move processor-count code to util.cc

3 files changed, 35 insertions, 25 deletions

diff --git a/src/ninja.cc b/src/ninja.cc
index 7929e68..ca45ab1 100644
--- a/src/ninja.cc
+++ b/src/ninja.cc
@@ -19,12 +19,6 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 
-#if defined(__APPLE__) || defined(__FreeBSD__)
-#include <sys/sysctl.h>
-#elif defined(linux)
-#include <sys/sysinfo.h>
-#endif
-
 #ifdef _WIN32
 #include "getopt.h"
 #include <direct.h>
@@ -107,25 +101,7 @@ void Usage(const BuildConfig& config) {
 
 /// Choose a default value for the -j (parallelism) flag.
 int GuessParallelism() {
-  int processors = 0;
-
-#if defined(linux)
-  processors = get_nprocs();
-#elif defined(__APPLE__) || defined(__FreeBSD__)
-  size_t processors_size = sizeof(processors);
-  int name[] = {CTL_HW, HW_NCPU};
-  if (sysctl(name, sizeof(name) / sizeof(int),
-             &processors, &processors_size,
-             NULL, 0) < 0) {
-    processors = 1;
-  }
-#elif defined(_WIN32)
-  SYSTEM_INFO info;
-  GetSystemInfo(&info);
-  processors = info.dwNumberOfProcessors;
-#endif
-
-  switch (processors) {
+  switch (int processors = GetProcessorCount()) {
   case 0:
   case 1:
     return 2;
diff --git a/src/util.cc b/src/util.cc
index 10c9dc6..4ce610b 100644
--- a/src/util.cc
+++ b/src/util.cc
@@ -38,6 +38,12 @@
 #include <direct.h>  // _mkdir
 #endif
 
+#if defined(__APPLE__) || defined(__FreeBSD__)
+#include <sys/sysctl.h>
+#elif defined(linux)
+#include <sys/sysinfo.h>
+#endif
+
 #include "edit_distance.h"
 #include "metrics.h"
 
@@ -283,6 +289,30 @@ string StripAnsiEscapeCodes(const string& in) {
   return stripped;
 }
 
+#if defined(linux)
+int GetProcessorCount() {
+  return get_nprocs();
+}
+#elif defined(__APPLE__) || defined(__FreeBSD__)
+int GetProcessorCount() {
+  int processors;
+  size_t processors_size = sizeof(processors);
+  int name[] = {CTL_HW, HW_NCPU};
+  if (sysctl(name, sizeof(name) / sizeof(int),
+             &processors, &processors_size,
+             NULL, 0) < 0) {
+    return 0;
+  }
+  return processors;
+}
+#elif defined(_WIN32)
+int GetProcessorCount() {
+  SYSTEM_INFO info;
+  GetSystemInfo(&info);
+  return info.dwNumberOfProcessors;
+}
+#endif
+
 #ifdef _WIN32
 double GetLoadAverage() {
   // TODO(nicolas.despres@gmail.com): Find a way to implement it on Windows.
diff --git a/src/util.h b/src/util.h
index 5caf644..9267091 100644
--- a/src/util.h
+++ b/src/util.h
@@ -62,6 +62,10 @@ const char* SpellcheckString(const string& text, ...);
 /// Removes all Ansi escape codes (http://www.termsys.demon.co.uk/vtansi.htm).
 string StripAnsiEscapeCodes(const string& in);
 
+/// @return the number of processors on the machine.  Useful for an initial
+/// guess for how many jobs to run in parallel.  @return 0 on error.
+int GetProcessorCount();
+
 /// @return the load average of the machine. A negative value is returned
 /// on error.
 double GetLoadAverage();