Add SkThreadPool for managing threads.

Skia-ized from https://codereview.appspot.com/6755043/

TODO: Use SkThread and platform independent features.

Review URL: https://codereview.appspot.com/6777064

git-svn-id: http://skia.googlecode.com/svn/trunk@6217 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 36 insertions, 0 deletions

diff --git a/include/utils/SkCountdown.h b/include/utils/SkCountdown.h
new file mode 100644
index 0000000000..6bcec7d5ff
--- /dev/null
+++ b/include/utils/SkCountdown.h
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkCountdown_DEFINED
+#define SkCountdown_DEFINED
+
+#include "SkCondVar.h"
+#include "SkRunnable.h"
+#include "SkTypes.h"
+
+class SkCountdown : public SkRunnable {
+public:
+    explicit SkCountdown(int32_t count);
+
+    /**
+     * Resets the countdown to the count provided.
+     */
+    void reset(int32_t count);
+
+    virtual void run() SK_OVERRIDE;
+
+    /**
+     * Blocks until run() has been called count times.
+     */
+    void wait();
+
+private:
+    SkCondVar fReady;
+    int32_t   fCount;
+};
+
+#endif