[Core] Race Conditions: Protect CDataWriterSHM m_memory_file_vec

Co-authored-by: Rex Schilasky <[email protected]>

ecal/core/src/readwrite/shm/ecal_writer_shm.cpp

@@ -88,7 +88,10 @@ namespace eCAL
     if (!m_created) return false;
     m_created = false;
 
-    m_memory_file_vec.clear();
+    {
+      const std::lock_guard<std::mutex> lock(m_memory_file_vec_mtx);
+      m_memory_file_vec.clear();
+    }
 
     return true;
   }
@@ -101,6 +104,8 @@ namespace eCAL
 
   bool CDataWriterSHM::SetBufferCount(size_t buffer_count_)
   {
+    const std::lock_guard<std::mutex> lock(m_memory_file_vec_mtx);
+
     // no need to adapt anything
     if (m_memory_file_vec.size() == buffer_count_) return true;
 
@@ -160,11 +165,15 @@ namespace eCAL
       ret_state |= true;
     }
 
-    // adapt write index if needed
-    m_write_idx %= m_memory_file_vec.size();
-
-    // check size and reserve new if needed
-    ret_state |= m_memory_file_vec[m_write_idx]->CheckSize(attr_.len);
+    {
+      const std::lock_guard<std::mutex> lock(m_memory_file_vec_mtx);
+
+      // adapt write index if needed
+      m_write_idx %= m_memory_file_vec.size();
+
+      // check size and reserve new if needed
+      ret_state |= m_memory_file_vec[m_write_idx]->CheckSize(attr_.len);
+    }
 
     return ret_state;
   }
@@ -173,6 +182,9 @@ namespace eCAL
   {
     if (!m_created) return false;
 
+    // protect m_memory_file_vec
+    const std::lock_guard<std::mutex> lock(m_memory_file_vec_mtx);
+
     // write content
     const bool force_full_write(m_memory_file_vec.size() > 1);
     const bool sent = m_memory_file_vec[m_write_idx]->Write(payload_, attr_, force_full_write);
@@ -188,6 +200,9 @@ namespace eCAL
   {
     if (!m_created) return;
 
+    // protect m_memory_file_vec
+    const std::lock_guard<std::mutex> lock(m_memory_file_vec_mtx);
+
     for (auto& memory_file : m_memory_file_vec)
     {
       memory_file->Connect(process_id_);
@@ -201,6 +216,10 @@ namespace eCAL
   {
     // starting from eCAL version > 5.8.13/5.9.0 the ConnectionParameter is defined as google protobuf
     eCAL::pb::ConnnectionPar connection_par;
+
+    // protect m_memory_file_vec
+    const std::lock_guard<std::mutex> lock(m_memory_file_vec_mtx);
+
     for (auto& memory_file : m_memory_file_vec)
     {
       connection_par.mutable_layer_par_shm()->add_memory_file_list(memory_file->GetName());

ecal/core/src/readwrite/shm/ecal_writer_shm.h

@@ -27,6 +27,7 @@
 #include "io/shm/ecal_memfile_sync.h"
 
 #include <memory>
+#include <mutex>
 #include <string>
 
 namespace eCAL
@@ -59,7 +60,10 @@ namespace eCAL
     size_t                                        m_write_idx    = 0;
     size_t                                        m_buffer_count = 1;
     SSyncMemoryFileAttr                           m_memory_file_attr = {};
+
+    std::mutex                                    m_memory_file_vec_mtx;
     std::vector<std::shared_ptr<CSyncMemoryFile>> m_memory_file_vec;
+
     static const std::string                      m_memfile_base_name;
   };
 }