KVM test: kvm_subprocess: minimize the number of modules imported by the server
Rearrange the code (put the server on top) so that the server imports only the
modules it requires. This reduces the startup time of child processes.
Signed-off-by: Michael Goldish <mgoldish@redhat.com>
git-svn-id: http://test.kernel.org/svn/autotest/trunk@3791 592f7852-d20e-0410-864c-8624ca9c26a4
diff --git a/client/tests/kvm/kvm_subprocess.py b/client/tests/kvm/kvm_subprocess.py
index f748586..424c801 100755
--- a/client/tests/kvm/kvm_subprocess.py
+++ b/client/tests/kvm/kvm_subprocess.py
@@ -5,8 +5,187 @@
@copyright: 2008-2009 Red Hat Inc.
"""
-import sys, subprocess, pty, select, os, time, signal, re, termios, fcntl
-import threading, logging, commands
+import os, sys, pty, select, termios, fcntl
+
+
+# The following helper functions are shared by the server and the client.
+
+def _lock(filename):
+ if not os.path.exists(filename):
+ open(filename, "w").close()
+ fd = os.open(filename, os.O_RDWR)
+ fcntl.lockf(fd, fcntl.LOCK_EX)
+ return fd
+
+
+def _unlock(fd):
+ fcntl.lockf(fd, fcntl.LOCK_UN)
+ os.close(fd)
+
+
+def _locked(filename):
+ try:
+ fd = os.open(filename, os.O_RDWR)
+ except:
+ return False
+ try:
+ fcntl.lockf(fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
+ except:
+ os.close(fd)
+ return True
+ fcntl.lockf(fd, fcntl.LOCK_UN)
+ os.close(fd)
+ return False
+
+
+def _wait(filename):
+ fd = _lock(filename)
+ _unlock(fd)
+
+
+def _get_filenames(base_dir, id):
+ return [os.path.join(base_dir, s + id) for s in
+ "shell-pid-", "status-", "output-", "inpipe-",
+ "lock-server-running-", "lock-client-starting-"]
+
+
+def _get_reader_filename(base_dir, id, reader):
+ return os.path.join(base_dir, "outpipe-%s-%s" % (reader, id))
+
+
+# The following is the server part of the module.
+
+if __name__ == "__main__":
+ id = sys.stdin.readline().strip()
+ echo = sys.stdin.readline().strip() == "True"
+ readers = sys.stdin.readline().strip().split(",")
+ command = sys.stdin.readline().strip() + " && echo %s > /dev/null" % id
+
+ # Define filenames to be used for communication
+ base_dir = "/tmp/kvm_spawn"
+ (shell_pid_filename,
+ status_filename,
+ output_filename,
+ inpipe_filename,
+ lock_server_running_filename,
+ lock_client_starting_filename) = _get_filenames(base_dir, id)
+
+ # Populate the reader filenames list
+ reader_filenames = [_get_reader_filename(base_dir, id, reader)
+ for reader in readers]
+
+ # Set $TERM = dumb
+ os.putenv("TERM", "dumb")
+
+ (shell_pid, shell_fd) = pty.fork()
+ if shell_pid == 0:
+ # Child process: run the command in a subshell
+ os.execv("/bin/sh", ["/bin/sh", "-c", command])
+ else:
+ # Parent process
+ lock_server_running = _lock(lock_server_running_filename)
+
+ # Set terminal echo on/off and disable pre- and post-processing
+ attr = termios.tcgetattr(shell_fd)
+ attr[0] &= ~termios.INLCR
+ attr[0] &= ~termios.ICRNL
+ attr[0] &= ~termios.IGNCR
+ attr[1] &= ~termios.OPOST
+ if echo:
+ attr[3] |= termios.ECHO
+ else:
+ attr[3] &= ~termios.ECHO
+ termios.tcsetattr(shell_fd, termios.TCSANOW, attr)
+
+ # Open output file
+ output_file = open(output_filename, "w")
+ # Open input pipe
+ os.mkfifo(inpipe_filename)
+ inpipe_fd = os.open(inpipe_filename, os.O_RDWR)
+ # Open output pipes (readers)
+ reader_fds = []
+ for filename in reader_filenames:
+ os.mkfifo(filename)
