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      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file under third_party_mods/chromium or at:
      4 // http://src.chromium.org/svn/trunk/src/LICENSE
      5 
      6 #ifndef WEBRTC_BASE_TRACE_EVENT_H_
      7 #define WEBRTC_BASE_TRACE_EVENT_H_
      8 
      9 #include <string>
     10 
     11 #include "webrtc/base/event_tracer.h"
     12 
     13 #if defined(TRACE_EVENT0)
     14 #error "Another copy of trace_event.h has already been included."
     15 #endif
     16 
     17 // Extracted from Chromium's src/base/debug/trace_event.h.
     18 
     19 // This header is designed to give you trace_event macros without specifying
     20 // how the events actually get collected and stored. If you need to expose trace
     21 // event to some other universe, you can copy-and-paste this file,
     22 // implement the TRACE_EVENT_API macros, and do any other necessary fixup for
     23 // the target platform. The end result is that multiple libraries can funnel
     24 // events through to a shared trace event collector.
     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
     42 // need them 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
     62 // ASYNC_BEGIN and 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.
     74 // Pointers can be used for the ID parameter, and they will be mangled
     75 // internally so that the same pointer on two different processes will not
     76 // match. For example:
     77 //   class MyTracedClass {
     78 //    public:
     79 //     MyTracedClass() {
     80 //       TRACE_EVENT_ASYNC_BEGIN0("category", "MyTracedClass", this);
     81 //     }
     82 //     ~MyTracedClass() {
     83 //       TRACE_EVENT_ASYNC_END0("category", "MyTracedClass", this);
     84 //     }
     85 //   }
     86 //
     87 // Trace event also supports counters, which is a way to track a quantity
     88 // as it varies over time. Counters are created with the following macro:
     89 //   TRACE_COUNTER1("MY_SUBSYSTEM", "myCounter", g_myCounterValue);
     90 //
     91 // Counters are process-specific. The macro itself can be issued from any
     92 // thread, however.
     93 //
     94 // Sometimes, you want to track two counters at once. You can do this with two
     95 // counter macros:
     96 //   TRACE_COUNTER1("MY_SUBSYSTEM", "myCounter0", g_myCounterValue[0]);
     97 //   TRACE_COUNTER1("MY_SUBSYSTEM", "myCounter1", g_myCounterValue[1]);
     98 // Or you can do it with a combined macro:
     99 //   TRACE_COUNTER2("MY_SUBSYSTEM", "myCounter",
    100 //       "bytesPinned", g_myCounterValue[0],
    101 //       "bytesAllocated", g_myCounterValue[1]);
    102 // This indicates to the tracing UI that these counters should be displayed
    103 // in a single graph, as a summed area chart.
    104 //
    105 // Since counters are in a global namespace, you may want to disembiguate with a
    106 // unique ID, by using the TRACE_COUNTER_ID* variations.
    107 //
    108 // By default, trace collection is compiled in, but turned off at runtime.
    109 // Collecting trace data is the responsibility of the embedding
    110 // application. In Chrome's case, navigating to about:tracing will turn on
    111 // tracing and display data collected across all active processes.
    112 //
    113 //
    114 // Memory scoping note:
    115 // Tracing copies the pointers, not the string content, of the strings passed
    116 // in for category, name, and arg_names.  Thus, the following code will
    117 // cause problems:
    118 //     char* str = strdup("impprtantName");
    119 //     TRACE_EVENT_INSTANT0("SUBSYSTEM", str);  // BAD!
    120 //     free(str);                   // Trace system now has dangling pointer
    121 //
    122 // To avoid this issue with the |name| and |arg_name| parameters, use the
    123 // TRACE_EVENT_COPY_XXX overloads of the macros at additional runtime overhead.
    124 // Notes: The category must always be in a long-lived char* (i.e. static const).
    125 //        The |arg_values|, when used, are always deep copied with the _COPY
    126 //        macros.
    127 //
    128 // When are string argument values copied:
    129 // const char* arg_values are only referenced by default:
    130 //     TRACE_EVENT1("category", "name",
    131 //                  "arg1", "literal string is only referenced");
    132 // Use TRACE_STR_COPY to force copying of a const char*:
    133 //     TRACE_EVENT1("category", "name",
    134 //                  "arg1", TRACE_STR_COPY("string will be copied"));
    135 // std::string arg_values are always copied:
    136 //     TRACE_EVENT1("category", "name",
    137 //                  "arg1", std::string("string will be copied"));
    138 //
    139 //
    140 // Thread Safety:
    141 // Thread safety is provided by methods defined in event_tracer.h. See the file
    142 // for details.
    143 
    144 
    145 // By default, const char* argument values are assumed to have long-lived scope
    146 // and will not be copied. Use this macro to force a const char* to be copied.
    147 #define TRACE_STR_COPY(str) \
    148     webrtc::trace_event_internal::TraceStringWithCopy(str)
    149 
    150 // This will mark the trace event as disabled by default. The user will need
    151 // to explicitly enable the event.
    152 #define TRACE_DISABLED_BY_DEFAULT(name) "disabled-by-default-" name
    153 
    154 // By default, uint64 ID argument values are not mangled with the Process ID in
    155 // TRACE_EVENT_ASYNC macros. Use this macro to force Process ID mangling.
    156 #define TRACE_ID_MANGLE(id) \
    157     webrtc::trace_event_internal::TraceID::ForceMangle(id)
    158 
    159 // Records a pair of begin and end events called "name" for the current
    160 // scope, with 0, 1 or 2 associated arguments. If the category is not
    161 // enabled, then this does nothing.
    162 // - category and name strings must have application lifetime (statics or
    163 //   literals). They may not include " chars.
