1#
2#
3#            Nim's Runtime Library
4#        (c) Copyright 2019 Andreas Rumpf
5#
6#    See the file "copying.txt", included in this
7#    distribution, for details about the copyright.
8#
9
10## Hooks for memory management. Can be used to implement custom garbage
11## collectors etc.
12
13type
14  GlobalMarkerProc = proc () {.nimcall, benign, raises: [], tags: [].}
15var
16  globalMarkersLen: int
17  globalMarkers: array[0..3499, GlobalMarkerProc]
18  threadLocalMarkersLen: int
19  threadLocalMarkers: array[0..3499, GlobalMarkerProc]
20
21proc nimRegisterGlobalMarker(markerProc: GlobalMarkerProc) {.compilerproc.} =
22  if globalMarkersLen <= high(globalMarkers):
23    globalMarkers[globalMarkersLen] = markerProc
24    inc globalMarkersLen
25  else:
26    cstderr.rawWrite("[GC] cannot register global variable; too many global variables")
27    quit 1
28
29proc nimRegisterThreadLocalMarker(markerProc: GlobalMarkerProc) {.compilerproc.} =
30  if threadLocalMarkersLen <= high(threadLocalMarkers):
31    threadLocalMarkers[threadLocalMarkersLen] = markerProc
32    inc threadLocalMarkersLen
33  else:
34    cstderr.rawWrite("[GC] cannot register thread local variable; too many thread local variables")
35    quit 1
36
37proc traverseGlobals*() =
38  for i in 0..globalMarkersLen-1:
39    globalMarkers[i]()
40
41proc traverseThreadLocals*() =
42  for i in 0..threadLocalMarkersLen-1:
43    threadLocalMarkers[i]()
44
45var
46  newObjHook*: proc (typ: PNimType, size: int): pointer {.nimcall, tags: [], raises: [], gcsafe.}
47  traverseObjHook*: proc (p: pointer, op: int) {.nimcall, tags: [], raises: [], gcsafe.}
48
49proc nimGCvisit(p: pointer, op: int) {.inl, compilerRtl.} =
50  traverseObjHook(p, op)
51
52proc newObj(typ: PNimType, size: int): pointer {.inl, compilerRtl.} =
53  result = newObjHook(typ, size)
54