Parsing /proc/cpuinfo for model on Android and Aura

base/cpu.cc

 // 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 "base/cpu.h"
 
 #include <string.h>
 
 #include <algorithm>
 
 #include "base/basictypes.h"
+#include "base/file_util.h"

[cpu_(ooo_6.6-7.5), 2014/04/24 03:36:50]

can we put the file_util.h on an #ifdef, in most platforms this whole class is
just a wrapper to the cpuid instruction. So it is pretty surprising to find file
IO here.

+#include "base/lazy_instance.h"
 #include "build/build_config.h"
 
 #if defined(ARCH_CPU_X86_FAMILY)
 #if defined(_MSC_VER)
 #include <intrin.h>
 #include <immintrin.h>  // For _xgetbv()
 #endif
 #endif
 
 namespace base {
@@ skipping 55 matching lines @@
 uint64 _xgetbv(uint32 xcr) {
   uint32 eax, edx;
 
   __asm__ volatile ("xgetbv" : "=a" (eax), "=d" (edx) : "c" (xcr));
   return (static_cast<uint64>(edx) << 32) | eax;
 }
 
 #endif  // !_MSC_VER
 #endif  // ARCH_CPU_X86_FAMILY
 
+#if defined(ARCH_CPU_ARM_FAMILY) && (defined(OS_ANDROID) || defined(OS_LINUX))
+
+std::string ParseCpuInfo() {
+  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(ARCH_CPU_ARM_FAMILY) && (defined(OS_ANDROID) ||
+        // defined(OS_LINUX))
+
 }  // anonymous namespace
 
 void CPU::Initialize() {
 #if defined(ARCH_CPU_X86_FAMILY)
   int cpu_info[4] = {-1};
   char cpu_string[48];
 
   // __cpuid with an InfoType argument of 0 returns the number of
   // valid Ids in CPUInfo[0] and the CPU identification string in
   // the other three array elements. The CPU identification string is
@@ skipping 53 matching lines @@
       cpu_string_ptr += sizeof(cpu_info);
     }
     cpu_brand_.assign(cpu_string, cpu_string_ptr - cpu_string);
   }
 
   const int parameter_containing_non_stop_time_stamp_counter = 0x80000007;
   if (max_parameter >= parameter_containing_non_stop_time_stamp_counter) {
     __cpuid(cpu_info, parameter_containing_non_stop_time_stamp_counter);
     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");
+#elif defined(ARCH_CPU_ARM_FAMILY) && (defined(OS_ANDROID) || defined(OS_LINUX))
+  cpu_brand_.assign(CpuBrandInfo());
 #endif
 }
 
 CPU::IntelMicroArchitecture CPU::GetIntelMicroArchitecture() const {
   if (has_avx()) return AVX;
   if (has_sse42()) return SSE42;
   if (has_sse41()) return SSE41;
   if (has_ssse3()) return SSSE3;
   if (has_sse3()) return SSE3;
   if (has_sse2()) return SSE2;
   if (has_sse()) return SSE;
   return PENTIUM;
 }
 
 }  // namespace base