SDK: Introduce fairmq error category

fairmq/sdk/AsioAsyncOp.h

@@ -14,7 +14,7 @@
 #include <asio/executor_work_guard.hpp>
 #include <asio/system_executor.hpp>
 #include <chrono>
-#include <fairmq/sdk/Exceptions.h>
+#include <fairmq/sdk/Error.h>
 #include <fairmq/sdk/Traits.h>
 #include <functional>
 #include <memory>

fairmq/sdk/CMakeLists.txt

@@ -30,6 +30,7 @@ set(SDK_SOURCE_FILES
   DDSEnvironment.cxx
   DDSSession.cxx
   DDSTopology.cxx
+  Error.cxx
   Topology.cxx
 )
 

fairmq/sdk/Error.cxx

@@ -0,0 +1,40 @@
+/********************************************************************************
+ *    Copyright (C) 2019 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH    *
+ *                                                                              *
+ *              This software is distributed under the terms of the             *
+ *              GNU Lesser General Public Licence (LGPL) version 3,             *
+ *                  copied verbatim in the file "LICENSE"                       *
+ ********************************************************************************/
+
+#include "Error.h"
+
+namespace fair {
+namespace mq {
+
+const char* ErrorCategory::name() const noexcept
+{
+    return "fairmq";
+}
+
+std::string ErrorCategory::message(int ev) const
+{
+    switch (static_cast<ErrorCode>(ev)) {
+        case ErrorCode::OperationInProgress:
+            return "async operation already in progress";
+        case ErrorCode::OperationTimeout:
+            return "async operation timed out";
+        case ErrorCode::OperationCanceled:
+            return "async operation canceled";
+        case ErrorCode::DeviceChangeStateFailed:
+            return "failed to change state of a fairmq device";
+        default:
+            return "(unrecognized error)";
+    }
+}
+
+const ErrorCategory errorCategory{};
+
+std::error_code MakeErrorCode(ErrorCode e) { return {static_cast<int>(e), errorCategory}; }
+
+}   // namespace mq
+}   // namespace fair

fairmq/sdk/Error.h

@@ -6,8 +6,8 @@
  *                  copied verbatim in the file "LICENSE"                       *
  ********************************************************************************/
 
-#ifndef FAIR_MQ_SDK_EXCEPTIONS_H
-#define FAIR_MQ_SDK_EXCEPTIONS_H
+#ifndef FAIR_MQ_SDK_ERROR_H
+#define FAIR_MQ_SDK_ERROR_H
 
 #include <fairmq/Tools.h>
 #include <stdexcept>
@@ -31,7 +31,32 @@ struct MixedStateError : RuntimeError
 };
 
 } /* namespace sdk */
+
+enum class ErrorCode
+{
+    OperationInProgress = 10,
+    OperationTimeout,
+    OperationCanceled,
+    DeviceChangeStateFailed
+};
+
+std::error_code MakeErrorCode(ErrorCode);
+
+struct ErrorCategory : std::error_category
+{
+  const char* name() const noexcept override;
+  std::string message(int ev) const override;
+};
+
 } /* namespace mq */
 } /* namespace fair */
 
-#endif /* FAIR_MQ_SDK_EXCEPTIONS_H */
+namespace std {
+
+template<>
+struct is_error_code_enum<fair::mq::ErrorCode> : true_type
+{};
+
+}   // namespace std
+
+#endif /* FAIR_MQ_SDK_ERROR_H */

fairmq/sdk/Topology.h

@@ -9,20 +9,20 @@
 #ifndef FAIR_MQ_SDK_TOPOLOGY_H
 #define FAIR_MQ_SDK_TOPOLOGY_H
 
+#include <chrono>
+#include <fairmq/States.h>
+#include <fairmq/Tools.h>
 #include <fairmq/sdk/DDSInfo.h>
 #include <fairmq/sdk/DDSSession.h>
 #include <fairmq/sdk/DDSTopology.h>
-#include <fairmq/States.h>
-#include <fairmq/Tools.h>
-
+#include <fairmq/sdk/Error.h>
 #include <functional>
-#include <unordered_map>
 #include <memory>
-#include <chrono>
 #include <ostream>
-#include <string>
-#include <vector>
 #include <stdexcept>
+#include <string>
+#include <unordered_map>
+#include <vector>
 
 namespace fair {
 namespace mq {