    164 #define TRACE_EVENT0(category, name) \
    165     INTERNAL_TRACE_EVENT_ADD_SCOPED(category, name)
    166 #define TRACE_EVENT1(category, name, arg1_name, arg1_val) \
    167     INTERNAL_TRACE_EVENT_ADD_SCOPED(category, name, arg1_name, arg1_val)
    168 #define TRACE_EVENT2(category, name, arg1_name, arg1_val, arg2_name, arg2_val) \
    169     INTERNAL_TRACE_EVENT_ADD_SCOPED(category, name, arg1_name, arg1_val, \
    170         arg2_name, arg2_val)
    171 
    172 // Same as TRACE_EVENT except that they are not included in official builds.
    173 #ifdef OFFICIAL_BUILD
    174 #define UNSHIPPED_TRACE_EVENT0(category, name) (void)0
    175 #define UNSHIPPED_TRACE_EVENT1(category, name, arg1_name, arg1_val) (void)0
    176 #define UNSHIPPED_TRACE_EVENT2(category, name, arg1_name, arg1_val, \
    177                                arg2_name, arg2_val) (void)0
    178 #define UNSHIPPED_TRACE_EVENT_INSTANT0(category, name) (void)0
    179 #define UNSHIPPED_TRACE_EVENT_INSTANT1(category, name, arg1_name, arg1_val) \
    180     (void)0
    181 #define UNSHIPPED_TRACE_EVENT_INSTANT2(category, name, arg1_name, arg1_val, \
    182                                        arg2_name, arg2_val) (void)0
    183 #else
    184 #define UNSHIPPED_TRACE_EVENT0(category, name) \
    185     TRACE_EVENT0(category, name)
    186 #define UNSHIPPED_TRACE_EVENT1(category, name, arg1_name, arg1_val) \
    187     TRACE_EVENT1(category, name, arg1_name, arg1_val)
    188 #define UNSHIPPED_TRACE_EVENT2(category, name, arg1_name, arg1_val, \
    189                                arg2_name, arg2_val) \
    190     TRACE_EVENT2(category, name, arg1_name, arg1_val, arg2_name, arg2_val)
    191 #define UNSHIPPED_TRACE_EVENT_INSTANT0(category, name) \
    192     TRACE_EVENT_INSTANT0(category, name)
    193 #define UNSHIPPED_TRACE_EVENT_INSTANT1(category, name, arg1_name, arg1_val) \
    194     TRACE_EVENT_INSTANT1(category, name, arg1_name, arg1_val)
    195 #define UNSHIPPED_TRACE_EVENT_INSTANT2(category, name, arg1_name, arg1_val, \
    196                                        arg2_name, arg2_val) \
    197     TRACE_EVENT_INSTANT2(category, name, arg1_name, arg1_val, \
    198                          arg2_name, arg2_val)
    199 #endif
    200 
    201 // Records a single event called "name" immediately, with 0, 1 or 2
    202 // associated arguments. If the category is not enabled, then this
    203 // does nothing.
    204 // - category and name strings must have application lifetime (statics or
    205 //   literals). They may not include " chars.
    206 #define TRACE_EVENT_INSTANT0(category, name) \
    207     INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_INSTANT, \
    208         category, name, TRACE_EVENT_FLAG_NONE)
    209 #define TRACE_EVENT_INSTANT1(category, name, arg1_name, arg1_val) \
    210     INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_INSTANT, \
    211         category, name, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val)
    212 #define TRACE_EVENT_INSTANT2(category, name, arg1_name, arg1_val, \
    213         arg2_name, arg2_val) \
    214     INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_INSTANT, \
    215         category, name, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val, \
    216         arg2_name, arg2_val)
    217 #define TRACE_EVENT_COPY_INSTANT0(category, name) \
    218     INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_INSTANT, \
    219         category, name, TRACE_EVENT_FLAG_COPY)
    220 #define TRACE_EVENT_COPY_INSTANT1(category, name, arg1_name, arg1_val) \
    221     INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_INSTANT, \
    222         category, name, TRACE_EVENT_FLAG_COPY, arg1_name, arg1_val)
    223 #define TRACE_EVENT_COPY_INSTANT2(category, name, arg1_name, arg1_val, \
    224         arg2_name, arg2_val) \
    225     INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_INSTANT, \
    226         category, name, TRACE_EVENT_FLAG_COPY, arg1_name, arg1_val, \
    227         arg2_name, arg2_val)
    228 
    229 // Records a single BEGIN event called "name" immediately, with 0, 1 or 2
    230 // associated arguments. If the category is not enabled, then this
    231 // does nothing.
    232 // - category and name strings must have application lifetime (statics or
    233 //   literals). They may not include " chars.
    234 #define TRACE_EVENT_BEGIN0(category, name) \
    235     INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_BEGIN, \
    236         category, name, TRACE_EVENT_FLAG_NONE)
    237 #define TRACE_EVENT_BEGIN1(category, name, arg1_name, arg1_val) \
    238     INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_BEGIN, \
    239         category, name, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val)
    240 #define TRACE_EVENT_BEGIN2(category, name, arg1_name, arg1_val, \
    241         arg2_name, arg2_val) \
    242     INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_BEGIN, \
    243         category, name, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val, \
    244         arg2_name, arg2_val)
    245 #define TRACE_EVENT_COPY_BEGIN0(category, name) \
    246     INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_BEGIN, \
    247         category, name, TRACE_EVENT_FLAG_COPY)
    248 #define TRACE_EVENT_COPY_BEGIN1(category, name, arg1_name, arg1_val) \
    249     INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_BEGIN, \
    250         category, name, TRACE_EVENT_FLAG_COPY, arg1_name, arg1_val)
    251 #define TRACE_EVENT_COPY_BEGIN2(category, name, arg1_name, arg1_val, \
    252         arg2_name, arg2_val) \
    253     INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_BEGIN, \
    254         category, name, TRACE_EVENT_FLAG_COPY, arg1_name, arg1_val, \
    255         arg2_name, arg2_val)
    256 
    257 // Records a single END event for "name" immediately. If the category
    258 // is not enabled, then this does nothing.
    259 // - category and name strings must have application lifetime (statics or
    260 //   literals). They may not include " chars.
