Bug/646 observer memory leaks

include/cosim/observer/time_series_observer.hpp

@@ -33,7 +33,7 @@ class time_series_observer : public time_series_provider
 {
 public:
     /**
-     * Default constructor. Creates an unbuffered `time_series_observer`.
+     * Default constructor. Creates a buffered `time_series_observer`, with a fixed buffer size of 10000 samples for each observed variable.
      */
     time_series_observer();
 

src/cosim/observer/file_observer.cpp

@@ -130,10 +130,10 @@ class file_observer::slave_value_writer
 
 private:
     template<typename T>
-    void write(const std::vector<T>& values)
+    void write(const std::vector<T>& values, std::stringstream& ss)
     {
         for (auto it = values.begin(); it != values.end(); ++it) {
-            ss_ << "," << *it;
+            ss << "," << *it;
         }
     }
 
@@ -190,6 +190,7 @@ class file_observer::slave_value_writer
     void create_log_file()
     {
         std::string filename;
+        std::stringstream ss;
         if (!timeStampedFileNames_) {
             filename = observable_->name().append(".csv");
         } else {
@@ -205,46 +206,45 @@ class file_observer::slave_value_writer
             throw std::runtime_error("Failed to open file stream for logging");
         }
 
-        ss_ << "Time,StepCount";
+        ss << "Time,StepCount";
 
         for (const auto& vd : realVars_) {
-            ss_ << "," << vd.name << " [" << vd.reference << " " << vd.type << " " << vd.causality << "]";
+            ss << "," << vd.name << " [" << vd.reference << " " << vd.type << " " << vd.causality << "]";
         }
         for (const auto& vd : intVars_) {
-            ss_ << "," << vd.name << " [" << vd.reference << " " << vd.type << " " << vd.causality << "]";
+            ss << "," << vd.name << " [" << vd.reference << " " << vd.type << " " << vd.causality << "]";
         }
         for (const auto& vd : boolVars_) {
-            ss_ << "," << vd.name << " [" << vd.reference << " " << vd.type << " " << vd.causality << "]";
+            ss << "," << vd.name << " [" << vd.reference << " " << vd.type << " " << vd.causality << "]";
         }
         for (const auto& vd : stringVars_) {
-            ss_ << "," << vd.name << " [" << vd.reference << " " << vd.type << " " << vd.causality << "]";
+            ss << "," << vd.name << " [" << vd.reference << " " << vd.type << " " << vd.causality << "]";
         }
 
-        ss_ << std::endl;
+        ss << std::endl;
 
         if (fsw_.is_open()) {
-            fsw_ << ss_.rdbuf();
+            fsw_ << ss.rdbuf();
         }
     }
 
     void persist()
     {
-        ss_.clear();
-
+        std::stringstream ss;
         if (fsw_.is_open()) {
 
             for (const auto& [stepCount, times] : timeSamples_) {
-                ss_ << times << "," << stepCount;
+                ss << times << "," << stepCount;
 
-                if (realSamples_.count(stepCount)) write<double>(realSamples_[stepCount]);
-                if (intSamples_.count(stepCount)) write<int>(intSamples_[stepCount]);
-                if (boolSamples_.count(stepCount)) write<bool>(boolSamples_[stepCount]);
-                if (stringSamples_.count(stepCount)) write<std::string_view>(stringSamples_[stepCount]);
+                if (realSamples_.count(stepCount)) write<double>(realSamples_[stepCount], ss);
+                if (intSamples_.count(stepCount)) write<int>(intSamples_[stepCount], ss);
+                if (boolSamples_.count(stepCount)) write<bool>(boolSamples_[stepCount], ss);
+                if (stringSamples_.count(stepCount)) write<std::string_view>(stringSamples_[stepCount], ss);
 
-                ss_ << std::endl;
+                ss << std::endl;
             }
 
-            fsw_ << ss_.rdbuf();
+            fsw_ << ss.rdbuf();
         }
 
         realSamples_.clear();
@@ -267,7 +267,6 @@ class file_observer::slave_value_writer
     cosim::filesystem::path logDir_;
     size_t decimationFactor_ = 1;
     std::ofstream fsw_;
-    std::stringstream ss_;
     std::atomic<bool> recording_ = true;
     std::mutex mutex_;
     bool timeStampedFileNames_ = true;

src/cosim/observer/time_series_observer.cpp

@@ -58,9 +58,6 @@ size_t get_samples(
 template<typename T>
 void adjustIfFull(std::map<step_number, T>& buffer, size_t maxSize)
 {
-    if (maxSize <= 0) {
-        return;
-    }
     if (buffer.size() > maxSize) {
         buffer.erase(buffer.begin());
     }
@@ -191,7 +188,7 @@ class time_series_observer::single_slave_observer
         steps[1] = lastStep;
     }
 
-    const std::map<step_number, double> get_real_samples_map(value_reference idx)
+    std::map<step_number, double> get_real_samples_map(value_reference idx)
     {
         std::lock_guard<std::mutex> lock(lock_);
         return realSamples_.at(idx);
@@ -207,13 +204,19 @@ class time_series_observer::single_slave_observer
 };
 
 time_series_observer::time_series_observer()
-    : bufSize_(0)
+    : bufSize_(10000)
 {
 }
 
 time_series_observer::time_series_observer(size_t bufferSize)
-    : bufSize_(bufferSize)
 {
+    if (bufferSize > 0)  {
+        bufSize_ = bufferSize;
+    } else {
+        std::ostringstream oss;
+        oss << "Can't define an observer with buffer size " << bufferSize << ", minimum allowed buffer size is 1.";
+        throw std::invalid_argument(oss.str());
+    }
 }
 
 void time_series_observer::simulator_added(simulator_index index, observable* simulator, time_point currentTime)