POSIX_TRACE_ATTR_GETINHERITEPDO(S3I)X Programmer's MPaOnSuIaXl_TRACE_ATTR_GETINHERITED(3)



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

NAME
       posix_trace_attr_getinherited, posix_trace_attr_getlogfullpolicy,
       posix_trace_attr_getstreamfullpolicy, posix_trace_attr_setinherited,
       posix_trace_attr_setlogfullpolicy, posix_trace_attr_setstreamfullpolicy
       -- retrieve and set the behavior of a trace stream (TRACING)

SYNOPSIS
       #include <trace.h>

       int posix_trace_attr_getinherited(const trace_attr_t *restrict attr,
           int *restrict inheritancepolicy);
       int posix_trace_attr_getlogfullpolicy(const trace_attr_t *restrict attr,
           int *restrict logpolicy);
       int posix_trace_attr_getstreamfullpolicy(const trace_attr_t *restrict
           attr, int *restrict streampolicy);
       int posix_trace_attr_setinherited(trace_attr_t *attr,
           int inheritancepolicy);
       int posix_trace_attr_setlogfullpolicy(trace_attr_t *attr,
           int logpolicy);
       int posix_trace_attr_setstreamfullpolicy(trace_attr_t *attr,
           int streampolicy);

DESCRIPTION
       The posix__trace__attr__getinherited() and posix__trace__attr__setinherited()
       functions, respectively, shall get and set the inheritance policy
       stored in the inheritance attribute for traced processes across the
       fork() and spawn() operations. The inheritance attribute of the
       attributes object pointed to by the attr argument shall be set to one
       of the following values defined by manifest constants in the <trace.h>
       header:

       POSIX_TRACE_CLOSE_FOR_CHILD
             After a fork() or spawn() operation, the child shall not be
             traced, and tracing of the parent shall continue.

       POSIX_TRACE_INHERITED
             After a fork() or spawn() operation, if the parent is being
             traced, its child shall be concurrently traced using the same
             trace stream.

       The default value for the inheritance attribute is
       POSIX_TRACE_CLOSE_FOR_CHILD.

       The posix__trace__attr__getlogfullpolicy() and
       posix__trace__attr__setlogfullpolicy() functions, respectively, shall get
       and set the trace log full policy stored in the log-full-policy
       attribute of the attributes object pointed to by the attr argument.

       The log-full-policy attribute shall be set to one of the following
       values defined by manifest constants in the <trace.h> header:

       POSIX_TRACE_LOOP
             The trace log shall loop until the associated trace stream is
             stopped.  This policy means that when the trace log gets full,
             the file system shall reuse the resources allocated to the oldest
             trace events that were recorded. In this way, the trace log will
             always contain the most recent trace events flushed.

       POSIX_TRACE_UNTIL_FULL
             The trace stream shall be flushed to the trace log until the
             trace log is full. This condition can be deduced from the
             posix__log__full__status member status (see the
             posix_trace_status_info structure defined in <trace.h>).  The
             last recorded trace event shall be the POSIX_TRACE_STOP trace
             event.

       POSIX_TRACE_APPEND
             The associated trace stream shall be flushed to the trace log
             without log size limitation. If the application specifies
             POSIX_TRACE_APPEND, the implementation shall ignore the log-max-
             size attribute.

       The default value for the log-full-policy attribute is
       POSIX_TRACE_LOOP.

       The posix__trace__attr__getstreamfullpolicy() and
       posix__trace__attr__setstreamfullpolicy() functions, respectively, shall
       get and set the trace stream full policy stored in the stream-full-
       policy attribute of the attributes object pointed to by the attr
       argument.

       The stream-full-policy attribute shall be set to one of the following
       values defined by manifest constants in the <trace.h> header:

       POSIX_TRACE_LOOP
             The trace stream shall loop until explicitly stopped by the
             posix__trace__stop() function. This policy means that when the
             trace stream is full, the trace system shall reuse the resources
             allocated to the oldest trace events recorded. In this way, the
             trace stream will always contain the most recent trace events
             recorded.

       POSIX_TRACE_UNTIL_FULL
             The trace stream will run until the trace stream resources are
             exhausted. Then the trace stream will stop. This condition can be
             deduced from posix__stream__status and posix__stream__full__status
             (see the posix_trace_status_info structure defined in <trace.h>).
             When this trace stream is read, a POSIX_TRACE_STOP trace event
             shall be reported after reporting the last recorded trace event.
             The trace system shall reuse the resources allocated to any trace
             events already reported--see the posix__trace__getnext__event(),
             posix__trace__trygetnext__event(), and
             posix__trace__timedgetnext__event() functions--or already flushed
             for an active trace stream with log if the Trace Log option is
             supported; see the posix__trace__flush() function. The trace system
             shall restart the trace stream when it is empty and may restart
             it sooner. A POSIX_TRACE_START trace event shall be reported
             before reporting the next recorded trace event.

       POSIX_TRACE_FLUSH
             If the Trace Log option is supported, this policy is identical to
             the POSIX_TRACE_UNTIL_FULL trace stream full policy except that
             the trace stream shall be flushed regularly as if
             posix__trace__flush() had been explicitly called. Defining this
             policy for an active trace stream without log shall be invalid.

       The default value for the stream-full-policy attribute shall be
       POSIX_TRACE_LOOP for an active trace stream without log.

       If the Trace Log option is supported, the default value for the stream-
       full-policy attribute shall be POSIX_TRACE_FLUSH for an active trace
       stream with log.

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__attr__getinherited() function shall store
       the inheritance attribute value in the object pointed to by
       inheritancepolicy.  Otherwise, the content of this object is undefined.

       If successful, the posix__trace__attr__getlogfullpolicy() function shall
       store the log-full-policy attribute value in the object pointed to by
       logpolicy.  Otherwise, the content of this object is undefined.

       If successful, the posix__trace__attr__getstreamfullpolicy() function
       shall store the stream-full-policy attribute value in the object
       pointed to by streampolicy.  Otherwise, the content of this object is
       undefined.

ERRORS
       These functions may fail if:

       EINVAL The value specified by at least one of the arguments is invalid.

       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       The following functions:

              posix__trace__attr__getinherited()
              posix__trace__attr__getlogfullpolicy()
              posix__trace__attr__getstreamfullpolicy()
              posix__trace__attr__setinherited()
              posix__trace__attr__setlogfullpolicy()
              posix__trace__attr__setstreamfullpolicy()

       may be removed in a future version.

SEE ALSO
       fork(), posix__trace__attr__destroy(), posix__trace__create(),
       posix__trace__get__attr(), posix__trace__getnext__event(),
       posix__trace__start()

       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 .



IEEE/The Open Group                  2017     POSIX_TRACE_ATTR_GETINHERITED(3)