    261 #define TRACE_EVENT_END0(category, name) \
    262     INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_END, \
    263         category, name, TRACE_EVENT_FLAG_NONE)
    264 #define TRACE_EVENT_END1(category, name, arg1_name, arg1_val) \
    265     INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_END, \
    266         category, name, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val)
    267 #define TRACE_EVENT_END2(category, name, arg1_name, arg1_val, \
    268         arg2_name, arg2_val) \
    269     INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_END, \
    270         category, name, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val, \
    271         arg2_name, arg2_val)
    272 #define TRACE_EVENT_COPY_END0(category, name) \
    273     INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_END, \
    274         category, name, TRACE_EVENT_FLAG_COPY)
    275 #define TRACE_EVENT_COPY_END1(category, name, arg1_name, arg1_val) \
    276     INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_END, \
    277         category, name, TRACE_EVENT_FLAG_COPY, arg1_name, arg1_val)
    278 #define TRACE_EVENT_COPY_END2(category, name, arg1_name, arg1_val, \
    279         arg2_name, arg2_val) \
    280     INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_END, \
    281         category, name, TRACE_EVENT_FLAG_COPY, arg1_name, arg1_val, \
    282         arg2_name, arg2_val)
    283 
    284 // Records the value of a counter called "name" immediately. Value
    285 // must be representable as a 32 bit integer.
    286 // - category and name strings must have application lifetime (statics or
    287 //   literals). They may not include " chars.
    288 #define TRACE_COUNTER1(category, name, value) \
    289     INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_COUNTER, \
    290         category, name, TRACE_EVENT_FLAG_NONE, \
    291         "value", static_cast<int>(value))
    292 #define TRACE_COPY_COUNTER1(category, name, value) \
    293     INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_COUNTER, \
    294         category, name, TRACE_EVENT_FLAG_COPY, \
    295         "value", static_cast<int>(value))
    296 
    297 // Records the values of a multi-parted counter called "name" immediately.
    298 // The UI will treat value1 and value2 as parts of a whole, displaying their
    299 // values as a stacked-bar chart.
    300 // - category and name strings must have application lifetime (statics or
    301 //   literals). They may not include " chars.
    302 #define TRACE_COUNTER2(category, name, value1_name, value1_val, \
    303         value2_name, value2_val) \
    304     INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_COUNTER, \
    305         category, name, TRACE_EVENT_FLAG_NONE, \
    306         value1_name, static_cast<int>(value1_val), \
    307         value2_name, static_cast<int>(value2_val))
    308 #define TRACE_COPY_COUNTER2(category, name, value1_name, value1_val, \
    309         value2_name, value2_val) \
    310     INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_COUNTER, \
    311         category, name, TRACE_EVENT_FLAG_COPY, \
    312         value1_name, static_cast<int>(value1_val), \
    313         value2_name, static_cast<int>(value2_val))
    314 
    315 // Records the value of a counter called "name" immediately. Value
    316 // must be representable as a 32 bit integer.
    317 // - category and name strings must have application lifetime (statics or
    318 //   literals). They may not include " chars.
    319 // - |id| is used to disambiguate counters with the same name. It must either
    320 //   be a pointer or an integer value up to 64 bits. If it's a pointer, the bits
    321 //   will be xored with a hash of the process ID so that the same pointer on
    322 //   two different processes will not collide.
    323 #define TRACE_COUNTER_ID1(category, name, id, value) \
    324     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_COUNTER, \
    325         category, name, id, TRACE_EVENT_FLAG_NONE, \
    326         "value", static_cast<int>(value))
    327 #define TRACE_COPY_COUNTER_ID1(category, name, id, value) \
    328     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_COUNTER, \
    329         category, name, id, TRACE_EVENT_FLAG_COPY, \
    330         "value", static_cast<int>(value))
    331 
    332 // Records the values of a multi-parted counter called "name" immediately.
    333 // The UI will treat value1 and value2 as parts of a whole, displaying their
    334 // values as a stacked-bar chart.
    335 // - category and name strings must have application lifetime (statics or
    336 //   literals). They may not include " chars.
    337 // - |id| is used to disambiguate counters with the same name. It must either
    338 //   be a pointer or an integer value up to 64 bits. If it's a pointer, the bits
    339 //   will be xored with a hash of the process ID so that the same pointer on
    340 //   two different processes will not collide.
    341 #define TRACE_COUNTER_ID2(category, name, id, value1_name, value1_val, \
    342         value2_name, value2_val) \
    343     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_COUNTER, \
    344         category, name, id, TRACE_EVENT_FLAG_NONE, \
    345         value1_name, static_cast<int>(value1_val), \
    346         value2_name, static_cast<int>(value2_val))
    347 #define TRACE_COPY_COUNTER_ID2(category, name, id, value1_name, value1_val, \
    348         value2_name, value2_val) \
    349     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_COUNTER, \
    350         category, name, id, TRACE_EVENT_FLAG_COPY, \
    351         value1_name, static_cast<int>(value1_val), \
    352         value2_name, static_cast<int>(value2_val))
    353 
    354 
    355 // Records a single ASYNC_BEGIN event called "name" immediately, with 0, 1 or 2
    356 // associated arguments. If the category is not enabled, then this
    357 // does nothing.
    358 // - category and name strings must have application lifetime (statics or
    359 //   literals). They may not include " chars.
    360 // - |id| is used to match the ASYNC_BEGIN event with the ASYNC_END event. ASYNC
    361 //   events are considered to match if their category, name and id values all
    362 //   match. |id| must either be a pointer or an integer value up to 64 bits. If
    363 //   it's a pointer, the bits will be xored with a hash of the process ID so
    364 //   that the same pointer on two different processes will not collide.
    365 // An asynchronous operation can consist of multiple phases. The first phase is
    366 // defined by the ASYNC_BEGIN calls. Additional phases can be defined using the
    367 // ASYNC_STEP macros. When the operation completes, call ASYNC_END.
