Proper closing EventCouner and Sampler when opening failed.

Author: jmuehlig

include/perfcpp/sampler.hpp

@@ -1323,4 +1323,4 @@ class CounterComparator
 private:
   const Counter& _counter;
 };
-}
+}

src/event_counter.cpp

@@ -466,16 +466,16 @@ perf::EventCounter::stop()
 void
 perf::EventCounter::close() noexcept
 {
-  if (const auto is_open = std::exchange(this->_is_opened, false); is_open) {
-    /// Close all groups.
-    for (auto& [group, _] : this->_hardware_event_groups) {
-      group.close();
-    }
+  this->_is_opened = false;
 
-    /// Close all live counters.
-    for (auto& live_counter : this->_hardware_live_counters) {
-      live_counter.close();
-    }
+  /// Close all groups, including groups that may have been partially opened before open() threw.
+  for (auto& [group, _] : this->_hardware_event_groups) {
+    group.close();
+  }
+
+  /// Close all live counters, including counters that may have been partially opened before open() threw.
+  for (auto& live_counter : this->_hardware_live_counters) {
+    live_counter.close();
   }
 }
 
@@ -849,4 +849,4 @@ perf::MultiCoreEventCounter::result_of_core(const std::uint16_t core_id, const s
   }
 
   return std::nullopt;
-}
+}

src/sampler.cpp

@@ -212,14 +212,13 @@ perf::Sampler::stop()
 void
 perf::Sampler::close() noexcept
 {
-  if (std::exchange(this->_is_opened, false)) {
-    /// Clear all buffers, groups, and event names
-    /// in order to enable opening again.
-    this->_sample_counter.clear();
+  this->_is_opened = false;
 
-    /// Clear the sample data.
-    this->_sample_data.clear();
-  }
+  /// Clear all buffers and groups, including groups that may have been partially opened before open() threw.
+  this->_sample_counter.clear();
+
+  /// Clear the sample data.
+  this->_sample_data.clear();
 }
 
 perf::Sampler::SampleCounter