remove sync recv, node cache msgs for sync recv.

lichao

2021-05-18 e54b8e58780c7d9f37b06cc4e1dc88badb2129c9

 src/shm.cpp

@@ -25,6 +25,7 @@
    mshm_t(open_or_create, name.c_str(), size, 0, AllowAll()),
    name_(name)
{
   pmutex_ = FindOrCreate<Mutex>("ShmSelfControlMutex0");
}

SharedMemory::~SharedMemory()