--- a/OrthancServer/ServerContext.cpp	Tue May 19 13:44:56 2020 +0200
+++ b/OrthancServer/ServerContext.cpp	Tue May 19 16:19:05 2020 +0200
@@ -84,7 +84,7 @@
       {
         const ServerIndexChange& change = dynamic_cast<const ServerIndexChange&>(*obj.get());
 
-        boost::recursive_mutex::scoped_lock lock(that->listenersMutex_);
+        boost::shared_lock<boost::shared_mutex> lock(that->listenersMutex_);
         for (ServerListeners::iterator it = that->listeners_.begin(); 
              it != that->listeners_.end(); ++it)
         {
@@ -331,7 +331,7 @@
     if (!done_)
     {
       {
-        boost::recursive_mutex::scoped_lock lock(listenersMutex_);
+        boost::unique_lock<boost::shared_mutex> lock(listenersMutex_);
         listeners_.clear();
       }
 
@@ -418,7 +418,7 @@
       bool accepted = true;
 
       {
-        boost::recursive_mutex::scoped_lock lock(listenersMutex_);
+        boost::shared_lock<boost::shared_mutex> lock(listenersMutex_);
 
         for (ServerListeners::iterator it = listeners_.begin(); it != listeners_.end(); ++it)
         {
@@ -508,7 +508,7 @@
       if (status == StoreStatus_Success ||
           status == StoreStatus_AlreadyStored)
       {
-        boost::recursive_mutex::scoped_lock lock(listenersMutex_);
+        boost::shared_lock<boost::shared_mutex> lock(listenersMutex_);
 
         for (ServerListeners::iterator it = listeners_.begin(); it != listeners_.end(); ++it)
         {
@@ -858,7 +858,7 @@
 #if ORTHANC_ENABLE_PLUGINS == 1
   void ServerContext::SetPlugins(OrthancPlugins& plugins)
   {
-    boost::recursive_mutex::scoped_lock lock(listenersMutex_);
+    boost::unique_lock<boost::shared_mutex> lock(listenersMutex_);
 
     plugins_ = &plugins;
 
@@ -871,7 +871,7 @@
 
   void ServerContext::ResetPlugins()
   {
-    boost::recursive_mutex::scoped_lock lock(listenersMutex_);
+    boost::unique_lock<boost::shared_mutex> lock(listenersMutex_);
 
     plugins_ = NULL;