Updates refactoring of CPU feature detection

runtime/vm/cpuinfo.h

+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file

[siva, 2014/02/21 19:28:55]

2014

[zra, 2014/02/21 21:51:55]

Done.

+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#ifndef VM_CPUINFO_H_
+#define VM_CPUINFO_H_
+
+#include "platform/assert.h"
+#include "vm/allocation.h"
+
+namespace dart {
+
+// Indices into cpuinfo field name arrays.
+enum CpuInfoIndices {
+  kCpuInfoProcessor = 0,
+  kCpuInfoModel = 1,
+  kCpuInfoHardware = 2,
+  kCpuInfoFeatures = 3,
+  kCpuInfoMax = 4,
+};
+
+// For Intel architectures, the method to use to get CPU information.
+enum CpuInfoMethod {
+  // Use the cpuid instruction.
+  kCpuInfoCpuId,
+
+  // Use system calls.
+  kCpuInfoSystem,
+
+  // Use whatever the default is for a particular OS:
+  // Linux, Windows -> CpuId,
+  // Android, MacOS -> System.
+  kCpuInfoDefault,
+};
+
+class CpuInfo : public AllStatic {
+ public:
+  // If necessary, allocates a buffer [data_] and reads cpuinfo into
+  // that buffer.
+  static void InitOnce(CpuInfoMethod method);
+
+  static const char* FieldName(CpuInfoIndices idx) {
+    ASSERT((idx >= 0) && (idx < kCpuInfoMax));
+    return fields_[idx];
+  }
+
+  // Returns true if the cpuinfo field contains the string.
+  static bool FieldContains(CpuInfoIndices idx, const char* search_string);
+  static bool FieldContainsByString(
+      const char* field, const char* search_string);
+
+  // Returns true if the cpuinfo field [field] exists and is non-empty.
+  static bool HasField(const char* field);
+
+  // Returns the field.
+  static const char* ExtractField(CpuInfoIndices idx);
+  static const char* ExtractFieldByString(const char* field);

[siva, 2014/02/21 19:28:55]

Document that the caller of this method is responsible to free the result
string.

[zra, 2014/02/21 21:51:55]

Done.

+
+  // Returns the field describing the CPU model.

[siva, 2014/02/21 19:28:55]

Document that the caller of this method should free the returned string

[zra, 2014/02/21 21:51:55]

Done.

+  static const char* GetCpuModel() {
+    ASSERT(HasField(FieldName(kCpuInfoModel)));
+    return ExtractField(kCpuInfoModel);
+  }
+
+ private:
+  // The method to use to acquire info about the CPU.
+  static CpuInfoMethod method_;
+
+  // Cpuinfo field names.
+  static const char* fields_[kCpuInfoMax];
+};
+
+}  // namespace dart
+
+#endif  // VM_CPUINFO_H_