8329840: Fix ZPhysicalMemorySegment::_end type

Reviewed-by: stefank, eosterlund

src/hotspot/share/gc/z/zAddress.inline.hpp

@@ -133,6 +133,10 @@ inline bool operator<(zoffset first, zoffset_end second) {
   return untype(first) < untype(second);
 }
 
+inline bool operator<=(zoffset_end first, zoffset second) {
+  return untype(first) <= untype(second);
+}
+
 inline bool operator>(zoffset first, zoffset_end second) {
   return untype(first) > untype(second);
 }

src/hotspot/share/gc/z/zPhysicalMemory.hpp

@@ -32,16 +32,16 @@
 
 class ZPhysicalMemorySegment : public CHeapObj<mtGC> {
 private:
-  zoffset _start;
-  zoffset _end;
-  bool    _committed;
+  zoffset     _start;
+  zoffset_end _end;
+  bool        _committed;
 
 public:
   ZPhysicalMemorySegment();
   ZPhysicalMemorySegment(zoffset start, size_t size, bool committed);
 
   zoffset start() const;
-  zoffset end() const;
+  zoffset_end end() const;
   size_t size() const;
 
   bool is_committed() const;

src/hotspot/share/gc/z/zPhysicalMemory.inline.hpp

@@ -31,19 +31,19 @@
 
 inline ZPhysicalMemorySegment::ZPhysicalMemorySegment()
   : _start(zoffset(UINTPTR_MAX)),
-    _end(zoffset(UINTPTR_MAX)),
+    _end(zoffset_end(UINTPTR_MAX)),
     _committed(false) {}
 
 inline ZPhysicalMemorySegment::ZPhysicalMemorySegment(zoffset start, size_t size, bool committed)
   : _start(start),
-    _end(start + size),
+    _end(to_zoffset_end(start, size)),
     _committed(committed) {}
 
 inline zoffset ZPhysicalMemorySegment::start() const {
   return _start;
 }
 
-inline zoffset ZPhysicalMemorySegment::end() const {
+inline zoffset_end ZPhysicalMemorySegment::end() const {
   return _end;
 }
 

test/hotspot/gtest/gc/z/test_zPhysicalMemory.cpp

@@ -25,7 +25,27 @@
 #include "gc/z/zPhysicalMemory.inline.hpp"
 #include "unittest.hpp"
 
+class ZAddressOffsetMaxSetter {
+private:
+  const size_t _old_max;
+  const size_t _old_mask;
+
+public:
+  ZAddressOffsetMaxSetter()
+    : _old_max(ZAddressOffsetMax),
+      _old_mask(ZAddressOffsetMask) {
+    ZAddressOffsetMax = size_t(16) * G * 1024;
+    ZAddressOffsetMask = ZAddressOffsetMax - 1;
+  }
+  ~ZAddressOffsetMaxSetter() {
+    ZAddressOffsetMax = _old_max;
+    ZAddressOffsetMask = _old_mask;
+  }
+};
+
 TEST(ZPhysicalMemoryTest, copy) {
+  ZAddressOffsetMaxSetter setter;
+
   const ZPhysicalMemorySegment seg0(zoffset(0), 100, true);
   const ZPhysicalMemorySegment seg1(zoffset(200), 100, true);
 
@@ -52,6 +72,8 @@ TEST(ZPhysicalMemoryTest, copy) {
 }
 
 TEST(ZPhysicalMemoryTest, add) {
+  ZAddressOffsetMaxSetter setter;
+
   const ZPhysicalMemorySegment seg0(zoffset(0), 1, true);
   const ZPhysicalMemorySegment seg1(zoffset(1), 1, true);
   const ZPhysicalMemorySegment seg2(zoffset(2), 1, true);
@@ -114,6 +136,8 @@ TEST(ZPhysicalMemoryTest, add) {
 }
 
 TEST(ZPhysicalMemoryTest, remove) {
+  ZAddressOffsetMaxSetter setter;
+
   ZPhysicalMemory pmem;
 
   pmem.add_segment(ZPhysicalMemorySegment(zoffset(10), 10, true));
@@ -130,6 +154,8 @@ TEST(ZPhysicalMemoryTest, remove) {
 }
 
 TEST(ZPhysicalMemoryTest, split) {
+  ZAddressOffsetMaxSetter setter;
+
   ZPhysicalMemory pmem;
 
   pmem.add_segment(ZPhysicalMemorySegment(zoffset(0), 10, true));
@@ -158,6 +184,8 @@ TEST(ZPhysicalMemoryTest, split) {
 }
 
 TEST(ZPhysicalMemoryTest, split_committed) {
+  ZAddressOffsetMaxSetter setter;
+
   ZPhysicalMemory pmem0;
   pmem0.add_segment(ZPhysicalMemorySegment(zoffset(0), 10, true));
   pmem0.add_segment(ZPhysicalMemorySegment(zoffset(10), 10, false));
@@ -172,3 +200,20 @@ TEST(ZPhysicalMemoryTest, split_committed) {
   EXPECT_EQ(pmem1.nsegments(), 2);
   EXPECT_EQ(pmem1.size(), 20u);
 }
+
+TEST(ZPhysicalMemoryTest, limits) {
+  ZAddressOffsetMaxSetter setter;
+
+  const size_t HalfZAddressOffsetMax = ZAddressOffsetMax >> 1;
+  ZPhysicalMemory pmem0;
+  pmem0.add_segment(ZPhysicalMemorySegment(zoffset(0), HalfZAddressOffsetMax, true));
+  pmem0.add_segment(ZPhysicalMemorySegment(zoffset(HalfZAddressOffsetMax), HalfZAddressOffsetMax, false));
+  EXPECT_EQ(pmem0.nsegments(), 2);
+  EXPECT_EQ(pmem0.size(), ZAddressOffsetMax);
+
+  ZPhysicalMemory pmem1 = pmem0.split_committed();
+  EXPECT_EQ(pmem0.nsegments(), 1);
+  EXPECT_EQ(pmem0.size(), HalfZAddressOffsetMax);
+  EXPECT_EQ(pmem1.nsegments(), 1);
+  EXPECT_EQ(pmem1.size(), HalfZAddressOffsetMax);
+}