Imported QtWebKit TP3 (git b57bc6801f1876c3220d5a4bfea33d620d477443)

Change-Id: I3b1d8a2808782c9f34d50240000e20cb38d3680f
Reviewed-by: Konstantin Tokarev <annulen@yandex.ru>

1 files changed, 8 insertions, 1 deletions

diff --git a/Source/JavaScriptCore/runtime/ArrayConventions.h b/Source/JavaScriptCore/runtime/ArrayConventions.h
index e5ef96336..9c62ea9b8 100644
--- a/Source/JavaScriptCore/runtime/ArrayConventions.h
+++ b/Source/JavaScriptCore/runtime/ArrayConventions.h
@@ -38,7 +38,7 @@ namespace JSC {
 // (specifically, this is only one property - the value 0xFFFFFFFFU as an unsigned 32-bit
 // integer) are not considered array indices and will be stored in the JSObject property map.
 //
-// All properties with a numeric identifer, representable as an unsigned integer i,
+// All properties with a numeric identifier, representable as an unsigned integer i,
 // where (i <= MAX_ARRAY_INDEX), are an array index and will be stored in either the
 // storage vector or the sparse map. An array index i will be handled in the following
 // fashion:
@@ -58,7 +58,14 @@ namespace JSC {
 
 // These values have to be macros to be used in max() and min() without introducing
 // a PIC branch in Mach-O binaries, see <rdar://problem/5971391>.
+
+// If you grow an ArrayStorage array by more than this, then the array will go sparse. Note that we
+// could probably make this smaller (it's large because it used to be conflated with
+// MIN_ARRAY_STORAGE_CONSTRUCTION_LENGTH).
 #define MIN_SPARSE_ARRAY_INDEX 100000U
+// If you try to allocate a contiguous array larger than this, then we will allocate an ArrayStorage
+// array instead. We allow for an array that occupies 1GB of VM.
+#define MIN_ARRAY_STORAGE_CONSTRUCTION_LENGTH 1024 * 1024 * 1024 / 8
 #define MAX_STORAGE_VECTOR_INDEX (MAX_STORAGE_VECTOR_LENGTH - 1)
 // 0xFFFFFFFF is a bit weird -- is not an array index even though it's an integer.
 #define MAX_ARRAY_INDEX 0xFFFFFFFEU