1 /* 2 * Copyright (C) 2011 Google Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY 15 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 16 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 17 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY 18 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 19 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 20 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 21 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26 // Trace events are for tracking application performance and resource usage. 27 // Macros are provided to track: 28 // Begin and end of function calls 29 // Counters 30 // 31 // Events are issued against categories. Whereas LOG's 32 // categories are statically defined, TRACE categories are created 33 // implicitly with a string. For example: 34 // TRACE_EVENT_INSTANT0("MY_SUBSYSTEM", "SomeImportantEvent") 35 // 36 // Events can be INSTANT, or can be pairs of BEGIN and END in the same scope: 37 // TRACE_EVENT_BEGIN0("MY_SUBSYSTEM", "SomethingCostly") 38 // doSomethingCostly() 39 // TRACE_EVENT_END0("MY_SUBSYSTEM", "SomethingCostly") 40 // Note: our tools can't always determine the correct BEGIN/END pairs unless 41 // these are used in the same scope. Use ASYNC_BEGIN/ASYNC_END macros if you need them 42 // to be in separate scopes. 43 // 44 // A common use case is to trace entire function scopes. This 45 // issues a trace BEGIN and END automatically: 46 // void doSomethingCostly() { 47 // TRACE_EVENT0("MY_SUBSYSTEM", "doSomethingCostly"); 48 // ... 49 // } 50 // 51 // Additional parameters can be associated with an event: 52 // void doSomethingCostly2(int howMuch) { 53 // TRACE_EVENT1("MY_SUBSYSTEM", "doSomethingCostly", 54 // "howMuch", howMuch); 55 // ... 56 // } 57 // 58 // The trace system will automatically add to this information the 59 // current process id, thread id, and a timestamp in microseconds. 60 // 61 // To trace an asynchronous procedure such as an IPC send/receive, use ASYNC_BEGIN and 62 // ASYNC_END: 63 // [single threaded sender code] 64 // static int send_count = 0; 65 // ++send_count; 66 // TRACE_EVENT_ASYNC_BEGIN0("ipc", "message", send_count); 67 // Send(new MyMessage(send_count)); 68 // [receive code] 69 // void OnMyMessage(send_count) { 70 // TRACE_EVENT_ASYNC_END0("ipc", "message", send_count); 71 // } 72 // The third parameter is a unique ID to match ASYNC_BEGIN/ASYNC_END pairs. 73 // ASYNC_BEGIN and ASYNC_END can occur on any thread of any traced process. Pointers can 74 // be used for the ID parameter, and they will be mangled internally so that 75 // the same pointer on two different processes will not match. For example: 76 // class MyTracedClass { 77 // public: 78 // MyTracedClass() { 79 // TRACE_EVENT_ASYNC_BEGIN0("category", "MyTracedClass", this); 80 // } 81 // ~MyTracedClass() { 82 // TRACE_EVENT_ASYNC_END0("category", "MyTracedClass", this); 83 // } 84 // } 85 // 86 // Trace event also supports counters, which is a way to track a quantity 87 // as it varies over time. Counters are created with the following macro: 88 // TRACE_COUNTER1("MY_SUBSYSTEM", "myCounter", g_myCounterValue); 89 // 90 // Counters are process-specific. The macro itself can be issued from any 91 // thread, however. 92 // 93 // Sometimes, you want to track two counters at once. You can do this with two 94 // counter macros: 95 // TRACE_COUNTER1("MY_SUBSYSTEM", "myCounter0", g_myCounterValue[0]); 96 // TRACE_COUNTER1("MY_SUBSYSTEM", "myCounter1", g_myCounterValue[1]); 97 // Or you can do it with a combined macro: 98 // TRACE_COUNTER2("MY_SUBSYSTEM", "myCounter", 99 // "bytesPinned", g_myCounterValue[0], 100 // "bytesAllocated", g_myCounterValue[1]); 101 // This indicates to the tracing UI that these counters should be displayed 102 // in a single graph, as a summed area chart. 103 // 104 // Since counters are in a global namespace, you may want to disembiguate with a 105 // unique ID, by using the TRACE_COUNTER_ID* variations. 106 // 107 // By default, trace collection is compiled in, but turned off at runtime. 108 // Collecting trace data is the responsibility of the embedding 109 // application. In Chrome's case, navigating to about:tracing will turn on 110 // tracing and display data collected across all active processes. 111 // 112 // 113 // Memory scoping note: 114 // Tracing copies the pointers, not the string content, of the strings passed 115 // in for category, name, and arg_names. Thus, the following code will 116 // cause problems: 117 // char* str = strdup("impprtantName"); 118 // TRACE_EVENT_INSTANT0("SUBSYSTEM", str); // BAD! 119 // free(str); // Trace system now has dangling pointer 120 // 121 // To avoid this issue with the |name| and |arg_name| parameters, use the 122 // TRACE_EVENT_COPY_XXX overloads of the macros at additional runtime overhead. 123 // Notes: The category must always be in a long-lived char* (i.e. static const). 