+#if ENABLE(CODEBLOCK_SAMPLING)
+ Mutex m_scriptSampleMapMutex;
+ OwnPtr<ScriptSampleRecordMap> m_scopeSampleMap;
+#endif
+ };
+
+ // AbstractSamplingCounter:
+ //
+ // Implements a named set of counters, printed on exit if ENABLE(SAMPLING_COUNTERS).
+ // See subclasses below, SamplingCounter, GlobalSamplingCounter and DeletableSamplingCounter.
+ class AbstractSamplingCounter {
+ friend class JIT;
+ friend class DeletableSamplingCounter;
+ public:
+ void count(uint32_t count = 1)
+ {
+ m_counter += count;
+ }
+
+ static void dump();
+
+ protected:
+ // Effectively the contructor, however called lazily in the case of GlobalSamplingCounter.
+ void init(const char* name)
+ {
+ m_counter = 0;
+ m_name = name;
+
+ // Set m_next to point to the head of the chain, and inform whatever is
+ // currently at the head that this node will now hold the pointer to it.
+ m_next = s_abstractSamplingCounterChain;
+ s_abstractSamplingCounterChain->m_referer = &m_next;
+ // Add this node to the head of the list.
+ s_abstractSamplingCounterChain = this;
+ m_referer = &s_abstractSamplingCounterChain;
+ }
+
+ int64_t m_counter;
+ const char* m_name;
+ AbstractSamplingCounter* m_next;
+ // This is a pointer to the pointer to this node in the chain; used to
+ // allow fast linked list deletion.
+ AbstractSamplingCounter** m_referer;
+ // Null object used to detect end of static chain.
+ static AbstractSamplingCounter s_abstractSamplingCounterChainEnd;
+ static AbstractSamplingCounter* s_abstractSamplingCounterChain;
+ static bool s_completed;
+ };
+
+#if ENABLE(SAMPLING_COUNTERS)
+ // SamplingCounter:
+ //
+ // This class is suitable and (hopefully!) convenient for cases where a counter is
+ // required within the scope of a single function. It can be instantiated as a
+ // static variable since it contains a constructor but not a destructor (static
+ // variables in WebKit cannot have destructors).
+ //
+ // For example:
+ //
+ // void someFunction()
+ // {
+ // static SamplingCounter countMe("This is my counter. There are many like it, but this one is mine.");
+ // countMe.count();
+ // // ...
+ // }
+ //
+ class SamplingCounter : public AbstractSamplingCounter {
+ public:
+ SamplingCounter(const char* name) { init(name); }
+ };
+
+ // GlobalSamplingCounter:
+ //
+ // This class is suitable for use where a counter is to be declared globally,
+ // since it contains neither a constructor nor destructor. Instead, ensure
+ // that 'name()' is called to provide the counter with a name (and also to
+ // allow it to be printed out on exit).
+ //
+ // GlobalSamplingCounter globalCounter;
+ //
+ // void firstFunction()
+ // {
+ // // Put this within a function that is definitely called!
+ // // (Or alternatively alongside all calls to 'count()').
+ // globalCounter.name("I Name You Destroyer.");
+ // globalCounter.count();
+ // // ...
+ // }
+ //
+ // void secondFunction()
+ // {
+ // globalCounter.count();
+ // // ...
+ // }
+ //
+ class GlobalSamplingCounter : public AbstractSamplingCounter {
+ public:
+ void name(const char* name)
+ {
+ // Global objects should be mapped in zero filled memory, so this should
+ // be a safe (albeit not necessarily threadsafe) check for 'first call'.
+ if (!m_next)
+ init(name);
+ }
+ };
+
+ // DeletableSamplingCounter:
+ //
+ // The above classes (SamplingCounter, GlobalSamplingCounter), are intended for
+ // use within a global or static scope, and as such cannot have a destructor.
+ // This means there is no convenient way for them to remove themselves from the
+ // static list of counters, and should an instance of either class be freed
+ // before 'dump()' has walked over the list it will potentially walk over an
+ // invalid pointer.
+ //
+ // This class is intended for use where the counter may possibly be deleted before
+ // the program exits. Should this occur, the counter will print it's value to
+ // stderr, and remove itself from the static list. Example:
+ //
+ // DeletableSamplingCounter* counter = new DeletableSamplingCounter("The Counter With No Name");
+ // counter->count();
+ // delete counter;
+ //
+ class DeletableSamplingCounter : public AbstractSamplingCounter {
+ public:
+ DeletableSamplingCounter(const char* name) { init(name); }
+
+ ~DeletableSamplingCounter()
+ {
+ if (!s_completed)
+ fprintf(stderr, "DeletableSamplingCounter \"%s\" deleted early (with count %lld)\n", m_name, m_counter);
+ // Our m_referer pointer should know where the pointer to this node is,
+ // and m_next should know that this node is the previous node in the list.
+ ASSERT(*m_referer == this);
+ ASSERT(m_next->m_referer == &m_next);
+ // Remove this node from the list, and inform m_next that we have done so.
+ m_next->m_referer = m_referer;
+ *m_referer = m_next;
+ }
projects / apple / javascriptcore.git / blobdiff