Branch Scheduling

distsys/archetyperesource.go

@@ -16,6 +16,12 @@ type ArchetypeResource interface {
 	// archetype is not running. Close will be called at most once by the MPCal
 	// Context.
 	Close() error
+	// FreshState will be called upon the first use of a resource during the execution of a
+	// critical section. It provides an ArchetypeResourceState whose purpose is to be used
+	// to perform operations during the execution of the critical section. A call to FreshState
+	// creates the expectation that there will be an eventual call to Commit/Abort on the
+	// resulting ArchetypeResourceState
+	// Note: FreshState is only meant to be used ONCE during a critical section for a resource
 	FreshState() ArchetypeResourceState
 }
 
@@ -50,6 +56,10 @@ type ArchetypeResourceState interface {
 	// ErrCriticalSectionAborted.
 	// This makes no sense for a value-like resource, and should be blocked off with ArchetypeResourceLeafMixin in that case.
 	Index(index tla.TLAValue) (ArchetypeResourceComponent, error)
+	// ForkState provides a copy to the ArchetypeResourceState such that operations performed on other ArchetypeResourceStates
+	// with the same parent ArchetypeResource will not cause side effects for the current ArchetypeResourceState.
+	// ForkState will clone all the parts of a resource whose properties are NOT idempotent. A call to ForkState
+	// creates the expectation that there will be an eventual call to Commit/Abort on the resulting ArchetypeResourceState
 	ForkState() ArchetypeResourceState
 }
 

distsys/mpcalctx.go

@@ -109,16 +109,6 @@ type ArchetypeResourceMakerStruct struct {
 	ConfigureFn func(res ArchetypeResource)
 }
 
-//type ForkedResourceNode struct {
-//	parent          *ForkedResourceNode
-//	resourceStates map[ArchetypeResourceHandle]ArchetypeResource
-//	path            string
-//}
-
-//type ForkedResourceTree struct {
-//	root *ForkedResourceNode
-//}
-
 var _ ArchetypeResourceMaker = ArchetypeResourceMakerStruct{}
 
 func (mkStruct ArchetypeResourceMakerStruct) Make() ArchetypeResource {
@@ -142,9 +132,6 @@ type MPCalContext struct {
 
 	// state for ArchetypeInterface.NextFairnessCounter
 	fairnessCounter FairnessCounter
-	// Forked resource tree
-	//forkedResourceTree ForkedResourceTree
-	//branchScheduler BranchScheduler
 
 	jumpTable MPCalJumpTable
 	procTable MPCalProcTable
@@ -431,27 +418,6 @@ func (ctx *MPCalContext) ensureArchetypeResource(name string, maker ArchetypeRes
 	return handle
 }
 
-//func (ctx *MPCalContext) getResourceByHandle(handle ArchetypeResourceHandle) ArchetypeResource {
-//	//node := ctx.forkedResourceTree.root
-//	//for {
-//	//	if node == nil {
-//	//		panic(fmt.Errorf("could not find resource with name %v", handle))
-//	//	}
-//	//
-//	//	res, ok := node.resourceStates[handle]
-//	//	if ok {
-//	//		return res
-//	//	}
-//	//	node = node.parent
-//	//}
-//
-//	//res, ok := ctx.resources[handle]
-//	//if !ok {
-//	//	panic(fmt.Errorf("could not find resource with name %v", handle))
-//	//}
-//	//return res
-//}
-
 func (ctx *MPCalContext) getResourceByHandle(handle ArchetypeResourceHandle) ArchetypeResource {
 	res, ok := ctx.resources[handle]
 	if !ok {