CTest: Add test for running many tests in parallel

In particular, this checks that CTest's use of select() has a sufficient
file descriptor set size limit (FD_SETSIZE) to handle many child
processes at the same time.  Running 20 tests requires more than 64
descriptors, the Cygwin default that we override.

1 files changed, 16 insertions, 0 deletions

diff --git a/Tests/CTestTestFdSetSize/sleep.c b/Tests/CTestTestFdSetSize/sleep.c
new file mode 100644
index 0000000..b2e6a87
--- /dev/null
+++ b/Tests/CTestTestFdSetSize/sleep.c
@@ -0,0 +1,16 @@
+#if defined(_WIN32)
+# include <windows.h>
+#else
+# include <unistd.h>
+#endif
+
+/* sleeps for 0.1 second */
+int main(int argc, char** argv)
+{
+#if defined(_WIN32)
+  Sleep(100);
+#else
+  usleep(100 * 1000);
+#endif
+  return 0;
+}