+ reader_fds.append(os.open(filename, os.O_RDWR))
+
+ # Write shell PID to file
+ file = open(shell_pid_filename, "w")
+ file.write(str(shell_pid))
+ file.close()
+
+ # Print something to stdout so the client can start working
+ print "Server %s ready" % id
+ sys.stdout.flush()
+
+ # Initialize buffers
+ buffers = ["" for reader in readers]
+
+ # Read from child and write to files/pipes
+ while True:
+ check_termination = False
+ # Make a list of reader pipes whose buffers are not empty
+ fds = [fd for (i, fd) in enumerate(reader_fds) if buffers[i]]
+ # Wait until there's something to do
+ r, w, x = select.select([shell_fd, inpipe_fd], fds, [], 0.5)
+ # If a reader pipe is ready for writing --
+ for (i, fd) in enumerate(reader_fds):
+ if fd in w:
+ bytes_written = os.write(fd, buffers[i])
+ buffers[i] = buffers[i][bytes_written:]
+ # If there's data to read from the child process --
+ if shell_fd in r:
+ try:
+ data = os.read(shell_fd, 16384)
+ except OSError:
+ data = ""
+ if not data:
+ check_termination = True
+ # Remove carriage returns from the data -- they often cause
+ # trouble and are normally not needed
+ data = data.replace("\r", "")
+ output_file.write(data)
+ output_file.flush()
+ for i in range(len(readers)):
+ buffers[i] += data
+ # If os.read() raised an exception or there was nothing to read --
+ if check_termination or shell_fd not in r:
+ pid, status = os.waitpid(shell_pid, os.WNOHANG)
+ if pid:
+ status = os.WEXITSTATUS(status)
+ break
+ # If there's data to read from the client --
+ if inpipe_fd in r:
+ data = os.read(inpipe_fd, 1024)
+ os.write(shell_fd, data)
+
+ # Write the exit status to a file
+ file = open(status_filename, "w")
+ file.write(str(status))
+ file.close()
+
+ # Wait for the client to finish initializing
+ _wait(lock_client_starting_filename)
+
+ # Delete FIFOs
+ for filename in reader_filenames + [inpipe_filename]:
+ try:
+ os.unlink(filename)
+ except OSError:
+ pass
+
+ # Close all files and pipes
+ output_file.close()
+ os.close(inpipe_fd)
+ for fd in reader_fds:
+ os.close(fd)
+
+ _unlock(lock_server_running)
+ exit(0)
+
+
+# The following is the client part of the module.
+
+import subprocess, time, signal, re, threading, logging
import common, kvm_utils
@@ -77,49 +256,6 @@
return (status, output)
-def _lock(filename):
- if not os.path.exists(filename):
- open(filename, "w").close()
- fd = os.open(filename, os.O_RDWR)
- fcntl.lockf(fd, fcntl.LOCK_EX)
- return fd
-
-
-def _unlock(fd):
- fcntl.lockf(fd, fcntl.LOCK_UN)
- os.close(fd)
-
-
-def _locked(filename):
- try:
- fd = os.open(filename, os.O_RDWR)
- except:
- return False
- try:
- fcntl.lockf(fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
- except:
- os.close(fd)
- return True
- fcntl.lockf(fd, fcntl.LOCK_UN)
- os.close(fd)
- return False
-
-
-def _wait(filename):
- fd = _lock(filename)
- _unlock(fd)
-
-
-def _get_filenames(base_dir, id):
- return [os.path.join(base_dir, s + id) for s in
- "shell-pid-", "status-", "output-", "inpipe-",
- "lock-server-running-", "lock-client-starting-"]
-
-
-def _get_reader_filename(base_dir, id, reader):
- return os.path.join(base_dir, "outpipe-%s-%s" % (reader, id))
-
-
class kvm_spawn:
"""
This class is used for spawning and controlling a child process.
@@ -1031,136 +1167,3 @@
internal_timeout,
print_func)
return output
-
-
-# The following is the server part of the module.
