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 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 /* Visual event tracer, creates a log of events on each thread for visualization */

 /**

  * The event tracer code is by default disabled in both build and run time.

  *

  * To enable this code at build time, add --enable-visual-profiling to your 

  * configure options.

  *

  * To enable this code at run time, export MOZ_TRACE_FILE env var with a

  * path to the file to write the log to. This is all you need to * produce

  * the log of all events instrumentation in the mozilla code. Check

  * MOZ_EVENT_TRACER_* macros below to add your own.

  *

  * To let the event tracer log only some events to save disk space, export 

  * MOZ_PROFILING_EVENTS with comma separated list of event names you want 

  * to record in the log.

  */

 #ifndef VisualEventTracer_h___

 #define VisualEventTracer_h___

 #include <stdint.h>

 #include "mozilla/Attributes.h"

 #include "mozilla/GuardObjects.h"

 #ifdef MOZ_VISUAL_EVENT_TRACER

 #include "nsIVisualEventTracer.h"

 // Bind an object instance, usually |this|, to a name, usually URL or 

 // host name, the instance deals with for its lifetime.  The name string 

 // is duplicated.

 // IMPORTANT: it is up to the caller to pass the correct static_cast

 // of the |instance| pointer to all these macros ; otherwise the linking

 // of events and objects will not work!

 // The name will show in details of the events on the timeline and also

 // will allow events filtering by host names, URLs etc.

 #define MOZ_EVENT_TRACER_NAME_OBJECT(instance, name) \

   mozilla::eventtracer::Mark(mozilla::eventtracer::eName, instance, name)

 // The same as MOZ_EVENT_TRACER_NAME_OBJECT, just simplifies building

 // names when it consists of two parts

 #define MOZ_EVENT_TRACER_COMPOUND_NAME(instance, name, name2) \

   mozilla::eventtracer::Mark(mozilla::eventtracer::eName, instance, name, name2)

 // Call the followings with the same |instance| reference as you have 

 // previously called MOZ_EVENT_TRACER_NAME_OBJECT.

 // Let |name| be the name of the event happening, like "resolving", 

 // "connecting", "loading" etc.

 // This will crate a single-point-in-time event marked with an arrow 

 // on the timeline, this is a way to indicate an event without a duration.

 #define MOZ_EVENT_TRACER_MARK(instance, name) \

   mozilla::eventtracer::Mark(mozilla::eventtracer::eShot, instance, name)

 // Following macros are used to log events with duration.

 // There always has to be complete WAIT,EXEC,DONE or EXEC,DONE 

 // uninterrupted and non-interferring tuple(s) for an event to be correctly 

 // shown on the timeline.  Each can be called on any thread, the event tape is

 // finally displayed on the thread where it has been EXECuted.

 // Example of 3 phases usage for "HTTP request channel":

 // WAIT: we've just created the channel and called AsyncOpen on it

 // EXEC: we've just got first call to OnDataAvailable, so we are actually

 //       receiving the content after some time like connection establising,

 //       opening a cache entry, sending the GET request...

 // DONE: we've just got OnStopRequest call that indicates the content

 //       has been completely delivered and the request is now finished

 // Indicate an event pending start, on the timeline this will 

 // start the event's interval tape with a pale color, the time will

 // show in details.  Usually used when an event is being posted or

 // we wait for a lock acquisition.

 // WAITING is not mandatory, some events don't have a pending phase.

 #define MOZ_EVENT_TRACER_WAIT(instance, name) \

   mozilla::eventtracer::Mark(mozilla::eventtracer::eWait, instance, name)

 // Indicate start of an event actual execution, on the timeline this will 

 // change the event's tape to a deeper color, the time will show in details.

 #define MOZ_EVENT_TRACER_EXEC(instance, name) \

   mozilla::eventtracer::Mark(mozilla::eventtracer::eExec, instance, name)

 // Indicate the end of an event execution (the event has been done),

 // on the timeline this will end the event's tape and show the time in

 // event details.

 // NOTE: when the event duration is extremely short, like 1ms, it will convert

 // to an event w/o a duration - the same as MOZ_EVENT_TRACER_MARK would be used.

 #define MOZ_EVENT_TRACER_DONE(instance, name) \

   mozilla::eventtracer::Mark(mozilla::eventtracer::eDone, instance, name)

 // The same meaning as the above macros, just for concurent events.

 // Concurent event means it can happen for the same instance on more

 // then just a single thread, e.g. a service method call, a global lock 

 // acquisition, enter and release.

