| rsc | cfa37a7 | 2004-04-10 18:53:55 +0000 | [diff] [blame] | 1 | .TH BIN 3 |
| 2 | .SH NAME |
| 3 | binalloc, bingrow, binfree \- grouped memory allocation |
| 4 | .SH SYNOPSIS |
| 5 | .B #include <u.h> |
| 6 | .br |
| 7 | .B #include <libc.h> |
| 8 | .br |
| 9 | .B #include <bin.h> |
| 10 | .PP |
| 11 | .ta \w'\fLvoid* 'u |
| 12 | .PP |
| 13 | .B |
| 14 | typedef struct Bin Bin; |
| 15 | .PP |
| 16 | .B |
| 17 | void *binalloc(Bin **bp, ulong size, int clr); |
| 18 | .PP |
| 19 | .B |
| 20 | void *bingrow(Bin **bp, void *op, ulong osize, |
| 21 | .br |
| 22 | .B |
| rsc | c8b6342 | 2005-01-13 04:49:19 +0000 | [diff] [blame] | 23 | ulong size, int clr); |
| rsc | cfa37a7 | 2004-04-10 18:53:55 +0000 | [diff] [blame] | 24 | .PP |
| 25 | .B |
| 26 | void binfree(Bin **bp); |
| 27 | .SH DESCRIPTION |
| 28 | These routines provide simple grouped memory allocation and deallocation. |
| 29 | Items allocated with |
| 30 | .I binalloc |
| 31 | are added to the |
| 32 | .I Bin |
| 33 | pointed to by |
| 34 | .IR bp . |
| 35 | All items in a bin may be freed with one call to |
| 36 | .IR binfree ; |
| 37 | there is no way to free a single item. |
| 38 | .PP |
| 39 | .I Binalloc |
| 40 | returns a pointer to a new block of at least |
| 41 | .I size |
| 42 | bytes. |
| 43 | The block is suitably aligned for storage of any type of object. |
| 44 | No two active pointers from |
| 45 | .I binalloc |
| 46 | will have the same value. |
| 47 | The call |
| 48 | .B binalloc(0) |
| 49 | returns a valid pointer rather than null. |
| 50 | If |
| 51 | .I clr |
| 52 | is non-zero, the allocated memory is set to 0; |
| 53 | otherwise, the contents are undefined. |
| 54 | .PP |
| 55 | .I Bingrow |
| 56 | is used to extend the size of a block of memory returned by |
| 57 | .IR binalloc . |
| 58 | .I Bp |
| 59 | must point to the same bin group used to allocate the original block, |
| 60 | and |
| 61 | .I osize |
| 62 | must be the last size used to allocate or grow the block. |
| 63 | A pointer to a block of at least |
| 64 | .I size |
| 65 | bytes is returned, with the same contents in the first |
| 66 | .I osize |
| 67 | locations. |
| 68 | If |
| 69 | .I clr |
| 70 | is non-zero, the remaining bytes are set to 0, |
| 71 | and are undefined otherwise. |
| 72 | If |
| 73 | .I op |
| 74 | is |
| 75 | .BR nil , |
| 76 | it and |
| 77 | .I osize |
| 78 | are ignored, and the result is the same as calling |
| 79 | .IR binalloc . |
| 80 | .PP |
| 81 | .I Binalloc |
| 82 | and |
| 83 | .I bingrow |
| 84 | allocate large chunks of memory using |
| rsc | bf8a59f | 2004-04-11 03:42:27 +0000 | [diff] [blame] | 85 | .IR malloc (3) |
| rsc | cfa37a7 | 2004-04-10 18:53:55 +0000 | [diff] [blame] | 86 | and return pieces of these chunks. |
| 87 | The chunks are |
| 88 | .IR free 'd |
| 89 | upon a call to |
| 90 | .IR binfree . |
| 91 | .SH SOURCE |
| rsc | c3674de | 2005-01-11 17:37:33 +0000 | [diff] [blame] | 92 | .B \*9/src/libbin |
| rsc | cfa37a7 | 2004-04-10 18:53:55 +0000 | [diff] [blame] | 93 | .SH SEE ALSO |
| rsc | bf8a59f | 2004-04-11 03:42:27 +0000 | [diff] [blame] | 94 | .IR malloc (3) |
| rsc | cfa37a7 | 2004-04-10 18:53:55 +0000 | [diff] [blame] | 95 | .SH DIAGNOSTICS |
| 96 | .I binalloc |
| 97 | and |
| 98 | .I bingrow |
| 99 | return 0 if there is no available memory. |
