FREE (%x,%d) FROM (%x,%d)\n", 509 freeBlk, count, 510 blk, radix 511 ); 512#endif 513 514 if (scan->u.bmu_avail == 0) { 515 /* 516 * ALL-ALLOCATED special case, with possible 517 * shortcut to ALL-FREE special case. 518 */ 519 scan->u.bmu_avail = count; 520 scan->bm_bighint = count; 521 522 if (count != radix) { 523 for (i = 1; i <= skip; i += next_skip) { 524 if (scan[i].bm_bighint == (daddr_t)-1) 525 break; 526 scan[i].bm_bighint = 0; 527 if (next_skip == 1) { 528 scan[i].u.bmu_bitmap = 0; 529 } else { 530 scan[i].u.bmu_avail = 0; 531 } 532 } 533 /* fall through */ 534 } 535 } else { 536 scan->u.bmu_avail += count; 537 /* scan->bm_bighint = radix; */ 538 } 539 540 /* 541 * ALL-FREE special case. 542 */ 543 544 if (scan->u.bmu_avail == radix) 545 return; 546 if (scan->u.bmu_avail > radix) 547 panic("blst_meta_free: freeing already free blocks (%d) %d/%d", count, scan->u.bmu_avail, radix); 548 549 /* 550 * Break the free down into its components 551 */ 552 553 radix >>= BLIST_META_RADIX_SHIFT; 554 555 i = (freeBlk - blk) / radix; 556 blk += i * radix; 557 i = i * next_skip + 1; 558 559 while (i <= skip && blk < freeBlk + count) { 560 daddr_t v; 561 562 v = blk + radix - freeBlk; 563 if (v > count) 564 v = count; 565 566 if (scan->bm_bighint == (daddr_t)-1) 567 panic("blst_meta_free: freeing unexpected range"); 568 569 if (next_skip == 1) { 570 blst_leaf_free(&scan[i], freeBlk, v); 571 } else { 572 blst_meta_free(&scan[i], freeBlk, v, radix, next_skip - 1, blk); 573 } 574 if (scan->bm_bighint < scan[i].bm_bighint) 575 scan->bm_bighint = scan[i].bm_bighint; 576 count -= v; 577 freeBlk += v; 578 blk += radix; 579 i += next_skip; 580 } 581} 582 583/* 584 * BLIST_RADIX_COPY() - copy one radix tree to another 585 * 586 * Locates free space in the source tree and frees it in the destination 587 * tree. The space may not already be free in the destination. 588 */ 589 590static void blst_copy( 591 blmeta_t *scan, 592 daddr_t blk, 593 daddr_t radix, 594 daddr_t skip, 595 blist_t dest, 596 daddr_t count 597) { 598 int next_skip; 599 int i; 600 601 /* 602 * Leaf node 603 */ 604 605 if (radix == BLIST_BMAP_RADIX) { 606 u_daddr_t v = scan->u.bmu_bitmap; 607 608 if (v == (u_daddr_t)-1) { 609 blist_free(dest, blk, count); 610 } else if (v != 0) { 611 int i; 612 613 for (i = 0; i < BLIST_BMAP_RADIX && i < count; ++i) { 614 if (v & (1 << i)) 615 blist_free(dest, blk + i, 1); 616 } 617 } 618 return; 619 } 620 621 /* 622 * Meta node 623 */ 624 625 if (scan->u.bmu_avail == 0) { 626 /* 627 * Source all allocated, leave dest allocated 628 */ 629 return; 630 } 631 if (scan->u.bmu_avail == radix) { 632 /* 633 * Source all free, free entire dest 634 */ 635 if (count < radix) 636 blist_free(dest, blk, count); 637 else 638 blist_free(dest, blk, radix); 639 return; 640 } 641 642 643 radix >>= BLIST_META_RADIX_SHIFT; 644 next_skip = (skip >> BLIST_META_RADIX_SHIFT); 645 646 for (i = 1; count && i <= skip; i += next_skip) { 647 if (scan[i].bm_bighint == (daddr_t)-1) 648 break; 649 650 if (count >= radix) { 651 blst_copy( 652 &scan[i], 653 blk, 654 radix, 655 next_skip - 1, 656 dest, 657 radix 658 ); 659 count -= radix; 660 } else { 661 if (count) { 662 blst_copy( 663 &scan[i], 664 blk, 665 radix, 666 next_skip - 1, 667 dest, 668 count 669 ); 670 } 671 count = 0; 672 } 673 blk += radix; 674 } 675} 676 677/* 678 * BLST_RADIX_INIT() - initialize radix tree 679 * 680 * Initialize our meta structures and bitmaps and calculate the exact 681 * amount of space required to manage 'count' blocks - this space may 682 * be considerably less then the calculated radix due to the large 683 * RADIX values we use. 684 */ 685 686static daddr_t 687blst_radix_init(blmeta_t *scan, daddr_t radix, int skip, daddr_t count) 688{ 689 int i; 690 int next_skip; 691 daddr_t memindex = 0; 692 693 /* 694 * Leaf node 695 */ 696 697 if (radix == BLIST_BMAP_RADIX) { 698 if (scan) { 699 scan->bm_bighint = 0; 700 scan->u.bmu_bitmap = 0; 701 } 702 return(memindex); 703 } 704 705 /* 706 * Meta node. If allocating the entire object we can special 707 * case it. However, we need to figure out how much memory 708 * is required to manage 'count' blocks, so we continue on anyway. 