namespace the collection functions
[babeltrace.git] / lib / trace-collection.c
1 /*
2 * trace-collection.c
3 *
4 * Babeltrace Library
5 *
6 * Copyright 2012 EfficiOS Inc. and Linux Foundation
7 *
8 * Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
9 *
10 * Permission is hereby granted, free of charge, to any person obtaining a copy
11 * of this software and associated documentation files (the "Software"), to deal
12 * in the Software without restriction, including without limitation the rights
13 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
14 * copies of the Software, and to permit persons to whom the Software is
15 * furnished to do so, subject to the following conditions:
16 *
17 * The above copyright notice and this permission notice shall be included in
18 * all copies or substantial portions of the Software.
19 *
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
23 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
25 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
26 * SOFTWARE.
27 */
28 #include <babeltrace/babeltrace.h>
29 #include <babeltrace/format.h>
30 #include <babeltrace/context.h>
31 #include <babeltrace/ctf/types.h>
32 #include <babeltrace/ctf-text/types.h>
33 #include <babeltrace/trace-collection.h>
34 #include <babeltrace/ctf-ir/metadata.h> /* for clocks */
35 #include <babeltrace/clock-internal.h>
36
37 #include <inttypes.h>
38
39 struct clock_match {
40 GHashTable *clocks;
41 struct ctf_clock *clock_match;
42 struct trace_collection *tc;
43 };
44
45 static void check_clock_match(gpointer key, gpointer value, gpointer user_data)
46 {
47 struct clock_match *match = user_data;
48 struct ctf_clock *clock_a = value, *clock_b;
49
50 if (clock_a->absolute) {
51 /*
52 * Absolute time references, such as NTP, are looked up
53 * by clock name.
54 */
55 clock_b = g_hash_table_lookup(match->clocks,
56 (gpointer) (unsigned long) clock_a->name);
57 if (clock_b) {
58 match->clock_match = clock_b;
59 return;
60 }
61 } else if (clock_a->uuid != 0) {
62 /*
63 * Lookup the the trace clocks into the collection
64 * clocks.
65 */
66 clock_b = g_hash_table_lookup(match->clocks,
67 (gpointer) (unsigned long) clock_a->uuid);
68 if (clock_b) {
69 match->clock_match = clock_b;
70 return;
71 }
72 }
73 }
74
75 /*
76 * Note: if using a frequency different from 1GHz for clock->offset, it
77 * is recommended to express the seconds in offset_s, otherwise there
78 * will be a loss of precision caused by the limited size of the double
79 * mantissa.
80 */
81 static
82 uint64_t clock_offset_ns(struct ctf_clock *clock)
83 {
84 return clock->offset_s * 1000000000ULL
85 + clock_cycles_to_ns(clock, clock->offset);
86 }
87
88 static void clock_add(gpointer key, gpointer value, gpointer user_data)
89 {
90 struct clock_match *clock_match = user_data;
91 GHashTable *tc_clocks = clock_match->clocks;
92 struct ctf_clock *t_clock = value;
93 GQuark v;
94
95 if (t_clock->absolute)
96 v = t_clock->name;
97 else
98 v = t_clock->uuid;
99 if (v) {
100 struct ctf_clock *tc_clock;
101
102 tc_clock = g_hash_table_lookup(tc_clocks,
103 (gpointer) (unsigned long) v);
104 if (!tc_clock) {
105 /*
106 * For now we only support CTF that has one
107 * single clock uuid or name (absolute ref) per
108 * trace.
109 */
110 if (g_hash_table_size(tc_clocks) > 0) {
111 fprintf(stderr, "[error] Only CTF traces with a single clock description are supported by this babeltrace version.\n");
112 }
113 if (!clock_match->tc->offset_nr) {
114 clock_match->tc->offset_first = clock_offset_ns(t_clock);
115 clock_match->tc->delta_offset_first_sum = 0;
116 clock_match->tc->offset_nr++;
117 clock_match->tc->single_clock_offset_avg =
118 clock_match->tc->offset_first;
119 }
120 g_hash_table_insert(tc_clocks,
121 (gpointer) (unsigned long) v,
122 value);
123 } else if (!t_clock->absolute) {
124 int64_t diff_ns;
125
126 /*
127 * For non-absolute clocks, check that the
128 * offsets match. If not, warn the user that we
129 * do an arbitrary choice.
