r"""
This is a script that can be used to run tests that require multiple
executables to be run e.g. those client-server tests.

Usage:
  python vtkTestDriver.py --process exe1 arg11 arg12 ...
                          --process exe2 arg21 arg22 ...
                          --process ...
"""

import sys
import subprocess

# Extract arguments for each process to execute.
command_lists = []
prev = None
for idx in range(1, len(sys.argv)):
    if sys.argv[idx] == "--process":
        if prev:
            command_lists.append(sys.argv[prev:idx])
        prev = idx+1
if prev <= len(sys.argv):
    command_lists.append(sys.argv[prev:])

procs = []
for cmdlist in command_lists:
    print "Executing '", " ".join(cmdlist), "'"
    proc = subprocess.Popen(cmdlist)
    procs.append(proc)

# Now wait for each of the processes to terminate.
# If ctest times out, it will kill this process and all subprocesses will be
# terminated anyways, so we don't need to handle timeout specially.
for proc in procs:
    proc.wait()

for proc in procs:
    if proc.returncode != 0:
        print "ERROR: A process exited with error. Test will fail."
        sys.exit(1) # error
print "All's well!"

@@ -316,16 +316,28 @@
 bprocess
+%0Aimport time
 %0A%0A# Extr
@@ -693,16 +693,31 @@
    print
+ %3E%3E sys.stderr,
  %22Execut
@@ -806,16 +806,83 @@
 nd(proc)
+%0A    # sleep to ensure that the process starts.%0A    time.sleep(0.1)
 %0A%0A# Now 
@@ -1168,16 +1168,31 @@
    print
+ %3E%3E sys.stderr,
  %22ERROR:

Add a delay between process launches.