ITS: optional stacktraces from allocations

Author: f3sch

Detectors/ITSMFT/ITS/tracking/include/ITStracking/BoundedAllocator.h

@@ -23,13 +23,20 @@
 #include <vector>
 #include <exception>
 
+#define ITS_TRACKMEMORY
+// #define ITS_TRACKMEMORYTRACE
+
+#ifdef ITS_TRACKMEMORYTRACE
+#include <execinfo.h>
+#include <unistd.h>
+#include <fstream>
+#endif
+
 #include "GPUCommonLogger.h"
 
 namespace o2::its
 {
 
-// #define ITS_TRACKMEMORY
-
 class BoundedMemoryResource final : public std::pmr::memory_resource
 {
  public:
@@ -75,6 +82,9 @@ class BoundedMemoryResource final : public std::pmr::memory_resource
 #ifdef ITS_TRACKMEMORY
     ++mCountAllocate;
 #endif
+
+    logStackTrace<true>(bytes);
+
     return mUpstream->allocate(bytes, alignment);
   }
 
@@ -83,6 +93,7 @@ class BoundedMemoryResource final : public std::pmr::memory_resource
 #ifdef ITS_TRACKMEMORY
     ++mCountDeallocate;
 #endif
+    logStackTrace<false>(bytes);
     mUpstream->deallocate(p, bytes, alignment);
     mUsedMemory.fetch_sub(bytes, std::memory_order_relaxed);
   }
@@ -124,11 +135,48 @@ class BoundedMemoryResource final : public std::pmr::memory_resource
   size_t mMaxMemory{std::numeric_limits<size_t>::max()};
   std::atomic<size_t> mCountThrow{0};
   std::atomic<size_t> mUsedMemory{0};
+  std::pmr::memory_resource* mUpstream;
+
 #ifdef ITS_TRACKMEMORY
   std::atomic<size_t> mCountAllocate{0};
   std::atomic<size_t> mCountDeallocate{0};
 #endif
-  std::pmr::memory_resource* mUpstream;
+#ifdef ITS_TRACKMEMORYTRACE
+  inline uint64_t currentMicros()
+  {
+    auto now = std::chrono::high_resolution_clock::now();
+    return std::chrono::duration_cast<std::chrono::microseconds>(now.time_since_epoch()).count();
+  }
+  std::ofstream mTraceFile{"stacktraces", std::ios::app}; // Appending mode
+  size_t mAllocId{0};                                     // Only for tracking
+  std::mutex mFileMutex;
+
+  template <bool isAlloc>
+  void logStackTrace(size_t bytes)
+  {
+    constexpr int maxFrames = 64;
+    void* frames[maxFrames];
+    int frameCount = backtrace(frames, maxFrames);
+    char** symbols = backtrace_symbols(frames, frameCount);
+    if (!symbols)
+      return;
+
+    std::lock_guard<std::mutex> lock(mFileMutex);
+    mTraceFile << ((isAlloc) ? "#ALLOC " : "#DEALLOC ") << mAllocId++ << " SIZE " << bytes << " TIME " << currentMicros() << '\n';
+    for (int i = 0; i < frameCount; ++i) {
+      mTraceFile << symbols[i] << "\n";
+    }
+    mTraceFile << "#END\n";
+    mTraceFile.flush(); // Flush for crash-safe logging
+
+    free(symbols);
+  }
+#else
+  template <bool isAlloc>
+  void logStackTrace(size_t)
+  {
+  }
+#endif
 };
 
 template <typename T>