124 // The |arg_values|, when used, are always deep copied with the _COPY 125 // macros. 126 // 127 // When are string argument values copied: 128 // const char* arg_values are only referenced by default: 129 // TRACE_EVENT1("category", "name", 130 // "arg1", "literal string is only referenced"); 131 // Use TRACE_STR_COPY to force copying of a const char*: 132 // TRACE_EVENT1("category", "name", 133 // "arg1", TRACE_STR_COPY("string will be copied")); 134 // std::string arg_values are always copied: 135 // TRACE_EVENT1("category", "name", 136 // "arg1", std::string("string will be copied")); 137 // 138 // 139 // Thread Safety: 140 // A thread safe singleton and mutex are used for thread safety. Category 141 // enabled flags are used to limit the performance impact when the system 142 // is not enabled. 143 // 144 // TRACE_EVENT macros first cache a pointer to a category. The categories are 145 // statically allocated and safe at all times, even after exit. Fetching a 146 // category is protected by the TraceLog::lock_. Multiple threads initializing 147 // the static variable is safe, as they will be serialized by the lock and 148 // multiple calls will return the same pointer to the category. 149 // 150 // Then the category_enabled flag is checked. This is a unsigned char, and 151 // not intended to be multithread safe. It optimizes access to addTraceEvent 152 // which is threadsafe internally via TraceLog::lock_. The enabled flag may 153 // cause some threads to incorrectly call or skip calling addTraceEvent near 154 // the time of the system being enabled or disabled. This is acceptable as 155 // we tolerate some data loss while the system is being enabled/disabled and 156 // because addTraceEvent is threadsafe internally and checks the enabled state 157 // again under lock. 158 // 159 // Without the use of these static category pointers and enabled flags all 160 // trace points would carry a significant performance cost of aquiring a lock 161 // and resolving the category. 162 163 #ifndef TraceEvent_h 164 #define TraceEvent_h 165 166 #include "core/platform/EventTracer.h" 167 168 #include "wtf/DynamicAnnotations.h" 169 #include "wtf/text/CString.h" 170 171 // By default, const char* argument values are assumed to have long-lived scope 172 // and will not be copied. Use this macro to force a const char* to be copied. 173 #define TRACE_STR_COPY(str) \ 174 WebCore::TraceEvent::TraceStringWithCopy(str) 175 176 // Records a pair of begin and end events called "name" for the current 177 // scope, with 0, 1 or 2 associated arguments. If the category is not 178 // enabled, then this does nothing. 179 // - category and name strings must have application lifetime (statics or 180 // literals). They may not include " chars. 181 #define TRACE_EVENT0(category, name) \ 182 INTERNAL_TRACE_EVENT_ADD_SCOPED(category, name) 183 #define TRACE_EVENT1(category, name, arg1_name, arg1_val) \ 184 INTERNAL_TRACE_EVENT_ADD_SCOPED(category, name, arg1_name, arg1_val) 185 #define TRACE_EVENT2(category, name, arg1_name, arg1_val, arg2_name, arg2_val) \ 186 INTERNAL_TRACE_EVENT_ADD_SCOPED(category, name, arg1_name, arg1_val, \ 187 arg2_name, arg2_val) 188 189 // Records a single event called "name" immediately, with 0, 1 or 2 190 // associated arguments. If the category is not enabled, then this 191 // does nothing. 192 // - category and name strings must have application lifetime (statics or 193 // literals). They may not include " chars. 194 #define TRACE_EVENT_INSTANT0(category, name) \ 195 INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_INSTANT, \ 196 category, name, TRACE_EVENT_FLAG_NONE) 197 #define TRACE_EVENT_INSTANT1(category, name, arg1_name, arg1_val) \ 198 INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_INSTANT, \ 199 category, name, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val) 200 #define TRACE_EVENT_INSTANT2(category, name, arg1_name, arg1_val, \ 201 arg2_name, arg2_val) \ 202 INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_INSTANT, \ 203 category, name, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val, \ 204 arg2_name, arg2_val) 205 #define TRACE_EVENT_COPY_INSTANT0(category, name) \ 206 INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_INSTANT, \ 207 category, name, TRACE_EVENT_FLAG_COPY) 208 #define TRACE_EVENT_COPY_INSTANT1(category, name, arg1_name, arg1_val) \ 209 INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_INSTANT, \ 210 category, name, TRACE_EVENT_FLAG_COPY, arg1_name, arg1_val) 211 #define TRACE_EVENT_COPY_INSTANT2(category, name, arg1_name, arg1_val, \ 212 arg2_name, arg2_val) \ 213 INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_INSTANT, \ 214 category, name, TRACE_EVENT_FLAG_COPY, arg1_name, arg1_val, \ 215 arg2_name, arg2_val) 216 217 // Records a single BEGIN event called "name" immediately, with 0, 1 or 2 218 // associated arguments. If the category is not enabled, then this 219 // does nothing. 