1POSIX_TRACE_CREATE(3P) POSIX Programmer's Manual POSIX_TRACE_CREATE(3P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
12 posix_trace_create, posix_trace_create_withlog, posix_trace_flush,
13 posix_trace_shutdown - trace stream initialization, flush, and shutdown
14 from a process (TRACING)
15
17 #include <sys/types.h>
18 #include <trace.h>
19 int posix_trace_create(pid_t pid,
21 const trace_attr_t *restrict attr,
22 trace_id_t *restrict trid);
23 int posix_trace_create_withlog(pid_t pid,
26 const trace_attr_t *restrict attr, int file_desc,
27 trace_id_t *restrict trid);
28 int posix_trace_flush(trace_id_t trid);
29 int posix_trace_shutdown(trace_id_t trid);
32
35 The posix_trace_create() function shall create an active trace stream.
36 It allocates all the resources needed by the trace stream being created
37 for tracing the process specified by pid in accordance with the attr
38 argument. The attr argument represents the initial attributes of the
39 trace stream and shall have been initialized by the function
40 posix_trace_attr_init() prior to the posix_trace_create() call. If the
41 argument attr is NULL, the default attributes shall be used. The attr
42 attributes object shall be manipulated through a set of functions
43 described in the posix_trace_attr family of functions. If the
44 attributes of the object pointed to by attr are modified later, the
45 attributes of the trace stream shall not be affected. The creation-time
46 attribute of the newly created trace stream shall be set to the value
47 of the system clock, if the Timers option is not supported, or to the
48 value of the CLOCK_REALTIME clock, if the Timers option is supported.
49 The pid argument represents the target process to be traced. If the
51 process executing this function does not have appropriate privileges to
52 trace the process identified by pid, an error shall be returned. If the
53 pid argument is zero, the calling process shall be traced.
54 The posix_trace_create() function shall store the trace stream identi‐
56 fier of the new trace stream in the object pointed to by the trid argu‐
57 ment. This trace stream identifier shall be used in subsequent calls to
58 control tracing. The trid argument may only be used by the following
59 functions:
60 posix_trace_clear() posix_trace_getnext_event()
68 posix_trace_eventid_equal() posix_trace_shutdown()
69 posix_trace_eventid_get_name() posix_trace_start()
70 posix_trace_eventtypelist_getnext_id() posix_trace_stop()
71 posix_trace_eventtypelist_rewind() posix_trace_timedgetnext_event()
72 posix_trace_get_attr() posix_trace_trid_eventid_open()
73 posix_trace_get_status() posix_trace_trygetnext_event()
74 If the Trace Event Filter option is supported, the following additional
77 functions may use the trid argument:
78 posix_trace_get_filter() posix_trace_set_filter()
80 In particular, notice that the operations normally used by a trace ana‐
82 lyzer process, such as posix_trace_rewind() or posix_trace_close(),
83 cannot be invoked using the trace stream identifier returned by the
84 posix_trace_create() function.
85 A trace stream shall be created in a suspended state. If the Trace
87 Event Filter option is supported, its trace event type filter shall be
88 empty.
89 The posix_trace_create() function may be called multiple times from the
91 same or different processes, with the system-wide limit indicated by
92 the runtime invariant value {TRACE_SYS_MAX}, which has the minimum
93 value {_POSIX_TRACE_SYS_MAX}.
94 The trace stream identifier returned by the posix_trace_create() func‐
96 tion in the argument pointed to by trid is valid only in the process
97 that made the function call. If it is used from another process, that
98 is a child process, in functions defined in IEEE Std 1003.1-2001, these
99 functions shall return with the error [EINVAL].
100 The posix_trace_create_withlog() function shall be equivalent to
102 posix_trace_create(), except that it associates a trace log with this
103 stream. The file_desc argument shall be the file descriptor designating
104 the trace log destination. The function shall fail if this file
105 descriptor refers to a file with a file type that is not compatible
106 with the log policy associated with the trace log. The list of the
107 appropriate file types that are compatible with each log policy is
108 implementation-defined.
109 The posix_trace_create_withlog() function shall return in the parameter
111 pointed to by trid the trace stream identifier, which uniquely identi‐
112 fies the newly created trace stream, and shall be used in subsequent
113 calls to control tracing. The trid argument may only be used by the
114 following functions:
115 posix_trace_clear() posix_trace_getnext_event()
117 posix_trace_eventid_equal() posix_trace_shutdown()
118 posix_trace_eventid_get_name() posix_trace_start()
119 posix_trace_eventtypelist_getnext_id() posix_trace_stop()
120 posix_trace_eventtypelist_rewind() posix_trace_timedgetnext_event()
121 posix_trace_flush() posix_trace_trid_eventid_open()
122 posix_trace_get_attr() posix_trace_trygetnext_event()
123 posix_trace_get_status()
124 If the Trace Event Filter option is supported, the following additional
127 functions may use the trid argument:
128 posix_trace_get_filter() posix_trace_set_filter()
130 In particular, notice that the operations normally used by a trace ana‐
132 lyzer process, such as posix_trace_rewind() or posix_trace_close(),
133 cannot be invoked using the trace stream identifier returned by the
134 posix_trace_create_withlog() function.
135 The posix_trace_flush() function shall initiate a flush operation which
137 copies the contents of the trace stream identified by the argument trid
138 into the trace log associated with the trace stream at the creation
139 time. If no trace log has been associated with the trace stream pointed
140 to by trid, this function shall return an error. The termination of the
141 flush operation can be polled by the posix_trace_get_status() function.
