1 files changed, 66 insertions, 1 deletions

diff --git a/tests/progress/driver.cxx b/tests/progress/driver.cxx
index 702319a..64e84fd 100644
--- a/tests/progress/driver.cxx
+++ b/tests/progress/driver.cxx
@@ -3,22 +3,57 @@
 // license   : MIT; see accompanying LICENSE file
 
 #ifndef _WIN32
+#  include <unistd.h> // write()
+
 #  include <thread> // this_thread::sleep_for()
 #else
 #  include <libbutl/win32-utility.hxx>
+
+#  include <io.h> //_write()
 #endif
 
 #include <cstddef>  // size_t
 #include <iostream>
 
+#include <libbutl/process.hxx>
+#include <libbutl/fdstream.hxx>    // fdnull(), stderr_fd()
 #include <libbutl/diagnostics.hxx>
 
 using namespace std;
 using namespace butl;
 
+// Usage:
+//
+// argv[0] [-n] [-c]
+//
+// -n
+//    Do not run child process. By default the program runs itself with -c
+//    option (see below).
+//
+// -c
+//    Run as a child process that just prints lines with a small but varying
+//    delay.
+//
 int
-main ()
+main (int argc, const char* argv[])
 {
+  bool child (false);
+  bool no_child (false);
+
+  assert (argc > 0);
+
+  for (int i (1); i != argc; ++i)
+  {
+    string v (argv[i]);
+
+    if (v == "-c")
+      child = true;
+    else if (v == "-n")
+      no_child = true;
+    else
+      assert (false);
+  }
+
   auto sleep = [] (size_t ms = 100)
   {
     // MINGW GCC 4.9 doesn't implement this_thread so use Win32 Sleep().
@@ -30,6 +65,34 @@ main ()
 #endif
   };
 
+  if (child)
+  {
+    auto print = [] (const string& s)
+    {
+#ifndef _WIN32
+      write (stderr_fd(), s.c_str (), s.size ());
+#else
+      _write (stderr_fd(), s.c_str (), static_cast<unsigned int> (s.size ()));
+#endif
+    };
+
+    for (size_t i (50); i != 0; --i)
+    {
+      print ("Child line " + to_string (i) + '\n');
+      sleep (200 - i);
+    }
+
+    return 0;
+  }
+
+  // @@ Can't compile unless convert to process_env() explicitly (GCC still
+  //    warns about calls ambiguity).
+  //
+  process pr (!no_child
+              ? process_start (fdnull (), fdnull (), stderr_fd (),
+                               process_env (argv[0]), "-c")
+              : process (process_exit (0))); // Exited normally.
+
   for (size_t i (100); i != 0; --i)
   {
     if (i % 10 == 0)
@@ -59,4 +122,6 @@ main ()
   }
 
   sleep (1000);
+
+  assert (pr.wait ());
 }