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_close, posix_trace_open, posix_trace_rewind — trace log management (TRACING)

SYNOPSIS

       #include <trace.h>

       int posix_trace_close(trace_id_t trid);
       int posix_trace_open(int file_desc, trace_id_t *trid);
       int posix_trace_rewind(trace_id_t trid);

DESCRIPTION

       The  posix_trace_close()  function  shall deallocate the trace log identifier indicated by
       trid, and all of its associated resources. If there is no valid trace log  pointed  to  by
       the trid, this function shall fail.

       The  posix_trace_open()  function shall allocate the necessary resources and establish the
       connection between a trace log identified by the file_desc argument  and  a  trace  stream
       identifier  identified  by  the  object  pointed  to  by  the trid argument. The file_desc
       argument should be a valid open file descriptor that  corresponds  to  a  trace  log.  The
       file_desc  argument  shall  be  open for reading. The current trace event timestamp, which
       specifies the timestamp of the trace  event  that  will  be  read  by  the  next  call  to
       posix_trace_getnext_event(),  shall  be  set  to  the  timestamp of the oldest trace event
       recorded in the trace log identified by trid.

       The posix_trace_open() function shall return a trace stream  identifier  in  the  variable
       pointed to by the trid argument, that may only be used by the following functions:

       posix_trace_close()                      posix_trace_get_attr()
       posix_trace_eventid_equal()              posix_trace_get_status()
       posix_trace_eventid_get_name()           posix_trace_getnext_event()
       posix_trace_eventtypelist_getnext_id()   posix_trace_rewind()
       posix_trace_eventtypelist_rewind()

       In  particular,  notice  that  the operations normally used by a trace controller process,
       such as posix_trace_start(),  posix_trace_stop(),  or  posix_trace_shutdown(),  cannot  be
       invoked using the trace stream identifier returned by the posix_trace_open() function.

       The  posix_trace_rewind()  function  shall  reset the current trace event timestamp, which
       specifies the timestamp of the trace  event  that  will  be  read  by  the  next  call  to
       posix_trace_getnext_event(),  to  the  timestamp of the oldest trace event recorded in the
       trace log identified by trid.

RETURN VALUE

       Upon successful completion, these functions shall return a value of zero. Otherwise,  they
       shall return the corresponding error number.

       If successful, the posix_trace_open() function stores the trace stream identifier value in
       the object pointed to by trid.

ERRORS

       The posix_trace_open() function shall fail if:

       EINTR  The operation was interrupted by a signal and thus no trace log was opened.

       EINVAL The object pointed to by file_desc does not correspond to a valid trace log.

       The posix_trace_close() and posix_trace_rewind() functions may fail if:

       EINVAL The object pointed to by trid does not correspond to a valid trace log.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       The posix_trace_close(), posix_trace_open(), and  posix_trace_rewind()  functions  may  be
       removed in a future version.

SEE ALSO

       posix_trace_get_attr(), posix_trace_get_filter(), 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 .