From 3624b34dde2afbd1d0e9e6dec251925faaefb311 Mon Sep 17 00:00:00 2001
From: Brian Warner <warner@lothar.com>
Date: Sun, 25 Aug 2024 15:53:18 -0700
Subject: [PATCH] updated tests

dropping a Remotable now checks for local recognizers, in preparation
for fixing #9956
---
 packages/swingset-liveslots/src/boyd-gc.js    | 18 +++++++++++++----
 .../test/liveslots-real-gc.test.js            | 20 +++++++++++++++++--
 2 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/packages/swingset-liveslots/src/boyd-gc.js b/packages/swingset-liveslots/src/boyd-gc.js
index ff7e8ac83654..c3b6cb3b23d9 100644
--- a/packages/swingset-liveslots/src/boyd-gc.js
+++ b/packages/swingset-liveslots/src/boyd-gc.js
@@ -276,6 +276,7 @@ export const makeBOYDKit = ({
       for (const vrefOrBaseRef of [...possiblyDeadSet].sort()) {
         const parsed = parseVatSlot(vrefOrBaseRef);
         assert.equal(parsed.type, 'object', vrefOrBaseRef);
+
         let res = {};
         if (parsed.virtual || parsed.durable) {
           const baseRef = vrefOrBaseRef;
@@ -287,12 +288,17 @@ export const makeBOYDKit = ({
           const vref = vrefOrBaseRef;
           res = checkImportPresence(vref);
         }
-        // note the syscalls we need to make at end-of-crank
+
+        // prepare our end-of-crank syscalls
         if (res.dropImport) {
           importsToDrop.add(res.dropImport);
+          possiblyRetiredSet.add(vrefOrBaseRef);
+        }
+        for (const facetVref of res.exportsToRetire || []) {
+          exportsToRetire.add(facetVref);
         }
-        res.exportsToRetire?.map(facetVref => exportsToRetire.add(facetVref));
         gcAgain ||= !!res.gcAgain;
+
         // remove the vref now, so we don't process it again in the
         // next pass unless something else shakes it loose before then
         possiblyDeadSet.delete(vrefOrBaseRef);
@@ -322,11 +328,15 @@ export const makeBOYDKit = ({
       const parsed = parseVatSlot(vref);
       assert.equal(parsed.type, 'object', vref);
       if (!parsed.allocatedByVat) {
+        // if we're dropping the vref, we can safely skip the
+        // isReachable check, because checkImportPresence already did
+        // it
+        const isReachable =
+          !importsToDrop.has(vref) &&
+          (slotToVal.has(vref) || vrm.isPresenceReachable(vref));
         // TODO: the old version used getValForSlot, which also
         // deref()ed the weakref (and assertNotMetered), think about
         // the significance
-        const isReachable =
-          slotToVal.has(vref) || vrm.isPresenceReachable(vref);
         const isRecognizable = isReachable || vrm.isVrefRecognizable(vref);
         if (!isRecognizable) {
           importsToRetire.add(vref);
diff --git a/packages/swingset-liveslots/test/liveslots-real-gc.test.js b/packages/swingset-liveslots/test/liveslots-real-gc.test.js
index 8832eb045461..80641d82a44d 100644
--- a/packages/swingset-liveslots/test/liveslots-real-gc.test.js
+++ b/packages/swingset-liveslots/test/liveslots-real-gc.test.js
@@ -308,6 +308,14 @@ test.serial('GC dispatch.dropExports', async t => {
   // that should allow ex1 to be collected
   t.true(collected.result);
 
+  // upon collection, the vat should scan for local recognizers (weak
+  // collection keys) in case any need to be dropped, and find none
+  t.deepEqual(log.shift(), {
+    type: 'vatstoreGetNextKey',
+    priorKey: `vom.ir.${ex1}|`,
+    result: 'vom.rc.o+d6/1',
+  });
+
   // and once it's collected, the vat should emit `syscall.retireExport`
   // because nobody else will be able to recognize it again
   const l2 = log.shift();
@@ -394,8 +402,16 @@ test.serial(
     // which should let the export be collected
     t.true(collected.result);
 
-    // the vat should *not* emit `syscall.retireExport`, because it already
-    // received a dispatch.retireExport
+    // the vat should scan for local recognizers (weak collection
+    // keys) in case any need to be dropped, and find none
+    t.deepEqual(log.shift(), {
+      type: 'vatstoreGetNextKey',
+      priorKey: 'vom.ir.o+10|',
+      result: 'vom.rc.o+d6/1',
+    });
+
+    // the vat should *not* emit `syscall.retireExport`, because it
+    // already received a dispatch.retireExport
     t.deepEqual(log, []);
   },
 );