struct return type version

src/allreduce_base.cc

@@ -561,8 +561,9 @@ AllreduceBase::TryBroadcast(void *sendrecvbuf_, size_t total_size, int root) {
     } else {
       // read from in link
       if (in_link >= 0 && selecter.CheckRead(links[in_link].sock)) {
-        if (!links[in_link].ReadToArray(sendrecvbuf_, total_size)) {
+        ReturnType ret = links[in_link].ReadToArray(sendrecvbuf_, total_size);
-          return kSockError;
+        if (ret != kSuccess) {
+          return ReportError(&links[in_link], ret);
         }
         size_in = links[in_link].size_read;
       }

src/allreduce_base.h

@@ -198,7 +198,7 @@ class AllreduceBase : public IEngine {
 
  protected:
   /*! \brief enumeration of possible returning results from Try functions */
-  enum ReturnType {
+  enum ReturnTypeEnum {
     /*! \brief execution is successful */
     kSuccess,
     /*! \brief a link was reset by peer */
@@ -213,6 +213,20 @@ class AllreduceBase : public IEngine {
      */
     kGetExcept
   };
+  /*! \brief struct return type to avoid implicit conversion to int/bool */
+  struct ReturnType {
+    /*! \brief internal return type */
+    ReturnTypeEnum value;
+    // constructor
+    ReturnType() {}
+    ReturnType(ReturnTypeEnum value) : value(value){}
+    inline bool operator==(const ReturnTypeEnum &v) const {
+      return value == v;
+    }
+    inline bool operator!=(const ReturnTypeEnum &v) const {
+      return value != v;
+    }
+  };
   /*! \brief translate errno to return type */
   inline static ReturnType Errno2Return(int errsv) {
     if (errsv == EAGAIN || errsv == EWOULDBLOCK) return kSuccess;

src/allreduce_robust.cc

@@ -432,7 +432,7 @@ bool AllreduceRobust::CheckAndRecover(ReturnType err_type) {
   // this was old way
   // TryResetLinks still causes possible errors, so not use this one
   while (err_type != kSuccess) {
-    switch (err_type) {
+    switch (err_type.value) {
       case kGetExcept: err_type = TryResetLinks(); break;
       case kSockError: {
         TryResetLinks();