PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

POSIX_TRACE_ATTR_GETLOGSIZE(3P) Programmer's ManualTRACE_ATTR_GETLOGSIZE(3P)

PROLOG         top

       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         top

       posix_trace_attr_getlogsize, posix_trace_attr_getmaxdatasize,
       posix_trace_attr_getmaxsystemeventsize,
       posix_trace_attr_getmaxusereventsize, posix_trace_attr_getstreamsize,
       posix_trace_attr_setlogsize, posix_trace_attr_setmaxdatasize,
       posix_trace_attr_setstreamsize — retrieve and set trace stream size
       attributes (TRACING)

SYNOPSIS         top

       #include <sys/types.h>
       #include <trace.h>

       int posix_trace_attr_getlogsize(const trace_attr_t *restrict attr,
           size_t *restrict logsize);
       int posix_trace_attr_getmaxdatasize(const trace_attr_t *restrict attr,
           size_t *restrict maxdatasize);
       int posix_trace_attr_getmaxsystemeventsize(
           const trace_attr_t *restrict attr,
           size_t *restrict eventsize);
       int posix_trace_attr_getmaxusereventsize(
           const trace_attr_t *restrict attr,
           size_t data_len, size_t *restrict eventsize);
       int posix_trace_attr_getstreamsize(const trace_attr_t *restrict attr,
           size_t *restrict streamsize);
       int posix_trace_attr_setlogsize(trace_attr_t *attr,
           size_t logsize);
       int posix_trace_attr_setmaxdatasize(trace_attr_t *attr,
           size_t maxdatasize);
       int posix_trace_attr_setstreamsize(trace_attr_t *attr,
           size_t streamsize);

DESCRIPTION         top

       The posix_trace_attr_getlogsize() function shall copy the log size,
       in bytes, from the log-max-size attribute of the attributes object
       pointed to by the attr argument into the variable pointed to by the
       logsize argument. This log size is the maximum total of bytes that
       shall be allocated for system and user trace events in the trace log.
       The default value for the log-max-size attribute is implementation-
       defined.

       The posix_trace_attr_setlogsize() function shall set the maximum
       allowed size, in bytes, in the log-max-size attribute of the
       attributes object pointed to by the attr argument, using the size
       value supplied by the logsize argument.

       The trace log size shall be used if the log-full-policy attribute is
       set to POSIX_TRACE_LOOP or POSIX_TRACE_UNTIL_FULL. If the log-full-
       policy attribute is set to POSIX_TRACE_APPEND, the implementation
       shall ignore the log-max-size attribute.

       The posix_trace_attr_getmaxdatasize() function shall copy the maximum
       user trace event data size, in bytes, from the max-data-size
       attribute of the attributes object pointed to by the attr argument
       into the variable pointed to by the maxdatasize argument. The default
       value for the max-data-size attribute is implementation-defined.

       The posix_trace_attr_getmaxsystemeventsize() function shall calculate
       the maximum memory size, in bytes, required to store a single system
       trace event. This value is calculated for the trace stream attributes
       object pointed to by the attr argument and is returned in the
       variable pointed to by the eventsize argument.

       The values returned as the maximum memory sizes of the user and
       system trace events shall be such that if the sum of the maximum
       memory sizes of a set of the trace events that may be recorded in a
       trace stream is less than or equal to the stream-min-size attribute
       of that trace stream, the system provides the necessary resources for
       recording all those trace events, without loss.

       The posix_trace_attr_getmaxusereventsize() function shall calculate
       the maximum memory size, in bytes, required to store a single user
       trace event generated by a call to posix_trace_event() with a
       data_len parameter equal to the data_len value specified in this
       call. This value is calculated for the trace stream attributes object
       pointed to by the attr argument and is returned in the variable
       pointed to by the eventsize argument.

       The posix_trace_attr_getstreamsize() function shall copy the stream
       size, in bytes, from the stream-min-size attribute of the attributes
       object pointed to by the attr argument into the variable pointed to
       by the streamsize argument.

       This stream size is the current total memory size reserved for system
       and user trace events in the trace stream. The default value for the
       stream-min-size attribute is implementation-defined. The stream size
       refers to memory used to store trace event records. Other stream data
       (for example, trace attribute values) shall not be included in this
       size.

       The posix_trace_attr_setmaxdatasize() function shall set the maximum
       allowed size, in bytes, in the max-data-size attribute of the
       attributes object pointed to by the attr argument, using the size
       value supplied by the maxdatasize argument. This maximum size is the
       maximum allowed size for the user data argument which may be passed
       to posix_trace_event().  The implementation shall be allowed to
       truncate data passed to trace_user_event which is longer than
       maxdatasize.

       The posix_trace_attr_setstreamsize() function shall set the minimum
       allowed size, in bytes, in the stream-min-size attribute of the
       attributes object pointed to by the attr argument, using the size
       value supplied by the streamsize argument.

RETURN VALUE         top

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

       The posix_trace_attr_getlogsize() function stores the maximum trace
       log allowed size in the object pointed to by logsize, if successful.

       The posix_trace_attr_getmaxdatasize() function stores the maximum
       trace event record memory size in the object pointed to by
       maxdatasize, if successful.

       The posix_trace_attr_getmaxsystemeventsize() function stores the
       maximum memory size to store a single system trace event in the
       object pointed to by eventsize, if successful.

       The posix_trace_attr_getmaxusereventsize() function stores the
       maximum memory size to store a single user trace event in the object
       pointed to by eventsize, if successful.

       The posix_trace_attr_getstreamsize() function stores the maximum
       trace stream allowed size in the object pointed to by streamsize, if
       successful.

ERRORS         top

       These functions may fail if:

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

       The following sections are informative.

EXAMPLES         top

       None.

APPLICATION USAGE         top

       None.

RATIONALE         top

       None.

FUTURE DIRECTIONS         top

       The following functions:

              posix_trace_attr_getlogsize()
              posix_trace_attr_getmaxdatasize()
              posix_trace_attr_getmaxsystemeventsize()
              posix_trace_attr_getmaxusereventsize()
              posix_trace_attr_getstreamsize()
              posix_trace_attr_setlogsize()
              posix_trace_attr_setmaxdatasize()
              posix_trace_attr_setstreamsize()

       may be removed in a future version.

SEE ALSO         top

       posix_trace_attr_destroy(3p), posix_trace_create(3p),
       posix_trace_event(3p), posix_trace_get_attr(3p)

       The   Base   Definitions  volume  of  POSIX.1‐2008,  sys_types.h(0p),
       trace.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) 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.unix.org/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                 2013     POSIX_TRACE_ATTR_GETLOGSIZE(3P)