nonblocking-pipe tests: Fix test failure on MSVC

[Bruno Haible]

On MSVC, I'm seeing this test failure:

FAIL: test-nonblocking-pipe.sh
==============================

c:\testdir-posix-msvc\gltests\test-nonblocking-reader.h:179: assertion 
'spent_time < 1.5' failed
FAIL test-nonblocking-pipe.sh (exit status: 1)

The comment says:
      /* This assertion fails if data_block_size is much larger than needed
         and SMALL_DELAY is too large, or if data_block_size is very large and
         ENABLE_DEBUGGING is 1.  */

And indeed, SMALL_DELAY was 1 second (due to the suboptimal usleep()), and
PIPE_DATA_BLOCK_SIZE was 70000. Improving usleep - done in the previous commit -
and reducing PIPE_DATA_BLOCK_SIZE fixes the test failure.


2019-07-02  Bruno Haible  <address@hidden>

        nonblocking-pipe tests: Fix test failure on MSVC.
        * tests/test-nonblocking-pipe.h (PIPE_DATA_BLOCK_SIZE): Set to 10000 on
        native Windows.

diff --git a/tests/test-nonblocking-pipe.h b/tests/test-nonblocking-pipe.h
index fd101c5..7edb64e 100644
--- a/tests/test-nonblocking-pipe.h
+++ b/tests/test-nonblocking-pipe.h
@@ -41,6 +41,8 @@
 # define PIPE_DATA_BLOCK_SIZE 140000
 #elif defined __linux__ && defined __powerpc__
 # define PIPE_DATA_BLOCK_SIZE 1100000
+#elif defined _WIN32 && !defined __CYGWIN__
+# define PIPE_DATA_BLOCK_SIZE 10000
 #else
 # define PIPE_DATA_BLOCK_SIZE 70000
 #endif