[Overview][Constants][Types][Procedures and functions][Index] Reference for unit 'ipc' (#rtl)

semget

Return the ID of a semaphore set, possibly creating the set

Declaration

Source position: ipc.pp line 510

function semget(

  key: TKey;

  nsems: cint;

  semflg: cint

):cint;

Description

msgget returns the ID of the semaphore set described by key. Depending on the flags in semflg, a new queue is created.

semflg can have one or more of the following values (combined by ORs):

IPC_CREAT
The queue is created if it doesn't already exist.
IPC_EXCL
If used in combination with IPC_CREAT, causes the call to fail if the set already exists. It cannot be used by itself.

Optionally, the flags can be ORed with a permission mode, which is the same mode that can be used in the file system.

if a new set of semaphores is created, then there will be nsems semaphores in it.

Errors

On error, -1 is returned, and IPCError is set.

See also

ftok

  

Create token from filename

semop

  

Perform semaphore operation.

semctl

  

Perform various control operations on a semaphore set

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