added clean-up for tests run under Cygwin

- certain tests (using "debug restart") cause additional processes to be
  spawned and not tracked due to changed process ID (Windows-specific
  behaviour), so we need to clean them up when running tests under Cygwin

tests/integration/psync2.tcl

@@ -180,6 +180,12 @@ start_server {} {
         }
         set new_sync_count [status $R($master_id) sync_full]
         assert {$sync_count == $new_sync_count}
+
+        if {$::uses_cygwin} {
+            # read Windows PID from "INFO" to be cleaned up at the end
+            set pid [status $R($slave_id) process_id]
+            lappend ::winpids $pid
+        }
     }
 
     test "PSYNC2: Replica RDB restart with EVALSHA in backlog issue #4483" {
@@ -227,6 +233,12 @@ start_server {} {
             incr retry -1
         }
 
+        if {$::uses_cygwin} {
+            # read Windows PID from "INFO" to be cleaned up at the end
+            set pid [status $R($slave_id) process_id]
+            lappend ::winpids $pid
+        }
+
         # The master should be back at 4 slaves eventually
         wait_for_condition 50 1000 {
             [status $R($master_id) connected_slaves] == 4
@@ -250,3 +262,7 @@ start_server {} {
     }
 
 }}}}}
+
+# clean up any additional processes started by "debug restart" under Windows
+#   when running tests from Cygwin
+cygwin_clean_up

tests/support/server.tcl

@@ -96,30 +96,41 @@ if { $tcl_platform(platform) != "windows" } {
   }
 }
 
+proc windows_is_alive config {
+    set pid [dict get $config pid]
+    set mfilter {PID eq }
+    append mfilter $pid
+    if { [string first $pid [exec tasklist.exe -FI ${mfilter}]] != -1 } {
+        return 1
+    } else {
+        return 0
+    }
+}
+
+proc windows_kill_proc config {
+    set pid [dict get $config pid]
+    catch {exec taskkill.exe /F /T /PID $pid}
+}
+
+proc windows_kill_proc2 pid {
+    catch {exec taskkill.exe /F /T /PID $pid}
+}
 
 if { $tcl_platform(platform) == "windows" } {
     proc is_alive config {
-        set pid [dict get $config pid]
-        set mfilter {PID eq }
-        append mfilter $pid
-        if { [string first $pid [exec tasklist.exe -FI ${mfilter}]] != -1 } {
-            return 1
-        } else {
-            return 0
-        }
+        return [windows_is_alive $config]
     }
 }
 
 if { $tcl_platform(platform) == "windows" } {
     proc kill_proc config {
-        set pid [dict get $config pid]
-        catch {exec taskkill.exe -F -T -PID $pid}
+        windows_kill_proc $config
     }
 }
 
 if { $tcl_platform(platform) == "windows" } {
     proc kill_proc2 pid {
-        catch {exec taskkill.exe -F -T -PID $pid}
+        windows_kill_proc2 $pid
     }
 }
 
@@ -389,3 +400,19 @@ proc start_server {options {code undefined}} {
         set _ $srv
     }
 }
+
+proc cygwin_clean_up {} {
+    # clean up any new processes started with "debug restart" using Windows-specific tools
+    foreach newpid $::winpids {
+        set config [dict create "pid" $newpid]
+
+        if {$::verbose} { puts "Checking if WINPID=$newpid is still alive" }
+        while {[windows_is_alive $config]} {
+            if {$::verbose} { puts "Trying to stop server with WINPID=$newpid" }
+            windows_kill_proc $config
+            after 1000
+        }
+    }
+
+    set ::winpids {}
+}

tests/test_helper.tcl

@@ -454,6 +454,18 @@ proc print_help_screen {} {
     } "\n"]
 }
 
+# [tporadowski] "debug restart" command in Redis for Windows causes a new process
+#  with new PID to be started, so we need to properly clean this up when running tests
+#  from Cygwin
+set ::winpids {}
+set ::uses_cygwin 0
+if {$::tcl_platform(platform) == "unix"} {
+    set uname [exec uname -s]
+    if {[string first "CYGWIN" $uname] != -1} {
+        set ::uses_cygwin 1
+    }
+}
+
 # parse arguments
 for {set j 0} {$j < [llength $argv]} {incr j} {
     set opt [lindex $argv $j]