Reorganized April 2024
xcall MIAMEX, MX_GETSIG, sigmask
xcall MIAMEX, MX_CLRSIG, sigmask
(Unix only)
MX_GETSIG (MIAMEX 54) returns a bitmap indicating which signals have been received since the MX_CLRSIG call was last used to reset the signal received bitmap.
MX_CLRSIG (MIAMEX 55) allows you to clear specific bits in the signal received mask. This would be useful in a situation where you wanted to check whether a certain signal was received during a certain time frame. First you would clear the bit for that signal, then later you would check, using MX_GETSIG, if the bit was set.
Parameters
sigmask (Signed Num) [in]
CLRSIG: Should be set to the sum of the signals from the table below that you want cleared. Use –1 to clear all of the signal flags. 0 does nothing.
GETSIG: Returns with zero or one of the following bits set to indicate which signal (if any) was received:
Symbol |
Value |
Name* |
Meaning |
|---|---|---|---|
SR_INT |
&h0001 |
SIGINT |
Ctrl+C |
SR_CHLD |
&h0002 |
SIGCHLD |
Child process terminated |
SR_USR1 |
&h0004 |
SIGUSR1 |
Receipt of ITC or IJC message |
SR_USR2 |
&h0008 |
SIGUSR2 |
PolyShell swap operation |
SR_HUP |
&h0010 |
SIGHUP |
Hangup (telnet or terminal session disconnected) |
SR_KILL |
&h0020 |
SIGKILL |
Kill (cannot be trapped so will never be seen) |
SR_TSTP |
&h0040 |
SIGTSTP |
Background task waiting for terminal context to perform input operation |
SR_ALARM |
&h0080 |
SIGALRM |
Alarm signal (used by sleep timers and WAKNOxs) |
SR_TERM |
&h0100 |
SIGTERM |
Default kill signal |
SR_PIPE |
&h0200 |
SIGPIPE |
Broken pipe or socket connect (other end has terminated) |
SR_SYSCALL |
&h4000 |
Not applicable |
Pseudo signal flag used by A-Shell to indicate that it is waiting on a system() call such as HOSTEXxs |
Definition file: ashell.def |
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* The terms in the "Name" column are the standard POSIX signal names for the subset of signals recognized by A-Shell. Note the standard signal names are associated with integer values that may vary between Unix flavors; the bit values used by A-Shell are independent of the underlying operating system signal values, and uniform across all platforms.
Comments
SUBMIT/W uses these functions. First it clears the SIGCHLD signal flag (2), then submits the task, then sleeps, checking every second to see if the SIGCHLD signal flag has been set, which it will be when the submitted task terminates.
