| 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 bt_trace_descriptor *trace) |
| 160 | { |
| 161 | if (!tc || !trace) |
| 162 | return -EINVAL; |
| 163 | |
| 164 | if (tc->array->len > 1) { |
| 165 | struct clock_match clock_match = { |
| 166 | .clocks = tc->clocks, |
| 167 | .clock_match = NULL, |
| 168 | .tc = NULL, |
| 169 | }; |
| 170 | |
| 171 | /* |
| 172 | * With two or more traces, we need correlation info |
| 173 | * avalable. |
| 174 | */ |
| 175 | g_hash_table_foreach(trace->clocks, |
| 176 | check_clock_match, |
| 177 | &clock_match); |
| 178 | if (!clock_match.clock_match) { |
| 179 | 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"); |
| 180 | goto error; |
| 181 | } |
| 182 | } |
| 183 | |
| 184 | g_ptr_array_add(tc->array, trace); |
| 185 | trace->collection = tc; |
| 186 | |
| 187 | { |
| 188 | struct clock_match clock_match = { |
| 189 | .clocks = tc->clocks, |
| 190 | .clock_match = NULL, |
| 191 | .tc = tc, |
| 192 | }; |
| 193 | |
| 194 | /* |
| 195 | * Add each clock from the trace clocks into the trace |
| 196 | * collection clocks. |
| 197 | */ |
| 198 | g_hash_table_foreach(trace->clocks, |
| 199 | clock_add, |
| 200 | &clock_match); |
| 201 | } |
| 202 | |
| 203 | return 0; |
| 204 | error: |
| 205 | return -EPERM; |
| 206 | } |
| 207 | |
| 208 | int bt_trace_collection_remove(struct trace_collection *tc, |
| 209 | struct bt_trace_descriptor *td) |
| 210 | { |
| 211 | if (!tc || !td) |
| 212 | return -EINVAL; |
| 213 | |
| 214 | if (g_ptr_array_remove(tc->array, td)) { |
| 215 | return 0; |
| 216 | } else { |
| 217 | return -1; |
| 218 | } |
| 219 | |
| 220 | } |
| 221 | |
| 222 | void bt_init_trace_collection(struct trace_collection *tc) |
| 223 | { |
| 224 | assert(tc); |
| 225 | tc->array = g_ptr_array_new(); |
| 226 | tc->clocks = g_hash_table_new(g_direct_hash, g_direct_equal); |
| 227 | tc->single_clock_offset_avg = 0; |
| 228 | tc->offset_first = 0; |
| 229 | tc->delta_offset_first_sum = 0; |
| 230 | tc->offset_nr = 0; |
| 231 | } |
| 232 | |
| 233 | /* |
| 234 | * bt_finalize_trace_collection() closes the opened traces for read |
| 235 | * and free the memory allocated for trace collection |
| 236 | */ |
| 237 | void bt_finalize_trace_collection(struct trace_collection *tc) |
| 238 | { |
| 239 | assert(tc); |
| 240 | g_ptr_array_free(tc->array, TRUE); |
| 241 | g_hash_table_destroy(tc->clocks); |
| 242 | } |