получать и устанавливать атрибуты размера потока трассировки (TRACING) (retrieve and set trace stream size attributes (TRACING))
Пролог (Prolog)
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.
Имя (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)
Синопсис (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);
Описание (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 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.
Возвращаемое значение (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.
Ошибки (Error)
These functions may fail if:
EINVAL The value specified by one of the arguments is invalid.
The following sections are informative.
Примеры (Examples)
None.
Использование в приложениях (Application usage)
None.
Обоснование (Rationale)
None.
Будущие направления (Future directions)
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.
Смотри также (See also)
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)
