mirror of https://github.com/mkerrisk/man-pages
139 lines
5.6 KiB
Plaintext
139 lines
5.6 KiB
Plaintext
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.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
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.TH "POSIX_TRACE_EVENT" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
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.\" posix_trace_event
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.SH NAME
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posix_trace_event, posix_trace_eventid_open \- trace functions for
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instrumenting application code
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(\fBTRACING\fP)
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.SH SYNOPSIS
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.LP
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\fB#include <sys/types.h>
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.br
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#include <trace.h>
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.br
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.sp
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void posix_trace_event(trace_event_id_t\fP \fIevent_id\fP\fB,
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.br
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\ \ \ \ \ \ const void *restrict\fP\fIdata_ptr\fP\fB, size_t\fP \fIdata_len\fP\fB);
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.br
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int posix_trace_eventid_open(const char *restrict\fP \fIevent_name\fP\fB,
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.br
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\ \ \ \ \ \ trace_event_id_t *restrict\fP \fIevent_id\fP\fB); \fP
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\fB
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.br
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\fP
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.SH DESCRIPTION
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.LP
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The \fIposix_trace_event\fP() function shall record the \fIevent_id\fP
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and the user data pointed to by \fIdata_ptr\fP in the
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trace stream into which the calling process is being traced and in
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which \fIevent_id\fP is not filtered out. If the total size of
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the user trace event data represented by \fIdata_len\fP is not greater
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than the declared maximum size for user trace event data,
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then the \fItruncation-status\fP attribute of the trace event recorded
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is POSIX_TRACE_NOT_TRUNCATED. Otherwise, the user trace
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event data is truncated to this declared maximum size and the \fItruncation-status\fP
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attribute of the trace event recorded is
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POSIX_TRACE_TRUNCATED_RECORD.
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.LP
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If there is no trace stream created for the process or if the created
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trace stream is not running, or if the trace event
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specified by \fIevent_id\fP is filtered out in the trace stream, the
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\fIposix_trace_event\fP() function shall have no effect.
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.LP
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The \fIposix_trace_eventid_open\fP() function shall associate a user
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trace event name with a trace event type identifier for
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the calling process. The trace event name is the string pointed to
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by the argument \fIevent_name\fP. It shall have a maximum of
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{TRACE_EVENT_NAME_MAX} characters (which has the minimum value {_POSIX_TRACE_EVENT_NAME_MAX}).
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The number of user trace event type
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identifiers that can be defined for any given process is limited by
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the maximum value {TRACE_USER_EVENT_MAX}, which has the minimum
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value {POSIX_TRACE_USER_EVENT_MAX}.
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.LP
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If the Trace Inherit option is not supported, the \fIposix_trace_eventid_open\fP()
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function shall associate the user trace
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event name pointed to by the \fIevent_name\fP argument with a trace
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event type identifier that is unique for the traced process,
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and is returned in the variable pointed to by the \fIevent_id\fP argument.
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If the user trace event name has already been mapped
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for the traced process, then the previously assigned trace event type
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identifier shall be returned. If the per-process user trace
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event name limit represented by {TRACE_USER_EVENT_MAX} has been reached,
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the pre-defined POSIX_TRACE_UNNAMED_USEREVENT (see \fITrace Option:
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User Trace Event\fP ) user trace event shall be returned.
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.LP
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If the Trace Inherit option is supported, the \fIposix_trace_eventid_open\fP()
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function shall associate the user trace event name
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pointed to by the \fIevent_name\fP argument with a trace event type
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identifier that is unique for all the processes being traced
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in this same trace stream, and is returned in the variable pointed
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to by the \fIevent_id\fP argument. If the user trace event name
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has already been mapped for the traced processes, then the previously
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assigned trace event type identifier shall be returned. If
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the per-process user trace event name limit represented by {TRACE_USER_EVENT_MAX}
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has been reached, the pre-defined
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POSIX_TRACE_UNNAMED_USEREVENT ( \fITrace Option: User Trace Event\fP
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) user trace event
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shall be returned.
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.TP 7
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\fBNote:\fP
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The above procedure, together with the fact that multiple processes
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can only be traced into the same trace stream by
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inheritance, ensure that all the processes that are traced into a
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trace stream have the same mapping of trace event names to trace
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event type identifiers.
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.sp
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.LP
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If there is no trace stream created, the \fIposix_trace_eventid_open\fP()
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function shall store this information for future
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trace streams created for this process.
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.SH RETURN VALUE
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.LP
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No return value is defined for the \fIposix_trace_event\fP() function.
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.LP
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Upon successful completion, the \fIposix_trace_eventid_open\fP() function
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shall return a value of zero. Otherwise, it shall
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return the corresponding error number. The \fIposix_trace_eventid_open\fP()
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function stores the trace event type identifier value
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in the object pointed to by \fIevent_id\fP, if successful.
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.SH ERRORS
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.LP
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The \fIposix_trace_eventid_open\fP() function shall fail if:
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.TP 7
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.B ENAMETOOLONG
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The size of the name pointed to by the \fIevent_name\fP argument was
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longer than the implementation-defined value
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{TRACE_EVENT_NAME_MAX}.
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.sp
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.LP
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\fIThe following sections are informative.\fP
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.SH EXAMPLES
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.LP
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None.
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.SH APPLICATION USAGE
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.LP
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None.
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.SH RATIONALE
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.LP
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None.
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.SH FUTURE DIRECTIONS
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.LP
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None.
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.SH SEE ALSO
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.LP
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\fITrace Option: User Trace Event\fP , \fIposix_trace_start\fP() ,
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\fIposix_trace_trid_eventid_open\fP() , the Base Definitions volume
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of
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IEEE\ Std\ 1003.1-2001, \fI<sys/types.h>\fP, \fI<trace.h>\fP
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.SH COPYRIGHT
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Portions of this text are reprinted and reproduced in electronic form
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from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
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-- Portable Operating System Interface (POSIX), The Open Group Base
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Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
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Electrical and Electronics Engineers, Inc and The Open Group. In the
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event of any discrepancy between this version and the original IEEE and
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The Open Group Standard, the original IEEE and The Open Group Standard
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is the referee document. The original Standard can be obtained online at
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http://www.opengroup.org/unix/online.html .
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