From b00299a2048948e38484e10cda644c3436ff593f Mon Sep 17 00:00:00 2001
From: Martin Quinson <martin.quinson@loria.fr>
Date: Fri, 27 Jan 2012 21:32:42 +0100
Subject: [PATCH 1/1] add a function xbt_os_get_numcores()

---
 buildtools/Cmake/CompleteInFiles.cmake |  2 ++
 src/include/xbt/xbt_os_thread.h        |  3 ++-
 src/portable.h                         |  7 +++++++
 src/xbt/xbt_os_thread.c                | 27 ++++++++++++++++++++++++++
 4 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/buildtools/Cmake/CompleteInFiles.cmake b/buildtools/Cmake/CompleteInFiles.cmake
index 90d3fbce9c..3b7ac73a6c 100644
--- a/buildtools/Cmake/CompleteInFiles.cmake
+++ b/buildtools/Cmake/CompleteInFiles.cmake
@@ -108,6 +108,8 @@ CHECK_INCLUDE_FILE("unistd.h" HAVE_UNISTD_H)
 CHECK_INCLUDE_FILE("execinfo.h" HAVE_EXECINFO_H)
 CHECK_INCLUDE_FILE("signal.h" HAVE_SIGNAL_H)
 CHECK_INCLUDE_FILE("sys/time.h" HAVE_SYS_TIME_H)
+CHECK_INCLUDE_FILE("sys/param.h" HAVE_SYS_PARAM_H)
+CHECK_INCLUDE_FILE("sys/sysctl.h" HAVE_SYS_SYSCTL_H)
 CHECK_INCLUDE_FILE("time.h" HAVE_TIME_H)
 CHECK_INCLUDE_FILE("dlfcn.h" HAVE_DLFCN_H)
 CHECK_INCLUDE_FILE("inttypes.h" HAVE_INTTYPES_H)
diff --git a/src/include/xbt/xbt_os_thread.h b/src/include/xbt/xbt_os_thread.h
index 61d4912064..e744be5ff5 100644
--- a/src/include/xbt/xbt_os_thread.h
+++ b/src/include/xbt/xbt_os_thread.h
@@ -36,12 +36,13 @@ typedef DWORD xbt_os_thread_key_t;
 #endif
 
 /* Calls pthread_atfork() if present, and else does nothing.
- * The only known user of this wrapper is mmalloc_preinit().
+ * The only known user of this wrapper is mmalloc_preinit(); This function may disapear in the near future.
  */
 XBT_PUBLIC(int) xbt_os_thread_atfork(void (*prepare)(void),
                                      void (*parent)(void),
                                      void (*child)(void));
 
+XBT_PUBLIC(int) xbt_os_get_numcores(void);
 
 XBT_PUBLIC(xbt_os_thread_t) xbt_os_thread_create(const char *name,
                                                  pvoid_f_pvoid_t start_routine,
diff --git a/src/portable.h b/src/portable.h
index f9dc951ba0..70701e009e 100644
--- a/src/portable.h
+++ b/src/portable.h
@@ -31,6 +31,13 @@
 #  include <unistd.h>
 #endif
 
+#ifdef HAVE_SYS_PARAM_H
+# include <sys/param.h>
+#endif
+#ifdef HAVE_SYS_SYSCTL_H
+# include <sys/sysctl.h>
+#endif
+
 /****
  **** Networking 
  ****/
diff --git a/src/xbt/xbt_os_thread.c b/src/xbt/xbt_os_thread.c
index f34fb398e1..8c9f2b02ca 100644
--- a/src/xbt/xbt_os_thread.c
+++ b/src/xbt/xbt_os_thread.c
@@ -1163,6 +1163,33 @@ void xbt_os_sem_get_value(xbt_os_sem_t sem, int *svalue)
 
 #endif
 
+
+/** @brief Returns the amount of cores on the current host */
+int xbt_os_get_numcores(void) {
+#ifdef WIN32
+    SYSTEM_INFO sysinfo;
+    GetSystemInfo(&sysinfo);
+    return sysinfo.dwNumberOfProcessors;
+#elif MACOS
+    int nm[2];
+    size_t len = 4;
+    uint32_t count;
+
+    nm[0] = CTL_HW; nm[1] = HW_AVAILCPU;
+    sysctl(nm, 2, &count, &len, NULL, 0);
+
+    if(count < 1) {
+        nm[1] = HW_NCPU;
+        sysctl(nm, 2, &count, &len, NULL, 0);
+        if(count < 1) { count = 1; }
+    }
+    return count;
+#else
+    return sysconf(_SC_NPROCESSORS_ONLN);
+#endif
+}
+
+
 /***** reentrant mutexes *****/
 typedef struct xbt_os_rmutex_ {
   xbt_os_mutex_t mutex;
-- 
2.20.1