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Re: allot which initialize the alloted space ?

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On 5/21/2017 16:16, Ron Aaron wrote:
> 
> 
> On 21/05/2017 18:01, hughaguilar96@gmail.com wrote:
> 
>> I used to have ZALLOT in the novice-package but I realized that it
>> is redundant --- there is no case in which I don't want to zero out
>> the memory --- so I just renamed it ALLOT ash shown above.
> 
> Really?  Why would you zero out the memory if, for instance, you
> were going to read from a file into that memory area?  Or if you were
> going to copy some other data to it?  The zeroing takes time.
> 

The only time an OS like Windows gives you memory that's not initialised 
to zero is memory you've allocated, used and freed yourself (where 
yourself is anything running in the process) on the heap. It can be 
requested zeroed by passing HEAP_ZERO_MEMORY to HeapAlloc.

VirtualAlloc (the basis of all memory reservation in Windows, including 
the provision of heaps) always zeroes memory.

About the only time you'd need to zero memory is when you're dealing 
with secure info like passwords, and the app should do that before 
passing the memory around or freeing it. Not doing so is a security hole.

In the future, zeroing persistent memory (persistent stuff faster than 
flash SSD but slower than DRAM) will be very expensive indeed, and will 
normally be done by requesting the device to do it, and not 
programmatically.

-- 
Alex

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allot which initialize the alloted space ? Andreas Klimas <klimas@w3group.de> - 2017-05-21 13:50 +0200
  Re: allot which initialize the alloted space ? Coos Haak <htrofhc@gmail.com> - 2017-05-21 14:13 +0200
  Re: allot which initialize the alloted space ? hughaguilar96@gmail.com - 2017-05-21 08:01 -0700
    Re: allot which initialize the alloted space ? Ron Aaron <rambamist@gmail.com> - 2017-05-21 18:16 +0300
      Re: allot which initialize the alloted space ? hughaguilar96@gmail.com - 2017-05-21 09:02 -0700
        Re: allot which initialize the alloted space ? Ron Aaron <rambamist@gmail.com> - 2017-05-21 19:17 +0300
          Re: allot which initialize the alloted space ? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-05-22 11:22 +0000
          Re: allot which initialize the alloted space ? hughaguilar96@gmail.com - 2017-05-24 08:03 -0700
            Re: allot which initialize the alloted space ? Alex <alex@rivadpm.com> - 2017-05-24 16:58 +0100
        Re: allot which initialize the alloted space ? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-05-22 07:40 +0000
          Re: allot which initialize the alloted space ? Mark Wills <markwills1970@gmail.com> - 2017-05-22 08:02 -0700
            Re: allot which initialize the alloted space ? "HAA" <someone@microsoft.com> - 2017-05-24 16:40 +1000
          Re: allot which initialize the alloted space ? hughaguilar96@gmail.com - 2017-05-22 13:27 -0700
      Re: allot which initialize the alloted space ? Alex <alex@rivadpm.com> - 2017-05-21 17:16 +0100
        Re: allot which initialize the alloted space ? Ron Aaron <rambamist@gmail.com> - 2017-05-21 19:22 +0300
          Re: allot which initialize the alloted space ? Alex <alex@rivadpm.com> - 2017-05-21 18:03 +0100
          Re: allot which initialize the alloted space ? albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2017-05-21 20:46 +0200
            Re: allot which initialize the alloted space ? Alex <alex@rivadpm.com> - 2017-05-21 20:34 +0100
      Re: allot which initialize the alloted space ? "HAA" <someone@microsoft.com> - 2017-05-24 16:41 +1000
  Re: allot which initialize the alloted space ? Julian Fondren <julian.fondren@gmail.com> - 2017-05-21 08:36 -0700

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