sysvipc

SVIPC(7)                   Linux Programmer's Manual                  SVIPC(7)



NAME
       sysvipc - System V interprocess communication mechanisms

DESCRIPTION
       System V IPC is the name given to three interprocess communication
       mechanisms that are widely available on UNIX systems: message queues,
       semaphore, and shared memory.

   Message queues
       System V message queues allow data to be exchanged in units called
       messages.  Each messages can have an associated priority, POSIX message
       queues provide an alternative API for achieving the same result; see
       mq_overview(7).

       The System V message queue API consists of the following system calls:

       msgget(2)
              Create a new message queue or obtain the ID of an existing
              message queue.  This call returns an identifier that is used in
              the remaining APIs.

       msgsnd(2)
              Add a message to a queue.

       msgrcv(2)
              Remove a message from a queue.

       msgctl(2)
              Perform various control operations on a queue, including
              deletion.

   Semaphore sets
       System V semaphores allow processes to synchronize their actions System
       V semaphores are allocated in groups called sets; each semaphore in a
       set is a counting semaphore.  POSIX semaphores provide an alternative
       API for achieving the same result; see sem_overview(7).

       The System V semaphore API consists of the following system calls:

       semget(2)
              Create a new set or obtain the ID of an existing set.  This call
              returns an identifier that is used in the remaining APIs.

       semop(2)
              Perform operations on the semaphores in a set.

       semctl(2)
              Perform various control operations on a set, including deletion.

   Shared memory segments
       System V shared memory allows processes to share a region a memory (a
       "segment").  POSIX shared memory is an alternative API for achieving
       the same result; see shm_overview(7).

       The System V shared memory API consists of the following system calls:

       shmget(2)
              Create a new segment or obtain the ID of an existing segment.
              This call returns an identifier that is used in the remaining
              APIs.

       shmat(2)
              Attach an existing shared memory object into the calling
              process's address space.

       shmdt(2)
              Detach a segment from the calling process's address space.

       shmctl(2)
              Perform various control operations on a segment, including
              deletion.

   IPC namespaces
       For a discussion of the interaction of System V IPC objects and IPC
       namespaces, see ipc_namespaces(7).

SEE ALSO
       ipcmk(1), ipcrm(1), ipcs(1), lsipc(1), ipc(2), msgctl(2), msgget(2),
       msgrcv(2), msgsnd(2), semctl(2), semget(2), semop(2), shmat(2),
       shmctl(2), shmdt(2), shmget(2), ftok(3), ipc_namespaces(7)

COLOPHON
       This page is part of release 5.07 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.



Linux                             2020-04-11                          SVIPC(7)