From fa6ba653d73bc04978a38150ca60b45b47a8f0a2 Mon Sep 17 00:00:00 2001
From: Mike Smith <grimbough@gmail.com>
Date: Fri, 4 May 2018 17:16:01 +0200
Subject: [PATCH] add timer to c program
---
exercises/hpc_example.cpp | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/exercises/hpc_example.cpp b/exercises/hpc_example.cpp
index e923b2f..8357d0f 100644
--- a/exercises/hpc_example.cpp
+++ b/exercises/hpc_example.cpp
@@ -6,6 +6,7 @@
#include <string.h>
#include <unistd.h>
#include <limits.h>
+#include <time.h>
#include <iostream> // std::cout, std::endl
#include <thread> // std::this_thread::sleep_for
#include <chrono> // std::chrono::seconds
@@ -18,15 +19,15 @@ int main(int argc,char* argv[])
std::vector <std::string> sources;
int *a;
size_t mem = 0;
- int time = 10;
+ int waittime = 10;
char hostname[HOST_NAME_MAX];
-
+ time_t t1, t2;
for (int i = 1; i < argc; ++i) {
if (std::string(argv[i]) == "-t") {
if (i + 1 < argc) { // Make sure we aren't at the end of argv!
std::stringstream ss1(argv[++i]);
- if (!(ss1 >> time))
+ if (!(ss1 >> waittime))
std::cerr << "Invalid number " << argv[i] << '\n';
} else { // Uh-oh, there was no argument to the destination option.
std::cerr << "-t option requires one argument." << std::endl;
@@ -46,19 +47,23 @@ int main(int argc,char* argv[])
}
}
+ time(&t1);
+
int result = gethostname(hostname, HOST_NAME_MAX);
std::string hostname2 = hostname;
std::cout << "Current host is: " + hostname2 << std::endl;
- std::cout << "Wait time is: " << time << " seconds" << std::endl;
+ std::cout << "Wait time is: " << waittime << " seconds" << std::endl;
std::cout << "Memory usage is: " << mem << "MB" << std::endl;
long int l = mem * 1024 * 1024;
a = (int*)calloc(mem, 1024 * 1024);
memset(a, 0, mem * 1024 * 1024);
- std::this_thread::sleep_for (std::chrono::seconds(time));
+ std::this_thread::sleep_for (std::chrono::seconds(waittime));
free(a);
+ time(&t2);
+ std::cout << "Actually running time: " << difftime(t2, t1) << " seconds" << std::endl;
return 0;
}
--
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