merge?

test/hotspot/gtest/nmt/test_virtualMemoryTracker.cpp

@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2023 SAP SE. All rights reserved.
+ * Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+#include "precompiled.hpp"
+#include "runtime/os.hpp"
+#include "services/memTracker.hpp"
+#include "services/virtualMemoryTracker.hpp"
+#include "unittest.hpp"
+
+static size_t get_committed() {
+  VirtualMemorySnapshot snapshot;
+  VirtualMemorySummary::snapshot(&snapshot);
+
+  return snapshot.by_type(mtThreadStack)->committed();
+}
+
+TEST_VM(VirtualMemoryTracker, MissingRemoveReleasedRegion) {
+  if (!MemTracker::enabled()) {
+    return;
+  }
+
+  // Simulate the case where we miss the ending of a thread.
+  for (int i = 100; i >= 0; --i) {
+    size_t size = 1024 * 1024;
+    NativeCallStack empty_stack;
+
+    // Get a region of mapped memory not tracked by the virtual memory tracker.
+    address base = (address) os::reserve_memory(2 * size, false);
+    VirtualMemoryTracker::remove_released_region(base, 2 * size);
+    size_t init_sz = get_committed();
+
+    // Reserve and commit everything. We have to, since getting the snapshot 'detects'
+    // committed but not reported memory for thread stacks and the detection will not work
+    // on MacOSX (not implemented).
+    VirtualMemoryTracker::add_reserved_region(base, size, empty_stack, mtThreadStack);
+    VirtualMemoryTracker::add_committed_region(base, size, empty_stack);
+
+    // Now pretend we have forgotten to call remove_released_region and allocate an new
+    // overlapping region with some commited memory.
+    VirtualMemoryTracker::add_reserved_region(base + size / 2, size, empty_stack, mtThreadStack);
+    VirtualMemoryTracker::add_committed_region(base + size / 2, size, empty_stack);
+
+    // And remove some of the the committed memory again by reserving a partially overlappinbg region.
+    VirtualMemoryTracker::add_reserved_region(base, size, empty_stack, mtThreadStack);
+    VirtualMemoryTracker::add_committed_region(base, size, empty_stack);
+    size_t new_sz = get_committed();
+
+    // Give back the memory.
+    VirtualMemoryTracker::remove_released_region(base, size);
+    VirtualMemoryTracker::add_reserved_region(base, 2 * size, empty_stack, mtThreadStack);
+    os::release_memory((char*) base, 2 * size);
+
+    // If a parallel thread committed memory concurrently, we get a wrong test result.
+    // This should not happen often, so try a few times.
+    if (new_sz - size == init_sz) {
+      break;
+    }
+
+    // If it fails too often log the values we see.
+    if (i < 50) {
+      tty->print_cr("init_sz: %d, new_sz %d, diff %d, region_size %d", (int) init_sz, (int) new_sz, (int) (new_sz - init_sz), (int) size);
+    }
+
+    // Trigger a test failure on the last run.
+    if (i == 0) {
+      EXPECT_TRUE(new_sz - size == init_sz) << "new_sz: " << new_sz << ", init_sz: " << init_sz <<
+                                               ", diff: " << (new_sz - init_sz) << ", region size: " << size;
+    }
+  }
+}