220 // - category and name strings must have application lifetime (statics or 221 // literals). They may not include " chars. 222 #define TRACE_EVENT_BEGIN0(category, name) \ 223 INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_BEGIN, \ 224 category, name, TRACE_EVENT_FLAG_NONE) 225 #define TRACE_EVENT_BEGIN1(category, name, arg1_name, arg1_val) \ 226 INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_BEGIN, \ 227 category, name, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val) 228 #define TRACE_EVENT_BEGIN2(category, name, arg1_name, arg1_val, \ 229 arg2_name, arg2_val) \ 230 INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_BEGIN, \ 231 category, name, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val, \ 232 arg2_name, arg2_val) 233 #define TRACE_EVENT_COPY_BEGIN0(category, name) \ 234 INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_BEGIN, \ 235 category, name, TRACE_EVENT_FLAG_COPY) 236 #define TRACE_EVENT_COPY_BEGIN1(category, name, arg1_name, arg1_val) \ 237 INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_BEGIN, \ 238 category, name, TRACE_EVENT_FLAG_COPY, arg1_name, arg1_val) 239 #define TRACE_EVENT_COPY_BEGIN2(category, name, arg1_name, arg1_val, \ 240 arg2_name, arg2_val) \ 241 INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_BEGIN, \ 242 category, name, TRACE_EVENT_FLAG_COPY, arg1_name, arg1_val, \ 243 arg2_name, arg2_val) 244 245 // Records a single END event for "name" immediately. If the category 246 // is not enabled, then this does nothing. 247 // - category and name strings must have application lifetime (statics or 248 // literals). They may not include " chars. 249 #define TRACE_EVENT_END0(category, name) \ 250 INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_END, \ 251 category, name, TRACE_EVENT_FLAG_NONE) 252 #define TRACE_EVENT_END1(category, name, arg1_name, arg1_val) \ 253 INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_END, \ 254 category, name, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val) 255 #define TRACE_EVENT_END2(category, name, arg1_name, arg1_val, \ 256 arg2_name, arg2_val) \ 257 INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_END, \ 258 category, name, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val, \ 259 arg2_name, arg2_val) 260 #define TRACE_EVENT_COPY_END0(category, name) \ 261 INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_END, \ 262 category, name, TRACE_EVENT_FLAG_COPY) 263 #define TRACE_EVENT_COPY_END1(category, name, arg1_name, arg1_val) \ 264 INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_END, \ 265 category, name, TRACE_EVENT_FLAG_COPY, arg1_name, arg1_val) 266 #define TRACE_EVENT_COPY_END2(category, name, arg1_name, arg1_val, \ 267 arg2_name, arg2_val) \ 268 INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_END, \ 269 category, name, TRACE_EVENT_FLAG_COPY, arg1_name, arg1_val, \ 270 arg2_name, arg2_val) 271 272 // Records the value of a counter called "name" immediately. Value 273 // must be representable as a 32 bit integer. 274 // - category and name strings must have application lifetime (statics or 275 // literals). They may not include " chars. 276 #define TRACE_COUNTER1(category, name, value) \ 277 INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_COUNTER, \ 278 category, name, TRACE_EVENT_FLAG_NONE, \ 279 "value", static_cast<int>(value)) 280 #define TRACE_COPY_COUNTER1(category, name, value) \ 281 INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_COUNTER, \ 282 category, name, TRACE_EVENT_FLAG_COPY, \ 283 "value", static_cast<int>(value)) 284 285 // Records the values of a multi-parted counter called "name" immediately. 286 // The UI will treat value1 and value2 as parts of a whole, displaying their 287 // values as a stacked-bar chart. 288 // - category and name strings must have application lifetime (statics or 289 // literals). They may not include " chars. 290 #define TRACE_COUNTER2(category, name, value1_name, value1_val, \ 291 value2_name, value2_val) \ 292 INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_COUNTER, \ 293 category, name, TRACE_EVENT_FLAG_NONE, \ 294 value1_name, static_cast<int>(value1_val), \ 295 value2_name, static_cast<int>(value2_val)) 296 #define TRACE_COPY_COUNTER2(category, name, value1_name, value1_val, \ 297 value2_name, value2_val) \ 298 INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_COUNTER, \ 299 category, name, TRACE_EVENT_FLAG_COPY, \ 300 value1_name, static_cast<int>(value1_val), \ 301 value2_name, static_cast<int>(value2_val)) 302 303 // Records the value of a counter called "name" immediately. Value 304 // must be representable as a 32 bit integer. 305 // - category and name strings must have application lifetime (statics or 306 // literals). They may not include " chars. 307 // - |id| is used to disambiguate counters with the same name. It must either 308 // be a pointer or an integer value up to 64 bits. If it's a pointer, the bits 309 // will be xored with a hash of the process ID so that the same pointer on 310 // two different processes will not collide. 