Add some support for CPU profiling

luprex/core/cpp/util.cpp

@@ -10,13 +10,26 @@
 #include <cassert>
 #include <algorithm>
 
+#ifdef WIN32
+#endif
+
 #ifndef WIN32
+#include <time.h>
 #include <unistd.h>
-#define stat _stat
 #endif
 
 namespace util {
 
+int64_t profiling_clock() {
+#ifdef WIN32
+    return 0.0;
+#else
+    struct timespec ts;
+    assert(0 == clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &ts));
+    return int64_t(ts.tv_nsec) + (int64_t(ts.tv_sec)*int64_t(1000000000));
+#endif
+}
+
 static bool ascii_isalpha(char c) {
     return ((c >= 'a') && (c <= 'z')) || ((c >= 'A') && (c <= 'Z'));
 }