Parsing /proc/cpuinfo for model on Android and Aura

base/cpu.cc

Index: base/cpu.cc
diff --git a/base/cpu.cc b/base/cpu.cc
index 66207a1e0b8b0539b99a72b85435936f847803bb..1d4590523858f3ef4fbf778d563307fbc07c24eb 100644
--- a/base/cpu.cc
+++ b/base/cpu.cc
@@ -9,6 +9,8 @@
 #include <algorithm>
 
 #include "base/basictypes.h"
+#include "base/file_util.h"
+#include "base/lazy_instance.h"
 #include "build/build_config.h"
 
 #if defined(ARCH_CPU_X86_FAMILY)
@@ -86,6 +88,48 @@ uint64 _xgetbv(uint32 xcr) {
 
 }  // anonymous namespace
 
+#if defined(ARCH_CPU_ARM_FAMILY)
+#if defined(OS_ANDROID) || defined(USE_AURA)

[Mark Mentovai, 2014/03/11 16:17:48]

This code is valid on any ARM Linux, right? That’s why I’m asking if Aura is
really the right thing to key off of. Isn’t OS_ANDROID || OS_LINUX really what
you mean?

[rptr, 2014/03/12 15:26:25]

Done.

+
+std::string ParseCpuInfo() {

[Mark Mentovai, 2014/03/11 16:17:48]

All of this should be in the unnamed namespace.

[rptr, 2014/03/12 15:26:25]

Done.

+  const char kProcessorPrefix[] = "Processor";
+  std::string contents, cpu_brand;
+  ReadFileToString(FilePath("/proc/cpuinfo"), &contents);
+  DCHECK(!contents.empty());
+  if (!contents.empty()) {
+    std::istringstream iss(contents);
+    std::string line;
+    while (std::getline(iss, line)) {
+      if (line.compare(0, strlen(kProcessorPrefix), kProcessorPrefix) == 0) {
+        size_t pos = line.find(": ");
+        if (pos != std::string::npos) {
+          cpu_brand.assign(line.substr(pos + 2));
+          break;
+        }
+      }
+    }
+  }
+  return cpu_brand;
+}
+
+class LazyCpuInfoValue {
+ public:
+  LazyCpuInfoValue() : value_(ParseCpuInfo()) {}
+  const std::string& value() { return value_; }
+
+ private:
+  const std::string value_;
+  DISALLOW_COPY_AND_ASSIGN(LazyCpuInfoValue);
+};
+
+base::LazyInstance<LazyCpuInfoValue> g_lazy_cpu_brand =
+    LAZY_INSTANCE_INITIALIZER;
+
+const std::string& CpuBrandInfo() { return g_lazy_cpu_brand.Get().value(); }
+
+#endif  // defined(OS_ANDROID) || defined(USE_AURA)
+#endif  // ARCH_CPU_ARM_FAMILY
+
 void CPU::Initialize() {
 #if defined(ARCH_CPU_X86_FAMILY)
   int cpu_info[4] = {-1};
@@ -158,12 +202,9 @@ void CPU::Initialize() {
     has_non_stop_time_stamp_counter_ = (cpu_info[3] & (1 << 8)) != 0;
   }
 #elif defined(ARCH_CPU_ARM_FAMILY)
-  // TODO(piman): Expand this. ARM has a CPUID register, but it's not available
-  // in user mode. /proc/cpuinfo has some information, but it's non standard,
-  // platform-specific, and not accessible from the sandbox.
-  // For some purposes, this first approximation is enough.
-  // crbug.com/313454
-  cpu_brand_.assign("ARM");
+#if defined(OS_ANDROID) || defined(USE_AURA)
+  cpu_brand_.assign(CpuBrandInfo());
+#endif
 #endif
 }