API Guide
601355 Rev A Getting Started 1-29
Getting Started
Asynchronous processing also gives the client more control
over the processing environment. The VSID_RETRY_LIMIT is
not applicable when the API software executes in asynchronous
mode. If the VSID_STATUS_WAIT_FLAG value is FALSE, the
API operates in asynchronous mode.
Synchronous For synchronous processing, the VolServ API returns control to
the client only after final status (or time-out) is received.
Synchronous processing allows processing of only one
command at a time. If the VSID_STATUS_WAIT_FLAG value is
TRUE, the API operates in synchronous mode.
VSCMD_
cmd
VS_Select Volume
VS_CallBack
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Server
1. Client Program calls the command function (VSCMD_cmd).
2. The VSCMD_cmd calls the Volume Server.
3. VolServ returns initial status to VSCMD_cmd.
4. VSCMD_cmd calls the VS_Select loop to wait for status.
5. VS_Select calls the command specific VS_Callback.
6. VS_Callback returns status to VS_Select.
7. VS_Select returns control to VSCMD_cmd.
8. VSCMD_cmd returns control to the Client Program.
Client
Program