311 #define TRACE_COUNTER_ID1(category, name, id, value) \ 312 INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_COUNTER, \ 313 category, name, id, TRACE_EVENT_FLAG_NONE, \ 314 "value", static_cast<int>(value)) 315 #define TRACE_COPY_COUNTER_ID1(category, name, id, value) \ 316 INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_COUNTER, \ 317 category, name, id, TRACE_EVENT_FLAG_COPY, \ 318 "value", static_cast<int>(value)) 319 320 // Records the values of a multi-parted counter called "name" immediately. 321 // The UI will treat value1 and value2 as parts of a whole, displaying their 322 // values as a stacked-bar chart. 323 // - category and name strings must have application lifetime (statics or 324 // literals). They may not include " chars. 325 // - |id| is used to disambiguate counters with the same name. It must either 326 // be a pointer or an integer value up to 64 bits. If it's a pointer, the bits 327 // will be xored with a hash of the process ID so that the same pointer on 328 // two different processes will not collide. 329 #define TRACE_COUNTER_ID2(category, name, id, value1_name, value1_val, \ 330 value2_name, value2_val) \ 331 INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_COUNTER, \ 332 category, name, id, TRACE_EVENT_FLAG_NONE, \ 333 value1_name, static_cast<int>(value1_val), \ 334 value2_name, static_cast<int>(value2_val)) 335 #define TRACE_COPY_COUNTER_ID2(category, name, id, value1_name, value1_val, \ 336 value2_name, value2_val) \ 337 INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_COUNTER, \ 338 category, name, id, TRACE_EVENT_FLAG_COPY, \ 339 value1_name, static_cast<int>(value1_val), \ 340 value2_name, static_cast<int>(value2_val)) 341 342 // Records a single ASYNC_BEGIN event called "name" immediately, with 0, 1 or 2 343 // associated arguments. If the category is not enabled, then this 344 // does nothing. 345 // - category and name strings must have application lifetime (statics or 346 // literals). They may not include " chars. 347 // - |id| is used to match the ASYNC_BEGIN event with the ASYNC_END event. ASYNC 348 // events are considered to match if their category, name and id values all 349 // match. |id| must either be a pointer or an integer value up to 64 bits. If 350 // it's a pointer, the bits will be xored with a hash of the process ID so 351 // that the same pointer on two different processes will not collide. 352 // An asynchronous operation can consist of multiple phases. The first phase is 353 // defined by the ASYNC_BEGIN calls. Additional phases can be defined using the 354 // ASYNC_STEP_BEGIN macros. When the operation completes, call ASYNC_END. 355 // An async operation can span threads and processes, but all events in that 356 // operation must use the same |name| and |id|. Each event can have its own 357 // args. 358 #define TRACE_EVENT_ASYNC_BEGIN0(category, name, id) \ 359 INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_BEGIN, \ 360 category, name, id, TRACE_EVENT_FLAG_NONE) 361 #define TRACE_EVENT_ASYNC_BEGIN1(category, name, id, arg1_name, arg1_val) \ 362 INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_BEGIN, \ 363 category, name, id, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val) 364 #define TRACE_EVENT_ASYNC_BEGIN2(category, name, id, arg1_name, arg1_val, \ 365 arg2_name, arg2_val) \ 366 INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_BEGIN, \ 367 category, name, id, TRACE_EVENT_FLAG_NONE, \ 368 arg1_name, arg1_val, arg2_name, arg2_val) 369 #define TRACE_EVENT_COPY_ASYNC_BEGIN0(category, name, id) \ 370 INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_BEGIN, \ 371 category, name, id, TRACE_EVENT_FLAG_COPY) 372 #define TRACE_EVENT_COPY_ASYNC_BEGIN1(category, name, id, arg1_name, arg1_val) \ 373 INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_BEGIN, \ 374 category, name, id, TRACE_EVENT_FLAG_COPY, \ 375 arg1_name, arg1_val) 376 #define TRACE_EVENT_COPY_ASYNC_BEGIN2(category, name, id, arg1_name, arg1_val, \ 377 arg2_name, arg2_val) \ 378 INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_BEGIN, \ 379 category, name, id, TRACE_EVENT_FLAG_COPY, \ 380 arg1_name, arg1_val, arg2_name, arg2_val) 381 382 // Records a single ASYNC_STEP event for |step| immediately. If the category 383 // is not enabled, then this does nothing. The |name| and |id| must match the 384 // ASYNC_BEGIN event above. The |step| param identifies this step within the 385 // async event. This should be called at the beginning of the next phase of an 386 // asynchronous operation. 