управление журналом трассировки (TRACING) (trace log management (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_close, posix_trace_open, posix_trace_rewind — trace
log management (TRACING)
Синопсис (Synopsis)
#include <trace.h>
int posix_trace_close(trace_id_t trid);
int posix_trace_open(int file_desc, trace_id_t *trid);
int posix_trace_rewind(trace_id_t trid);
Описание (Description)
The posix_trace_close() function shall deallocate the trace log
identifier indicated by trid, and all of its associated
resources. If there is no valid trace log pointed to by the trid,
this function shall fail.
The posix_trace_open() function shall allocate the necessary
resources and establish the connection between a trace log
identified by the file_desc argument and a trace stream
identifier identified by the object pointed to by the trid
argument. The file_desc argument should be a valid open file
descriptor that corresponds to a trace log. The file_desc
argument shall be open for reading. The current trace event
timestamp, which specifies the timestamp of the trace event that
will be read by the next call to posix_trace_getnext_event(),
shall be set to the timestamp of the oldest trace event recorded
in the trace log identified by trid.
The posix_trace_open() function shall return a trace stream
identifier in the variable pointed to by the trid argument, that
may only be used by the following functions:
posix_trace_close() posix_trace_get_attr()
posix_trace_eventid_equal() posix_trace_get_status()
posix_trace_eventid_get_name() posix_trace_getnext_event()
posix_trace_eventtypelist_getnext_id() posix_trace_rewind()
posix_trace_eventtypelist_rewind()
In particular, notice that the operations normally used by a
trace controller process, such as posix_trace_start(),
posix_trace_stop(), or posix_trace_shutdown(), cannot be invoked
using the trace stream identifier returned by the
posix_trace_open() function.
The posix_trace_rewind() function shall reset the current trace
event timestamp, which specifies the timestamp of the trace event
that will be read by the next call to
posix_trace_getnext_event(), to the timestamp of the oldest trace
event recorded in the trace log identified by trid.
Возвращаемое значение (Return value)
Upon successful completion, these functions shall return a value
of zero. Otherwise, they shall return the corresponding error
number.
If successful, the posix_trace_open() function stores the trace
stream identifier value in the object pointed to by trid.
Ошибки (Error)
The posix_trace_open() function shall fail if:
EINTR The operation was interrupted by a signal and thus no
trace log was opened.
EINVAL The object pointed to by file_desc does not correspond to
a valid trace log.
The posix_trace_close() and posix_trace_rewind() functions may
fail if:
EINVAL The object pointed to by trid does not correspond to a
valid trace log.
The following sections are informative.
Примеры (Examples)
None.
Использование в приложениях (Application usage)
None.
Обоснование (Rationale)
None.
Будущие направления (Future directions)
The posix_trace_close(), posix_trace_open(), and
posix_trace_rewind() functions may be removed in a future
version.
Смотри также (See also)
posix_trace_get_attr(3p), posix_trace_get_filter(3p),
posix_trace_getnext_event(3p)
The Base Definitions volume of POSIX.1‐2017, trace.h(0p)
