Add some support for CPU profiling

luprex/core/cpp/lpxclient.cpp

@@ -150,6 +150,17 @@ public:
         rescan_lua_source();
     }
 
+    void do_work_command(const util::StringVec &words) {
+        int reps = 10000;
+        int64_t t1 = util::profiling_clock();
+        for (int i = 0; i < reps; i++) {
+            world_to_synchronous();
+            world_to_asynchronous();
+        }
+        int64_t t2 = util::profiling_clock();
+        stdostream() << "Snapshot/rollback took " << ((t2-t1)/reps) << " nanosec." << std::endl;
+    }
+
     void do_quit_command(const util::StringVec &words) {
         abandon_server();
         stop_driver();
@@ -165,6 +176,7 @@ public:
         else if (words[0] == "choose") do_choose_command(words);
         else if (words[0] == "tick") do_tick_command(words);
         else if (words[0] == "cpl") do_cpl_command(words);
+        else if (words[0] == "work") do_work_command(words);
         else if (words[0] == "quit") do_quit_command(words);
         else {
             stdostream() << "Unsupported command: " << words[0] << std::endl;

luprex/core/cpp/luaconsole.cpp

@@ -86,6 +86,10 @@ void LuaConsole::simplify(const StringVec &words) {
         if (words.size() != 1) {
             synerr("/cpl takes no arguments");
         }
+    } else if (words[0] == "work") {
+        if (words.size() != 1) {
+            synerr("/work takes no arguments");
+        }
     } else {
         synerr("unrecognized command");
     }

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'));
 }

luprex/core/cpp/util.hpp

@@ -37,6 +37,9 @@ using LuaSourcePtr = std::unique_ptr<LuaSourceVec>;
 using HashValue = std::pair<uint64_t, uint64_t>;
 using IdVector = std::vector<int64_t>;
 
+// Return nanoseconds elapsed, for profiling purposes.
+int64_t profiling_clock();
+
 // Return true if the string is a valid lua identifier.
 bool is_identifier(const std::string &str);