Changeset 47845 in webkit for trunk/JavaScriptCore/wtf

Timestamp:

Aug 27, 2009, 5:11:22 PM (16 years ago)

Author:

[email protected]

Message:

Reviewed by Oliver Hunt.

​https://bugs.webkit.org/show_bug.cgi?id=28753
<rdar://problem/7173448> Excessive number of threads (and a crash)

Coalesce DNS prefetch requests to reduce strain on CFHost. Currently, the algorithm is as follows:

• when resolver is idle, the first few requests are sent immediately (they may or may not hit the wire);
• if there are a few requests in flight already, coalesce all requests for one second;
• to avoid pathological cases with lots of links to different sites on a page, only ask CFHost about a handful of names (dropping the rest).

Coalescing reduces the number of requests dramatically, as prefetchDNS is called for each
link, and these tend to have identical host name.

• platform/network/cf/DNSCFNet.cpp: (WebCore::DNSResolveQueue::DNSResolveQueue): (WebCore::DNSResolveQueue::shared): (WebCore::DNSResolveQueue::add): (WebCore::DNSResolveQueue::decrementRequestCount): (WebCore::DNSResolveQueue::fired): (WebCore::clientCallback): (WebCore::DNSResolveQueue::resolve): (WebCore::prefetchDNS):

File:

• trunk/JavaScriptCore/wtf/Threading.h (modified) (4 diffs)

trunk/JavaScriptCore/wtf/Threading.h

@@ -216 +216 @@
 
 #if COMPILER(MINGW) || COMPILER(MSVC7) || PLATFORM(WINCE)
-inline void atomicIncrement(int* addend) { InterlockedIncrement(reinterpret_cast<long*>(addend)); }
+inline int atomicIncrement(int* addend) { return InterlockedIncrement(reinterpret_cast<long*>(addend)); }
 inline int atomicDecrement(int* addend) { return InterlockedDecrement(reinterpret_cast<long*>(addend)); }
 #else
-inline void atomicIncrement(int volatile* addend) { InterlockedIncrement(reinterpret_cast<long volatile*>(addend)); }
+inline int atomicIncrement(int volatile* addend) { return InterlockedIncrement(reinterpret_cast<long volatile*>(addend)); }
 inline int atomicDecrement(int volatile* addend) { return InterlockedDecrement(reinterpret_cast<long volatile*>(addend)); }
 #endif
@@ -226 +226 @@
 #define WTF_USE_LOCKFREE_THREADSAFESHARED 1
 
-inline void atomicIncrement(int volatile* addend) { OSAtomicIncrement32Barrier(const_cast<int*>(addend)); }
+inline int atomicIncrement(int volatile* addend) { return OSAtomicIncrement32Barrier(const_cast<int*>(addend)); }
 inline int atomicDecrement(int volatile* addend) { return OSAtomicDecrement32Barrier(const_cast<int*>(addend)); }
 
@@ -232 +232 @@
 #define WTF_USE_LOCKFREE_THREADSAFESHARED 1
 
-inline void atomicIncrement(int volatile* addend) { __gnu_cxx::__atomic_add(addend, 1); }
+inline int atomicIncrement(int volatile* addend) { return __gnu_cxx::__exchange_and_add(addend, 1) + 1; }
 inline int atomicDecrement(int volatile* addend) { return __gnu_cxx::__exchange_and_add(addend, -1) - 1; }
 
@@ -326 +326 @@
 using WTF::ThreadSafeShared;
 
+using WTF::atomicDecrement;
+using WTF::atomicIncrement;
 using WTF::createThread;
 using WTF::currentThread;