tests: try to make sleeping portable by avoiding select

select does not support just waiting on Windows:
https://perldoc.perl.org/perlport.html#select

Reviewed-By: Daniel Stenberg
Closes #5035

tests/ftp.pm

@@ -5,7 +5,7 @@
 #                            | (__| |_| |  _ <| |___
 #                             \___|\___/|_| \_\_____|
 #
-# Copyright (C) 1998 - 2010, Daniel Stenberg, <daniel@haxx.se>, et al.
+# Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
 #
 # This software is licensed as described in the file COPYING, which
 # you should have received as part of this distribution. The terms
@@ -20,6 +20,14 @@
 #
 ###########################################################################
 
+BEGIN {
+    # portable sleeping needs Time::HiRes
+    eval {
+        no warnings "all";
+        require Time::HiRes;
+    }
+}
+
 use strict;
 use warnings;
 
@@ -29,6 +37,27 @@ use serverhelp qw(
     datasockf_pidfilename
     );
 
+#######################################################################
+# portable_sleep uses Time::HiRes::sleep if available and falls back
+# to the classic approach of using select(undef, undef, undef, ...).
+# even though that one is not portable due to being implemented using
+# select on Windows: https://perldoc.perl.org/perlport.html#select
+# On Windows it also just uses full-second sleep for waits >1 second.
+#
+sub portable_sleep {
+    my ($seconds) = @_;
+
+    if($Time::HiRes::VERSION) {
+        Time::HiRes::sleep($seconds);
+    }
+    elsif ($seconds > 1 && ($^O eq 'MSWin32' || $^O eq 'msys')) {
+        sleep($seconds);
+    }
+    else {
+        select(undef, undef, undef, $seconds);
+    }
+}
+
 #######################################################################
 # pidfromfile returns the pid stored in the given pidfile.  The value
 # of the returned pid will never be a negative value. It will be zero
@@ -216,7 +245,7 @@ sub killpid {
                 }
             }
             last if(not scalar(@signalled));
-            select(undef, undef, undef, 0.05);
+            portable_sleep(0.05);
         }
     }
 

tests/ftpserver.pl

@@ -493,7 +493,7 @@ sub sendcontrol {
 
         for(@a) {
             sockfilt $_;
-            select(undef, undef, undef, 0.01);
+            portable_sleep(0.01);
         }
     }
     my $log;
@@ -530,7 +530,7 @@ sub senddata {
             # pause between each byte
             for (split(//,$l)) {
                 sockfiltsecondary $_;
-                select(undef, undef, undef, 0.01);
+                portable_sleep(0.01);
             }
         }
     }
@@ -3199,7 +3199,7 @@ while(1) {
             logmsg("Sleep for $delay seconds\n");
             my $twentieths = $delay * 20;
             while($twentieths--) {
-                select(undef, undef, undef, 0.05) unless($got_exit_signal);
+                portable_sleep(0.05) unless($got_exit_signal);
             }
         }
 

tests/runtests.pl

@@ -482,7 +482,7 @@ sub startnew {
             logmsg "startnew: failed to write fake $pidfile with pid=$child\n";
         }
         # could/should do a while connect fails sleep a bit and loop
-        sleep $timeout;
+        portable_sleep($timeout);
         if (checkdied($child)) {
             logmsg "startnew: child process has failed to start\n" if($verbose);
             return (-1,-1);
@@ -3823,7 +3823,7 @@ sub singletest {
     if($serverlogslocktimeout) {
         my $lockretry = $serverlogslocktimeout * 20;
         while((-f $SERVERLOGS_LOCK) && $lockretry--) {
-            select(undef, undef, undef, 0.05);
+            portable_sleep(0.05);
         }
         if(($lockretry < 0) &&
            ($serverlogslocktimeout >= $defserverlogslocktimeout)) {
@@ -3840,7 +3840,7 @@ sub singletest {
     # based tests might need a small delay once that the client command has
     # run to avoid false test failures.
 
-    sleep($postcommanddelay) if($postcommanddelay);
+    portable_sleep($postcommanddelay) if($postcommanddelay);
 
     # timestamp removal of server logs advisor read lock
     $timesrvrlog{$testnum} = Time::HiRes::time();