DM: make GPU tasks multithreaded again. Big refactor.

src/utils/SkThreadPool.cpp

Index: src/utils/SkThreadPool.cpp
diff --git a/src/utils/SkThreadPool.cpp b/src/utils/SkThreadPool.cpp
deleted file mode 100644
index 125a5d9b6ad78674e057af791b8859e7159bd36e..0000000000000000000000000000000000000000
--- a/src/utils/SkThreadPool.cpp
+++ /dev/null
@@ -1,127 +0,0 @@
-/*
- * Copyright 2012 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "SkRunnable.h"
-#include "SkThreadPool.h"
-#include "SkThreadUtils.h"
-#include "SkTypes.h"
-
-#if defined(SK_BUILD_FOR_UNIX) || defined(SK_BUILD_FOR_MAC) || defined(SK_BUILD_FOR_ANDROID)
-#include <unistd.h>
-#endif
-
-// Returns the number of cores on this machine.
-static int num_cores() {
-#if defined(SK_BUILD_FOR_WIN32)
-    SYSTEM_INFO sysinfo;
-    GetSystemInfo(&sysinfo);
-    return sysinfo.dwNumberOfProcessors;
-#elif defined(SK_BUILD_FOR_UNIX) || defined(SK_BUILD_FOR_MAC) || defined(SK_BUILD_FOR_ANDROID)
-    return sysconf(_SC_NPROCESSORS_ONLN);
-#else
-    return 1;
-#endif
-}
-
-SkThreadPool::SkThreadPool(int count)
-: fState(kRunning_State), fBusyThreads(0) {
-    if (count < 0) count = num_cores();
-    // Create count threads, all running SkThreadPool::Loop.
-    for (int i = 0; i < count; i++) {
-        SkThread* thread = SkNEW_ARGS(SkThread, (&SkThreadPool::Loop, this));
-        *fThreads.append() = thread;
-        thread->start();
-    }
-}
-
-SkThreadPool::~SkThreadPool() {
-    if (kRunning_State == fState) {
-        this->wait();
-    }
-}
-
-void SkThreadPool::wait() {
-    fReady.lock();
-    fState = kWaiting_State;
-    fReady.broadcast();
-    fReady.unlock();
-
-    // Wait for all threads to stop.
-    for (int i = 0; i < fThreads.count(); i++) {
-        fThreads[i]->join();
-        SkDELETE(fThreads[i]);
-    }
-    SkASSERT(fQueue.isEmpty());
-}
-
-/*static*/ void SkThreadPool::Loop(void* arg) {
-    // The SkThreadPool passes itself as arg to each thread as they're created.
-    SkThreadPool* pool = static_cast<SkThreadPool*>(arg);
-
-    while (true) {
-        // We have to be holding the lock to read the queue and to call wait.
-        pool->fReady.lock();
-        while(pool->fQueue.isEmpty()) {
-            // Does the client want to stop and are all the threads ready to stop?
-            // If so, we move into the halting state, and whack all the threads so they notice.
-            if (kWaiting_State == pool->fState && pool->fBusyThreads == 0) {
-                pool->fState = kHalting_State;
-                pool->fReady.broadcast();
-            }
-            // Any time we find ourselves in the halting state, it's quitting time.
-            if (kHalting_State == pool->fState) {
-                pool->fReady.unlock();
-                return;
-            }
-            // wait yields the lock while waiting, but will have it again when awoken.
-            pool->fReady.wait();
-        }
-        // We've got the lock back here, no matter if we ran wait or not.
-
-        // The queue is not empty, so we have something to run.  Claim it.
-        LinkedRunnable* r = pool->fQueue.tail();
-
-        pool->fQueue.remove(r);
-
-        // Having claimed our SkRunnable, we now give up the lock while we run it.
-        // Otherwise, we'd only ever do work on one thread at a time, which rather
-        // defeats the point of this code.
-        pool->fBusyThreads++;
-        pool->fReady.unlock();
-
-        // OK, now really do the work.
-        r->fRunnable->run();
-        SkDELETE(r);
-
-        // Let everyone know we're not busy.
-        pool->fReady.lock();
-        pool->fBusyThreads--;
-        pool->fReady.unlock();
-    }
-
-    SkASSERT(false); // Unreachable.  The only exit happens when pool->fState is kHalting_State.
-}
-
-void SkThreadPool::add(SkRunnable* r) {
-    if (NULL == r) {
-        return;
-    }
-
-    // If we don't have any threads, obligingly just run the thing now.
-    if (fThreads.isEmpty()) {
-        return r->run();
-    }
-
-    // We have some threads.  Queue it up!
-    fReady.lock();
-    SkASSERT(fState != kHalting_State);  // Shouldn't be able to add work when we're halting.
-    LinkedRunnable* linkedRunnable = SkNEW(LinkedRunnable);
-    linkedRunnable->fRunnable = r;
-    fQueue.addToHead(linkedRunnable);
-    fReady.signal();
-    fReady.unlock();
-}