Properly queue order dealloca.

shortfin/python/lib_ext.cc

@@ -329,7 +329,7 @@ class PyProgramInvocation {
         results_failure_(other.results_failure_) {}
 
   // Fields that can be bound.
-  bool assume_no_alias = false;
+  bool assume_no_alias = true;
   static std::optional<bool> global_assume_no_alias;
 
   void CheckValid() {

shortfin/src/shortfin/local/scheduler.cc

@@ -120,18 +120,25 @@ TimelineResourceDestructor TimelineResource::CreateAsyncBufferDestructor(
     iree_hal_device_t *hal_device = scoped_device.raw_device()->hal_device();
     auto queue_affinity = scoped_device.affinity().queue_affinity();
     SHORTFIN_TRACE_SCOPE_NAMED("TimelineResource::AsyncBufferDestructor");
-    iree_hal_semaphore_list_t wait_semaphore_list = res.use_barrier();
-    // TODO: If desiring strict memory reclamation ordering, we want to queue
-    // order the successors to the deallocation.
+
+    // The dealloca needs to wait on the current timepoint+all uses, and it
+    // needs to signal the next timepoint. Since this is a destructor, we
+    // now have exclusive control of the TimelineResource and simply record
+    // the current timepoint in its uses as a (small) optimization for merging
+    // the wait semaphore list, prior to acquiring a new timepoint
+    // (to signal).
     auto fiber = res.fiber();
     auto &account = fiber->scheduler().GetDefaultAccount(scoped_device);
     iree_hal_semaphore_t *timeline_sem = account.timeline_sem();
+    res.use_barrier_insert(timeline_sem, account.timeline_idle_timepoint());
     uint64_t signal_timepoint = account.timeline_acquire_timepoint();
+    iree_hal_semaphore_list_t wait_semaphore_list = res.use_barrier();
     iree_hal_semaphore_list_t signal_semaphore_list{
         .count = 1,
         .semaphores = &timeline_sem,
         .payload_values = &signal_timepoint,
     };
+
     if (SHORTFIN_SCHED_LOG_ENABLED) {
       auto wait_sum = iree::DebugPrintSemaphoreList(wait_semaphore_list);
       auto signal_sum = iree::DebugPrintSemaphoreList(signal_semaphore_list);

shortfin/src/shortfin/support/logging.h

@@ -16,7 +16,7 @@
 #endif
 
 // Scheduler logging.
-#define SHORTFIN_SCHED_LOG_ENABLED 1
+#define SHORTFIN_SCHED_LOG_ENABLED 0
 #if SHORTFIN_SCHED_LOG_ENABLED
 #define SHORTFIN_SCHED_LOG(...) shortfin::logging::info("SCHED: " __VA_ARGS__)
 #else