Convert tst-epoll.cc to standard C++

Replace OSv-specific constructs in tst-epoll.cc by their standard C++
counterparts (i.e., std::thread, std::chrono, std::cout).
This test now also runs (and of course, succeeds) on Linux.

In general, it is important at all our Linux-ABI tests (where we test our
implementation of the Linux/glibc functionality) to be able to run on Linux
as well. Otherwise, it is possible our tests don't actually test the right
thing (we may test for some expected behavior, but the actual behavior on
Linux is different).

I'm doing this in preparation for fixing issue #188 (fix edge-triggered
epoll).

Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

tests/tst-epoll.cc

 /*
- * Copyright (C) 2013 Cloudius Systems, Ltd.
+ * Copyright (C) 2013-2014 Cloudius Systems, Ltd.
  *
  * This work is open source software, licensed under the terms of the
  * BSD license as described in the LICENSE file in the top-level directory.
@@ -8,17 +8,20 @@
 #include <sys/epoll.h>
 #include <sys/poll.h>
 #include <unistd.h>
-#include <osv/sched.hh>
-#include <osv/debug.hh>
-#include <osv/clock.hh>
+#include <errno.h>
 
-int tests = 0, fails = 0;
+#include <string>
+#include <iostream>
+#include <chrono>
+#include <thread>
 
-static void report(bool ok, const char* msg)
+static int tests = 0, fails = 0;
+
+static void report(bool ok, std::string msg)
 {
     ++tests;
     fails += !ok;
-    debug("%s: %s\n", (ok ? "PASS" : "FAIL"), msg);
+    std::cout << (ok ? "PASS" : "FAIL") << ": " << msg << "\n";
 }
 
 int main(int ac, char** av)
@@ -30,7 +33,7 @@ int main(int ac, char** av)
     int r = pipe(s);
     report(r == 0, "create pipe");
 
-#define MAXEVENTS 1024
+    constexpr int MAXEVENTS = 1024;
     struct epoll_event events[MAXEVENTS];
 
     r = epoll_wait(ep, events, MAXEVENTS, 0);
@@ -73,7 +76,7 @@ int main(int ac, char** av)
     report(r == 0, "epoll after read");
 
 
-    sched::thread t1([&] {
+    std::thread t1([&] {
         int r2 = epoll_wait(ep, events, MAXEVENTS, 5000);
         report(r2 == 1 && (events[0].events & EPOLLIN) &&
                 (events[0].data.u32 == 123), "epoll_wait in thread");
@@ -84,20 +87,18 @@ int main(int ac, char** av)
         r = epoll_wait(ep, events, MAXEVENTS, 0);
         report(r == 0, "epoll after read");
     });
-    t1.start();
-    usleep(500000);
+    std::this_thread::sleep_for(std::chrono::microseconds(500000));
     r = write(s[1], &c, 1);
     report(r == 1, "write single character");
     t1.join();
 
-    auto ts = osv::clock::uptime::now();
+    auto ts = std::chrono::high_resolution_clock::now();
     r = epoll_wait(ep, events, MAXEVENTS, 300);
-    auto te = osv::clock::uptime::now();
-    using namespace osv::clock::literals;
-    report(r == 0 && ((te - ts) > 200_ms), "epoll timeout");
-
+    auto te = std::chrono::high_resolution_clock::now();
+    report(r == 0 && ((te - ts) > std::chrono::milliseconds(200)),
+            "epoll timeout");
 
-    debug("SUMMARY: %d tests, %d failures\n", tests, fails);
+    std::cout << "SUMMARY: " << tests << ", " << fails << " failures\n";
 }