387 #define TRACE_EVENT_ASYNC_STEP0(category, name, id, step) \ 388 INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_STEP, \ 389 category, name, id, TRACE_EVENT_FLAG_NONE, "step", step) 390 #define TRACE_EVENT_ASYNC_STEP1(category, name, id, step, \ 391 arg1_name, arg1_val) \ 392 INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_STEP, \ 393 category, name, id, TRACE_EVENT_FLAG_NONE, "step", step, \ 394 arg1_name, arg1_val) 395 #define TRACE_EVENT_COPY_ASYNC_STEP0(category, name, id, step) \ 396 INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_STEP, \ 397 category, name, id, TRACE_EVENT_FLAG_COPY, "step", step) 398 #define TRACE_EVENT_COPY_ASYNC_STEP1(category, name, id, step, \ 399 arg1_name, arg1_val) \ 400 INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_STEP, \ 401 category, name, id, TRACE_EVENT_FLAG_COPY, "step", step, \ 402 arg1_name, arg1_val) 403 404 // Records a single ASYNC_END event for "name" immediately. If the category 405 // is not enabled, then this does nothing. 406 #define TRACE_EVENT_ASYNC_END0(category, name, id) \ 407 INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_END, \ 408 category, name, id, TRACE_EVENT_FLAG_NONE) 409 #define TRACE_EVENT_ASYNC_END1(category, name, id, arg1_name, arg1_val) \ 410 INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_END, \ 411 category, name, id, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val) 412 #define TRACE_EVENT_ASYNC_END2(category, name, id, arg1_name, arg1_val, \ 413 arg2_name, arg2_val) \ 414 INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_END, \ 415 category, name, id, TRACE_EVENT_FLAG_NONE, \ 416 arg1_name, arg1_val, arg2_name, arg2_val) 417 #define TRACE_EVENT_COPY_ASYNC_END0(category, name, id) \ 418 INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_END, \ 419 category, name, id, TRACE_EVENT_FLAG_COPY) 420 #define TRACE_EVENT_COPY_ASYNC_END1(category, name, id, arg1_name, arg1_val) \ 421 INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_END, \ 422 category, name, id, TRACE_EVENT_FLAG_COPY, \ 423 arg1_name, arg1_val) 424 #define TRACE_EVENT_COPY_ASYNC_END2(category, name, id, arg1_name, arg1_val, \ 425 arg2_name, arg2_val) \ 426 INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_END, \ 427 category, name, id, TRACE_EVENT_FLAG_COPY, \ 428 arg1_name, arg1_val, arg2_name, arg2_val) 429 430 // Creates a scope of a sampling state with the given category and name (both must 431 // be constant strings). These states are intended for a sampling profiler. 432 // Implementation note: we store category and name together because we don't 433 // want the inconsistency/expense of storing two pointers. 434 // |thread_bucket| is [0..2] and is used to statically isolate samples in one 435 // thread from others. 436 // 437 // { // The sampling state is set within this scope. 438 // TRACE_EVENT_SAMPLING_STATE_SCOPE_FOR_BUCKET(0, "category", "name"); 439 // ...; 440 // } 441 #define TRACE_EVENT_SCOPED_SAMPLING_STATE_FOR_BUCKET(bucket_number, category, name) \ 442 TraceEvent::SamplingStateScope<bucket_number> traceEventSamplingScope(category "\0" name); 443 444 // Returns a current sampling state of the given bucket. 445 // The format of the returned string is "category\0name". 446 #define TRACE_EVENT_GET_SAMPLING_STATE_FOR_BUCKET(bucket_number) \ 447 TraceEvent::SamplingStateScope<bucket_number>::current() 448 449 // Sets a current sampling state of the given bucket. 450 // |category| and |name| have to be constant strings. 451 #define TRACE_EVENT_SET_SAMPLING_STATE_FOR_BUCKET(bucket_number, category, name) \ 452 TraceEvent::SamplingStateScope<bucket_number>::set(category "\0" name) 453 454 // Sets a current sampling state of the given bucket. 455 // |categoryAndName| doesn't need to be a constant string. 456 // The format of the string is "category\0name". 457 #define TRACE_EVENT_SET_NONCONST_SAMPLING_STATE_FOR_BUCKET(bucket_number, categoryAndName) \ 458 TraceEvent::SamplingStateScope<bucket_number>::set(categoryAndName) 459 460 // Syntactic sugars for the sampling tracing in the main thread. 461 #define TRACE_EVENT_SCOPED_SAMPLING_STATE(category, name) \ 462 TRACE_EVENT_SCOPED_SAMPLING_STATE_FOR_BUCKET(0, category, name) 463 #define TRACE_EVENT_GET_SAMPLING_STATE() \ 464 TRACE_EVENT_GET_SAMPLING_STATE_FOR_BUCKET(0) 465 #define TRACE_EVENT_SET_SAMPLING_STATE(category, name) \ 466 TRACE_EVENT_SET_SAMPLING_STATE_FOR_BUCKET(0, category, name) 467 #define TRACE_EVENT_SET_NONCONST_SAMPLING_STATE(categoryAndName) \ 468 TRACE_EVENT_SET_NONCONST_SAMPLING_STATE_FOR_BUCKET(0, categoryAndName) 469 470 //////////////////////////////////////////////////////////////////////////////// 471 // Implementation specific tracing API definitions. 472 473 // Get a pointer to the enabled state of the given trace category. Only 474 // long-lived literal strings should be given as the category name. The returned 475 // pointer can be held permanently in a local static for example. If the 476 // unsigned char is non-zero, tracing is enabled. If tracing is enabled, 477 // TRACE_EVENT_API_ADD_TRACE_EVENT can be called. It's OK if tracing is disabled 478 // between the load of the tracing state and the call to 479 // TRACE_EVENT_API_ADD_TRACE_EVENT, because this flag only provides an early out 480 // for best performance when tracing is disabled. 