Test that queues are flushed by clReleaseCommandQueue (#923)

... as required by the OpenCL specification.

Also introduce a utility function to manage polling for changes
via a user-supplied function. Several tests we introduced lately
could have used this.

Signed-off-by: Kévin Petit <kpet@free.fr>

test_common/harness/kernelHelpers.cpp

@@ -1693,3 +1693,23 @@ Version get_max_OpenCL_C_for_context(cl_context context)
                   });
     return current_version;
 }
+
+bool poll_until(unsigned timeout_ms, unsigned interval_ms,
+                std::function<bool()> fn)
+{
+    unsigned time_spent_ms = 0;
+    bool ret = false;
+
+    while (time_spent_ms < timeout_ms)
+    {
+        ret = fn();
+        if (ret)
+        {
+            break;
+        }
+        usleep(interval_ms * 1000);
+        time_spent_ms += interval_ms;
+    }
+
+    return ret;
+}

test_common/harness/kernelHelpers.h

@@ -40,6 +40,8 @@
 #include "deviceInfo.h"
 #include "harness/alloc.h"
 
+#include <functional>
+
 /*
  *  The below code is intended to be used at the top of kernels that appear inline in files to set line and file info for the kernel:
  *
@@ -181,4 +183,8 @@ Version get_device_cl_c_version(cl_device_id device);
 // the OpenCL C version supported by all devices in a context.
 Version get_max_OpenCL_C_for_context(cl_context context);
 
+// Poll fn every interval_ms until timeout_ms or it returns true
+bool poll_until(unsigned timeout_ms, unsigned interval_ms,
+                std::function<bool()> fn);
+
 #endif // _kernelHelpers_h