Forgot to add concurrent_runner implementation for ios

platform/ios_concurrent_runner.mm

@@ -0,0 +1,63 @@
+#include "concurrent_runner.hpp"
+
+#include "../base/assert.hpp"
+#include "../base/logging.hpp"
+
+#include <dispatch/dispatch.h>
+
+namespace threads
+{
+  class ConcurrentRunner::Impl
+  {
+  public:
+    dispatch_group_t m_group;
+
+    Impl()
+    {
+      m_group = dispatch_group_create();
+    }
+    ~Impl()
+    {
+      dispatch_release(m_group);
+    }
+
+  };
+
+  ConcurrentRunner::ConcurrentRunner() : m_pImpl(new ConcurrentRunner::Impl)
+  {
+  }
+
+  ConcurrentRunner::~ConcurrentRunner()
+  {
+    delete m_pImpl;
+  }
+
+  // work-around for runtime boost exception, see
+  // http://stackoverflow.com/questions/5438613/why-cant-i-use-a-boostfunction-in-an-objective-c-block
+  struct BoostExceptionFixer
+  {
+    RunnerFuncT m_f;
+    BoostExceptionFixer(RunnerFuncT const & f) : m_f(f) {}
+
+    void operator()() const
+    {
+      m_f();
+      // selfdestruct
+      delete this;
+    }
+  };
+
+  void ConcurrentRunner::Run(RunnerFuncT f)
+  {
+    dispatch_queue_t globalQ = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
+    BoostExceptionFixer * tmp = new BoostExceptionFixer(f);
+    dispatch_group_async(m_pImpl->m_group, globalQ, ^{
+                         (*tmp)();
+    });
+  }
+
+  void ConcurrentRunner::Join()
+  {
+    dispatch_group_wait(m_pImpl->m_group, DISPATCH_TIME_FOREVER);
+  }
+}