Re: Re[2]: [Haskell-cafe] heap lifetime question

In which directory are they? Vasili On Thu, Aug 7, 2008 at 12:58 AM, Bulat Ziganshin wrote:

Hello Vasili,

Thursday, August 7, 2008, 9:33:32 AM, you wrote:

oh, it was my mistake. alloca behavior is completely defined by it's generic implementation:

allocaBytes :: Int -> (Ptr a -> IO b) -> IO b allocaBytes size = bracket (mallocBytes size) free

although GHC implementation is much more efficient

btw, why you can't download ghc library sources and read them yourself??

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If I am correct, I cannot associate a ForeignPtr with alloca or allocaBytes object via "newForeignPtr" because the alloca/allocaBytes heap object will be GC'd when I leave the function that allocated this object/. I.e. if I have a heap object that I want to live beyond a function invocation, I must be very careful in coding....

Vasili

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On Thu, Aug 7, 2008 at 12:30 AM, Galchin, Vasili wrote:

so Bulat ..

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You seem to be saying what I suspect ... i.e. if an allocaBytes call is inside a function, when the function is exited then the said heap object is GC'd??

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Regards, Vasili

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On Thu, Aug 7, 2008 at 12:25 AM, Bulat Ziganshin wrote: Hello Vasili,

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Thursday, August 7, 2008, 9:13:43 AM, you wrote:

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What is the lifetime of various heap objects ... e.g. created by

allocaBytes, alloca, etc?

alloca/allocaBytes just mimicks stack allocation but actually allocates buffer in usual heap. this buffer lives while references to it exists

on practice, it's usually gc'ed by next minor GC

-- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com

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-- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com