posix_trace_attr_getlogsize(3p) — Linux manual page

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

POSIX_T...TLOGSIZE(3P)  POSIX Programmer's Manual POSIX_T...TLOGSIZE(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.1‐2017, sys_types.h(0p),
       trace.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in  electronic
       form   from   IEEE  Std  1003.1-2017,  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_T...TLOGSIZE(3P)

Pages that refer to this page: trace.h(0p)posix_trace_attr_getstreamsize(3p)posix_trace_attr_setlogsize(3p)posix_trace_attr_setstreamsize(3p)