The Open Group Base Specifications Issue 6
IEEE Std 1003.1, 2004 Edition
Copyright © 2001-2004 The IEEE and The Open Group, All Rights reserved.

#### 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_setmaxdatasize, posix_trace_attr_setstreamsize - retrieve and set trace stream size attributes (TRACING)

#### SYNOPSIS

> ``[TRC] #include <sys/types.h>
> #include <trace.h>
> ``
> ``[TRC TRL] int posix_trace_attr_getlogsize(const trace_attr_t *restrict` attr`,
> size_t *restrict` logsize`);
> ``
> ``[TRC] 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`);
> ``
> ``[TRC TRL] int posix_trace_attr_setlogsize(trace_attr_t *`attr`,
> size_t` logsize`);
> ``
> ``[TRC] 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

> [TRL] 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

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

> [TRL] 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>

#### CHANGE HISTORY

> First released in Issue 6. Derived from IEEE Std 1003.1q-2000.

End of informative text.

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