    368 // An ASYNC trace typically occur on a single thread (if not, they will only be
    369 // drawn on the thread defined in the ASYNC_BEGIN event), but all events in that
    370 // operation must use the same |name| and |id|. Each event can have its own
    371 // args.
    372 #define TRACE_EVENT_ASYNC_BEGIN0(category, name, id) \
    373     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_BEGIN, \
    374         category, name, id, TRACE_EVENT_FLAG_NONE)
    375 #define TRACE_EVENT_ASYNC_BEGIN1(category, name, id, arg1_name, arg1_val) \
    376     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_BEGIN, \
    377         category, name, id, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val)
    378 #define TRACE_EVENT_ASYNC_BEGIN2(category, name, id, arg1_name, arg1_val, \
    379         arg2_name, arg2_val) \
    380     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_BEGIN, \
    381         category, name, id, TRACE_EVENT_FLAG_NONE, \
    382         arg1_name, arg1_val, arg2_name, arg2_val)
    383 #define TRACE_EVENT_COPY_ASYNC_BEGIN0(category, name, id) \
    384     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_BEGIN, \
    385         category, name, id, TRACE_EVENT_FLAG_COPY)
    386 #define TRACE_EVENT_COPY_ASYNC_BEGIN1(category, name, id, arg1_name, arg1_val) \
    387     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_BEGIN, \
    388         category, name, id, TRACE_EVENT_FLAG_COPY, \
    389         arg1_name, arg1_val)
    390 #define TRACE_EVENT_COPY_ASYNC_BEGIN2(category, name, id, arg1_name, arg1_val, \
    391         arg2_name, arg2_val) \
    392     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_BEGIN, \
    393         category, name, id, TRACE_EVENT_FLAG_COPY, \
    394         arg1_name, arg1_val, arg2_name, arg2_val)
    395 
    396 // Records a single ASYNC_STEP event for |step| immediately. If the category
    397 // is not enabled, then this does nothing. The |name| and |id| must match the
    398 // ASYNC_BEGIN event above. The |step| param identifies this step within the
    399 // async event. This should be called at the beginning of the next phase of an
    400 // asynchronous operation.
    401 #define TRACE_EVENT_ASYNC_STEP0(category, name, id, step) \
    402     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_STEP, \
    403         category, name, id, TRACE_EVENT_FLAG_NONE, "step", step)
    404 #define TRACE_EVENT_ASYNC_STEP1(category, name, id, step, \
    405                                       arg1_name, arg1_val) \
    406     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_STEP, \
    407         category, name, id, TRACE_EVENT_FLAG_NONE, "step", step, \
    408         arg1_name, arg1_val)
    409 #define TRACE_EVENT_COPY_ASYNC_STEP0(category, name, id, step) \
    410     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_STEP, \
    411         category, name, id, TRACE_EVENT_FLAG_COPY, "step", step)
    412 #define TRACE_EVENT_COPY_ASYNC_STEP1(category, name, id, step, \
    413         arg1_name, arg1_val) \
    414     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_STEP, \
    415         category, name, id, TRACE_EVENT_FLAG_COPY, "step", step, \
    416         arg1_name, arg1_val)
    417 
    418 // Records a single ASYNC_END event for "name" immediately. If the category
    419 // is not enabled, then this does nothing.
    420 #define TRACE_EVENT_ASYNC_END0(category, name, id) \
    421     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_END, \
    422         category, name, id, TRACE_EVENT_FLAG_NONE)
    423 #define TRACE_EVENT_ASYNC_END1(category, name, id, arg1_name, arg1_val) \
    424     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_END, \
    425         category, name, id, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val)
    426 #define TRACE_EVENT_ASYNC_END2(category, name, id, arg1_name, arg1_val, \
    427         arg2_name, arg2_val) \
    428     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_END, \
    429         category, name, id, TRACE_EVENT_FLAG_NONE, \
    430         arg1_name, arg1_val, arg2_name, arg2_val)
    431 #define TRACE_EVENT_COPY_ASYNC_END0(category, name, id) \
    432     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_END, \
    433         category, name, id, TRACE_EVENT_FLAG_COPY)
    434 #define TRACE_EVENT_COPY_ASYNC_END1(category, name, id, arg1_name, arg1_val) \
    435     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_END, \
    436         category, name, id, TRACE_EVENT_FLAG_COPY, \
    437         arg1_name, arg1_val)
    438 #define TRACE_EVENT_COPY_ASYNC_END2(category, name, id, arg1_name, arg1_val, \
    439         arg2_name, arg2_val) \
    440     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_END, \
    441         category, name, id, TRACE_EVENT_FLAG_COPY, \
    442         arg1_name, arg1_val, arg2_name, arg2_val)
    443 
    444 
    445 // Records a single FLOW_BEGIN event called "name" immediately, with 0, 1 or 2
    446 // associated arguments. If the category is not enabled, then this
    447 // does nothing.
    448 // - category and name strings must have application lifetime (statics or
    449 //   literals). They may not include " chars.
    450 // - |id| is used to match the FLOW_BEGIN event with the FLOW_END event. FLOW
    451 //   events are considered to match if their category, name and id values all
    452 //   match. |id| must either be a pointer or an integer value up to 64 bits. If
    453 //   it's a pointer, the bits will be xored with a hash of the process ID so
    454 //   that the same pointer on two different processes will not collide.
    455 // FLOW events are different from ASYNC events in how they are drawn by the
    456 // tracing UI. A FLOW defines asynchronous data flow, such as posting a task
    457 // (FLOW_BEGIN) and later executing that task (FLOW_END). Expect FLOWs to be
    458 // drawn as lines or arrows from FLOW_BEGIN scopes to FLOW_END scopes. Similar
    459 // to ASYNC, a FLOW can consist of multiple phases. The first phase is defined
    460 // by the FLOW_BEGIN calls. Additional phases can be defined using the FLOW_STEP
    461 // macros. When the operation completes, call FLOW_END. An async operation can
    462 // span threads and processes, but all events in that operation must use the
    463 // same |name| and |id|. Each event can have its own args.
