|
PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT |
|
POSIX_TRACE_CREATE(3P) POSIX Programmer's Manual POSIX_TRACE_CREATE(3P)
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_create, posix_trace_create_withlog, posix_trace_flush,
posix_trace_shutdown — trace stream initialization, flush, and
shutdown from a process (TRACING)
#include <sys/types.h>
#include <trace.h>
int posix_trace_create(pid_t pid,
const trace_attr_t *restrict attr,
trace_id_t *restrict trid);
int posix_trace_create_withlog(pid_t pid,
const trace_attr_t *restrict attr, int file_desc,
trace_id_t *restrict trid);
int posix_trace_flush(trace_id_t trid);
int posix_trace_shutdown(trace_id_t trid);
The posix_trace_create() function shall create an active trace
stream. It allocates all the resources needed by the trace stream
being created for tracing the process specified by pid in accordance
with the attr argument. The attr argument represents the initial
attributes of the trace stream and shall have been initialized by the
function posix_trace_attr_init() prior to the posix_trace_create()
call. If the argument attr is NULL, the default attributes shall be
used. The attr attributes object shall be manipulated through a set
of functions described in the posix_trace_attr family of functions.
If the attributes of the object pointed to by attr are modified
later, the attributes of the trace stream shall not be affected. The
creation-time attribute of the newly created trace stream shall be
set to the value of the system clock, if the Timers option is not
supported, or to the value of the CLOCK_REALTIME clock, if the Timers
option is supported.
The pid argument represents the target process to be traced. If the
process executing this function does not have appropriate privileges
to trace the process identified by pid, an error shall be returned.
If the pid argument is zero, the calling process shall be traced.
The posix_trace_create() function shall store the trace stream
identifier of the new trace stream in the object pointed to by the
trid argument. This trace stream identifier shall be used in
subsequent calls to control tracing. The trid argument may only be
used by the following functions:
posix_trace_clear() posix_trace_getnext_event()
posix_trace_eventid_equal() posix_trace_shutdown()
posix_trace_eventid_get_name() posix_trace_start()
posix_trace_eventtypelist_getnext_id() posix_trace_stop()
posix_trace_eventtypelist_rewind() posix_trace_timedgetnext_event()
posix_trace_get_attr() posix_trace_trid_eventid_open()
posix_trace_get_status() posix_trace_trygetnext_event()
If the Trace Event Filter option is supported, the following
additional functions may use the trid argument:
posix_trace_get_filter() posix_trace_set_filter()
In particular, notice that the operations normally used by a trace
analyzer process, such as posix_trace_rewind() or
posix_trace_close(), cannot be invoked using the trace stream
identifier returned by the posix_trace_create() function.
A trace stream shall be created in a suspended state. If the Trace
Event Filter option is supported, its trace event type filter shall
be empty.
The posix_trace_create() function may be called multiple times from
the same or different processes, with the system-wide limit indicated
by the runtime invariant value {TRACE_SYS_MAX}, which has the minimum
value {_POSIX_TRACE_SYS_MAX}.
The trace stream identifier returned by the posix_trace_create()
function in the argument pointed to by trid is valid only in the
process that made the function call. If it is used from another
process, that is a child process, in functions defined in
POSIX.1‐2008, these functions shall return with the error [EINVAL].
The posix_trace_create_withlog() function shall be equivalent to
posix_trace_create(), except that it associates a trace log with this
stream. The file_desc argument shall be the file descriptor
designating the trace log destination. The function shall fail if
this file descriptor refers to a file with a file type that is not
compatible with the log policy associated with the trace log. The
list of the appropriate file types that are compatible with each log
policy is implementation-defined.
The posix_trace_create_withlog() function shall return in the
parameter pointed to by trid the trace stream identifier, which
uniquely identifies the newly created trace stream, and shall be used
in subsequent calls to control tracing. The trid argument may only be
used by the following functions:
posix_trace_clear() posix_trace_get_status()
posix_trace_eventid_equal() posix_trace_getnext_event()
posix_trace_eventid_get_name() posix_trace_shutdown()
posix_trace_eventtypelist_getnext_id() posix_trace_start()
posix_trace_eventtypelist_rewind() posix_trace_stop()
posix_trace_flush() posix_trace_timedgetnext_event()
posix_trace_get_attr() posix_trace_trid_eventid_open()
If the Trace Event Filter option is supported, the following
additional functions may use the trid argument:
posix_trace_get_filter() posix_trace_set_filter()
In particular, notice that the operations normally used by a trace
analyzer process, such as posix_trace_rewind() or
posix_trace_close(), cannot be invoked using the trace stream
identifier returned by the posix_trace_create_withlog() function.
The posix_trace_flush() function shall initiate a flush operation
which copies the contents of the trace stream identified by the
argument trid into the trace log associated with the trace stream at
the creation time. If no trace log has been associated with the trace
stream pointed to by trid, this function shall return an error. The
termination of the flush operation can be polled by the
posix_trace_get_status() function. During the flush operation, it
shall be possible to trace new trace events up to the point when the
trace stream becomes full. After flushing is completed, the space
used by the flushed trace events shall be available for tracing new
trace events.
