#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);
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_eventid_equal() posix_trace_eventid_get_name() posix_trace_eventtypelist_getnext_id() posix_trace_eventtypelist_rewind() |
posix_trace_get_attr()
posix_trace_get_status()
posix_trace_getnext_event()
posix_trace_rewind()
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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.
If successful, the posix_trace_open() function stores the trace stream identifier value in the object pointed to by trid.
The posix_trace_close() and posix_trace_rewind() functions may fail if:
The following sections are informative.
The Base Definitions volume of POSIX.1-2017, <trace.h>
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