Set Android/V8 memory limits from dalvik.vm.heapsize.

webkit/glue/dalvik_heap_size_android.cc

Index: webkit/glue/dalvik_heap_size_android.cc
diff --git a/webkit/glue/dalvik_heap_size_android.cc b/webkit/glue/dalvik_heap_size_android.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2eb82b9da9c1bc2933d4718de196910955ca3a5b
--- /dev/null
+++ b/webkit/glue/dalvik_heap_size_android.cc
@@ -0,0 +1,39 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "webkit/glue/dalvik_heap_size_android.h"

[jamesr, 2012/04/20 00:44:26]

i can't figure out why this class is here. it has nothing to do with WebKit or
with glue - so why on earth is it in webkit/glue ?

[ulan, 2012/04/20 08:55:43]

Moved it to webkitplatformsupport_impl.cc, where it is used to set memory
limits.

+
+#include <sys/system_properties.h>
+
+#include "base/memory/singleton.h"
+#include "base/string_number_conversions.h"
+
+namespace webkit_glue {
+
+DalvikHeapSize* DalvikHeapSize::GetInstance() {
+  return Singleton<DalvikHeapSize>::get();
+}
+
+DalvikHeapSize::DalvikHeapSize() : heap_size_mb_(0) {
+  char heap_size_str[PROP_VALUE_MAX];
+  __system_property_get("dalvik.vm.heapsize", heap_size_str);
+  heap_size_mb_ = ParseHeapSize(std::string(heap_size_str));
+}
+
+DalvikHeapSize::~DalvikHeapSize() {}
+
+int DalvikHeapSize::HeapSizeMB() const { return heap_size_mb_; }
+
+int DalvikHeapSize::ParseHeapSize(const std::string& str) const {
+  CHECK_GT(str.size(), 0u);
+  DCHECK_EQ('m', str[str.size() - 1]);

[jamesr, 2012/04/20 00:44:26]

this seems a bit fragile - you can't have a value of '2g' say?

[ulan, 2012/04/20 08:55:43]

Added handling of 'k', 'g' and switched to int64 to avoid overflows.

+  int result = 0;
+  base::StringToInt(str.substr(0, str.size() - 1), &result);

[jamesr, 2012/04/20 00:44:26]

base::StringToInt() returns a bool indicating if the parse was successful - why
aren't we checking it if we're parsing a user-writable value?

[ulan, 2012/04/20 08:55:43]

Done.

+  DCHECK_GT(result, 0);
+  // dalvik.vm.heapsize property is writable by user,
+  // truncate it to reasonable value to avoid overflows later.
+  return std::min(std::max(32, result), 1024);
+}
+
+} // webkit_glue namespace