Disable Metrics Library after Metric Tracer usage.

Metric Tracer can use Metrics Library to generate gpu commands 
for Metric Tracer marker. Closing Metrics Library will force it to reintialize,
so Metric Query can use Linux time based sampling stream exclusively 
(needed to activate metric set or to obtain context switch/triggered reports).

Change-Id: I3105febfbbd78b537ef0688d1b9c08ab54f9a875

Author: PiotrMaciejewskiIntel

level_zero/tools/source/metrics/metric_query_imp.h

@@ -45,6 +45,9 @@ struct MetricsLibrary {
     bool isInitialized();
     static const char *getFilename();
 
+    // Deinitialization.
+    void release();
+
     // Metric query.
     bool createMetricQuery(const uint32_t slotsCount, QueryHandle_1_0 &query,
                            NEO::GraphicsAllocation *&pAllocation);
@@ -66,7 +69,6 @@ struct MetricsLibrary {
 
   protected:
     void initialize();
-    void release();
 
     bool createContext();
     virtual bool getContextData(Device &device, ContextCreateData_1_0 &contextData);

level_zero/tools/source/metrics/metric_tracer_imp.cpp

@@ -47,9 +47,18 @@ ze_result_t MetricTracerImp::close() {
     const auto result = stopMeasurements();
     if (result == ZE_RESULT_SUCCESS) {
 
-        // Clear metric tracer reference in context.
         auto device = Device::fromHandle(hDevice);
-        device->getMetricContext().setMetricTracer(nullptr);
+        auto &metricContext = device->getMetricContext();
+        auto &metricsLibrary = metricContext.getMetricsLibrary();
+
+        // Clear metric tracer reference in context.
+        // Another metric tracer instance or query can be used.
+        metricContext.setMetricTracer(nullptr);
+
+        // Close metrics library (if was used to generate tracer's marker gpu commands).
+        // It will allow metric query to use Linux Tbs stream exclusively
+        // (to activate metric sets and to read context switch reports).
+        metricsLibrary.release();
 
         // Release notification event.
         if (pNotificationEvent != nullptr) {