add SendQ TrySend() TryRecv(); handle re-register.

lichao

2021-04-14 aa1542b6d6a4680088ac715c4ce40f97ada554fb

 .gitignore

@@ -6,3 +6,6 @@
utest/utest
*.bak
gmon.out
box/bhshmqbox
box/bhshmq_center
box/help