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7588 :: Custom allocator with --gc:arc

• vitreo12 (orginal) [2021-03-07T18:13:09+01:00] view original

  Hello,

  Is it possible to hook my own alloc / dealloc functions to work with --gc:arc? I couldn't find examples on this.

  Thanks!

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• Araq (orginal) [2021-03-07T21:15:49+01:00] view original

  Compile with -d:useMalloc and use the usual mechanisms to override the malloc implementation.

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• vitreo12 (orginal) [2021-03-07T23:04:58+01:00] view original

  I see, thanks! Should I override the mechanism directly in nim or perhaps include a C file? Are the procs called malloc / free or do they have a special name?

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• Araq (orginal) [2021-03-07T23:23:30+01:00] view original

  The procs need to be called malloc and free and realloc and you need some linking command to resolve this. However, editing lib/system/memalloc.nim might be easier.

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• vitreo12 (orginal) [2021-03-11T10:37:09+01:00] view original

  Sorry to come back to this again. Is there a way that I can import my own memalloc.nim file without having to modify the one in the nim installation? This would allow me to easily bundle the implementation together with my code.

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• Araq (orginal) [2021-03-11T13:40:44+01:00] view original

  There is a patchFile mechanism for config.nims.

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• vitreo12 (orginal) [2021-03-11T14:14:27+01:00] view original

  Thanks!

  However, it's not working for me. I'm doing:

  
  patchFile("system", "memalloc", "patches/memalloc")
  Run

  Does it look good? my memalloc.nim file contains the same procs that are defined in the system/memalloc one, but hooked into my allocator. However, it seems like nothing is changed

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• vitreo12 (orginal) [2021-03-11T19:05:40+01:00] view original

  Following up:

  In config.nims I have tried all these different options without any success.

  patchFile("system", "", "custom_alloc")

  patchFile("system", "mm/malloc", "custom_alloc")

  patchFile("system", "memalloc", "custom_alloc")

  Whenever I use something like allocImpl in my code, I have the ambiguous call error:

  
  Error: ambiguous call;
  both system.allocImpl(size: Natural) [declared in /home/francesco/.choosenim/toolchains/nim-1.4.4/lib/system/mm/malloc.nim(4, 6)]
  and custom_alloc.allocImpl(size: Natural) [declared in /home/francesco/Sources/omnijit/omnijit/custom_alloc.nim(3, 6)]
  match for: (int literal(10))
  Run

  The new allocImpl won't even work internally for any other calls (e.g. when allocating a seq or string)

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• vitreo12 (orginal) [2021-03-12T11:21:37+01:00] view original

  After many tries, I managed to find a solution. The file to patch is:

  patchFile("stdlib", malloc", "custom_alloc")

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