[exception_vs_return.cpp]: add

cpp-perf/exception_vs_return.cpp

@@ -0,0 +1,88 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <sys/time.h>
+#include <iostream>
+#include <fstream>
+#include <random>
+#include <functional>
+#include <vector>
+#include <string>
+#include <atomic>
+#include <memory>
+#include <map>
+#include <set>
+#include <thread>
+#include <algorithm>
+#include <functional>
+#include <future>
+#include <string.h>
+#include <boost/version.hpp>
+#include <boost/utility/string_ref.hpp>
+#include <boost/algorithm/string.hpp>
+#include <boost/locale.hpp>
+#include <boost/format.hpp>
+#include <openssl/md5.h>
+
+#include <glog/logging.h>
+
+#include <iostream>
+#include <iomanip>
+#include <sstream>
+
+#include "util.h"
+
+using namespace std;  
+
+void fun_throw()
+{
+    throw "hello";
+}
+
+int fun_return()
+{
+    return -1;
+}
+
+// ----------------------------------------------------------------------
+// try catch 不是一般的慢啊，-O3 优化输出是这样
+// 
+//   throw
+//   10000
+//   40417.9µs
+//   return
+//   10000
+//   6.675µs
+//   
+// try/catch 10000 次要花 40ms, 这在线上服务中是无法接受的，至少比较深的
+// 逻辑是绝对不能用 try/catch 的，为了避免区分的麻烦，还是都不用了
+// ----------------------------------------------------------------------
+int main(int argc, char *argv[])
+{
+    {
+        cout << "throw" << endl;
+        Timing t;
+        auto k = 0u;
+        for (auto i = 0u; i < 10000; ++i) {
+            try {
+                fun_throw();
+            } catch(...) {
+                ++k;
+            }
+        }
+        cout << k << endl;
+    }
+
+    {
+        cout << "return" << endl;
+        Timing t;
+        auto k = 0u;
+        for (auto i = 0; i < 10000; ++i) {
+            if (fun_return() != 0) {
+                ++k;
+            }
+        }
+        cout << k << endl;
+    }
+    return 0;
+}
+