POSIX_TRACE_ATTR_GETLOGSIZE(3P)                     POSIX Programmer's Manual                    POSIX_TRACE_ATTR_GETLOGSIZE(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_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_set-
       maxdatasize, posix_trace_attr_setstreamsize - retrieve and set trace stream size attributes (TRACING)

SYNOPSIS
       #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
       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 maxdata-
       size 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 argu-
       ment.

RETURN VALUE
       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
       These functions may fail if:

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


       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       posix_trace_attr_init(), posix_trace_create(), posix_trace_event(), posix_trace_get_attr(), the Base  Definitions  volume
       of IEEE Std 1003.1-2001, <sys/types.h>, <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_ATTR_GETLOGSIZE(3P)