    464 #define TRACE_EVENT_FLOW_BEGIN0(category, name, id) \
    465     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_BEGIN, \
    466         category, name, id, TRACE_EVENT_FLAG_NONE)
    467 #define TRACE_EVENT_FLOW_BEGIN1(category, name, id, arg1_name, arg1_val) \
    468     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_BEGIN, \
    469         category, name, id, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val)
    470 #define TRACE_EVENT_FLOW_BEGIN2(category, name, id, arg1_name, arg1_val, \
    471         arg2_name, arg2_val) \
    472     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_BEGIN, \
    473         category, name, id, TRACE_EVENT_FLAG_NONE, \
    474         arg1_name, arg1_val, arg2_name, arg2_val)
    475 #define TRACE_EVENT_COPY_FLOW_BEGIN0(category, name, id) \
    476     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_BEGIN, \
    477         category, name, id, TRACE_EVENT_FLAG_COPY)
    478 #define TRACE_EVENT_COPY_FLOW_BEGIN1(category, name, id, arg1_name, arg1_val) \
    479     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_BEGIN, \
    480         category, name, id, TRACE_EVENT_FLAG_COPY, \
    481         arg1_name, arg1_val)
    482 #define TRACE_EVENT_COPY_FLOW_BEGIN2(category, name, id, arg1_name, arg1_val, \
    483         arg2_name, arg2_val) \
    484     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_BEGIN, \
    485         category, name, id, TRACE_EVENT_FLAG_COPY, \
    486         arg1_name, arg1_val, arg2_name, arg2_val)
    487 
    488 // Records a single FLOW_STEP event for |step| immediately. If the category
    489 // is not enabled, then this does nothing. The |name| and |id| must match the
    490 // FLOW_BEGIN event above. The |step| param identifies this step within the
    491 // async event. This should be called at the beginning of the next phase of an
    492 // asynchronous operation.
    493 #define TRACE_EVENT_FLOW_STEP0(category, name, id, step) \
    494     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_STEP, \
    495         category, name, id, TRACE_EVENT_FLAG_NONE, "step", step)
    496 #define TRACE_EVENT_FLOW_STEP1(category, name, id, step, \
    497         arg1_name, arg1_val) \
    498     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_STEP, \
    499         category, name, id, TRACE_EVENT_FLAG_NONE, "step", step, \
    500         arg1_name, arg1_val)
    501 #define TRACE_EVENT_COPY_FLOW_STEP0(category, name, id, step) \
    502     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_STEP, \
    503         category, name, id, TRACE_EVENT_FLAG_COPY, "step", step)
    504 #define TRACE_EVENT_COPY_FLOW_STEP1(category, name, id, step, \
    505         arg1_name, arg1_val) \
    506     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_STEP, \
    507         category, name, id, TRACE_EVENT_FLAG_COPY, "step", step, \
    508         arg1_name, arg1_val)
    509 
    510 // Records a single FLOW_END event for "name" immediately. If the category
    511 // is not enabled, then this does nothing.
    512 #define TRACE_EVENT_FLOW_END0(category, name, id) \
    513     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_END, \
    514         category, name, id, TRACE_EVENT_FLAG_NONE)
    515 #define TRACE_EVENT_FLOW_END1(category, name, id, arg1_name, arg1_val) \
    516     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_END, \
    517         category, name, id, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val)
    518 #define TRACE_EVENT_FLOW_END2(category, name, id, arg1_name, arg1_val, \
    519         arg2_name, arg2_val) \
    520     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_END, \
    521         category, name, id, TRACE_EVENT_FLAG_NONE, \
    522         arg1_name, arg1_val, arg2_name, arg2_val)
    523 #define TRACE_EVENT_COPY_FLOW_END0(category, name, id) \
    524     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_END, \
    525         category, name, id, TRACE_EVENT_FLAG_COPY)
    526 #define TRACE_EVENT_COPY_FLOW_END1(category, name, id, arg1_name, arg1_val) \
    527     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_END, \
    528         category, name, id, TRACE_EVENT_FLAG_COPY, \
    529         arg1_name, arg1_val)
    530 #define TRACE_EVENT_COPY_FLOW_END2(category, name, id, arg1_name, arg1_val, \
    531         arg2_name, arg2_val) \
    532     INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_END, \
    533         category, name, id, TRACE_EVENT_FLAG_COPY, \
    534         arg1_name, arg1_val, arg2_name, arg2_val)
    535 
    536 
    537 ////////////////////////////////////////////////////////////////////////////////
    538 // Implementation specific tracing API definitions.
    539 
    540 // Get a pointer to the enabled state of the given trace category. Only
    541 // long-lived literal strings should be given as the category name. The returned
    542 // pointer can be held permanently in a local static for example. If the
    543 // unsigned char is non-zero, tracing is enabled. If tracing is enabled,
    544 // TRACE_EVENT_API_ADD_TRACE_EVENT can be called. It's OK if tracing is disabled
    545 // between the load of the tracing state and the call to
    546 // TRACE_EVENT_API_ADD_TRACE_EVENT, because this flag only provides an early out
    547 // for best performance when tracing is disabled.
    548 // const unsigned char*
    549 //     TRACE_EVENT_API_GET_CATEGORY_ENABLED(const char* category_name)
    550 #define TRACE_EVENT_API_GET_CATEGORY_ENABLED \
    551     webrtc::EventTracer::GetCategoryEnabled
    552 
    553 // Add a trace event to the platform tracing system.
    554 // void TRACE_EVENT_API_ADD_TRACE_EVENT(
    555 //                    char phase,
    556 //                    const unsigned char* category_enabled,
    557 //                    const char* name,
    558 //                    unsigned long long id,
    559 //                    int num_args,
    560 //                    const char** arg_names,
    561 //                    const unsigned char* arg_types,
    562 //                    const unsigned long long* arg_values,
    563 //                    unsigned char flags)
    564 #define TRACE_EVENT_API_ADD_TRACE_EVENT webrtc::EventTracer::AddTraceEvent
    565 
    566 ////////////////////////////////////////////////////////////////////////////////
    567 
    568 // Implementation detail: trace event macros create temporary variables
    569 // to keep instrumentation overhead low. These macros give each temporary
    570 // variable a unique name based on the line number to prevent name collissions.
