| 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 | #include <babeltrace/babeltrace.h> |
| 21 | #include <babeltrace/format.h> |
| 22 | #include <babeltrace/context.h> |
| 23 | #include <babeltrace/ctf/types.h> |
| 24 | #include <babeltrace/ctf-text/types.h> |
| 25 | #include <babeltrace/trace-collection.h> |
| 26 | #include <babeltrace/ctf-ir/metadata.h> /* for clocks */ |
| 27 | |
| 28 | #include <inttypes.h> |
| 29 | |
| 30 | struct clock_match { |
| 31 | GHashTable *clocks; |
| 32 | struct ctf_clock *clock_match; |
| 33 | struct trace_collection *tc; |
| 34 | }; |
| 35 | |
| 36 | static void check_clock_match(gpointer key, gpointer value, gpointer user_data) |
| 37 | { |
| 38 | struct clock_match *match = user_data; |
| 39 | struct ctf_clock *clock_a = value, *clock_b; |
| 40 | |
| 41 | if (clock_a->uuid != 0) { |
| 42 | /* |
| 43 | * Lookup the the trace clocks into the collection |
| 44 | * clocks. |
| 45 | */ |
| 46 | clock_b = g_hash_table_lookup(match->clocks, |
| 47 | (gpointer) (unsigned long) clock_a->uuid); |
| 48 | if (clock_b) { |
| 49 | match->clock_match = clock_b; |
| 50 | return; |
| 51 | } |
| 52 | } else if (clock_a->absolute) { |
| 53 | /* |
| 54 | * Absolute time references, such as NTP, are looked up |
| 55 | * by clock name. |
| 56 | */ |
| 57 | clock_b = g_hash_table_lookup(match->clocks, |
| 58 | (gpointer) (unsigned long) clock_a->name); |
| 59 | if (clock_b) { |
| 60 | match->clock_match = clock_b; |
| 61 | return; |
| 62 | } |
| 63 | } |
| 64 | } |
| 65 | |
| 66 | static void clock_add(gpointer key, gpointer value, gpointer user_data) |
| 67 | { |
| 68 | struct clock_match *clock_match = user_data; |
| 69 | GHashTable *tc_clocks = clock_match->clocks; |
| 70 | struct ctf_clock *t_clock = value; |
| 71 | GQuark v; |
| 72 | |
| 73 | if (t_clock->absolute) |
| 74 | v = t_clock->name; |
| 75 | else |
| 76 | v = t_clock->uuid; |
| 77 | if (v) { |
| 78 | struct ctf_clock *tc_clock; |
| 79 | |
| 80 | tc_clock = g_hash_table_lookup(tc_clocks, |
| 81 | (gpointer) (unsigned long) v); |
| 82 | if (!tc_clock) { |
| 83 | /* |
| 84 | * For now, we only support CTF that has one |
| 85 | * single clock uuid or name (absolute ref). |
| 86 | */ |
| 87 | if (g_hash_table_size(tc_clocks) > 0) { |
| 88 | fprintf(stderr, "[error] Only CTF traces with a single clock description are supported by this babeltrace version.\n"); |
| 89 | } |
| 90 | if (!clock_match->tc->offset_nr) { |
| 91 | clock_match->tc->offset_first = |
| 92 | (t_clock->offset_s * 1000000000ULL) + t_clock->offset; |
| 93 | clock_match->tc->delta_offset_first_sum = 0; |
| 94 | clock_match->tc->offset_nr++; |
| 95 | clock_match->tc->single_clock_offset_avg = |
| 96 | clock_match->tc->offset_first; |
| 97 | } |
| 98 | g_hash_table_insert(tc_clocks, |
| 99 | (gpointer) (unsigned long) v, |
| 100 | value); |
| 101 | } else { |
| 102 | int64_t diff_ns; |
| 103 | |
| 104 | /* |
| 105 | * Check that the offsets match. If not, warn |
| 106 | * the user that we do an arbitrary choice. |
| 107 | */ |
| 108 | diff_ns = tc_clock->offset_s; |
| 109 | diff_ns -= t_clock->offset_s; |
| 110 | diff_ns *= 1000000000ULL; |
| 111 | diff_ns += tc_clock->offset; |
| 112 | diff_ns -= t_clock->offset; |
| 113 | printf_debug("Clock \"%s\" offset between traces has a delta of %" PRIu64 " ns.", |
