Originální popis anglicky:
posix_trace_close, posix_trace_open, posix_trace_rewind - trace log management (
TRACING)
Návod, kniha: POSIX Programmer's Manual
#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);
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_eventid_equal()
posix_trace_eventid_get_name()
posix_trace_eventtypelist_getnext_id()
posix_trace_eventtypelist_rewind() |
posix_trace_get_attr() posix_trace_get_status()
posix_trace_getnext_event() posix_trace_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.
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.
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.
None.
None.
None.
None.
posix_trace_get_attr() ,
posix_trace_get_filter() ,
posix_trace_getnext_event() , the Base Definitions volume of
IEEE Std 1003.1-2001,
<trace.h>
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, Copyright (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.opengroup.org/unix/online.html
.