130 */
131 diff_ns = clock_offset_ns(tc_clock) - clock_offset_ns(t_clock);
132 printf_debug("Clock \"%s\" offset between traces has a delta of %" PRIu64 " ns.",
133 g_quark_to_string(tc_clock->name),
134 diff_ns < 0 ? -diff_ns : diff_ns);
135 if (diff_ns > 10000 || diff_ns < -10000) {
136 fprintf(stderr, "[warning] Clock \"%s\" offset differs between traces (delta %" PRIu64 " ns). Using average.\n",
137 g_quark_to_string(tc_clock->name),
138 diff_ns < 0 ? -diff_ns : diff_ns);
139 }
140 /* Compute average */
141 clock_match->tc->delta_offset_first_sum +=
142 clock_offset_ns(t_clock) - clock_match->tc->offset_first;
143 clock_match->tc->offset_nr++;
144 clock_match->tc->single_clock_offset_avg =
145 clock_match->tc->offset_first
146 + (clock_match->tc->delta_offset_first_sum / clock_match->tc->offset_nr);
147 /* Time need to use offset average */
148 clock_match->tc->clock_use_offset_avg = 1;
149 }
150 }
151 }
152
153 /*
154 * Whenever we add a trace to the trace collection, check that we can
155 * correlate this trace with at least one other clock in the trace and
156 * convert the index from cycles to real time.
157 */
158 int bt_trace_collection_add(struct trace_collection *tc,
159 struct trace_descriptor *td)
160 {
161 struct ctf_trace *trace;
162
163 if (!tc || !td)
164 return -EINVAL;
165
166 trace = container_of(td, struct ctf_trace, parent);
167 g_ptr_array_add(tc->array, td);
168 trace->collection = tc;
169
170 if (tc->array->len > 1) {
171 struct clock_match clock_match = {
172 .clocks = tc->clocks,
173 .clock_match = NULL,
174 .tc = NULL,
175 };
176
177 /*
178 * With two or more traces, we need correlation info
179 * avalable.
180 */
181 g_hash_table_foreach(trace->clocks,
182 check_clock_match,
183 &clock_match);
184 if (!clock_match.clock_match) {
185 fprintf(stderr, "[error] No clocks can be correlated and multiple traces are added to the collection. If you are certain those traces can be correlated, try using \"--clock-force-correlate\".\n");
186 goto error;
187 }
188 }
189
190 {
191 struct clock_match clock_match = {
192 .clocks = tc->clocks,
193 .clock_match = NULL,
194 .tc = tc,
195 };
196
197 /*
198 * Add each clock from the trace clocks into the trace
199 * collection clocks.
200 */
201 g_hash_table_foreach(trace->clocks,
202 clock_add,
203 &clock_match);
204 }
205
206 return 0;
207 error:
208 return -EPERM;
209 }
210
211 int bt_trace_collection_remove(struct trace_collection *tc,
212 struct trace_descriptor *td)
213 {
214 if (!tc || !td)
215 return -EINVAL;
216
217 if (g_ptr_array_remove(tc->array, td)) {
218 return 0;
219 } else {
220 return -1;
221 }
222
223 }
224
225 void bt_init_trace_collection(struct trace_collection *tc)
226 {
227 assert(tc);
228 tc->array = g_ptr_array_new();
229 tc->clocks = g_hash_table_new(g_direct_hash, g_direct_equal);
230 tc->single_clock_offset_avg = 0;
231 tc->offset_first = 0;
232 tc->delta_offset_first_sum = 0;
233 tc->offset_nr = 0;
234 }
235
236 /*
237 * bt_finalize_trace_collection() closes the opened traces for read
238 * and free the memory allocated for trace collection
239 */
240 void bt_finalize_trace_collection(struct trace_collection *tc)
241 {
242 assert(tc);
243 g_ptr_array_free(tc->array, TRUE);
244 g_hash_table_destroy(tc->clocks);
245 }
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