709 */ 710 711 if (scan) { 712 scan->bm_bighint = 0; 713 scan->u.bmu_avail = 0; 714 } 715 716 radix >>= BLIST_META_RADIX_SHIFT; 717 next_skip = (skip >> BLIST_META_RADIX_SHIFT); 718 719 for (i = 1; i <= skip; i += next_skip) { 720 if (count >= radix) { 721 /* 722 * Allocate the entire object 723 */ 724 memindex = i + blst_radix_init( 725 ((scan) ? &scan[i] : NULL), 726 radix, 727 next_skip - 1, 728 radix 729 ); 730 count -= radix; 731 } else if (count > 0) { 732 /* 733 * Allocate a partial object 734 */ 735 memindex = i + blst_radix_init( 736 ((scan) ? &scan[i] : NULL), 737 radix, 738 next_skip - 1, 739 count 740 ); 741 count = 0; 742 } else { 743 /* 744 * Add terminator and break out 745 */ 746 if (scan) 747 scan[i].bm_bighint = (daddr_t)-1; 748 break; 749 } 750 } 751 if (memindex < i) 752 memindex = i; 753 return(memindex); 754} 755 756#ifdef BLIST_DEBUG 757 758static void 759blst_radix_print(blmeta_t *scan, daddr_t blk, daddr_t radix, int skip, int tab) 760{ 761 int i; 762 int next_skip; 763 int lastState = 0; 764 765 if (radix == BLIST_BMAP_RADIX) { 766 printf( 767 "%*.*s(%04x,%d): bitmap %08x big=%d\n", 768 tab, tab, "", 769 blk, radix, 770 scan->u.bmu_bitmap, 771 scan->bm_bighint 772 ); 773 return; 774 } 775 776 if (scan->u.bmu_avail == 0) { 777 printf( 778 "%*.*s(%04x,%d) ALL ALLOCATED\n", 779 tab, tab, "", 780 blk, 781 radix 782 ); 783 return; 784 } 785 if (scan->u.bmu_avail == radix) { 786 printf( 787 "%*.*s(%04x,%d) ALL FREE\n", 788 tab, tab, "", 789 blk, 790 radix 791 ); 792 return; 793 } 794 795 printf( 796 "%*.*s(%04x,%d): subtree (%d/%d) big=%d {\n", 797 tab, tab, "", 798 blk, radix, 799 scan->u.bmu_avail, 800 radix, 801 scan->bm_bighint 802 ); 803 804 radix >>= BLIST_META_RADIX_SHIFT; 805 next_skip = (skip >> BLIST_META_RADIX_SHIFT); 806 tab += 4; 807 808 for (i = 1; i <= skip; i += next_skip) { 809 if (scan[i].bm_bighint == (daddr_t)-1) { 810 printf( 811 "%*.*s(%04x,%d): Terminator\n", 812 tab, tab, "", 813 blk, radix 814 ); 815 lastState = 0; 816 break; 817 } 818 blst_radix_print( 819 &scan[i], 820 blk, 821 radix, 822 next_skip - 1, 823 tab 824 ); 825 blk += radix; 826 } 827 tab -= 4; 828 829 printf( 830 "%*.*s}\n", 831 tab, tab, "" 832 ); 833} 834 835#endif 836 837#ifdef BLIST_DEBUG 838 839int 840main(int ac, char **av) 841{ 842 int size = 1024; 843 int i; 844 blist_t bl; 845 846 for (i = 1; i < ac; ++i) { 847 const char *ptr = av[i]; 848 if (*ptr != '-') { 849 size = strtol(ptr, NULL, 0); 850 continue; 851 } 852 ptr += 2; 853 fprintf(stderr, "Bad option: %s\n", ptr - 2); 854 exit(1); 855 } 856 bl = blist_create(size); 857 blist_free(bl, 0, size); 858 859 for (;;) { 860 char buf[1024]; 861 daddr_t da = 0; 862 daddr_t count = 0; 863 864 865 printf("%d/%d/%d> ", bl->bl_free, size, bl->bl_radix); 866 fflush(stdout); 867 if (fgets(buf, sizeof(buf), stdin) == NULL) 868 break; 869 switch(buf[0]) { 870 case 'r': 871 if (sscanf(buf + 1, "%d", &count) == 1) { 872 blist_resize(&bl, count, 1); 873 } else { 874 printf("?\n"); 875 } 876 case 'p': 877 blist_print(bl); 878 break; 879 case 'a': 880 if (sscanf(buf + 1, "%d", &count) == 1) { 881 daddr_t blk = blist_alloc(bl, count); 882 printf(" R=%04x\n", blk); 883 } else { 884 printf("?\n"); 885 } 886 break; 887 case 'f': 888 if (sscanf(buf + 1, "%x %d", &da, &count) == 2) { 889 blist_free(bl, da, count); 890 } else { 891 printf("?\n"); 892 } 893 break; 894 case '?': 895 case 'h': 896 puts( 897 "p -print\n" 898 "a %d -allocate\n" 899 "f %x %d -free\n" 900 "r %d -resize\n" 901 "h/? -help" 902 ); 903 break; 904 default: 905 printf("?\n"); 906 break; 907 } 908 } 909 return(0); 910} 911 912void 913panic(const char *ctl, ...) 914{ 915 va_list va; 916 917 va_start(va, ctl); 918 vfprintf(stderr, ctl, va); 919 fprintf(stderr, "\n"); 920 va_end(va); 921 exit(1); 922} 923 924#endif 925 926