Change the default value of the bthread_tag in class ServerOptions to…

… BTHREAD_TAG_DEFAULT (#2824)

* Change the default value of the bthread_tag in class ServerOptions to BTHREAD_TAG_DEFAULT.

* update

src/brpc/server.cpp

@@ -151,7 +151,7 @@ ServerOptions::ServerOptions()
     , health_reporter(NULL)
     , rtmp_service(NULL)
     , redis_service(NULL)
-    , bthread_tag(BTHREAD_TAG_INVALID)
+    , bthread_tag(BTHREAD_TAG_DEFAULT)
     , rpc_pb_message_factory(new DefaultRpcPBMessageFactory())
     , ignore_eovercrowded(false) {
     if (s_ncore > 0) {
@@ -846,10 +846,6 @@ int Server::StartInternal(const butil::EndPoint& endpoint,
 #endif
     }
 
-    auto original_bthread_tag = _options.bthread_tag;
-    if (original_bthread_tag == BTHREAD_TAG_INVALID) {
-        _options.bthread_tag = BTHREAD_TAG_DEFAULT;
-    }
     if (_options.bthread_tag < BTHREAD_TAG_DEFAULT ||
         _options.bthread_tag >= FLAGS_task_group_ntags) {
         LOG(ERROR) << "Fail to set tag " << _options.bthread_tag << ", tag range is ["

src/bthread/bthread.cpp

@@ -400,18 +400,15 @@ int bthread_setconcurrency_by_tag(int num, bthread_tag_t tag) {
     auto tag_ngroup = c->concurrency(tag);
     auto add = num - tag_ngroup;
 
-    if (add > 0) {
+    if (add >= 0) {
         auto added = c->add_workers(add, tag);
         bthread::FLAGS_bthread_concurrency += added;
         return (add == added ? 0 : EPERM);
-
-    } else if (add < 0){
+    } else {
         LOG(WARNING) << "Fail to set concurrency by tag: " << tag
-                     << ", tag concurrency must larger than old oncurrency. old concurrency: "
+                     << ", tag concurrency should be larger than old oncurrency. old concurrency: "
                      << tag_ngroup << ", new concurrency: " << num;
         return EPERM;
-    } else {
-        return 0;
     }
 }