test-results.txt

connolly@jambox:~/projects/agoric/agoric-sdk/packages/xsnap$ yarn test test/test-xs-perf.js 
yarn run v1.22.5
$ ava test/test-xs-perf.js

  meter details

    ℹ {
        allocate: 42074144,
        allocateSlotsCalls: 2,
        compute: 1260179,
        cumulativeHash: 1245307666,
        garbageCollectionCount: 0,
        mapSetAddCount: 40002,
        mapSetRemoveCount: 40000,
        maxBucketSize: 164,
      }

  test/test-xs-perf.js:52

   51:   t.log(meters);  
   52:   t.deepEqual(    
   53:     shape(meters),

  auxiliary (non-consensus) meters are available

  Difference:

    {
      allocate: 'number',
  +   allocateChunksCalls: 'number',
      allocateSlotsCalls: 'number',
      compute: 'number',
  -   cumulativeHash: 'number',
      garbageCollectionCount: 'number',
      mapSetAddCount: 'number',
      mapSetRemoveCount: 'number',
      maxBucketSize: 'number',
    }

  › test/test-xs-perf.js:52:5

  ─

  1 test failed
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
connolly@jambox:~/projects/agoric/agoric-sdk/packages/xsnap$ yarn test test/test-xs-perf.js 
yarn run v1.22.5
$ ava test/test-xs-perf.js

  meter details

    ℹ {
        allocate: 42074144,
        allocateSlotsCalls: 2,
        compute: 1260179,
        cumulativeHash: 1245304738,
        garbageCollectionCount: 0,
        mapSetAddCount: 40002,
        mapSetRemoveCount: 40000,
        maxBucketSize: 164,
      }

  test/test-xs-perf.js:52

   51:   t.log(meters);  
   52:   t.deepEqual(    
   53:     shape(meters),

  auxiliary (non-consensus) meters are available

  Difference:

    {
      allocate: 'number',
  +   allocateChunksCalls: 'number',
      allocateSlotsCalls: 'number',
      compute: 'number',
  -   cumulativeHash: 'number',
      garbageCollectionCount: 'number',
      mapSetAddCount: 'number',
      mapSetRemoveCount: 'number',
      maxBucketSize: 'number',
    }

  › test/test-xs-perf.js:52:5

  ─

  1 test failed
error Command failed with exit code 1.

xsMapSet.c.patch

diff --git a/xs/sources/xsMapSet.c b/xs/sources/xsMapSet.c
index 29c4b06f..29ac97c2 100644
--- a/xs/sources/xsMapSet.c
+++ b/xs/sources/xsMapSet.c
@@ -948,6 +948,7 @@ txU4 fxSumEntry(txMachine* the, txSlot* slot)
 		sum = (sum << 1) + kind;
 	}
 	sum &= 0x7FFFFFFF;
+        the->cumulativeHash += sum;
 	return sum;
 }
 

xsnap.c.patch

diff --git a/packages/xsnap/moddable b/packages/xsnap/moddable
--- a/packages/xsnap/moddable
+++ b/packages/xsnap/moddable
@@ -1 +1 @@
-Subproject commit fb8632bd5ade099bb660d12851e000c4608a7e5f
+Subproject commit fb8632bd5ade099bb660d12851e000c4608a7e5f-dirty
diff --git a/packages/xsnap/src/xsnap.c b/packages/xsnap/src/xsnap.c
index 42c6fdd9e..7c151d996 100644
--- a/packages/xsnap/src/xsnap.c
+++ b/packages/xsnap/src/xsnap.c
@@ -1398,7 +1398,7 @@ static int fxWriteOkay(FILE* outStream, xsUnsignedValue meterIndex, txMachine *t
 				  "{"
 				  "\"compute\":%u,"
 				  "\"allocate\":%u,"
-				  "\"allocateChunksCalls\":%u,"
+				  "\"cumulativeHash\":%u,"
 				  "\"allocateSlotsCalls\":%u,"
 				  "\"garbageCollectionCount\":%u,"
 				  "\"mapSetAddCount\":%u,"
@@ -1412,7 +1412,8 @@ static int fxWriteOkay(FILE* outStream, xsUnsignedValue meterIndex, txMachine *t
 	// Prepend the meter usage to the reply.
 	snprintf(prefix, sizeof(prefix) - 1, fmt,
 			 meterIndex, the->allocatedSpace,
-			 the->allocateChunksCallCount, the->allocateSlotsCallCount,
+			 the->cumulativeHash,
+			 the->allocateSlotsCallCount,
 			 the->garbageCollectionCount,
 			 the->mapSetAddCount, the->mapSetRemoveCount,
 			 the->maxBucketSize);
diff --git a/packages/xsnap/src/xsnap.h b/packages/xsnap/src/xsnap.h
index be95b6dc6..254d0c623 100644
--- a/packages/xsnap/src/xsnap.h
+++ b/packages/xsnap/src/xsnap.h
@@ -72,6 +72,7 @@
 	txUnsigned allocateChunksCallCount; \
 	txUnsigned allocateSlotsCallCount; \
 	txUnsigned garbageCollectionCount; \
+	txUnsigned cumulativeHash; \
 	txUnsigned mapSetAddCount; \
 	txUnsigned mapSetRemoveCount; \
 	txUnsigned maxBucketSize; \