Distributed-Run-Time-Resource-Manager/RCCE_V2.0/man/man3/.svn/text-base/RCCE_shmalloc.3.svn-base

.TH RCCE 3  "September 2010" "RCCE MANPAGE" "RCCE Library"
.SH NAME

RCCE_shmalloc \- allocates size bytes of shared SCC memory that is not of type MPBT.   

.SH SYNOPSIS
.B #include <rcce.h>
.sp

.BI "volatile char * RCCE_shmalloc(size_t " size );

.SH DESCRIPTION
.BR RCCE_shmalloc 
allocates size bytes of shared SCC memory that is not of type MPBT.  
It returns a pointer to this memory
The memory is allocated from off-chip DRAM. The data move between the registers 
of a core and shared memory (that is, it bypasses the caches entirely) with 
a granularity of 1, 2, 4 or 8 bytes. For these memory operations, 
due to the restrictions of the P54C architecture, only one read or write 
may be active at one time to an address. 
.PP
This is a collective call that should be issued by all participating cores. 
All cores will allocate space that is exactly overlapping. 
.PP
RCCE_shmalloc() maintains a linked list of pointers to memory. Each pointer 
has associated with it a field specifying whether that block of memory is 
free or not.
.PP
Alternatively, you could use RCCE_shmalloc() to determine the beginning of 
the off-chip shared memory on all cores and subsequently let just one core 
do all the allocating and freeing. This core can then pass offsets to other 
cores that need to know what shared memory regions were involved.

.TP
.B size
Size in bytes of the requested space.

.SH "RETURN VALUE"
Upon successful completion
.BR RCCE_shmalloc()
returns a char * pointer to the start of the allocated bytes.
.SH ERRORS
Look in 
.BR rcce.h
for additional error codes.

.SH "SEE ALSO"
rcce.h(5)

.SH EXAMPLE
.PP
To be supplied.