hpux man page for ttrace_wait

ttrace_wait(2)							System Calls Manual						    ttrace_wait(2)

NAME
       ttrace_wait - wait for ttrace event

SYNOPSIS
DESCRIPTION
       The system call provides a means to wait for a event to occur.  A tracing process (debugger) will normally invoke after a process or any of
       its threads has been set running.

       synchronizes tracing requests directed at threads within the traced process.  This mechanism differs from the process-oriented synchroniza-
       tion provided by or (see wait(2)).

       The  pid  argument identifies the process-id of a traced process which the debugger expects to stop.  If pid is a positive value, and lwpid
       is zero, then will wait for any thread in the traced process identified by pid to stop in response to an  outstanding  ttrace  event.   The
       information concerning the thread that hit the event point is available in the ttstate_t structure (see ttrace(2)).

       The  lwpid  argument  identifies the Lightweight Process (LWP) id of a thread in the traced process pid for which the debugger must wait to
       validate request completion.  If both pid and lwpid are non-zero values, suspends the calling process until the specified LWP in the traced
       process stops.

       When  multiple  child  processes  are simultaneously traced, can be used to identify the process-id and LWP id of a thread which stopped in
       response to any outstanding request established for the group of traced child processes.  This is achieved by invoking with  both  pid  and
       lwpid set to 0 (zero).

       A zero pid and non-zero lwpid will return an error.

       The  option  argument  must specify either or These values control the synchronizing effect of on the calling process.  The value causes to
       behave in non-blocking mode and return to the calling process immediately whether or not a pre-existing ttrace request completed on  behalf
       of the tracing process.	With suspends the calling process until the requested pid and/or LWP stop.

       As  mentioned  above, the tsp argument references a ttstate_t structure (see ttrace(2)) which provides all the needed information regarding
       the stopped thread.  The size argument specifies the size of the ttstate_t structure referenced by addr.

RETURN VALUE
       If the call succeeds, will return 1 (one) if the event was never waited for, 0 (zero) otherwise.  If the call fails, -1 is returned and	is
       set to the appropriate value.

ERRORS
       The system call fails if one or more of the following is true:

	      [EINVAL]	  pid is zero and lwpid is non-zero.

	      [EINVAL]	  The option is invalid.

	      [EINVAL]	  The lwpid is not controlled by process pid.

	      [ESRCH]	  The pid or lwpid do not identify an existing process (LWP).

	      [EACCES]	  The pid does not identify a process debugged by the invoking process.

	      [ECHILD]	  The process (LWP) died while it was waited for.

	      [EINTR]	  was interrupted by a signal.

	      [EFAULT]	  An invalid address was given for the kernel to write data into.

AUTHOR
       was developed by HP.

SEE ALSO
       ttrace(2), wait(2).

																    ttrace_wait(2)