NAME
posix_trace_close, posix_trace_open, posix_trace_rewind - trace log
management (TRACING)
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);
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.
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.
ERRORS
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.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
posix_trace_get_attr() , posix_trace_get_filter() ,
posix_trace_getnext_event() , the Base Definitions volume of
IEEE Std 1003.1-2001, <trace.h>
COPYRIGHT
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 .