summary refs log tree commit diff stats
path: root/lib/core/allocators.nim
blob: 5189bb7621c3ffd45fb5bc9f343271c18566cd2d (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
#
#
#            Nim's Runtime Library
#        (c) Copyright 2017 Nim contributors
#
#    See the file "copying.txt", included in this
#    distribution, for details about the copyright.
#

type
  AllocatorFlag* {.pure.} = enum  ## flags describing the properties of the allocator
    ThreadLocal ## the allocator is thread local only.
    ZerosMem    ## the allocator always zeros the memory on an allocation
  Allocator* = ptr AllocatorObj
  AllocatorObj* {.inheritable.} = object
    alloc*: proc (a: Allocator; size: int; alignment: int = 8): pointer {.nimcall.}
    dealloc*: proc (a: Allocator; p: pointer; size: int) {.nimcall.}
    realloc*: proc (a: Allocator; p: pointer; oldSize, newSize: int): pointer {.nimcall.}
    deallocAll*: proc (a: Allocator) {.nimcall.}
    flags*: set[AllocatorFlag]
    allocCount: int
    deallocCount: int

var
  localAllocator {.threadvar.}: Allocator
  sharedAllocator: Allocator
  allocatorStorage {.threadvar.}: AllocatorObj

proc getLocalAllocator*(): Allocator =
  result = localAllocator
  if result == nil:
    result = addr allocatorStorage
    result.alloc = proc (a: Allocator; size: int; alignment: int = 8): pointer {.nimcall.} =
      result = system.alloc(size)
      inc a.allocCount
    result.dealloc = proc (a: Allocator; p: pointer; size: int) {.nimcall.} =
      system.dealloc(p)
      inc a.deallocCount
    result.realloc = proc (a: Allocator; p: pointer; oldSize, newSize: int): pointer {.nimcall.} =
      result = system.realloc(p, newSize)
    result.deallocAll = nil
    result.flags = {ThreadLocal}
    localAllocator = result

proc setLocalAllocator*(a: Allocator) =
  localAllocator = a

proc getSharedAllocator*(): Allocator =
  result = sharedAllocator

proc setSharedAllocator*(a: Allocator) =
  sharedAllocator = a

proc allocCounters*(): (int, int) =
  let a = getLocalAllocator()
  result = (a.allocCount, a.deallocCount)