Merge pull request #1161 from heyuyi0906/fix_h2_req_check_failed

fix h2_req check failed when retry after ELIMIT error

src/brpc/channel.cpp

@@ -464,6 +464,15 @@ void Channel::CallMethod(const google::protobuf::MethodDescriptor* method,
     // Share the lb with controller.
     cntl->_lb = _lb;
 
+    // Ensure that serialize_request is done before pack_request in all
+    // possible executions, including:
+    //   HandleSendFailed => OnVersionedRPCReturned => IssueRPC(pack_request)
+    _serialize_request(&cntl->_request_buf, cntl, request);
+    if (cntl->FailedInline()) {
+        // Handle failures caused by serialize_request, and these error_codes
+        // should be excluded from the retry_policy.
+        return cntl->HandleSendFailed();
+    }
     if (FLAGS_usercode_in_pthread &&
         done != NULL &&
         TooManyUserCode()) {
@@ -471,15 +480,6 @@ void Channel::CallMethod(const google::protobuf::MethodDescriptor* method,
                         "-usercode_in_pthread is on");
         return cntl->HandleSendFailed();
     }
-    if (cntl->FailedInline()) {
-        // probably failed before RPC, not called until all necessary
-        // parameters in `cntl' are set.
-        return cntl->HandleSendFailed();
-    }
-    _serialize_request(&cntl->_request_buf, cntl, request);
-    if (cntl->FailedInline()) {
-        return cntl->HandleSendFailed();
-    }
 
     if (cntl->_request_stream != INVALID_STREAM_ID) {
         // Currently we cannot handle retry and backup request correctly