[LCP] mapping memory

[Mark Farnell]

I mean different logical address.

In a process, suppose I malloc a piece a memory

#define SIZE 1024

void *a = malloc(SIZE);

Are there any functions which produces a logical mapping of the chunk
I've malloced on a *different* address space (but in fact point to the
same chunk)

void *b = map(a, size);

so that b is the base address of a different block (address looks
different to a), yet if a thread changes the content pointed to b, it
actually maps to the block pointed to by a.

The application is that I have a process which spawns multiple POSIX
threads.  The process malloc's a piece of memory.  Then what I intend
to do is that for each thread, map that piece of memory to a different
address space, each mapping can have individual mprotect operations
that does not affect other mappings owned by other threads.

However if a mapping is written to, it actually writes to the piece of
memory malloc'ed by the master.

So memcpy etc will *not* do the job.  I am not asking how to copy contents.

Can this be done?

Thanks!

Mark

>hi mark,

>Mark Farnell wrote:
>> In a Linux process, I have malloc'ed a piece of memory.  Within this
>> process, are there any ways to map this chunk of memory to a different
>> address?

>what do you mean by "a different address"?

>regards,

>kim
>--
>Operating Systems, Services and Operations
>Information Technology Services, The University of Adelaide
>kim.hawtin at adelaide.edu.au