[M3devel] unsafety in RTAllocator (Malloc/Free)

[Tony Hosking]

On 3 Feb 2009, at 19:07, Jay wrote:

>
> Sorry, fair enough. I don't think about safety much.
>
>
> Can I put these in a new unsafe RTAllocateUnsafe.i3 or  
> RTUnsafeAllocator.i3?
>  And then the function names I had come up with MallocUninitialized,  
> MallocZeroed.

What do you need them for?  RTAllocator is there so one can allocate  
by typecode.  I don't see the point of Malloc/Free.

> Using array of char seems non-ideal to me somehow.
> It seems like a "workaround".
> It doesn't seem really any safer than not having a type at all.
> I understand, the array, the type, does imply a size, and so I would  
> get some bounds checking against it, except I never access these  
> things anyway, I just pass them on to unsafe C code.
>
>
> Related but tangential question, something I also didn't pay close  
> enough attention to:
> What is the deal with OutOfMemory vs. RuntimeError.T.OutOfMemory?

The first is an explicit exception while the latter is implicit.

> Why don't Malloc, GetUntracedOpenArray, GetUntracedObj, etc. raise  
> OutOfMemory directly?

Because the exception is implicit.  Any procedure can raise a  
RuntimeError.

>
>
>
> - Jay
>
>
> ----------------------------------------
>> To: jkrell at elego.de
>> Date: Mon, 2 Feb 2009 22:21:53 -0800
>> From: mika at async.caltech.edu
>> CC: m3devel at elegosoft.com
>> Subject: Re: [M3devel] [M3commit] CVS Update: cm3
>>
>> Jay Krell writes:
>>> CVSROOT: /usr/cvs
>>> Changes by: jkrell at birch. 09/02/03 06:17:25
>>>
>>> Modified files:
>>> cm3/m3-libs/m3core/src/runtime/common/: RTAllocator.i3
>>> RTAllocator.m3
>>>
>>> Log message:
>>> expose RTAllocator.MallocZeroed (calloc), and RTAllocator.Free
>>
>> RTAllocator isn't UNSAFE is it (it isn't in my installation)? Surely
>> you can't have Free in a non-UNSAFE interface...
>>
>> Mika
>>
>>> introduce internal RTAlloc.MallocUninitialized
>>>
>>> These include Disable/EnableSwitching, and
>>> raising exceptions upon failure.
>>> (Disable/Enable only do something for user threads).