POSIX_TRACE_EVENTID_EQUAL(3P)                       POSIX Programmer's Manual                      POSIX_TRACE_EVENTID_EQUAL(3P)



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult the corresponding Linux manual page for details of Linux behavior), or the  interface  may  not  be  implemented  on
       Linux.

NAME
       posix_trace_eventid_equal,  posix_trace_eventid_get_name, posix_trace_trid_eventid_open - manipulate the trace event type
       identifier (TRACING)

SYNOPSIS
       #include <trace.h>

       int posix_trace_eventid_equal(trace_id_t trid, trace_event_id_t event1,
              trace_event_id_t event2);
       int posix_trace_eventid_get_name(trace_id_t trid,
              trace_event_id_t event, char *event_name);


       int posix_trace_trid_eventid_open(trace_id_t trid,
              const char *restrict event_name,
              trace_event_id_t *restrict event);


DESCRIPTION
       The posix_trace_eventid_equal() function shall compare the trace event type identifiers event1 and event2 from  the  same
       trace stream or the same trace log identified by the trid argument. If the trace event type identifiers event1 and event2
       are from different trace streams, the return value shall be unspecified.

       The posix_trace_eventid_get_name() function shall return, in the argument pointed to by event_name, the trace event  name
       associated  with  the trace event type identifier identified by the argument event, for the trace stream or for the trace
       log identified by the trid argument. The name of the trace event shall have a maximum of  {TRACE_EVENT_NAME_MAX}  charac-
       ters  (which has the minimum value {_POSIX_TRACE_EVENT_NAME_MAX}).  Successive calls to this function with the same trace
       event type identifier and the same trace stream identifier shall return the same event name.

       The posix_trace_trid_eventid_open() function shall associate a user trace event name with a trace event  type  identifier
       for  a  given  trace stream. The trace stream is identified by the trid argument, and it shall be an active trace stream.
       The  trace  event  name  is  the  string  pointed  to  by  the  argument  event_name.   It  shall  have  a   maximum   of
       {TRACE_EVENT_NAME_MAX}  characters  (which has the minimum value {_POSIX_TRACE_EVENT_NAME_MAX}). The number of user trace
       event type identifiers that can be defined for any given process is limited by the maximum value  {TRACE_USER_EVENT_MAX},
       which has the minimum value {_POSIX_TRACE_USER_EVENT_MAX}.

       If the Trace Inherit option is not supported, the posix_trace_trid_eventid_open() function shall associate the user trace
       event name pointed to by the event_name argument with a trace event type identifier that is unique for the process  being
       traced in the trace stream identified by the trid argument, and is returned in the variable pointed to by the event argu-
       ment. If the user trace event name has already been mapped for the traced process, then  the  previously  assigned  trace
       event   type   identifier   shall   be  returned.  If  the  per-process  user  trace  event  name  limit  represented  by
       {TRACE_USER_EVENT_MAX} has been reached, the pre-defined POSIX_TRACE_UNNAMED_USEREVENT  (see  Trace  Option:  User  Trace
       Event ) user trace event shall be returned.

       If  the  Trace  Inherit  option is supported, the posix_trace_trid_eventid_open() function shall associate the user trace
       event name pointed to by the event_name argument with a trace event type identifier that is unique for all the  processes
       being traced in the trace stream identified by the trid argument, and is returned in the variable pointed to by the event
       argument. If the user trace event name has already been mapped for the traced processes,  then  the  previously  assigned
       trace  event  type  identifier  shall  be  returned.  If  the  per-process  user  trace  event  name limit represented by
       {TRACE_USER_EVENT_MAX} has been reached, the pre-defined POSIX_TRACE_UNNAMED_USEREVENT  (see  Trace  Option:  User  Trace
       Event ) user trace event shall be returned.

RETURN VALUE
       Upon  successful  completion,  the  posix_trace_eventid_get_name()  and  posix_trace_trid_eventid_open()  functions shall
       return a value of zero. Otherwise, they shall return the corresponding error number.

       The posix_trace_eventid_equal() function shall return a non-zero value if event1 and event2 are equal; otherwise, a value
       of  zero shall be returned. No errors are defined.  If either event1 or event2 are not valid trace event type identifiers
       for the trace stream specified by trid or if the trid is invalid, the behavior shall be unspecified.

       The posix_trace_eventid_get_name() function stores the trace event name value in the object pointed to by event_name,  if
       successful.

       The  posix_trace_trid_eventid_open()  function  stores  the trace event type identifier value in the object pointed to by
       event, if successful.

ERRORS
       The posix_trace_eventid_get_name() and   posix_trace_trid_eventid_open() functions shall fail if:

       EINVAL The trid argument was not a valid trace stream identifier.


       The posix_trace_trid_eventid_open() function shall fail if:

       ENAMETOOLONG

              The size of the name pointed to by the event_name  argument  was  longer  than  the  implementation-defined  value
              {TRACE_EVENT_NAME_MAX}.


       The posix_trace_eventid_get_name() function shall fail if:

       EINVAL The trace event type identifier event was not associated with any name.


       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       Trace  Option:  User  Trace  Event,  posix_trace_event(),  posix_trace_getnext_event(),  the  Base  Definitions volume of
       IEEE Std 1003.1-2001, <trace.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003  Edition,  Standard  for
       Information  Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copy-
       right (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any
       discrepancy  between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group
       Standard  is  the  referee   document.   The   original   Standard   can   be   obtained   online   at   http://www.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                 POSIX_TRACE_EVENTID_EQUAL(3P)