481 // const unsigned char* 482 // TRACE_EVENT_API_GET_CATEGORY_ENABLED(const char* category_name) 483 #define TRACE_EVENT_API_GET_CATEGORY_ENABLED \ 484 WebCore::EventTracer::getTraceCategoryEnabledFlag 485 486 // Add a trace event to the platform tracing system. 487 // void TRACE_EVENT_API_ADD_TRACE_EVENT( 488 // char phase, 489 // const unsigned char* category_enabled, 490 // const char* name, 491 // unsigned long long id, 492 // int num_args, 493 // const char** arg_names, 494 // const unsigned char* arg_types, 495 // const unsigned long long* arg_values, 496 // unsigned char flags) 497 #define TRACE_EVENT_API_ADD_TRACE_EVENT \ 498 WebCore::EventTracer::addTraceEvent 499 500 //////////////////////////////////////////////////////////////////////////////// 501 502 // Implementation detail: trace event macros create temporary variables 503 // to keep instrumentation overhead low. These macros give each temporary 504 // variable a unique name based on the line number to prevent name collissions. 505 #define INTERNAL_TRACE_EVENT_UID3(a, b) \ 506 trace_event_unique_##a##b 507 #define INTERNAL_TRACE_EVENT_UID2(a, b) \ 508 INTERNAL_TRACE_EVENT_UID3(a, b) 509 #define INTERNALTRACEEVENTUID(name_prefix) \ 510 INTERNAL_TRACE_EVENT_UID2(name_prefix, __LINE__) 511 512 // Implementation detail: internal macro to create static category. 513 // - WTF_ANNOTATE_BENIGN_RACE, see Thread Safety above. 514 #define INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category) \ 515 static const unsigned char* INTERNALTRACEEVENTUID(catstatic) = 0; \ 516 WTF_ANNOTATE_BENIGN_RACE(&INTERNALTRACEEVENTUID(catstatic), \ 517 "trace_event category"); \ 518 if (!INTERNALTRACEEVENTUID(catstatic)) \ 519 INTERNALTRACEEVENTUID(catstatic) = \ 520 TRACE_EVENT_API_GET_CATEGORY_ENABLED(category); 521 522 // Implementation detail: internal macro to create static category and add 523 // event if the category is enabled. 524 #define INTERNAL_TRACE_EVENT_ADD(phase, category, name, flags, ...) \ 525 do { \ 526 INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category); \ 527 if (*INTERNALTRACEEVENTUID(catstatic)) { \ 528 WebCore::TraceEvent::addTraceEvent( \ 529 phase, INTERNALTRACEEVENTUID(catstatic), name, \ 530 WebCore::TraceEvent::noEventId, flags, ##__VA_ARGS__); \ 531 } \ 532 } while (0) 533 534 // Implementation detail: internal macro to create static category and add begin 535 // event if the category is enabled. Also adds the end event when the scope 536 // ends. 537 #define INTERNAL_TRACE_EVENT_ADD_SCOPED(category, name, ...) \ 538 INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category); \ 539 WebCore::TraceEvent::TraceEndOnScopeClose \ 540 INTERNALTRACEEVENTUID(profileScope); \ 541 if (*INTERNALTRACEEVENTUID(catstatic)) { \ 542 WebCore::TraceEvent::addTraceEvent( \ 543 TRACE_EVENT_PHASE_BEGIN, \ 544 INTERNALTRACEEVENTUID(catstatic), \ 545 name, WebCore::TraceEvent::noEventId, \ 546 TRACE_EVENT_FLAG_NONE, ##__VA_ARGS__); \ 547 INTERNALTRACEEVENTUID(profileScope).initialize( \ 548 INTERNALTRACEEVENTUID(catstatic), name); \ 549 } 550 551 // Implementation detail: internal macro to create static category and add 552 // event if the category is enabled. 553 #define INTERNAL_TRACE_EVENT_ADD_WITH_ID(phase, category, name, id, flags, \ 554 ...) \ 555 do { \ 556 INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category); \ 557 if (*INTERNALTRACEEVENTUID(catstatic)) { \ 558 unsigned char traceEventFlags = flags | TRACE_EVENT_FLAG_HAS_ID; \ 559 WebCore::TraceEvent::TraceID traceEventTraceID( \ 560 id, &traceEventFlags); \ 561 WebCore::TraceEvent::addTraceEvent( \ 562 phase, INTERNALTRACEEVENTUID(catstatic), \ 563 name, traceEventTraceID.data(), traceEventFlags, \ 564 ##__VA_ARGS__); \ 565 } \ 566 } while (0) 567 568 // Notes regarding the following definitions: 569 // New values can be added and propagated to third party libraries, but existing 570 // definitions must never be changed, because third party libraries may use old 571 // definitions. 572 573 // Phase indicates the nature of an event entry. E.g. part of a begin/end pair. 574 #define TRACE_EVENT_PHASE_BEGIN ('B') 575 #define TRACE_EVENT_PHASE_END ('E') 576 #define TRACE_EVENT_PHASE_INSTANT ('I') 577 #define TRACE_EVENT_PHASE_ASYNC_BEGIN ('S') 578 #define TRACE_EVENT_PHASE_ASYNC_STEP ('T') 579 #define TRACE_EVENT_PHASE_ASYNC_END ('F') 580 #define TRACE_EVENT_PHASE_METADATA ('M') 581 #define TRACE_EVENT_PHASE_COUNTER ('C') 582 #define TRACE_EVENT_PHASE_SAMPLE ('P') 583 584 // Flags for changing the behavior of TRACE_EVENT_API_ADD_TRACE_EVENT. 585 #define TRACE_EVENT_FLAG_NONE (static_cast<unsigned char>(0)) 586 #define TRACE_EVENT_FLAG_COPY (static_cast<unsigned char>(1 << 0)) 587 #define TRACE_EVENT_FLAG_HAS_ID (static_cast<unsigned char>(1 << 1)) 588 #define TRACE_EVENT_FLAG_MANGLE_ID (static_cast<unsigned char>(1 << 2)) 589 590 // Type values for identifying types in the TraceValue union. 