PROLOG

       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of
       this interface may differ (consult 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}      characters      (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  argument.  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 Table 2-7, 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 Table 2-7, 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

       The        posix_trace_eventid_equal(),        posix_trace_eventid_get_name(),         and
       posix_trace_trid_eventid_open() functions may be removed in a future version.

SEE ALSO

       Table 2-7, Trace Option: User Trace Event, exec, posix_trace_event(),
       posix_trace_getnext_event()

       The Base Definitions volume of POSIX.1‐2017, <trace.h>

COPYRIGHT

       Portions of this text are reprinted and  reproduced  in  electronic  form  from  IEEE  Std
       1003.1-2017,  Standard  for  Information Technology -- Portable Operating System Interface
       (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C)  2018  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.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are most  likely  to  have
       been  introduced  during  the conversion of the source files to man page format. To report
       such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .