Last edited by
MBrown on January 30, 1984 11:49:28 am PST
Taft on 1-Feb-82 13:01:29
Hauser, March 7, 1985 2:13:07 pm PST
Bob Hagmann April 21, 1988 4:06:23 pm PDT
YggImport:
CEDAR DEFINITIONS
LOCKS s.first
USING s: Handle =
BEGIN
Handle: TYPE = REF opaque; (really defined below, allowing us to use inlines)
Register:
PROC [server: YggEnvironment.FileStore]
RETURNS [Handle];
Returns a Handle that is (permanently) associated with the indicated server.
This call performs no communication; in particular, there is no guarantee that
a Handle ever contains an interface bound to the indicated server.
Client may use the built-in assignment operation on Handles, and may
use the following additional operations:
Equal:
PROC [s, t: Handle]
RETURNS [
BOOLEAN] =
INLINE {
RETURN [s=t] };
Name:
PROC [s: Handle]
RETURNS [YggEnvironment.FileStore] =
INLINE {
RETURN [s.first.server] };
DeviceCharacteristicsForFileStore:
PROC [server: YggEnvironment.FileStore]
RETURNS [YggEnvironment.DeviceCharacteristics];
GetTransMgrInterface: ENTRY PROC [s: Handle]
RETURNS [AlpineTransMgrRpcControl.InterfaceRecord] = INLINE {
ENABLE UNWIND => NULL;
IF s.first.transMgrInterface = NIL THEN NewInterfaces[s];
RETURN [s.first.transMgrInterface] };
Makes one binding try, and returns NIL as the second result if it fails.
Otherwise returns an AlpineCoordinator interface that is bound to the server
implied by Handle s.
It is CRUCIAL that the client hang on to the REF AlpineCoordinatorIR during
any call made through the interface; this is what prevents the binding of the
interface from changing out from under the client. This is guaranteed as long
as the client does not FORK the interface procedure or pass the procedure value
to someone else.
TransMgrInterfaceCallFailed: PROC [
s: Handle, i: AlpineTransMgrRpcControl.InterfaceRecord];
This call serves notice that a call made through interface i, which was derived
from Handle s, has failed and hence the interface should probably be discarded.
The following should be considered opaque to the client, but is here to allow
Equal, Name, and GetTransMgrInterface to be defined inline.
Object:
TYPE =
MONITORED
RECORD [
server: YggEnvironment.FileStore,
immutable, since clients store Handles in their data structures.
local:
BOOL ←
FALSE,
part of the kludge for providing local calls: tells ConversationTable what to do
mostRecentRegister: BasicTime.GMT,
mostRecentBind: BasicTime.GMT
transMgrInterface: AlpineTransMgrRpcControl.InterfaceRecord ← NIL
protected by monitor
];
Handle: TYPE = LIST OF Object;
nullHandle: Handle = NIL;
NewInterfaces:
PRIVATE
PROC [s: Handle];
! (none.)
END.--YggImport