142 During the flush operation, it shall be possible to trace new trace
143 events up to the point when the trace stream becomes full. After flush‐
144 ing is completed, the space used by the flushed trace events shall be
145 available for tracing new trace events.
146 If flushing the trace stream causes the resulting trace log to become
148 full, the trace log full policy shall be applied. If the trace log-
149 full-policy attribute is set, the following occurs:
150 POSIX_TRACE_UNTIL_FULL
152 The trace events that have not yet been flushed shall be dis‐
154 carded.
155 POSIX_TRACE_LOOP
157 The trace events that have not yet been flushed shall be written
159 to the beginning of the trace log, overwriting previous trace
160 events stored there.
161 POSIX_TRACE_APPEND
163 The trace events that have not yet been flushed shall be
165 appended to the trace log.
166 The posix_trace_shutdown() function shall stop the tracing of trace
169 events in the trace stream identified by trid, as if posix_trace_stop()
170 had been invoked. The posix_trace_shutdown() function shall free all
171 the resources associated with the trace stream.
172 The posix_trace_shutdown() function shall not return until all the
174 resources associated with the trace stream have been freed. When the
175 posix_trace_shutdown() function returns, the trid argument becomes an
176 invalid trace stream identifier. A call to this function shall uncondi‐
177 tionally deallocate the resources regardless of whether all trace
178 events have been retrieved by the analyzer process. Any thread blocked
179 on one of the trace_getnext_event() functions (which specified this
180 trid) before this call is unblocked with the error [EINVAL].
181 If the process exits, invokes a member of the exec family of functions,
183 or is terminated, the trace streams that the process had created and
184 that have not yet been shut down, shall be automatically shut down as
185 if an explicit call were made to the posix_trace_shutdown() function.
186 For an active trace stream with log, when the posix_trace_shutdown()
188 function is called, all trace events that have not yet been flushed to
189 the trace log shall be flushed, as in the posix_trace_flush() function,
190 and the trace log shall be closed.
191 When a trace log is closed, all the information that may be retrieved
193 later from the trace log through the trace interface shall have been
194 written to the trace log. This information includes the trace
195 attributes, the list of trace event types (with the mapping between
196 trace event names and trace event type identifiers), and the trace sta‐
197 tus.
198 In addition, unspecified information shall be written to the trace log
200 to allow detection of a valid trace log during the posix_trace_open()
201 operation.
202 The posix_trace_shutdown() function shall not return until all trace
204 events have been flushed.
205
207 Upon successful completion, these functions shall return a value of
208 zero. Otherwise, they shall return the corresponding error number.
209 The posix_trace_create() and posix_trace_create_withlog() functions
211 store the trace stream identifier value in the object pointed to by
212 trid, if successful.
213
215 The posix_trace_create() and posix_trace_create_withlog() functions
216 shall fail if:
217 EAGAIN No more trace streams can be started now. {TRACE_SYS_MAX} has
219 been exceeded.
220 EINTR The operation was interrupted by a signal. No trace stream was
222 created.
223 EINVAL One or more of the trace parameters specified by the attr param‐
225 eter is invalid.
226 ENOMEM The implementation does not currently have sufficient memory to
228 create the trace stream with the specified parameters.
229 EPERM The caller does not have appropriate privilege to trace the
231 process specified by pid.
232 ESRCH The pid argument does not refer to an existing process.
234 The posix_trace_create_withlog() function shall fail if:
237 EBADF The file_desc argument is not a valid file descriptor open for
239 writing.
240 EINVAL The file_desc argument refers to a file with a file type that
242 does not support the log policy associated with the trace log.
243 ENOSPC No space left on device. The device corresponding to the argu‐
245 ment file_desc does not contain the space required to create
246 this trace log.
247 The posix_trace_flush() and posix_trace_shutdown() functions shall
250 fail if:
251 EINVAL The value of the trid argument does not correspond to an active
253 trace stream with log.
254 EFBIG The trace log file has attempted to exceed an implementation-
256 defined maximum file size.
257 ENOSPC No space left on device.
259 The following sections are informative.
262
264 None.
265
267 None.
268
270 None.
271
273 None.
274
276 clock_getres(), exec(), posix_trace_attr_init(), posix_trace_clear(),
277 posix_trace_close(), posix_trace_eventid_equal(), posix_trace_event‐
278 typelist_getnext_id(), posix_trace_flush(), posix_trace_get_attr(),
279 posix_trace_get_filter(), posix_trace_get_status(), posix_trace_get‐
280 next_event(), posix_trace_open(), posix_trace_set_filter() ,
281 posix_trace_shutdown(), posix_trace_start(), posix_trace_timedget‐
282 next_event(), posix_trace_trid_eventid_open(), posix_trace_start(),
283 time(), the Base Definitions volume of IEEE Std 1003.1-2001,
284 <sys/types.h>, <trace.h>
285
287 Portions of this text are reprinted and reproduced in electronic form
288 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
289 -- Portable Operating System Interface (POSIX), The Open Group Base
290 Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
291 Electrical and Electronics Engineers, Inc and The Open Group. In the
292 event of any discrepancy between this version and the original IEEE and
293 The Open Group Standard, the original IEEE and The Open Group Standard
294 is the referee document. The original Standard can be obtained online
295 at http://www.opengroup.org/unix/online.html .
296IEEE/The Open Group 2003 POSIX_TRACE_CREATE(3P)