 #define MOZ_EVENT_TRACER_WAIT_THREADSAFE(instance, name) \

   mozilla::eventtracer::Mark(mozilla::eventtracer::eWait | mozilla::eventtracer::eThreadConcurrent, instance, name)

 #define MOZ_EVENT_TRACER_EXEC_THREADSAFE(instance, name) \

   mozilla::eventtracer::Mark(mozilla::eventtracer::eExec | mozilla::eventtracer::eThreadConcurrent, instance, name)

 #define MOZ_EVENT_TRACER_DONE_THREASAFE(instance, name) \

   mozilla::eventtracer::Mark(mozilla::eventtracer::eDone | mozilla::eventtracer::eThreadConcurrent, instance, name)

 #else 

 // MOZ_VISUAL_EVENT_TRACER disabled

 #define MOZ_EVENT_TRACER_NAME_OBJECT(instance, name) (void)0

 #define MOZ_EVENT_TRACER_COMPOUND_NAME(instance, name, name2) (void)0

 #define MOZ_EVENT_TRACER_MARK(instance, name) (void)0

 #define MOZ_EVENT_TRACER_WAIT(instance, name) (void)0

 #define MOZ_EVENT_TRACER_EXEC(instance, name) (void)0

 #define MOZ_EVENT_TRACER_DONE(instance, name) (void)0

 #define MOZ_EVENT_TRACER_WAIT_THREADSAFE(instance, name) (void)0

 #define MOZ_EVENT_TRACER_EXEC_THREADSAFE(instance, name) (void)0

 #define MOZ_EVENT_TRACER_DONE_THREASAFE(instance, name) (void)0

 #endif

 namespace mozilla {

 namespace eventtracer {

 // Initialize the event tracer engine, called automatically on XPCOM startup.

 void Init();

 // Shuts the event tracer engine down and closes the log file, called 

 // automatically during XPCOM shutdown.

 void Shutdown();

 enum MarkType {

   eNone, // No operation, ignored

   eName, // This is used to bind an object instance with a name

   eShot, // An event with no duration

   eWait, // Start of waiting for execution (lock acquire, post...)

   eExec, // Start of the execution it self

   eDone, // End of the execution

   eLast, // Sentinel

   // Flags

   // The same object can execute the same event on several threads concurently

   eThreadConcurrent = 0x10000

 };

 // Records an event on the calling thread. 

 // @param aType 

 //    One of MarkType fields, can be bitwise or'ed with the flags.

 // @param aItem

 //    Reference to the object we want to bind a name to or the event is

 //    happening on.  Can be actually anything, but valid poitners should

 //    be used.

 // @param aText

 //    Text of the name (for eName) or event's name for others.  The string

 //    is duplicated.

 // @param aText2

 //    Optional second part of the instnace name, or event name.

 //    Event filtering does apply only to the first part (aText).

 void Mark(uint32_t aType, void * aItem, 

           const char * aText, const char * aText2 = 0);

 // Helper guard object.  Use to mark an event in the constructor and a different

 // event in the destructor.

 //

 // Example:

 // int class::func()

 // {

 //    AutoEventTracer tracer(this, eventtracer::eExec, eventtracer::eDone, "func");

 //

 //    do_something_taking_a_long_time();

 // }

 class MOZ_STACK_CLASS AutoEventTracer

 {

 public:

   AutoEventTracer(void * aInstance, 

                uint32_t aTypeOn, // MarkType marked in constructor

                uint32_t aTypeOff, // MarkType marked in destructor

                const char * aName, 

                const char * aName2 = 0 

                MOZ_GUARD_OBJECT_NOTIFIER_PARAM)

     : mInstance(aInstance)

     , mName(aName)

     , mName2(aName2)

     , mTypeOn(aTypeOn)

     , mTypeOff(aTypeOff)

   {

     MOZ_GUARD_OBJECT_NOTIFIER_INIT;

     ::mozilla::eventtracer::Mark(mTypeOn, mInstance, mName, mName2);

   }

   ~AutoEventTracer()

   {

     ::mozilla::eventtracer::Mark(mTypeOff, mInstance, mName, mName2);

   }

 private:

   void * mInstance;

   const char * mName;

   const char * mName2;

   uint32_t mTypeOn;

   uint32_t mTypeOff;

   MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER

 };

 #ifdef MOZ_VISUAL_EVENT_TRACER

 // The scriptable class that drives the event tracer

 class VisualEventTracer : public nsIVisualEventTracer

 {

   NS_DECL_ISUPPORTS

   NS_DECL_NSIVISUALEVENTTRACER

 };

 #define NS_VISUALEVENTTRACER_CID \

   { 0xb9e5e102, 0xc2f4, 0x497a,  \

     { 0xa6, 0xe4, 0x54, 0xde, 0xf3, 0x71, 0xf3, 0x9d } }

 #define NS_VISUALEVENTTRACER_CONTRACTID "@mozilla.org/base/visual-event-tracer;1"

 #define NS_VISUALEVENTTRACER_CLASSNAME "Visual Event Tracer"

 #endif

 } // eventtracer

 } // mozilla

 #endif /* VisualEventTracer_h___ */