libgo/runtime/mfixalloc.c

   1 // Copyright 2009 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 // Fixed-size object allocator.  Returned memory is not zeroed.
   6 //
   7 // See malloc.h for overview.
   8
   9 #include "runtime.h"
  10 #include "arch.h"
  11 #include "malloc.h"
  12
  13 // Initialize f to allocate objects of the given size,
  14 // using the allocator to obtain chunks of memory.
  15 void
  16 runtime_FixAlloc_Init(FixAlloc *f, uintptr size, void (*first)(void*, byte*), void *arg, uint64 *stat)
  17 {
  18         f->size = size;
  19         f->first = first;
  20         f->arg = arg;
  21         f->list = nil;
  22         f->chunk = nil;
  23         f->nchunk = 0;
  24         f->inuse = 0;
  25         f->stat = stat;
  26 }
  27
  28 void*
  29 runtime_FixAlloc_Alloc(FixAlloc *f)
  30 {
  31         void *v;
  32
  33         if(f->size == 0) {
  34                 runtime_printf("runtime: use of FixAlloc_Alloc before FixAlloc_Init\n");
  35                 runtime_throw("runtime: internal error");
  36         }
  37
  38         if(f->list) {
  39                 v = f->list;
  40                 f->list = *(void**)f->list;
  41                 f->inuse += f->size;
  42                 return v;
  43         }
  44         if(f->nchunk < f->size) {
  45                 f->chunk = runtime_persistentalloc(FixAllocChunk, 0, f->stat);
  46                 f->nchunk = FixAllocChunk;
  47         }
  48         v = f->chunk;
  49         if(f->first)
  50                 f->first(f->arg, v);
  51         f->chunk += f->size;
  52         f->nchunk -= f->size;
  53         f->inuse += f->size;
  54         return v;
  55 }
  56
  57 void
  58 runtime_FixAlloc_Free(FixAlloc *f, void *p)
  59 {
  60         f->inuse -= f->size;
  61         *(void**)p = f->list;
  62         f->list = p;
  63 }
  64