dpk%brl-vgr@sri-unix.UUCP (01/19/84)
From: Doug Kingston <dpk@brl-vgr> The following is a manual page for the system call interface sigrestartable, as developed at BRL and discussed on this list. sigrestartable.2: .TH SIGRESTARTABLE 2B "11 January 1984" .UC 4 .SH NAME sigrestartable \- change system call restart behavior .SH SYNOPSIS .nf .B sigrestartable(flag); .B int flag; .SH DESCRIPTION .I Sigrestartable is used to change the system call restart behavior when a system call is interrupted by a signal. If the .I flag is one (01), then system calls will be restarted if they are interrupted by a signal and no data has been transferred yet. This is the default behavior on 4.2 BSD. .PP If the .I flag is 0, then restarting of system calls is disabled. If a system call is interrupted and no data has been transferred, the system call will return -1 with .I errno set to EINTR. Interrupted system calls that have started transfering data will return the amount of data actually transferred. This is the signal behavior found on 4.1 BSD and AT&T System V UNIX systems. .PP Note that the new 4.2 BSD signal handling semantics are not altered in any other way. Most notably, signal handlers always remain installed until explicitly changed by a subsequent sigvec(2) call, and the signal mask operates as documented in sigvec(2). Programs may switch between restartable and interruptable system call operation as often as desired in the execution of a program. .PP Issuing an sigrestartable(2) system call during the execution of a signal handler will cause the new action to take place on the \fInext\fR signal to be caught. .SH "RETURN VALUE None. .SH "SEE ALSO" sigvec(2), sigblock(2), sigpause(2), sigsetmask(2). .SH CAVEAT This is a BRL-developed system call, and may not have been adopted on all systems. Hence, while using this system call may make life easier locally, it does not enhance the portability of code to other 4.2 BSD systems. ------- end of man page source ---------