Add support for querying the amount of memory on a system to sys_info.

Review URL: http://codereview.chromium.org/2927

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@2303 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 59 insertions, 1 deletions

diff --git a/base/sys_info.h b/base/sys_info.h
index 65949a0..c82b0d3 100644
--- a/base/sys_info.h
+++ b/base/sys_info.h
@@ -5,12 +5,17 @@
 #ifndef BASE_SYS_INFO_H_
 #define BASE_SYS_INFO_H_
 
+#include "base/basictypes.h"
+
 namespace base {
 
 class SysInfo {
  public:
   // Return the number of logical processors/cores on the current machine.
   static int NumberOfProcessors();
+  
+  // Return the number of bytes of physical memory on the current machine.
+  static int64 AmountOfPhysicalMemory();
 };
 
 }  // namespace base
diff --git a/base/sys_info_posix.cc b/base/sys_info_posix.cc
index 093e607..a9a91cd 100644
--- a/base/sys_info_posix.cc
+++ b/base/sys_info_posix.cc
@@ -3,12 +3,17 @@
 // found in the LICENSE file.
 
 #include "base/sys_info.h"
+#include "base/basictypes.h"
 
 #include <errno.h>
 #include <string.h>
 #include <unistd.h>
 
-#include "base/basictypes.h"
+#if defined(OS_MACOSX)
+#include <mach/mach_host.h>
+#include <mach/mach_init.h>
+#endif
+
 #include "base/logging.h"
 
 namespace base {
@@ -25,4 +30,33 @@ int SysInfo::NumberOfProcessors() {
   return static_cast<int>(res);
 }
 
+// static
+int64 SysInfo::AmountOfPhysicalMemory() {
+  // _SC_PHYS_PAGES is not part of POSIX and not available on OS X
+#if defined(OS_MACOSX)
+  struct host_basic_info hostinfo;
+  mach_msg_type_number_t count = HOST_BASIC_INFO_COUNT;
+  int result = host_info(mach_host_self(),
+                         HOST_BASIC_INFO,
+                         reinterpret_cast<host_info_t>(&hostinfo),
+                         &count);
+  DCHECK_EQ(HOST_BASIC_INFO_COUNT, count);
+  if (result != KERN_SUCCESS) {
+    NOTREACHED();
+    return 0;
+  }
+  
+  return static_cast<int64>(hostinfo.max_mem);
+#else
+  long pages = sysconf(_SC_PHYS_PAGES);
+  long page_size = sysconf(_SC_PAGE_SIZE);
+  if (pages == -1 || page_size == -1) {
+    NOTREACHED();
+    return 0;
+  }
+
+  return static_cast<int64>(pages) * page_size;
+#endif
+}
+
 }  // namespace base
diff --git a/base/sys_info_unittest.cc b/base/sys_info_unittest.cc
index 4ed2834..edaf2aa 100644
--- a/base/sys_info_unittest.cc
+++ b/base/sys_info_unittest.cc
@@ -9,3 +9,8 @@ TEST(SysInfoTest, NumProcs) {
   // We aren't actually testing that it's correct, just that it's sane.
   EXPECT_GE(base::SysInfo::NumberOfProcessors(), 1);
 }
+
+TEST(SysInfoTest, AmountOfMem) {
+  // We aren't actually testing that it's correct, just that it's sane.
+  EXPECT_GT(base::SysInfo::AmountOfPhysicalMemory(), 0);
+}
diff --git a/base/sys_info_win.cc b/base/sys_info_win.cc
index 4d32489..8b6dfea 100644
--- a/base/sys_info_win.cc
+++ b/base/sys_info_win.cc
@@ -6,6 +6,8 @@
 
 #include <windows.h>
 
+#include "base/logging.h"
+
 namespace base {
 
 // static
@@ -15,4 +17,16 @@ int SysInfo::NumberOfProcessors() {
   return static_cast<int>(info.dwNumberOfProcessors);
 }
 
+// static
+int64 SysInfo::AmountOfPhysicalMemory() {
+  MEMORYSTATUSEX memory_info;
+  memory_info.dwLength = sizeof(memory_info);
+  if (!GlobalMemoryStatusEx(&memory_info)) {
+    NOTREACHED();
+    return 0;
+  }
+
+  return static_cast<int64>(memory_info.ullTotalPhys);
+}
+
 }  // namespace base