    571 #define INTERNAL_TRACE_EVENT_UID3(a,b) \
    572     trace_event_unique_##a##b
    573 #define INTERNAL_TRACE_EVENT_UID2(a,b) \
    574     INTERNAL_TRACE_EVENT_UID3(a,b)
    575 #define INTERNAL_TRACE_EVENT_UID(name_prefix) \
    576     INTERNAL_TRACE_EVENT_UID2(name_prefix, __LINE__)
    577 
    578 // Implementation detail: internal macro to create static category.
    579 #define INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category) \
    580     static const unsigned char* INTERNAL_TRACE_EVENT_UID(catstatic) = 0; \
    581     if (!INTERNAL_TRACE_EVENT_UID(catstatic)) { \
    582       INTERNAL_TRACE_EVENT_UID(catstatic) = \
    583           TRACE_EVENT_API_GET_CATEGORY_ENABLED(category); \
    584     }
    585 
    586 // Implementation detail: internal macro to create static category and add
    587 // event if the category is enabled.
    588 #define INTERNAL_TRACE_EVENT_ADD(phase, category, name, flags, ...) \
    589     do { \
    590       INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category); \
    591       if (*INTERNAL_TRACE_EVENT_UID(catstatic)) { \
    592         webrtc::trace_event_internal::AddTraceEvent(          \
    593             phase, INTERNAL_TRACE_EVENT_UID(catstatic), name, \
    594             webrtc::trace_event_internal::kNoEventId, flags, ##__VA_ARGS__); \
    595       } \
    596     } while (0)
    597 
    598 // Implementation detail: internal macro to create static category and add begin
    599 // event if the category is enabled. Also adds the end event when the scope
    600 // ends.
    601 #define INTERNAL_TRACE_EVENT_ADD_SCOPED(category, name, ...) \
    602     INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category); \
    603     webrtc::trace_event_internal::TraceEndOnScopeClose  \
    604         INTERNAL_TRACE_EVENT_UID(profileScope); \
    605     if (*INTERNAL_TRACE_EVENT_UID(catstatic)) { \
    606       webrtc::trace_event_internal::AddTraceEvent(      \
    607           TRACE_EVENT_PHASE_BEGIN, \
    608           INTERNAL_TRACE_EVENT_UID(catstatic), \
    609           name, webrtc::trace_event_internal::kNoEventId,       \
    610           TRACE_EVENT_FLAG_NONE, ##__VA_ARGS__); \
    611       INTERNAL_TRACE_EVENT_UID(profileScope).Initialize( \
    612           INTERNAL_TRACE_EVENT_UID(catstatic), name); \
    613     }
    614 
    615 // Implementation detail: internal macro to create static category and add
    616 // event if the category is enabled.
    617 #define INTERNAL_TRACE_EVENT_ADD_WITH_ID(phase, category, name, id, flags, \
    618                                          ...) \
    619     do { \
    620       INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category); \
    621       if (*INTERNAL_TRACE_EVENT_UID(catstatic)) { \
    622         unsigned char trace_event_flags = flags | TRACE_EVENT_FLAG_HAS_ID; \
    623         webrtc::trace_event_internal::TraceID trace_event_trace_id( \
    624             id, &trace_event_flags); \
    625         webrtc::trace_event_internal::AddTraceEvent( \
    626             phase, INTERNAL_TRACE_EVENT_UID(catstatic), \
    627             name, trace_event_trace_id.data(), trace_event_flags, \
    628             ##__VA_ARGS__); \
    629       } \
    630     } while (0)
    631 
    632 // Notes regarding the following definitions:
    633 // New values can be added and propagated to third party libraries, but existing
    634 // definitions must never be changed, because third party libraries may use old
    635 // definitions.
    636 
    637 // Phase indicates the nature of an event entry. E.g. part of a begin/end pair.
    638 #define TRACE_EVENT_PHASE_BEGIN    ('B')
    639 #define TRACE_EVENT_PHASE_END      ('E')
    640 #define TRACE_EVENT_PHASE_INSTANT  ('I')
    641 #define TRACE_EVENT_PHASE_ASYNC_BEGIN ('S')
    642 #define TRACE_EVENT_PHASE_ASYNC_STEP  ('T')
    643 #define TRACE_EVENT_PHASE_ASYNC_END   ('F')
    644 #define TRACE_EVENT_PHASE_FLOW_BEGIN ('s')
    645 #define TRACE_EVENT_PHASE_FLOW_STEP  ('t')
    646 #define TRACE_EVENT_PHASE_FLOW_END   ('f')
    647 #define TRACE_EVENT_PHASE_METADATA ('M')
    648 #define TRACE_EVENT_PHASE_COUNTER  ('C')
    649 
    650 // Flags for changing the behavior of TRACE_EVENT_API_ADD_TRACE_EVENT.
    651 #define TRACE_EVENT_FLAG_NONE        (static_cast<unsigned char>(0))
    652 #define TRACE_EVENT_FLAG_COPY        (static_cast<unsigned char>(1 << 0))
    653 #define TRACE_EVENT_FLAG_HAS_ID      (static_cast<unsigned char>(1 << 1))
    654 #define TRACE_EVENT_FLAG_MANGLE_ID   (static_cast<unsigned char>(1 << 2))
    655 
    656 // Type values for identifying types in the TraceValue union.
