Changeset 190324 in webkit

Timestamp:

Sep 29, 2015 1:25:42 PM (9 years ago)

Author:

fpizlo@apple.com

Message:

ParallelHelperPool::runFunctionInParallel() shouldn't allocate, and ParallelHelperPool.h shouldn't be included everywhere
​https://bugs.webkit.org/show_bug.cgi?id=149635

Reviewed by Saam Barati.

Source/JavaScriptCore:

It bugged me that this change caused a whole-world recompile. So, I changed the code so
that ParallelHelperPool.h is only included by Heap.cpp and not by Heap.h.

• heap/Heap.cpp:

(JSC::Heap::Heap):
(JSC::Heap::markRoots):
(JSC::Heap::copyBackingStores):

• heap/Heap.h:

Source/WTF:

• wtf/ParallelHelperPool.h:

(WTF::ParallelHelperClient::runFunctionInParallel): Stack-allocate the task instead of heap-allocating it.

Location:

trunk/Source

Files:

• JavaScriptCore/ChangeLog (modified) (1 diff)
• JavaScriptCore/heap/Heap.cpp (modified) (5 diffs)
• JavaScriptCore/heap/Heap.h (modified) (2 diffs)
• WTF/ChangeLog (modified) (1 diff)
• WTF/wtf/ParallelHelperPool.h (modified) (1 diff)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2015-09-29  Filip Pizlo  <fpizlo@apple.com>
+
+        ParallelHelperPool::runFunctionInParallel() shouldn't allocate, and ParallelHelperPool.h shouldn't be included everywhere
+        https://bugs.webkit.org/show_bug.cgi?id=149635
+
+        Reviewed by Saam Barati.
+
+        It bugged me that this change caused a whole-world recompile. So, I changed the code so
+        that ParallelHelperPool.h is only included by Heap.cpp and not by Heap.h.
+
+        * heap/Heap.cpp:
+        (JSC::Heap::Heap):
+        (JSC::Heap::markRoots):
+        (JSC::Heap::copyBackingStores):
+        * heap/Heap.h:
+
 2015-09-29  Filip Pizlo  <fpizlo@apple.com>
 

trunk/Source/JavaScriptCore/heap/Heap.cpp

@@ -54 +54 @@
 #include <wtf/RAMSize.h>
 #include <wtf/CurrentTime.h>
+#include <wtf/ParallelHelperPool.h>
 #include <wtf/ParallelVectorIterator.h>
 #include <wtf/ProcessID.h>
@@ -358 +359 @@
     , m_delayedReleaseRecursionCount(0)
 #endif
-    , m_helperClient(&heapHelperPool())
+    , m_helperClient(std::make_unique<ParallelHelperClient>(&heapHelperPool()))
 {
     m_storageSpace.init();
@@ -548 +549 @@
     m_parallelMarkersShouldExit = false;
 
-    m_helperClient.setFunction(
+    m_helperClient->setFunction(
         [this] () {
             SlotVisitor* slotVisitor;
@@ -605 +606 @@
         m_markingConditionVariable.notifyAll();
     }
-    m_helperClient.finish();
+    m_helperClient->finish();
     updateObjectCounts(gcStartTime);
     resetVisitors();
@@ -638 +639 @@
         // we have created is not going to be running anymore. Hence, everything on the stack here
         // outlives the task.
-        m_helperClient.runFunctionInParallel(
+        m_helperClient->runFunctionInParallel(
             [&] () {
                 CopyVisitor copyVisitor(*this);

trunk/Source/JavaScriptCore/heap/Heap.h

@@ -46 +46 @@
 #include <wtf/HashCountedSet.h>
 #include <wtf/HashSet.h>
-#include <wtf/ParallelHelperPool.h>
+
+namespace WTF {
+class ParallelHelperClient;
+}
+using WTF::ParallelHelperClient;
 
 namespace JSC {
@@ -442 +446 @@
     ListableHandler<UnconditionalFinalizer>::List m_unconditionalFinalizers;
 
-    ParallelHelperClient m_helperClient;
+    std::unique_ptr<ParallelHelperClient> m_helperClient;
 };
 

trunk/Source/WTF/ChangeLog

@@ +1 @@
+2015-09-29  Filip Pizlo  <fpizlo@apple.com>
+
+        ParallelHelperPool::runFunctionInParallel() shouldn't allocate, and ParallelHelperPool.h shouldn't be included everywhere
+        https://bugs.webkit.org/show_bug.cgi?id=149635
+
+        Reviewed by Saam Barati.
+
+        * wtf/ParallelHelperPool.h:
+        (WTF::ParallelHelperClient::runFunctionInParallel): Stack-allocate the task instead of heap-allocating it.
+
 2015-09-29  Filip Pizlo  <fpizlo@apple.com>
 

trunk/Source/WTF/wtf/ParallelHelperPool.h

@@ -149 +149 @@
     WTF_EXPORT_PRIVATE void runTaskInParallel(RefPtr<SharedTask>);
 
-    // Equivalent to:
+    // Semantically equivalent to:
     // client->setFunction(functor);
     // client->doSomeHelping();
     // client->finish();
+    //
+    // Except, unlike the above sequence, this won't allocate the task in the heap. This allocates
+    // the task on the stack because it knows that the task is not reachable after this method is
+    // done.
     template<typename Functor>
     void runFunctionInParallel(const Functor& functor)
     {
-        runTaskInParallel(createSharedTask(functor));
+        SharedTaskFunctor<Functor> sharedTask(functor);
+        runTaskInParallel(&sharedTask);
     }