api server callback change tag to src; refactor.

lichao

2021-04-20 1f3729698a131b3f701f67adb6a1258aa1235dce

 src/bh_api.h

@@ -45,7 +45,7 @@
                                const int proc_id_len,
                                const void *data,
                                const int data_len,
                                const void *tag);
                                void *src);

typedef void (*FClientCallback)(const void *proc_id,
                                const int proc_id_len,
@@ -55,10 +55,6 @@
                                const int data_len);

void BHStartWorker(FServerCallback server_cb, FSubDataCallback sub_cb, FClientCallback client_cb);

int BHServerCallbackReply(const void *tag,
                          const void *data,
                          const int data_len);

int BHHeartbeatEasy(const int timeout_ms);
int BHHeartbeat(const void *proc_info,