SEMOP(2)

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SEMOP(2)

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semop - ��

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        #include <sys/types.h>
        #include <sys/ipc.h>
        #include <sys/sem.h>
        
        int semop (semid, sops, nsops);
        int semid;
        struct sembuf **sops;
        unsigned nsops;

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�� semop �� , �� semid. �� sops �� , �� (��. ��). �� nsops �� . �� , �� , �� :

             short sem_num; /* ����� �������� */
             short sem_op;  /* �������� ��� ��������� */
             short sem_flg; /* ����� �������� */

�� , �� sem_op, �� , �� semid � sem_num.

�� sem_op �� :

�� sem_op ��, �� {�� .}:
- �� semval [��. intro(2)] �� sem_op, �� sem_op �� semval. ��, �� (sem_flg & SEM_UNDO) ��, �� sem_op �� semadj �� [��. exit(2)].
- �� semval �� sem_op � �� (sem_flg & IPC_NOWAIT) ��, �� .
- �� semval �� sem_op � �� (sem_flg & IPC_NOWAIT) ��, �� semncnt �� :
  �� semval �� sem_op. �� , �� semncnt �� 1, �� sem_op �� semval �, �� (sem_flg & IPC_UNDO) ��, �� sem_op �� semadj �� .
  �� , �� , �� [��. semctl(2)]. �� , �� errno �� EIDRM � �� -1.
  �� , �� . �� , �� semncnt, �� , �� 1 � �� , �� signal(2).
�� sem_op ��, �� semval �, �� (sem_flg & SEM_UNDO) ��, �� sem_op �� semadj �� . {�� .}
�� sem_op �� , �� {�� }:
- �� semval �� , �� .
- �� (sem_flg & IPC_NOWAIT) ��, �� .
- �� (sem_flg & IPC_NOWAIT) ��, �� semzcnt �� 1 � �� :
  �� semval �� . �� , �� semzcnt �� 1.
  �� , �� , �� . �� , �� errno �� EIDRM � �� -1.
  �� , �� . �� , �� semzcnt, �� , �� 1 � �� , �� signal(2).

�� semop �� , �� :

[EINVAL]: �� semid �� .
[EFBIG]: �� sem_num �� , �� semid.
[E2BIG]: �� nsops �� .
[EACCES]: � �� [��. intro(2)].
[EAGAIN]: �� , � �� (semflg & IPC_NOWAIT) ��.
[ENOSPC]: �� , �� SEM_UNDO.
[EINVAL]: �� , �� SEM_UNDO.
[ERANGE]: �� semval �� .
[ERANGE]: �� semadj �� .
[EFAULT]: �� sops �� .

�� sempid �� , �� , �� sops, �� (��) �� .

��. ��
exec(2), exit(2), fork(2), intro(2), semctl(2), semget(2).

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�� semop �� -�� , �� -1, � �� errno �� EINTR. �� semop �� -�� semid , �� -1 � errno �� EIDRM.

�� 0; � �� -1, � �� errno �� .