If flushing the trace stream causes the resulting trace log to become
full, the trace log full policy shall be applied. If the trace log-
full-policy attribute is set, the following occurs:
POSIX_TRACE_UNTIL_FULL
The trace events that have not yet been flushed shall be
discarded.
POSIX_TRACE_LOOP
The trace events that have not yet been flushed shall be
written to the beginning of the trace log, overwriting previous
trace events stored there.
POSIX_TRACE_APPEND
The trace events that have not yet been flushed shall be
appended to the trace log.
The posix_trace_shutdown() function shall stop the tracing of trace
events in the trace stream identified by trid, as if
posix_trace_stop() had been invoked. The posix_trace_shutdown()
function shall free all the resources associated with the trace
stream.
The posix_trace_shutdown() function shall not return until all the
resources associated with the trace stream have been freed. When the
posix_trace_shutdown() function returns, the trid argument becomes an
invalid trace stream identifier. A call to this function shall
unconditionally deallocate the resources regardless of whether all
trace events have been retrieved by the analyzer process. Any thread
blocked on one of the trace_getnext_event() functions (which
specified this trid) before this call is unblocked with the error
[EINVAL].
If the process exits, invokes a member of the exec family of
functions, or is terminated, the trace streams that the process had
created and that have not yet been shut down, shall be automatically
shut down as if an explicit call were made to the
posix_trace_shutdown() function.
For an active trace stream with log, when the posix_trace_shutdown()
function is called, all trace events that have not yet been flushed
to the trace log shall be flushed, as in the posix_trace_flush()
function, and the trace log shall be closed.
When a trace log is closed, all the information that may be retrieved
later from the trace log through the trace interface shall have been
written to the trace log. This information includes the trace
attributes, the list of trace event types (with the mapping between
trace event names and trace event type identifiers), and the trace
status.
In addition, unspecified information shall be written to the trace
log to allow detection of a valid trace log during the
posix_trace_open() operation.
The posix_trace_shutdown() function shall not return until all trace
events have been flushed.
Upon successful completion, these functions shall return a value of
zero. Otherwise, they shall return the corresponding error number.
The posix_trace_create() and posix_trace_create_withlog() functions
store the trace stream identifier value in the object pointed to by
trid, if successful.
The posix_trace_create() and posix_trace_create_withlog() functions
shall fail if:
EAGAIN No more trace streams can be started now. {TRACE_SYS_MAX} has
been exceeded.
EINTR The operation was interrupted by a signal. No trace stream was
created.
EINVAL One or more of the trace parameters specified by the attr
parameter is invalid.
ENOMEM The implementation does not currently have sufficient memory
to create the trace stream with the specified parameters.
EPERM The caller does not have appropriate privileges to trace the
process specified by pid.
ESRCH The pid argument does not refer to an existing process.
The posix_trace_create_withlog() function shall fail if:
EBADF The file_desc argument is not a valid file descriptor open for
writing.
EINVAL The file_desc argument refers to a file with a file type that
does not support the log policy associated with the trace log.
ENOSPC No space left on device. The device corresponding to the
argument file_desc does not contain the space required to
create this trace log.
The posix_trace_flush() and posix_trace_shutdown() functions shall
fail if:
EINVAL The value of the trid argument does not correspond to an
active trace stream with log.
EFBIG The trace log file has attempted to exceed an implementation-
defined maximum file size.
ENOSPC No space left on device.
The following sections are informative.
None.
None.
None.
The posix_trace_create(), posix_trace_create_withlog(),
posix_trace_flush(), and posix_trace_shutdown() functions may be
removed in a future version.
clock_getres(3p), exec(1p), posix_trace_attr_destroy(3p),
posix_trace_clear(3p), posix_trace_close(3p),
posix_trace_eventid_equal(3p),
posix_trace_eventtypelist_getnext_id(3p), posix_trace_get_attr(3p),
posix_trace_get_filter(3p), posix_trace_getnext_event(3p),
posix_trace_start(3p), posix_trace_start(3p), time(3p)
The Base Definitions volume of POSIX.1‐2008, sys_types.h(0p),
trace.h(0p)
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 .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the
source files to man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 POSIX_TRACE_CREATE(3P)
Pages that refer to this page: trace.h(0p), exec(3p), _Exit(3p), posix_trace_attr_destroy(3p), posix_trace_attr_getclockres(3p), posix_trace_attr_getinherited(3p), posix_trace_attr_getlogsize(3p), posix_trace_clear(3p), posix_trace_flush(3p), posix_trace_get_attr(3p), posix_trace_getnext_event(3p), posix_trace_shutdown(3p), posix_trace_start(3p)
|
HTML rendering created 2018-02-02 by Michael Kerrisk, author of The Linux Programming Interface, maintainer of the Linux man-pages project. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH.
|
|