Changeset 53579 in webkit for trunk/JavaScriptCore/wtf/FastMalloc.cpp

Timestamp:

Jan 20, 2010, 5:01:54 PM (15 years ago)

Author:

[email protected]

Message:

<rdar://problem/7215063> Use GCD instead of an extra thread for FastMalloc scavenging on platforms where it is supported

Reviewed by Oliver Hunt.

Abstract the background scavenging slightly so that an alternate implementation that uses GCD can be used on platforms
where it is supported.

• wtf/FastMalloc.cpp:

(WTF::TCMalloc_PageHeap::init):
(WTF::TCMalloc_PageHeap::initializeScavenger):
(WTF::TCMalloc_PageHeap::signalScavenger):
(WTF::TCMalloc_PageHeap::shouldContinueScavenging):
(WTF::TCMalloc_PageHeap::Delete):
(WTF::TCMalloc_PageHeap::periodicScavenge):

• wtf/Platform.h:

File:

• trunk/JavaScriptCore/wtf/FastMalloc.cpp (modified) (9 diffs)

trunk/JavaScriptCore/wtf/FastMalloc.cpp

@@ -392 +392 @@
 #include <wtf/Vector.h>
 #endif
+#if HAVE(DISPATCH_H)
+#include <dispatch/dispatch.h>
+#endif
+
 
 #ifndef PRIuS
@@ -1373 +1377 @@
 
 #if USE_BACKGROUND_THREAD_TO_SCAVENGE_MEMORY
+  void initializeScavenger();
+  ALWAYS_INLINE void signalScavenger();
+  void scavenge();
+  ALWAYS_INLINE bool shouldContinueScavenging() const;
+
+#if !HAVE(DISPATCH_H)
   static NO_RETURN void* runScavengerThread(void*);
-
   NO_RETURN void scavengerThread();
-
-  void scavenge();
-
-  inline bool shouldContinueScavenging() const;
-
-  pthread_mutex_t m_scavengeMutex;
-
-  pthread_cond_t m_scavengeCondition;
 
   // Keeps track of whether the background thread is actively scavenging memory every kScavengeTimerDelayInSeconds, or
   // it's blocked waiting for more pages to be deleted.
   bool m_scavengeThreadActive;
+
+  pthread_mutex_t m_scavengeMutex;
+  pthread_cond_t m_scavengeCondition;
+#else // !HAVE(DISPATCH_H)
+  void periodicScavenge();
+
+  dispatch_queue_t m_scavengeQueue;
+  dispatch_source_t m_scavengeTimer;
+  bool m_scavengingScheduled;
+#endif
+
 #endif  // USE_BACKGROUND_THREAD_TO_SCAVENGE_MEMORY
 };
@@ -1415 +1427 @@
 
 #if USE_BACKGROUND_THREAD_TO_SCAVENGE_MEMORY
+  initializeScavenger();
+#endif  // USE_BACKGROUND_THREAD_TO_SCAVENGE_MEMORY
+}
+
+#if USE_BACKGROUND_THREAD_TO_SCAVENGE_MEMORY
+
+#if !HAVE(DISPATCH_H)
+
+void TCMalloc_PageHeap::initializeScavenger()
+{
   pthread_mutex_init(&m_scavengeMutex, 0);
   pthread_cond_init(&m_scavengeCondition, 0);
@@ -1420 +1442 @@
   pthread_t thread;
   pthread_create(&thread, 0, runScavengerThread, this);
-#endif  // USE_BACKGROUND_THREAD_TO_SCAVENGE_MEMORY
-}
-
-#if USE_BACKGROUND_THREAD_TO_SCAVENGE_MEMORY
+}
+
 void* TCMalloc_PageHeap::runScavengerThread(void* context)
 {
@@ -1432 +1452 @@
 #endif
 }
+
+ALWAYS_INLINE void TCMalloc_PageHeap::signalScavenger()
+{
+  if (!m_scavengeThreadActive && shouldContinueScavenging())
+    pthread_cond_signal(&m_scavengeCondition);
+}
+
+#else // !HAVE(DISPATCH_H)
+
+void TCMalloc_PageHeap::initializeScavenger()
+{
+  m_scavengeQueue = dispatch_queue_create("com.apple.JavaScriptCore.FastMallocSavenger", NULL);
+  m_scavengeTimer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, m_scavengeQueue);
+  dispatch_time_t startTime = dispatch_time(DISPATCH_TIME_NOW, kScavengeTimerDelayInSeconds * NSEC_PER_SEC);
+  dispatch_source_set_timer(m_scavengeTimer, startTime, kScavengeTimerDelayInSeconds * NSEC_PER_SEC, 1000 * NSEC_PER_USEC);
+  dispatch_source_set_context(m_scavengeTimer, this);
+  dispatch_source_set_event_handler(m_scavengeTimer, ^{ periodicScavenge(); });
+  m_scavengingScheduled = false;
+}
+
+ALWAYS_INLINE void TCMalloc_PageHeap::signalScavenger()
+{
+  if (!m_scavengingScheduled && shouldContinueScavenging()) {
+    m_scavengingScheduled = true;
+    dispatch_resume(m_scavengeTimer);
+  }
+}
+
+#endif
 
 void TCMalloc_PageHeap::scavenge() 
@@ -1468 +1517 @@
 }
 
-inline bool TCMalloc_PageHeap::shouldContinueScavenging() const 
+ALWAYS_INLINE bool TCMalloc_PageHeap::shouldContinueScavenging() const 
 {
     return free_committed_pages_ > kMinimumFreeCommittedPageCount; 
@@ -1730 +1779 @@
 
   // Make sure the scavenge thread becomes active if we have enough freed pages to release some back to the system.
-  if (!m_scavengeThreadActive && shouldContinueScavenging())
-      pthread_cond_signal(&m_scavengeCondition);
+  signalScavenger();
 #else
   IncrementalScavenge(n);
@@ -2274 +2322 @@
 
 #if USE_BACKGROUND_THREAD_TO_SCAVENGE_MEMORY
+
+#if !HAVE(DISPATCH_H)
 #if OS(WINDOWS)
 static void sleep(unsigned seconds)
@@ -2303 +2353 @@
   }
 }
+
+#else
+
+void TCMalloc_PageHeap::periodicScavenge()
+{
+  {
+    SpinLockHolder h(&pageheap_lock);
+    pageheap->scavenge();
+  }
+
+  if (!shouldContinueScavenging()) {
+    m_scavengingScheduled = false;
+    dispatch_suspend(m_scavengeTimer);
+  }
+}
+#endif // HAVE(DISPATCH_H)
+
 #endif