| 114 | g_quark_to_string(tc_clock->name), |
| 115 | diff_ns < 0 ? -diff_ns : diff_ns); |
| 116 | if (diff_ns > 10000) { |
| 117 | fprintf(stderr, "[warning] Clock \"%s\" offset differs between traces (delta %" PRIu64 " ns). Using average.\n", |
| 118 | g_quark_to_string(tc_clock->name), |
| 119 | diff_ns < 0 ? -diff_ns : diff_ns); |
| 120 | } |
| 121 | /* Compute average */ |
| 122 | clock_match->tc->delta_offset_first_sum += |
| 123 | (t_clock->offset_s * 1000000000ULL) + t_clock->offset |
| 124 | - clock_match->tc->offset_first; |
| 125 | clock_match->tc->offset_nr++; |
| 126 | clock_match->tc->single_clock_offset_avg = |
| 127 | clock_match->tc->offset_first |
| 128 | + (clock_match->tc->delta_offset_first_sum / clock_match->tc->offset_nr); |
| 129 | } |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | /* |
| 134 | * Whenever we add a trace to the trace collection, check that we can |
| 135 | * correlate this trace with at least one other clock in the trace. |
| 136 | */ |
| 137 | int trace_collection_add(struct trace_collection *tc, |
| 138 | struct trace_descriptor *td) |
| 139 | { |
| 140 | struct ctf_trace *trace = container_of(td, struct ctf_trace, parent); |
| 141 | |
| 142 | g_ptr_array_add(tc->array, td); |
| 143 | trace->collection = tc; |
| 144 | |
| 145 | if (tc->array->len > 1) { |
| 146 | struct clock_match clock_match = { |
| 147 | .clocks = tc->clocks, |
| 148 | .clock_match = NULL, |
| 149 | .tc = NULL, |
| 150 | }; |
| 151 | |
| 152 | /* |
| 153 | * With two or more traces, we need correlation info |
| 154 | * avalable. |
| 155 | */ |
| 156 | g_hash_table_foreach(trace->clocks, |
| 157 | check_clock_match, |
| 158 | &clock_match); |
| 159 | if (!clock_match.clock_match) { |
| 160 | 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"); |
| 161 | goto error; |
| 162 | } |
| 163 | } |
| 164 | |
| 165 | { |
| 166 | struct clock_match clock_match = { |
| 167 | .clocks = tc->clocks, |
| 168 | .clock_match = NULL, |
| 169 | .tc = tc, |
| 170 | }; |
| 171 | |
| 172 | /* |
| 173 | * Add each clock from the trace clocks into the trace |
| 174 | * collection clocks. |
| 175 | */ |
| 176 | g_hash_table_foreach(trace->clocks, |
| 177 | clock_add, |
| 178 | &clock_match); |
| 179 | } |
| 180 | return 0; |
| 181 | error: |
| 182 | return -EPERM; |
| 183 | } |
| 184 | |
| 185 | int trace_collection_remove(struct trace_collection *tc, |
| 186 | struct trace_descriptor *td) |
| 187 | { |
| 188 | if (g_ptr_array_remove(tc->array, td)) { |
| 189 | return 0; |
| 190 | } else { |
| 191 | return -1; |
| 192 | } |
| 193 | |
| 194 | } |
| 195 | |
| 196 | void init_trace_collection(struct trace_collection *tc) |
| 197 | { |
| 198 | tc->array = g_ptr_array_new(); |
| 199 | tc->clocks = g_hash_table_new(g_direct_hash, g_direct_equal); |
| 200 | tc->single_clock_offset_avg = 0; |
| 201 | tc->offset_first = 0; |
| 202 | tc->delta_offset_first_sum = 0; |
| 203 | tc->offset_nr = 0; |
| 204 | } |
| 205 | |
| 206 | /* |
| 207 | * finalize_trace_collection() closes the opened traces for read |
| 208 | * and free the memory allocated for trace collection |
| 209 | */ |
| 210 | void finalize_trace_collection(struct trace_collection *tc) |
| 211 | { |
| 212 | g_ptr_array_free(tc->array, TRUE); |
| 213 | g_hash_table_destroy(tc->clocks); |
| 214 | } |