591 #define TRACE_VALUE_TYPE_BOOL (static_cast<unsigned char>(1)) 592 #define TRACE_VALUE_TYPE_UINT (static_cast<unsigned char>(2)) 593 #define TRACE_VALUE_TYPE_INT (static_cast<unsigned char>(3)) 594 #define TRACE_VALUE_TYPE_DOUBLE (static_cast<unsigned char>(4)) 595 #define TRACE_VALUE_TYPE_POINTER (static_cast<unsigned char>(5)) 596 #define TRACE_VALUE_TYPE_STRING (static_cast<unsigned char>(6)) 597 #define TRACE_VALUE_TYPE_COPY_STRING (static_cast<unsigned char>(7)) 598 599 600 namespace WebCore { 601 602 namespace TraceEvent { 603 604 // Specify these values when the corresponding argument of addTraceEvent is not 605 // used. 606 const int zeroNumArgs = 0; 607 const unsigned long long noEventId = 0; 608 609 // TraceID encapsulates an ID that can either be an integer or pointer. Pointers 610 // are mangled with the Process ID so that they are unlikely to collide when the 611 // same pointer is used on different processes. 612 class TraceID { 613 public: 614 explicit TraceID(const void* id, unsigned char* flags) : 615 m_data(static_cast<unsigned long long>(reinterpret_cast<unsigned long>(id))) 616 { 617 *flags |= TRACE_EVENT_FLAG_MANGLE_ID; 618 } 619 explicit TraceID(unsigned long long id, unsigned char* flags) : m_data(id) { (void)flags; } 620 explicit TraceID(unsigned long id, unsigned char* flags) : m_data(id) { (void)flags; } 621 explicit TraceID(unsigned int id, unsigned char* flags) : m_data(id) { (void)flags; } 622 explicit TraceID(unsigned short id, unsigned char* flags) : m_data(id) { (void)flags; } 623 explicit TraceID(unsigned char id, unsigned char* flags) : m_data(id) { (void)flags; } 624 explicit TraceID(long long id, unsigned char* flags) : 625 m_data(static_cast<unsigned long long>(id)) { (void)flags; } 626 explicit TraceID(long id, unsigned char* flags) : 627 m_data(static_cast<unsigned long long>(id)) { (void)flags; } 628 explicit TraceID(int id, unsigned char* flags) : 629 m_data(static_cast<unsigned long long>(id)) { (void)flags; } 630 explicit TraceID(short id, unsigned char* flags) : 631 m_data(static_cast<unsigned long long>(id)) { (void)flags; } 632 explicit TraceID(signed char id, unsigned char* flags) : 633 m_data(static_cast<unsigned long long>(id)) { (void)flags; } 634 635 unsigned long long data() const { return m_data; } 636 637 private: 638 unsigned long long m_data; 639 }; 640 641 // Simple union to store various types as unsigned long long. 642 union TraceValueUnion { 643 bool m_bool; 644 unsigned long long m_uint; 645 long long m_int; 646 double m_double; 647 const void* m_pointer; 648 const char* m_string; 649 }; 650 651 // Simple container for const char* that should be copied instead of retained. 652 class TraceStringWithCopy { 653 public: 654 explicit TraceStringWithCopy(const char* str) : m_str(str) { } 655 operator const char* () const { return m_str; } 656 private: 657 const char* m_str; 658 }; 659 660 // Define setTraceValue for each allowed type. It stores the type and 661 // value in the return arguments. This allows this API to avoid declaring any 662 // structures so that it is portable to third_party libraries. 663 #define INTERNAL_DECLARE_SET_TRACE_VALUE(actual_type, \ 664 union_member, \ 665 value_type_id) \ 666 static inline void setTraceValue(actual_type arg, \ 667 unsigned char* type, \ 668 unsigned long long* value) { \ 669 TraceValueUnion typeValue; \ 670 typeValue.union_member = arg; \ 671 *type = value_type_id; \ 672 *value = typeValue.m_uint; \ 673 } 674 // Simpler form for int types that can be safely casted. 675 #define INTERNAL_DECLARE_SET_TRACE_VALUE_INT(actual_type, \ 676 value_type_id) \ 677 static inline void setTraceValue(actual_type arg, \ 678 unsigned char* type, \ 679 unsigned long long* value) { \ 680 *type = value_type_id; \ 681 *value = static_cast<unsigned long long>(arg); \ 682 } 683 684 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(unsigned long long, TRACE_VALUE_TYPE_UINT) 685 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(unsigned int, TRACE_VALUE_TYPE_UINT) 686 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(unsigned short, TRACE_VALUE_TYPE_UINT) 687 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(unsigned char, TRACE_VALUE_TYPE_UINT) 688 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(long long, TRACE_VALUE_TYPE_INT) 689 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(int, TRACE_VALUE_TYPE_INT) 690 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(short, TRACE_VALUE_TYPE_INT) 691 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(signed char, TRACE_VALUE_TYPE_INT) 692 INTERNAL_DECLARE_SET_TRACE_VALUE(bool, m_bool, TRACE_VALUE_TYPE_BOOL) 693 INTERNAL_DECLARE_SET_TRACE_VALUE(double, m_double, TRACE_VALUE_TYPE_DOUBLE) 694 INTERNAL_DECLARE_SET_TRACE_VALUE(const void*, m_pointer, 695 TRACE_VALUE_TYPE_POINTER) 696 INTERNAL_DECLARE_SET_TRACE_VALUE(const char*, m_string, 697 TRACE_VALUE_TYPE_STRING) 698 INTERNAL_DECLARE_SET_TRACE_VALUE(const TraceStringWithCopy&, m_string, 699 TRACE_VALUE_TYPE_COPY_STRING) 700 701 #undef INTERNAL_DECLARE_SET_TRACE_VALUE 702 #undef INTERNAL_DECLARE_SET_TRACE_VALUE_INT 703 704 // WTF::String version of setTraceValue so that trace arguments can be strings. 