    657 #define TRACE_VALUE_TYPE_BOOL         (static_cast<unsigned char>(1))
    658 #define TRACE_VALUE_TYPE_UINT         (static_cast<unsigned char>(2))
    659 #define TRACE_VALUE_TYPE_INT          (static_cast<unsigned char>(3))
    660 #define TRACE_VALUE_TYPE_DOUBLE       (static_cast<unsigned char>(4))
    661 #define TRACE_VALUE_TYPE_POINTER      (static_cast<unsigned char>(5))
    662 #define TRACE_VALUE_TYPE_STRING       (static_cast<unsigned char>(6))
    663 #define TRACE_VALUE_TYPE_COPY_STRING  (static_cast<unsigned char>(7))
    664 
    665 namespace webrtc {
    666 namespace trace_event_internal {
    667 
    668 // Specify these values when the corresponding argument of AddTraceEvent is not
    669 // used.
    670 const int kZeroNumArgs = 0;
    671 const unsigned long long kNoEventId = 0;
    672 
    673 // TraceID encapsulates an ID that can either be an integer or pointer. Pointers
    674 // are mangled with the Process ID so that they are unlikely to collide when the
    675 // same pointer is used on different processes.
    676 class TraceID {
    677  public:
    678   class ForceMangle {
    679     public:
    680      explicit ForceMangle(unsigned long long id) : data_(id) {}
    681      explicit ForceMangle(unsigned long id) : data_(id) {}
    682      explicit ForceMangle(unsigned int id) : data_(id) {}
    683      explicit ForceMangle(unsigned short id) : data_(id) {}
    684      explicit ForceMangle(unsigned char id) : data_(id) {}
    685      explicit ForceMangle(long long id)
    686          : data_(static_cast<unsigned long long>(id)) {}
    687      explicit ForceMangle(long id)
    688          : data_(static_cast<unsigned long long>(id)) {}
    689      explicit ForceMangle(int id)
    690          : data_(static_cast<unsigned long long>(id)) {}
    691      explicit ForceMangle(short id)
    692          : data_(static_cast<unsigned long long>(id)) {}
    693      explicit ForceMangle(signed char id)
    694          : data_(static_cast<unsigned long long>(id)) {}
    695 
    696      unsigned long long data() const { return data_; }
    697 
    698     private:
    699      unsigned long long data_;
    700   };
    701 
    702   explicit TraceID(const void* id, unsigned char* flags)
    703       : data_(static_cast<unsigned long long>(
    704               reinterpret_cast<uintptr_t>(id))) {
    705     *flags |= TRACE_EVENT_FLAG_MANGLE_ID;
    706   }
    707   explicit TraceID(ForceMangle id, unsigned char* flags) : data_(id.data()) {
    708     *flags |= TRACE_EVENT_FLAG_MANGLE_ID;
    709   }
    710   explicit TraceID(unsigned long long id, unsigned char* flags)
    711       : data_(id) { (void)flags; }
    712   explicit TraceID(unsigned long id, unsigned char* flags)
    713       : data_(id) { (void)flags; }
    714   explicit TraceID(unsigned int id, unsigned char* flags)
    715       : data_(id) { (void)flags; }
    716   explicit TraceID(unsigned short id, unsigned char* flags)
    717       : data_(id) { (void)flags; }
    718   explicit TraceID(unsigned char id, unsigned char* flags)
    719       : data_(id) { (void)flags; }
    720   explicit TraceID(long long id, unsigned char* flags)
    721       : data_(static_cast<unsigned long long>(id)) { (void)flags; }
    722   explicit TraceID(long id, unsigned char* flags)
    723       : data_(static_cast<unsigned long long>(id)) { (void)flags; }
    724   explicit TraceID(int id, unsigned char* flags)
    725       : data_(static_cast<unsigned long long>(id)) { (void)flags; }
    726   explicit TraceID(short id, unsigned char* flags)
    727       : data_(static_cast<unsigned long long>(id)) { (void)flags; }
    728   explicit TraceID(signed char id, unsigned char* flags)
    729       : data_(static_cast<unsigned long long>(id)) { (void)flags; }
    730 
    731   unsigned long long data() const { return data_; }
    732 
    733  private:
    734   unsigned long long data_;
    735 };
    736 
    737 // Simple union to store various types as unsigned long long.
    738 union TraceValueUnion {
    739   bool as_bool;
    740   unsigned long long as_uint;
    741   long long as_int;
    742   double as_double;
    743   const void* as_pointer;
    744   const char* as_string;
    745 };
    746 
    747 // Simple container for const char* that should be copied instead of retained.
    748 class TraceStringWithCopy {
    749  public:
    750   explicit TraceStringWithCopy(const char* str) : str_(str) {}
    751   operator const char* () const { return str_; }
    752  private:
    753   const char* str_;
    754 };
    755 
    756 // Define SetTraceValue for each allowed type. It stores the type and
    757 // value in the return arguments. This allows this API to avoid declaring any
    758 // structures so that it is portable to third_party libraries.
    759 #define INTERNAL_DECLARE_SET_TRACE_VALUE(actual_type, \
    760                                          union_member, \
    761                                          value_type_id) \
    762     static inline void SetTraceValue(actual_type arg, \
    763                                      unsigned char* type, \
    764                                      unsigned long long* value) { \
    765       TraceValueUnion type_value; \
    766       type_value.union_member = arg; \
    767       *type = value_type_id; \
    768       *value = type_value.as_uint; \
    769     }
    770 // Simpler form for int types that can be safely casted.
