Replace OS::NumberOfCores() with CPU::NumberOfProcessorsOnline().

src/cpu.cc

Index: src/cpu.cc
diff --git a/src/cpu.cc b/src/cpu.cc
index 06a03115bbe8692d4d56e8298d423f8b3b647b44..26eca616e347e7175b94bb0ab1eeca3270d61da9 100644
--- a/src/cpu.cc
+++ b/src/cpu.cc
@@ -30,14 +30,21 @@
 #if V8_CC_MSVC
 #include <intrin.h>  // __cpuid()
 #endif
+#if V8_OS_POSIX
+#include <unistd.h>  // sysconf()
+#endif
 
 #include <algorithm>
 #include <cctype>
+#include <climits>
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
 
 #include "checks.h"
+#if V8_OS_WIN
+#include "win32-headers.h"
+#endif
 
 namespace v8 {
 namespace internal {
@@ -444,4 +451,16 @@ CPU::CPU() : stepping_(0),
 #endif
 }
 
+
+// static
+int CPU::NumberOfProcessorsOnline() {

[tfarina, 2013/08/31 22:10:46]

looks like the ninja implementation is stronger.

see:
https://github.com/martine/ninja/blob/master/src/util.cc#L303

[Benedikt Meurer, 2013/09/01 08:32:44]

No, just unnecessarily complex:
- The BSDs implement sysconf(_SC_NPROCESSORS_ONLN) in terms of sysctl({CTL_HW,
HW_NCPU}), and at least FreeBSD attempts to use ELF aux info if available.
- glibc implements sysconf(_SC_NPROCESSORS_ONLN) in terms of get_nprocs(). And
the #if defined(linux) is broken, because get_nprocs() is a glibc extension and
has nothing to do with Linux.
So basically we have 20 fewer lines, for exactly the same result.

+#if V8_OS_WIN
+  SYSTEM_INFO info;
+  GetSystemInfo(&info);
+  return info.dwNumberOfProcessors;
+#else
+  return static_cast<int>(sysconf(_SC_NPROCESSORS_ONLN));
+#endif
+}
+
 } }  // namespace v8::internal