705 static inline void setTraceValue(const WTF::CString& arg, 706 unsigned char* type, 707 unsigned long long* value) { 708 TraceValueUnion typeValue; 709 typeValue.m_string = arg.data(); 710 *type = TRACE_VALUE_TYPE_COPY_STRING; 711 *value = typeValue.m_uint; 712 } 713 714 // These addTraceEvent template functions are defined here instead of in the 715 // macro, because the arg values could be temporary string objects. In order to 716 // store pointers to the internal c_str and pass through to the tracing API, the 717 // arg values must live throughout these procedures. 718 719 static inline void addTraceEvent(char phase, 720 const unsigned char* categoryEnabled, 721 const char* name, 722 unsigned long long id, 723 unsigned char flags) { 724 TRACE_EVENT_API_ADD_TRACE_EVENT( 725 phase, categoryEnabled, name, id, 726 zeroNumArgs, 0, 0, 0, 727 flags); 728 } 729 730 template<class ARG1_TYPE> 731 static inline void addTraceEvent(char phase, 732 const unsigned char* categoryEnabled, 733 const char* name, 734 unsigned long long id, 735 unsigned char flags, 736 const char* arg1Name, 737 const ARG1_TYPE& arg1Val) { 738 const int numArgs = 1; 739 unsigned char argTypes[1]; 740 unsigned long long argValues[1]; 741 setTraceValue(arg1Val, &argTypes[0], &argValues[0]); 742 TRACE_EVENT_API_ADD_TRACE_EVENT( 743 phase, categoryEnabled, name, id, 744 numArgs, &arg1Name, argTypes, argValues, 745 flags); 746 } 747 748 template<class ARG1_TYPE, class ARG2_TYPE> 749 static inline void addTraceEvent(char phase, 750 const unsigned char* categoryEnabled, 751 const char* name, 752 unsigned long long id, 753 unsigned char flags, 754 const char* arg1Name, 755 const ARG1_TYPE& arg1Val, 756 const char* arg2Name, 757 const ARG2_TYPE& arg2Val) { 758 const int numArgs = 2; 759 const char* argNames[2] = { arg1Name, arg2Name }; 760 unsigned char argTypes[2]; 761 unsigned long long argValues[2]; 762 setTraceValue(arg1Val, &argTypes[0], &argValues[0]); 763 setTraceValue(arg2Val, &argTypes[1], &argValues[1]); 764 return TRACE_EVENT_API_ADD_TRACE_EVENT( 765 phase, categoryEnabled, name, id, 766 numArgs, argNames, argTypes, argValues, 767 flags); 768 } 769 770 // Used by TRACE_EVENTx macro. Do not use directly. 771 class TraceEndOnScopeClose { 772 public: 773 // Note: members of m_data intentionally left uninitialized. See initialize. 774 TraceEndOnScopeClose() : m_pdata(0) { } 775 ~TraceEndOnScopeClose() 776 { 777 if (m_pdata) 778 addEventIfEnabled(); 779 } 780 781 void initialize(const unsigned char* categoryEnabled, 782 const char* name) 783 { 784 m_data.categoryEnabled = categoryEnabled; 785 m_data.name = name; 786 m_pdata = &m_data; 787 } 788 789 private: 790 // Add the end event if the category is still enabled. 791 void addEventIfEnabled() 792 { 793 // Only called when m_pdata is non-null. 794 if (*m_pdata->categoryEnabled) { 795 TRACE_EVENT_API_ADD_TRACE_EVENT( 796 TRACE_EVENT_PHASE_END, 797 m_pdata->categoryEnabled, 798 m_pdata->name, noEventId, 799 zeroNumArgs, 0, 0, 0, 800 TRACE_EVENT_FLAG_NONE); 801 } 802 } 803 804 // This Data struct workaround is to avoid initializing all the members 805 // in Data during construction of this object, since this object is always 806 // constructed, even when tracing is disabled. If the members of Data were 807 // members of this class instead, compiler warnings occur about potential 808 // uninitialized accesses. 809 struct Data { 810 const unsigned char* categoryEnabled; 811 const char* name; 812 }; 813 Data* m_pdata; 814 Data m_data; 815 }; 816 817 // TraceEventSamplingStateScope records the current sampling state 818 // and sets a new sampling state. When the scope exists, it restores 819 // the sampling state having recorded. 820 template<size_t BucketNumber> 821 class SamplingStateScope { 822 WTF_MAKE_FAST_ALLOCATED; 823 public: 824 SamplingStateScope(const char* categoryAndName) 825 { 826 m_previousState = SamplingStateScope<BucketNumber>::current(); 827 SamplingStateScope<BucketNumber>::set(categoryAndName); 828 } 829 830 ~SamplingStateScope() 831 { 832 SamplingStateScope<BucketNumber>::set(m_previousState); 833 } 834 835 // FIXME: Make load/store to traceSamplingState[] thread-safe and atomic. 836 static inline const char* current() 837 { 838 return reinterpret_cast<const char*>(*WebCore::traceSamplingState[BucketNumber]); 839 } 840 static inline void set(const char* categoryAndName) 841 { 842 *WebCore::traceSamplingState[BucketNumber] = reinterpret_cast<long>(const_cast<char*>(categoryAndName)); 843 } 844 845 private: 846 const char* m_previousState; 847 }; 848 849 } // namespace TraceEvent 850 851 } // namespace WebCore 852 853 #endif 854
