'\" et
.TH POSIX_TRACE_CLEAR "3P" 2013 "IEEE/The Open Group" "POSIX Programmer's Manual"
.SH 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.

.SH NAME
posix_trace_clear
\(em clear trace stream and trace log
(\fBTRACING\fP)
.SH SYNOPSIS
.LP
.nf
#include <sys/types.h>
#include <trace.h>
.P
int posix_trace_clear(trace_id_t \fItrid\fP);
.fi
.SH DESCRIPTION
The
\fIposix_trace_clear\fR()
function shall reinitialize the trace stream identified by the argument
.IR trid
as if it were returning from the
\fIposix_trace_create\fR()
function, except that the same allocated resources shall be reused, the
mapping of trace event type identifiers to trace event names shall be
unchanged, and the trace stream status shall remain unchanged (that is,
if it was running, it remains running and if it was suspended, it
remains suspended).
.P
All trace events in the trace stream recorded before the call to
\fIposix_trace_clear\fR()
shall be lost. The
.IR posix_stream_full_status
status shall be set to POSIX_TRACE_NOT_FULL.
There is no guarantee that all trace events that occurred during the
\fIposix_trace_clear\fR()
call are recorded; the behavior with respect to trace points that may
occur during this call is unspecified.
.P
If the Trace Log option is supported and the trace stream has been
created with a log, the
\fIposix_trace_clear\fR()
function shall reinitialize the trace stream with the same behavior as
if the trace stream was created without the log, plus it shall
reinitialize the trace log associated with the trace stream identified
by the argument
.IR trid
as if it were returning from the
\fIposix_trace_create_withlog\fR()
function, except that the same allocated resources, for the trace log,
may be reused and the associated trace stream status remains unchanged.
The first trace event recorded in the trace log after the call to
\fIposix_trace_clear\fR()
shall be the same as the first trace event recorded in the active trace
stream after the call to
\fIposix_trace_clear\fR().
The
.IR posix_log_full_status
status shall be set to POSIX_TRACE_NOT_FULL. There is no guarantee
that all trace events that occurred during the
\fIposix_trace_clear\fR()
call are recorded in the trace log; the behavior with respect to trace
points that may occur during this call is unspecified. If the log full
policy is POSIX_TRACE_APPEND, the effect of a call to this function is
unspecified for the trace log associated with the trace stream
identified by the
.IR trid
argument.
.SH "RETURN VALUE"
Upon successful completion, the
\fIposix_trace_clear\fR()
function shall return a value of zero. Otherwise, it shall return the
corresponding error number.
.SH ERRORS
The
\fIposix_trace_clear\fR()
function shall fail if:
.TP
.BR EINVAL
The value of the
.IR trid
argument does not correspond to an active trace stream.
.LP
.IR "The following sections are informative."
.SH EXAMPLES
None.
.SH "APPLICATION USAGE"
None.
.SH RATIONALE
None.
.SH "FUTURE DIRECTIONS"
The
\fIposix_trace_clear\fR()
function may be removed in a future version.
.SH "SEE ALSO"
.ad l
.IR "\fIposix_trace_attr_destroy\fR\^(\|)",
.IR "\fIposix_trace_create\fR\^(\|)",
.IR "\fIposix_trace_get_attr\fR\^(\|)"
.ad b
.P
The Base Definitions volume of POSIX.1\(hy2008,
.IR "\fB<sys_types.h>\fP",
.IR "\fB<trace.h>\fP"
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
(This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/online.html .

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