[testrunner] Properly terminate worker processes on Windows

Bug: v8:8170
Change-Id: I4b4a2919f6cf613779eeabc6c2cec1b08fa4d80f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1981152
Reviewed-by: Tamer Tas <tmrts@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65626}

tools/testrunner/local/command.py

@@ -184,6 +184,22 @@ class PosixCommand(BaseCommand):
     process.kill()
 
 
+def taskkill_windows(process, verbose=False, force=True):
+  force_flag = ' /F' if force else ''
+  tk = subprocess.Popen(
+      'taskkill /T%s /PID %d' % (force_flag, process.pid),
+      stdout=subprocess.PIPE,
+      stderr=subprocess.PIPE,
+  )
+  stdout, stderr = tk.communicate()
+  if verbose:
+    print('Taskkill results for %d' % process.pid)
+    print(stdout)
+    print(stderr)
+    print('Return code: %d' % tk.returncode)
+    sys.stdout.flush()
+
+
 class WindowsCommand(BaseCommand):
   def _start_process(self, **kwargs):
     # Try to change the error mode to avoid dialogs on fatal errors. Don't
@@ -213,18 +229,7 @@ class WindowsCommand(BaseCommand):
     return subprocess.list2cmdline(self._to_args_list())
 
   def _kill_process(self, process):
-    tk = subprocess.Popen(
-        'taskkill /T /F /PID %d' % process.pid,
-        stdout=subprocess.PIPE,
-        stderr=subprocess.PIPE,
-    )
-    stdout, stderr = tk.communicate()
-    if self.verbose:
-      print('Taskkill results for %d' % process.pid)
-      print(stdout)
-      print(stderr)
-      print('Return code: %d' % tk.returncode)
-      sys.stdout.flush()
+    taskkill_windows(process, self.verbose)
 
 
 class AndroidCommand(BaseCommand):

tools/testrunner/local/pool.py

@@ -19,6 +19,7 @@ except ImportError:
   from Queue import Empty  # Python 2
 
 from . import command
+from . import utils
 
 
 def setup_testing():
@@ -243,6 +244,13 @@ class Pool():
     """
     self.abort_now = True
 
+  def _terminate_processes(self):
+    for p in self.processes:
+      if utils.IsWindows():
+        command.taskkill_windows(p, verbose=True, force=False)
+      else:
+        os.kill(p.pid, signal.SIGTERM)
+
   def _terminate(self):
     """Terminates execution and cleans up the queues.
 
@@ -267,8 +275,7 @@ class Pool():
       self.work_queue.put("STOP")
 
     if self.abort_now:
-      for p in self.processes:
-        os.kill(p.pid, signal.SIGTERM)
+      self._terminate_processes()
 
     self.notify("Joining workers")
     for p in self.processes: