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

src/cpu.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 12 matching lines @@
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include "cpu.h"
 
 #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 {
 
 #if V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64
 
 // Define __cpuid() for non-MSVC compilers.
 #if !V8_CC_MSVC
 
 static V8_INLINE(void __cpuid(int cpu_info[4], int info_type)) {
@@ skipping 386 matching lines @@
   // to user-space applications.  According to MIPS (early 2010), no similar
   // facility is universally available on the MIPS architectures,
   // so it's up to individual OSes to provide such.
   CPUInfo cpu_info;
   char* cpu_model = cpu_info.ExtractField("cpu model");
   has_fpu_ = HasListItem(cpu_model, "FPU");
   delete[] cpu_model;
 #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