Originální popis anglicky:
posix_trace_event, posix_trace_eventid_open - trace functions for instrumenting
application code (
TRACING)
Návod, kniha: POSIX Programmer's Manual
#include <sys/types.h>
#include <trace.h>
void posix_trace_event(trace_event_id_t
event_id,
const void *restrict
data_ptr , size_t
data_len);
int posix_trace_eventid_open(const char *restrict
event_name ,
trace_event_id_t *restrict
event_id);
The
posix_trace_event() function shall record the
event_id and the
user data pointed to by
data_ptr in the trace stream into which the
calling process is being traced and in which
event_id is not filtered
out. If the total size of the user trace event data represented by
data_len is not greater than the declared maximum size for user trace
event data, then the
truncation-status attribute of the trace event
recorded is POSIX_TRACE_NOT_TRUNCATED. Otherwise, the user trace event data is
truncated to this declared maximum size and the
truncation-status
attribute of the trace event recorded is POSIX_TRACE_TRUNCATED_RECORD.
If there is no trace stream created for the process or if the created trace
stream is not running, or if the trace event specified by
event_id is
filtered out in the trace stream, the
posix_trace_event() function
shall have no effect.
The
posix_trace_eventid_open() function shall associate a user trace
event name with a trace event type identifier for the calling process. The
trace event name is the string pointed to by the argument
event_name.
It shall have a maximum of {TRACE_EVENT_NAME_MAX} characters (which has the
minimum value {_POSIX_TRACE_EVENT_NAME_MAX}). The number of user trace event
type identifiers that can be defined for any given process is limited by the
maximum value {TRACE_USER_EVENT_MAX}, which has the minimum value
{POSIX_TRACE_USER_EVENT_MAX}.
If the Trace Inherit option is not supported, the
posix_trace_eventid_open() function shall associate the user trace
event name pointed to by the
event_name argument with a trace event
type identifier that is unique for the traced process, and is returned in the
variable pointed to by the
event_id argument. If the user trace event
name has already been mapped for the traced process, then the previously
assigned trace event type identifier shall be returned. If the per-process
user trace event name limit represented by {TRACE_USER_EVENT_MAX} has been
reached, the pre-defined POSIX_TRACE_UNNAMED_USEREVENT (see
Trace
Option: User Trace Event ) user trace event shall be returned.
If the Trace Inherit option is supported, the
posix_trace_eventid_open()
function shall associate the user trace event name pointed to by the
event_name argument with a trace event type identifier that is unique
for all the processes being traced in this same trace stream, and is returned
in the variable pointed to by the
event_id argument. If the user trace
event name has already been mapped for the traced processes, then the
previously assigned trace event type identifier shall be returned. If the
per-process user trace event name limit represented by {TRACE_USER_EVENT_MAX}
has been reached, the pre-defined POSIX_TRACE_UNNAMED_USEREVENT (
Trace
Option: User Trace Event ) user trace event shall be returned.
- Note:
- The above procedure, together with the fact that multiple
processes can only be traced into the same trace stream by inheritance,
ensure that all the processes that are traced into a trace stream have the
same mapping of trace event names to trace event type identifiers.
If there is no trace stream created, the
posix_trace_eventid_open()
function shall store this information for future trace streams created for
this process.
No return value is defined for the
posix_trace_event() function.
Upon successful completion, the
posix_trace_eventid_open() function shall
return a value of zero. Otherwise, it shall return the corresponding error
number. The
posix_trace_eventid_open() function stores the trace event
type identifier value in the object pointed to by
event_id, if
successful.
The
posix_trace_eventid_open() function shall fail if:
- ENAMETOOLONG
- The size of the name pointed to by the event_name
argument was longer than the implementation-defined value
{TRACE_EVENT_NAME_MAX}.
The following sections are informative.
None.
None.
None.
None.
Trace Option: User Trace Event ,
posix_trace_start() ,
posix_trace_trid_eventid_open() , the Base Definitions volume of
IEEE Std 1003.1-2001,
<sys/types.h>,
<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
.
