From 492e6f2e52d4a622548ea0e7689fbeb5ea6f0660 Mon Sep 17 00:00:00 2001
From: Paul Bone <pbone@mozilla.com>
Date: Wed, 15 Nov 2017 17:08:39 +1100
Subject: [PATCH] Bug 1417315 - Calculate lazy_capacity perf value before
 resizing the nursery r=sfink

---
 js/src/gc/Nursery.cpp | 7 ++++---
 js/src/gc/Nursery.h   | 1 +
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/js/src/gc/Nursery.cpp b/js/src/gc/Nursery.cpp
index 1ff3e038b5c4..7954d590c9a6 100644
--- a/js/src/gc/Nursery.cpp
+++ b/js/src/gc/Nursery.cpp
@@ -554,9 +554,8 @@ js::Nursery::renderProfileJSON(JSONPrinter& json) const
     const size_t newCapacity = spaceToEnd(maxChunkCount());
     if (newCapacity != previousGC.nurseryCapacity)
         json.property("new_capacity", newCapacity);
-    const size_t lazyCapacity = spaceToEnd(allocatedChunkCount());
-    if (lazyCapacity != previousGC.nurseryCapacity)
-        json.property("lazy_capacity", lazyCapacity);
+    if (previousGC.nurseryLazyCapacity != previousGC.nurseryCapacity)
+        json.property("lazy_capacity", previousGC.nurseryLazyCapacity);
     if (!timeInChunkAlloc_.IsZero())
         json.property("chunk_alloc_us", timeInChunkAlloc_, json.MICROSECONDS);
 
@@ -680,6 +679,7 @@ js::Nursery::collect(JS::gcreason::Reason reason)
     } else {
         previousGC.nurseryUsedBytes = 0;
         previousGC.nurseryCapacity = spaceToEnd(maxChunkCount());
+        previousGC.nurseryLazyCapacity = spaceToEnd(allocatedChunkCount());
         previousGC.tenuredBytes = 0;
     }
 
@@ -867,6 +867,7 @@ js::Nursery::doCollection(JS::gcreason::Reason reason,
 
     previousGC.reason = reason;
     previousGC.nurseryCapacity = initialNurseryCapacity;
+    previousGC.nurseryLazyCapacity = spaceToEnd(allocatedChunkCount());
     previousGC.nurseryUsedBytes = initialNurseryUsedBytes;
     previousGC.tenuredBytes = mover.tenuredSize;
 }
diff --git a/js/src/gc/Nursery.h b/js/src/gc/Nursery.h
index 06158799dc0e..2f368dc6a80e 100644
--- a/js/src/gc/Nursery.h
+++ b/js/src/gc/Nursery.h
@@ -380,6 +380,7 @@ class Nursery
     struct {
         JS::gcreason::Reason reason;
         size_t nurseryCapacity;
+        size_t nurseryLazyCapacity;
         size_t nurseryUsedBytes;
         size_t tenuredBytes;
     } previousGC;