bsd/kern/sys_pipe.c

1121 	struct pipe *mpipe = (struct pipe *)fp->f_data;
1126 	PIPE_LOCK(mpipe);
1129 	error = mac_pipe_check_ioctl(kauth_cred_get(), mpipe, cmd);
1131 		PIPE_UNLOCK(mpipe);
1140 		PIPE_UNLOCK(mpipe);
1145 			mpipe->pipe_state |= PIPE_ASYNC;
1147 			mpipe->pipe_state &= ~PIPE_ASYNC;
1149 		PIPE_UNLOCK(mpipe);
1153 		*(int *)data = mpipe->pipe_buffer.cnt;
1154 		PIPE_UNLOCK(mpipe);
1158 		mpipe->pipe_pgid = *(int *)data;
1160 		PIPE_UNLOCK(mpipe);
1164 		*(int *)data = mpipe->pipe_pgid;
1166 		PIPE_UNLOCK(mpipe);
1170 	PIPE_UNLOCK(mpipe);