1 files changed, 131 insertions, 0 deletions
diff --git a/devtools/shared/heapsnapshot/tests/xpcshell/test_HeapSnapshot_takeCensus_11.js b/devtools/shared/heapsnapshot/tests/xpcshell/test_HeapSnapshot_takeCensus_11.js
new file mode 100644
index 0000000000..151437bb41
--- /dev/null
+++ b/devtools/shared/heapsnapshot/tests/xpcshell/test_HeapSnapshot_takeCensus_11.js
@@ -0,0 +1,131 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+// Test that Debugger.Memory.prototype.takeCensus and
+// HeapSnapshot.prototype.takeCensus return the same data for the same heap
+// graph.
+
+function doLiveAndOfflineCensus(g, dbg, opts) {
+  dbg.memory.allocationSamplingProbability = 1;
+  dbg.memory.trackingAllocationSites = true;
+  g.eval(`                                          // 1
+         (function unsafeAtAnySpeed() {             // 2
+           for (var i = 0; i < 100; i++) {          // 3
+             this.markers.push(allocationMarker()); // 4
+           }                                        // 5
+         }());                                      // 6
+         `);
+  dbg.memory.trackingAllocationSites = false;
+
+  return {
+    live: dbg.memory.takeCensus(opts),
+    offline: saveHeapSnapshotAndTakeCensus(dbg, opts),
+  };
+}
+
+function getMarkerSize(g, dbg) {
+  dbg.memory.allocationSamplingProbability = 1;
+  dbg.memory.trackingAllocationSites = true;
+  g.eval("var hold = allocationMarker();");
+  dbg.memory.trackingAllocationSites = false;
+  const live = dbg.memory.takeCensus({
+    breakdown: { by: "objectClass", then: { by: "count" } },
+  });
+  g.hold = null;
+  equal(live.AllocationMarker.count, 1);
+  return live.AllocationMarker.bytes;
+}
+
+function run_test() {
+  const g = newGlobal();
+  const dbg = new Debugger(g);
+
+  g.eval("this.markers = []");
+  const markerSize = getMarkerSize(g, dbg);
+
+  // First, test that we get the same counts and sizes as we allocate and retain
+  // more things.
+
+  let prevCount = 0;
+  let prevBytes = 0;
+
+  for (let i = 0; i < 10; i++) {
+    const { live, offline } = doLiveAndOfflineCensus(g, dbg, {
+      breakdown: { by: "objectClass", then: { by: "count" } },
+    });
+
+    equal(live.AllocationMarker.count, offline.AllocationMarker.count);
+    equal(live.AllocationMarker.bytes, offline.AllocationMarker.bytes);
+    equal(live.AllocationMarker.count, prevCount + 100);
+    equal(live.AllocationMarker.bytes, prevBytes + 100 * markerSize);
+
+    prevCount = live.AllocationMarker.count;
+    prevBytes = live.AllocationMarker.bytes;
+  }
+
+  // Second, test that the reported allocation stacks and counts and sizes at
+  // those allocation stacks match up.
+
+  const { live, offline } = doLiveAndOfflineCensus(g, dbg, {
+    breakdown: { by: "objectClass", then: { by: "allocationStack" } },
+  });
+
+  equal(live.AllocationMarker.size, offline.AllocationMarker.size);
+  // One stack with the loop further above, and another stack featuring the call
+  // right above.
+  equal(live.AllocationMarker.size, 2);
+
+  // Note that because SavedFrame stacks reconstructed from an offline heap
+  // snapshot don't have the same principals as SavedFrame stacks captured from
+  // a live stack, the live and offline allocation stacks won't be identity
+  // equal, but should be structurally the same.
+
+  const liveEntries = [];
+  live.AllocationMarker.forEach((v, k) => {
+    dumpn("Allocation stack:");
+    k.toString()
+      .split(/\n/g)
+      .forEach(s => dumpn(s));
+
+    equal(k.functionDisplayName, "unsafeAtAnySpeed");
+    equal(k.line, 4);
+
+    liveEntries.push([k.toString(), v]);
+  });
+
+  const offlineEntries = [];
+  offline.AllocationMarker.forEach((v, k) => {
+    dumpn("Allocation stack:");
+    k.toString()
+      .split(/\n/g)
+      .forEach(s => dumpn(s));
+
+    equal(k.functionDisplayName, "unsafeAtAnySpeed");
+    equal(k.line, 4);
+
+    offlineEntries.push([k.toString(), v]);
+  });
+
+  const sortEntries = (a, b) => {
+    if (a[0] < b[0]) {
+      return -1;
+    } else if (a[0] > b[0]) {
+      return 1;
+    }
+    return 0;
+  };
+  liveEntries.sort(sortEntries);
+  offlineEntries.sort(sortEntries);
+
+  equal(liveEntries.length, live.AllocationMarker.size);
+  equal(liveEntries.length, offlineEntries.length);
+
+  for (let i = 0; i < liveEntries.length; i++) {
+    equal(liveEntries[i][0], offlineEntries[i][0]);
+    equal(liveEntries[i][1].count, offlineEntries[i][1].count);
+    equal(liveEntries[i][1].bytes, offlineEntries[i][1].bytes);
+  }
+
+  do_test_finished();
+}