better synchronization

better deadlock detection to also track wait/sync

backend-simulators/pim/pim-simulator/tests/sync.rs

@@ -297,7 +297,7 @@ fn multiple_send_recv_test() {
 }
 
 #[test]
-fn sync_wait_tokens_test() {
+fn sync_wait_exact_count_resets_test() {
     let cpu = common::empty_cpu(2);
     let mut cores = CoreInstructionsBuilder::new(2);
     let mut instructions = InstructionsBuilder::new();
@@ -313,14 +313,68 @@ fn sync_wait_tokens_test() {
     cores.set_core(1, instructions.build());
 
     data.set_core_indx(2).fix_core_indx();
-    for _ in 0..2 {
-        instructions.make_inst(wait, data.set_offset_select_value(0, 1).build());
-    }
+    instructions.make_inst(wait, data.set_offset_select_value(0, 2).build());
     cores.set_core(2, instructions.build());
 
     Executable::new(cpu, cores.build()).execute().unwrap();
 }
 
+#[test]
+fn sync_wait_rejects_overshoot() {
+    let cpu = common::empty_cpu(3);
+    let mut cores = CoreInstructionsBuilder::new(3);
+    let mut instructions = InstructionsBuilder::new();
+    let mut data = InstructionDataBuilder::new();
+
+    data.set_core_indx(1).fix_core_indx();
+    instructions.make_inst(
+        sync,
+        data.set_imm_core(3).set_offset_select_value(0, 0).build(),
+    );
+    cores.set_core(1, instructions.build());
+
+    data.set_core_indx(2).fix_core_indx();
+    instructions.make_inst(
+        sync,
+        data.set_imm_core(3).set_offset_select_value(0, 0).build(),
+    );
+    cores.set_core(2, instructions.build());
+
+    data.set_core_indx(3).fix_core_indx();
+    instructions.make_inst(wait, data.set_offset_select_value(0, 1).build());
+    cores.set_core(3, instructions.build());
+
+    let error = Executable::new(cpu, cores.build()).execute().unwrap_err();
+    assert!(error.to_string().contains("overshot exact value"));
+}
+
+#[test]
+fn sync_wait_deadlock_cycle_is_reported() {
+    let cpu = common::empty_cpu(2);
+    let mut cores = CoreInstructionsBuilder::new(2);
+    let mut instructions = InstructionsBuilder::new();
+    let mut data = InstructionDataBuilder::new();
+
+    data.set_core_indx(1).fix_core_indx();
+    instructions.make_inst(wait, data.set_offset_select_value(0, 1).build());
+    instructions.make_inst(
+        sync,
+        data.set_imm_core(2).set_offset_select_value(0, 0).build(),
+    );
+    cores.set_core(1, instructions.build());
+
+    data.set_core_indx(2).fix_core_indx();
+    instructions.make_inst(wait, data.set_offset_select_value(0, 1).build());
+    instructions.make_inst(
+        sync,
+        data.set_imm_core(1).set_offset_select_value(0, 0).build(),
+    );
+    cores.set_core(2, instructions.build());
+
+    let error = Executable::new(cpu, cores.build()).execute().unwrap_err();
+    assert!(error.to_string().contains("wait event"));
+}
+
 #[test]
 fn blocked_transfers_do_not_starve_sync_producer() {
     let cpu = common::empty_cpu(4);