posix_trace_get_attr man page

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.

posix_trace_get_attr, posix_trace_get_status — retrieve the trace attributes or trace status (TRACING)

Synopsis

#include <trace.h>

int posix_trace_get_attr(trace_id_t trid, trace_attr_t *attr);
int posix_trace_get_status(trace_id_t trid,
    struct posix_trace_status_info *statusinfo);

Description

The posix_trace_get_attr() function shall copy the attributes of the active trace stream identified by trid into the object pointed to by the attr argument. If the Trace Log option is supported, trid may represent a pre-recorded trace log.

The posix_trace_get_status() function shall return, in the structure pointed to by the statusinfo argument, the current trace status for the trace stream identified by the trid argument. These status values returned in the structure pointed to by statusinfo shall have been appropriately read to ensure that the returned values are consistent. If the Trace Log option is supported and the trid argument refers to a pre-recorded trace stream, the status shall be the status of the completed trace stream.

Each time the posix_trace_get_status() function is used, the overrun status of the trace stream shall be reset to POSIX_TRACE_NO_OVERRUN immediately after the call completes. If the Trace Log option is supported, the posix_trace_get_status() function shall behave the same as when the option is not supported except for the following differences:

*
If the trid argument refers to a trace stream with log, each time the posix_trace_get_status() function is used, the log overrun status of the trace stream shall be reset to POSIX_TRACE_NO_OVERRUN and the flush_error status shall be reset to zero immediately after the call completes.
*
If the trid argument refers to a pre-recorded trace stream, the status returned shall be the status of the completed trace stream and the status values of the trace stream shall not be reset.

Return Value

Upon successful completion, these functions shall return a value of zero. Otherwise, they shall return the corresponding error number.

The posix_trace_get_attr() function stores the trace attributes in the object pointed to by attr, if successful.

The posix_trace_get_status() function stores the trace status in the object pointed to by statusinfo, if successful.

Errors

These functions shall fail if:

EINVAL
The trace stream argument trid does not correspond to a valid active trace stream or a valid trace log.

The following sections are informative.

Future Directions

The posix_trace_get_attr() and posix_trace_get_status() functions may be removed in a future version.

See Also

posix_trace_attr_destroy(), posix_trace_close(), posix_trace_create()

The Base Definitions volume of POSIX.1‐2008, <trace.h>

Info

2013 IEEE/The Open Group POSIX Programmer's Manual