SYS$CRMPSC (OpenVMS) SYS$CRMPSC (OpenVMS)
NAME
shmget - get ID for shared memory region
shmat - attach to a shared memory section
SYS$CRMPSC - Create and map global section
SYS$MGBLSC - Map global section
EXPLAINATION
The Digital UNIX shmget and shmat system calls together are similar to
the SYS$CRMPSC and the SYS$MGBLSC OpenVMS system services. The shmget
function and the shmat function typically work together. The shmget
function gets the ID of the shared memory section and creates the sec‐
tion if necessary. However, it does not actually bring the memory into
the processes virtual memory space. The shmat attaches the shared mem‐
ory (referenced by an ID obtained from shmget) to the virtual memory
map of the calling process. Both shmget and shmat operate only on
shared memory paged only to the swap disk. They do not handle memory
mapping files, it is recommended that the mmap function be used to
implement memory mapping files.
RELATED INFORMATION
Digital UNIX Functions:
shmget(2), shmctl(2), shmat(2), shmdt(2), mmap(2) delim off
SYS$CRMPSC (OpenVMS)