    771 #define INTERNAL_DECLARE_SET_TRACE_VALUE_INT(actual_type, \
    772                                              value_type_id) \
    773     static inline void SetTraceValue(actual_type arg, \
    774                                      unsigned char* type, \
    775                                      unsigned long long* value) { \
    776       *type = value_type_id; \
    777       *value = static_cast<unsigned long long>(arg); \
    778     }
    779 
    780 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(unsigned long long, TRACE_VALUE_TYPE_UINT)
    781 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(unsigned long, TRACE_VALUE_TYPE_UINT)
    782 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(unsigned int, TRACE_VALUE_TYPE_UINT)
    783 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(unsigned short, TRACE_VALUE_TYPE_UINT)
    784 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(unsigned char, TRACE_VALUE_TYPE_UINT)
    785 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(long long, TRACE_VALUE_TYPE_INT)
    786 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(long, TRACE_VALUE_TYPE_INT)
    787 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(int, TRACE_VALUE_TYPE_INT)
    788 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(short, TRACE_VALUE_TYPE_INT)
    789 INTERNAL_DECLARE_SET_TRACE_VALUE_INT(signed char, TRACE_VALUE_TYPE_INT)
    790 INTERNAL_DECLARE_SET_TRACE_VALUE(bool, as_bool, TRACE_VALUE_TYPE_BOOL)
    791 INTERNAL_DECLARE_SET_TRACE_VALUE(double, as_double, TRACE_VALUE_TYPE_DOUBLE)
    792 INTERNAL_DECLARE_SET_TRACE_VALUE(const void*, as_pointer,
    793                                  TRACE_VALUE_TYPE_POINTER)
    794 INTERNAL_DECLARE_SET_TRACE_VALUE(const char*, as_string,
    795                                  TRACE_VALUE_TYPE_STRING)
    796 INTERNAL_DECLARE_SET_TRACE_VALUE(const TraceStringWithCopy&, as_string,
    797                                  TRACE_VALUE_TYPE_COPY_STRING)
    798 
    799 #undef INTERNAL_DECLARE_SET_TRACE_VALUE
    800 #undef INTERNAL_DECLARE_SET_TRACE_VALUE_INT
    801 
    802 // std::string version of SetTraceValue so that trace arguments can be strings.
    803 static inline void SetTraceValue(const std::string& arg,
    804                                  unsigned char* type,
    805                                  unsigned long long* value) {
    806   TraceValueUnion type_value;
    807   type_value.as_string = arg.c_str();
    808   *type = TRACE_VALUE_TYPE_COPY_STRING;
    809   *value = type_value.as_uint;
    810 }
    811 
    812 // These AddTraceEvent template functions are defined here instead of in the
    813 // macro, because the arg_values could be temporary objects, such as
    814 // std::string. In order to store pointers to the internal c_str and pass
    815 // through to the tracing API, the arg_values must live throughout
    816 // these procedures.
    817 
    818 static inline void AddTraceEvent(char phase,
    819                                 const unsigned char* category_enabled,
    820                                 const char* name,
    821                                 unsigned long long id,
    822                                 unsigned char flags) {
    823   TRACE_EVENT_API_ADD_TRACE_EVENT(
    824       phase, category_enabled, name, id,
    825       kZeroNumArgs, NULL, NULL, NULL,
    826       flags);
    827 }
    828 
    829 template<class ARG1_TYPE>
    830 static inline void AddTraceEvent(char phase,
    831                                 const unsigned char* category_enabled,
    832                                 const char* name,
    833                                 unsigned long long id,
    834                                 unsigned char flags,
    835                                 const char* arg1_name,
    836                                 const ARG1_TYPE& arg1_val) {
    837   const int num_args = 1;
    838   unsigned char arg_types[1];
    839   unsigned long long arg_values[1];
    840   SetTraceValue(arg1_val, &arg_types[0], &arg_values[0]);
    841   TRACE_EVENT_API_ADD_TRACE_EVENT(
    842       phase, category_enabled, name, id,
    843       num_args, &arg1_name, arg_types, arg_values,
    844       flags);
    845 }
    846 
    847 template<class ARG1_TYPE, class ARG2_TYPE>
    848 static inline void AddTraceEvent(char phase,
    849                                 const unsigned char* category_enabled,
    850                                 const char* name,
    851                                 unsigned long long id,
    852                                 unsigned char flags,
    853                                 const char* arg1_name,
    854                                 const ARG1_TYPE& arg1_val,
    855                                 const char* arg2_name,
    856                                 const ARG2_TYPE& arg2_val) {
    857   const int num_args = 2;
    858   const char* arg_names[2] = { arg1_name, arg2_name };
    859   unsigned char arg_types[2];
    860   unsigned long long arg_values[2];
    861   SetTraceValue(arg1_val, &arg_types[0], &arg_values[0]);
    862   SetTraceValue(arg2_val, &arg_types[1], &arg_values[1]);
    863   TRACE_EVENT_API_ADD_TRACE_EVENT(
    864       phase, category_enabled, name, id,
    865       num_args, arg_names, arg_types, arg_values,
    866       flags);
    867 }
    868 
    869 // Used by TRACE_EVENTx macro. Do not use directly.
    870 class TraceEndOnScopeClose {
    871  public:
    872   // Note: members of data_ intentionally left uninitialized. See Initialize.
    873   TraceEndOnScopeClose() : p_data_(NULL) {}
    874   ~TraceEndOnScopeClose() {
    875     if (p_data_)
    876       AddEventIfEnabled();
    877   }
    878 
    879   void Initialize(const unsigned char* category_enabled,
    880                   const char* name) {
    881     data_.category_enabled = category_enabled;
    882     data_.name = name;
    883     p_data_ = &data_;
    884   }
    885 
    886  private:
    887   // Add the end event if the category is still enabled.
    888   void AddEventIfEnabled() {
    889     // Only called when p_data_ is non-null.
    890     if (*p_data_->category_enabled) {
    891       TRACE_EVENT_API_ADD_TRACE_EVENT(
    892           TRACE_EVENT_PHASE_END,
    893           p_data_->category_enabled,
    894           p_data_->name, kNoEventId,
    895           kZeroNumArgs, NULL, NULL, NULL,
    896           TRACE_EVENT_FLAG_NONE);
    897     }
    898   }
    899 
    900   // This Data struct workaround is to avoid initializing all the members
    901   // in Data during construction of this object, since this object is always
    902   // constructed, even when tracing is disabled. If the members of Data were
    903   // members of this class instead, compiler warnings occur about potential
    904   // uninitialized accesses.
    905   struct Data {
    906     const unsigned char* category_enabled;
    907     const char* name;
    908   };
    909   Data* p_data_;
    910   Data data_;
    911 };
    912 
    913 }  // namespace trace_event_internal
    914 }  // namespace webrtc
    915 
    916 #endif  // WEBRTC_BASE_TRACE_EVENT_H_
    917