-
-def _server_main():
- id = sys.stdin.readline().strip()
- echo = sys.stdin.readline().strip() == "True"
- readers = sys.stdin.readline().strip().split(",")
- command = sys.stdin.readline().strip() + " && echo %s > /dev/null" % id
-
- # Define filenames to be used for communication
- base_dir = "/tmp/kvm_spawn"
- (shell_pid_filename,
- status_filename,
- output_filename,
- inpipe_filename,
- lock_server_running_filename,
- lock_client_starting_filename) = _get_filenames(base_dir, id)
-
- # Populate the reader filenames list
- reader_filenames = [_get_reader_filename(base_dir, id, reader)
- for reader in readers]
-
- # Set $TERM = dumb
- os.putenv("TERM", "dumb")
-
- (shell_pid, shell_fd) = pty.fork()
- if shell_pid == 0:
- # Child process: run the command in a subshell
- os.execv("/bin/sh", ["/bin/sh", "-c", command])
- else:
- # Parent process
- lock_server_running = _lock(lock_server_running_filename)
-
- # Set terminal echo on/off and disable pre- and post-processing
- attr = termios.tcgetattr(shell_fd)
- attr[0] &= ~termios.INLCR
- attr[0] &= ~termios.ICRNL
- attr[0] &= ~termios.IGNCR
- attr[1] &= ~termios.OPOST
- if echo:
- attr[3] |= termios.ECHO
- else:
- attr[3] &= ~termios.ECHO
- termios.tcsetattr(shell_fd, termios.TCSANOW, attr)
-
- # Open output file
- output_file = open(output_filename, "w")
- # Open input pipe
- os.mkfifo(inpipe_filename)
- inpipe_fd = os.open(inpipe_filename, os.O_RDWR)
- # Open output pipes (readers)
- reader_fds = []
- for filename in reader_filenames:
- os.mkfifo(filename)
- reader_fds.append(os.open(filename, os.O_RDWR))
-
- # Write shell PID to file
- file = open(shell_pid_filename, "w")
- file.write(str(shell_pid))
- file.close()
-
- # Print something to stdout so the client can start working
- print "Server %s ready" % id
- sys.stdout.flush()
-
- # Initialize buffers
- buffers = ["" for reader in readers]
-
- # Read from child and write to files/pipes
- while True:
- check_termination = False
- # Make a list of reader pipes whose buffers are not empty
- fds = [fd for (i, fd) in enumerate(reader_fds) if buffers[i]]
- # Wait until there's something to do
- r, w, x = select.select([shell_fd, inpipe_fd], fds, [], 0.5)
- # If a reader pipe is ready for writing --
- for (i, fd) in enumerate(reader_fds):
- if fd in w:
- bytes_written = os.write(fd, buffers[i])
- buffers[i] = buffers[i][bytes_written:]
- # If there's data to read from the child process --
- if shell_fd in r:
- try:
- data = os.read(shell_fd, 16384)
- except OSError:
- data = ""
- if not data:
- check_termination = True
- # Remove carriage returns from the data -- they often cause
- # trouble and are normally not needed
- data = data.replace("\r", "")
- output_file.write(data)
- output_file.flush()
- for i in range(len(readers)):
- buffers[i] += data
- # If os.read() raised an exception or there was nothing to read --
- if check_termination or shell_fd not in r:
- pid, status = os.waitpid(shell_pid, os.WNOHANG)
- if pid:
- status = os.WEXITSTATUS(status)
- break
- # If there's data to read from the client --
- if inpipe_fd in r:
- data = os.read(inpipe_fd, 1024)
- os.write(shell_fd, data)
-
- # Write the exit status to a file
- file = open(status_filename, "w")
- file.write(str(status))
- file.close()
-
- # Wait for the client to finish initializing
- _wait(lock_client_starting_filename)
-
- # Delete FIFOs
- for filename in reader_filenames + [inpipe_filename]:
- try:
- os.unlink(filename)
- except OSError:
- pass
-
- # Close all files and pipes
- output_file.close()
- os.close(inpipe_fd)
- for fd in reader_fds:
- os.close(fd)
-
- _unlock(lock_server_running)
-
-
-if __name__ == "__main__":
- _server_main()