Some more scheduler cleanups:

  * Split task control msg handling out into its own function for readability
  * Cleanup some comments
  * Move the transaction-start inside the task thread -- this way delayed-start transactions are less likely to get serialization conflict.
  * Add TaskConflictRetry message for tx serialization conflict results, and have the scheduler receive them, though they are still unhandled (panic).  (#13)
  * Move VM creation into the VM host, since *it* knows what kind of VM it needs.
  * Remove some redundant arguments/value-passing.
  * Break task's command handling out of the msg match and into its own function for readability

crates/kernel/src/tasks/mod.rs

@@ -30,7 +30,6 @@ pub mod vm_test_utils {
     use crate::tasks::vm_host::{VMHost, VMHostResponse};
     use crate::tasks::VerbCall;
     use crate::vm::vm_execute::VmExecParams;
-    use crate::vm::VM;
     use moor_values::model::world_state::WorldState;
     use moor_values::var::Var;
     use moor_values::SYSTEM_OBJECT;
@@ -43,16 +42,9 @@ pub mod vm_test_utils {
         verb_name: &str,
         args: Vec<Var>,
     ) -> Var {
-        let vm = VM::new();
         let (scs_tx, _scs_rx) = tokio::sync::mpsc::unbounded_channel();
-        let mut vm_host = MooVmHost::new(
-            vm,
-            20,
-            90_000,
-            Duration::from_secs(5),
-            session.clone(),
-            scs_tx,
-        );
+        let mut vm_host =
+            MooVmHost::new(20, 90_000, Duration::from_secs(5), session.clone(), scs_tx);
 
         let (sched_send, _) = tokio::sync::mpsc::unbounded_channel();
         let _vm_exec_params = VmExecParams {

crates/kernel/src/tasks/moo_vm_host.rs

@@ -39,13 +39,13 @@ pub struct MooVmHost {
 
 impl MooVmHost {
     pub fn new(
-        vm: VM,
         max_stack_depth: usize,
         max_ticks: usize,
         max_time: Duration,
         sessions: Arc<dyn Session>,
         scheduler_control_sender: UnboundedSender<(TaskId, SchedulerControlMsg)>,
     ) -> Self {
+        let vm = VM::new();
         // Created in an initial suspended state.
         Self {
             vm,