1POSIX_TRACE_ATTR_GETLOGSIZE(P3OPS)IX Programmer's MaPnOuSaIlX_TRACE_ATTR_GETLOGSIZE(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_attr_getlogsize, posix_trace_attr_getmaxdatasize,
13 posix_trace_attr_getmaxsystemeventsize, posix_trace_attr_get‐
14 maxusereventsize, posix_trace_attr_getstreamsize, posix_trace_attr_set‐
15 logsize, posix_trace_attr_setmaxdatasize, posix_trace_attr_setstream‐
16 size — retrieve and set trace stream size attributes (TRACING)
17
19 #include <sys/types.h>
20 #include <trace.h>
21 int posix_trace_attr_getlogsize(const trace_attr_t *restrict attr,
23 size_t *restrict logsize);
24 int posix_trace_attr_getmaxdatasize(const trace_attr_t *restrict attr,
25 size_t *restrict maxdatasize);
26 int posix_trace_attr_getmaxsystemeventsize(
27 const trace_attr_t *restrict attr,
28 size_t *restrict eventsize);
29 int posix_trace_attr_getmaxusereventsize(
30 const trace_attr_t *restrict attr,
31 size_t data_len, size_t *restrict eventsize);
32 int posix_trace_attr_getstreamsize(const trace_attr_t *restrict attr,
33 size_t *restrict streamsize);
34 int posix_trace_attr_setlogsize(trace_attr_t *attr,
35 size_t logsize);
36 int posix_trace_attr_setmaxdatasize(trace_attr_t *attr,
37 size_t maxdatasize);
38 int posix_trace_attr_setstreamsize(trace_attr_t *attr,
39 size_t streamsize);
40
42 The posix_trace_attr_getlogsize() function shall copy the log size, in
43 bytes, from the log-max-size attribute of the attributes object pointed
44 to by the attr argument into the variable pointed to by the logsize
45 argument. This log size is the maximum total of bytes that shall be
46 allocated for system and user trace events in the trace log. The
47 default value for the log-max-size attribute is implementation-defined.
48 The posix_trace_attr_setlogsize() function shall set the maximum
50 allowed size, in bytes, in the log-max-size attribute of the attributes
51 object pointed to by the attr argument, using the size value supplied
52 by the logsize argument.
53 The trace log size shall be used if the log-full-policy attribute is
55 set to POSIX_TRACE_LOOP or POSIX_TRACE_UNTIL_FULL. If the log-full-pol‐
56 icy attribute is set to POSIX_TRACE_APPEND, the implementation shall
57 ignore the log-max-size attribute.
58 The posix_trace_attr_getmaxdatasize() function shall copy the maximum
60 user trace event data size, in bytes, from the max-data-size attribute
61 of the attributes object pointed to by the attr argument into the vari‐
62 able pointed to by the maxdatasize argument. The default value for the
63 max-data-size attribute is implementation-defined.
64 The posix_trace_attr_getmaxsystemeventsize() function shall calculate
66 the maximum memory size, in bytes, required to store a single system
67 trace event. This value is calculated for the trace stream attributes
68 object pointed to by the attr argument and is returned in the variable
69 pointed to by the eventsize argument.
70 The values returned as the maximum memory sizes of the user and system
72 trace events shall be such that if the sum of the maximum memory sizes
73 of a set of the trace events that may be recorded in a trace stream is
74 less than or equal to the stream-min-size attribute of that trace
75 stream, the system provides the necessary resources for recording all
76 those trace events, without loss.
77 The posix_trace_attr_getmaxusereventsize() function shall calculate the
79 maximum memory size, in bytes, required to store a single user trace
80 event generated by a call to posix_trace_event() with a data_len param‐
81 eter equal to the data_len value specified in this call. This value is
82 calculated for the trace stream attributes object pointed to by the
83 attr argument and is returned in the variable pointed to by the event‐
84 size argument.
85 The posix_trace_attr_getstreamsize() function shall copy the stream
87 size, in bytes, from the stream-min-size attribute of the attributes
88 object pointed to by the attr argument into the variable pointed to by
89 the streamsize argument.
90 This stream size is the current total memory size reserved for system
92 and user trace events in the trace stream. The default value for the
93 stream-min-size attribute is implementation-defined. The stream size
94 refers to memory used to store trace event records. Other stream data
95 (for example, trace attribute values) shall not be included in this
96 size.
97 The posix_trace_attr_setmaxdatasize() function shall set the maximum
99 allowed size, in bytes, in the max-data-size attribute of the
100 attributes object pointed to by the attr argument, using the size value
101 supplied by the maxdatasize argument. This maximum size is the maximum
102 allowed size for the user data argument which may be passed to
103 posix_trace_event(). The implementation shall be allowed to truncate
104 data passed to trace_user_event which is longer than maxdatasize.
105 The posix_trace_attr_setstreamsize() function shall set the minimum
107 allowed size, in bytes, in the stream-min-size attribute of the
108 attributes object pointed to by the attr argument, using the size value
109 supplied by the streamsize argument.
110
112 Upon successful completion, these functions shall return a value of
113 zero. Otherwise, they shall return the corresponding error number.
114 The posix_trace_attr_getlogsize() function stores the maximum trace log
116 allowed size in the object pointed to by logsize, if successful.
117 The posix_trace_attr_getmaxdatasize() function stores the maximum trace
119 event record memory size in the object pointed to by maxdatasize, if
120 successful.
121 The posix_trace_attr_getmaxsystemeventsize() function stores the maxi‐
123 mum memory size to store a single system trace event in the object
124 pointed to by eventsize, if successful.
125 The posix_trace_attr_getmaxusereventsize() function stores the maximum
127 memory size to store a single user trace event in the object pointed to
128 by eventsize, if successful.
129 The posix_trace_attr_getstreamsize() function stores the maximum trace
131 stream allowed size in the object pointed to by streamsize, if success‐
132 ful.
133
135 These functions may fail if:
136 EINVAL The value specified by one of the arguments is invalid.
138 The following sections are informative.
140
142 None.
143
145 None.
146
148 None.
149
151 The following functions:
152 posix_trace_attr_getlogsize()
154 posix_trace_attr_getmaxdatasize()
155 posix_trace_attr_getmaxsystemeventsize()
156 posix_trace_attr_getmaxusereventsize()
157 posix_trace_attr_getstreamsize()
158 posix_trace_attr_setlogsize()
159 posix_trace_attr_setmaxdatasize()
160 posix_trace_attr_setstreamsize()
161 may be removed in a future version.
163
165 posix_trace_attr_destroy(), posix_trace_create(), posix_trace_event(),
166 posix_trace_get_attr()
167 The Base Definitions volume of POSIX.1‐2017, <sys_types.h>, <trace.h>
169
171 Portions of this text are reprinted and reproduced in electronic form
172 from IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
173 table Operating System Interface (POSIX), The Open Group Base Specifi‐
174 cations Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of
175 Electrical and Electronics Engineers, Inc and The Open Group. In the
176 event of any discrepancy between this version and the original IEEE and
177 The Open Group Standard, the original IEEE and The Open Group Standard
178 is the referee document. The original Standard can be obtained online
179 at http://www.opengroup.org/unix/online.html .
180 Any typographical or formatting errors that appear in this page are
182 most likely to have been introduced during the conversion of the source
183 files to man page format. To report such errors, see https://www.ker‐
184 nel.org/doc/man-pages/reporting_bugs.html .
185IEEE/The Open Group 2017 POSIX_TRACE_ATTR_GETLOGSIZE(3P)