def execv(filename, args):
# Create an O_TEMPORARY file and pass its name to the slave process.
# When this master process dies, the file will be deleted and the
# slave process will know to terminate.
try:
tdir = environ["TEMP"]
except:
tdir = None
if tdir:
try:
nt.mkdir(pathjoin(tdir, "esky-slave-procs"), 0600)
except EnvironmentError:
pass
if exists(pathjoin(tdir, "esky-slave-procs")):
flags = nt.O_CREAT | nt.O_EXCL | nt.O_TEMPORARY | nt.O_NOINHERIT
for i in xrange(10):
tfilenm = "slave-%d.%d.txt" % (nt.getpid(), i)
tfilenm = pathjoin(tdir, "esky-slave-procs", tfilenm)
try:
os_open(tfilenm, flags, 0600)
args.insert(1, tfilenm)
args.insert(1, "--esky-slave-proc")
break
except EnvironmentError:
pass
# Ensure all arguments are quoted (to allow spaces in paths)
for i, arg in enumerate(args):
if arg[0] != '"' and args[-1] != '"':
args[i] = '"{}"'.format(arg)
res = spawnv(P_WAIT, filename, args)
_exit_code[0] = res
raise SystemExit(res)
def lock_version_dir(vdir):
"""Lock the given version dir so it cannot be uninstalled."""
if sys.platform == "win32":
# On win32, we just hold bootstrap file open for reading.
# This will prevent it from being renamed during uninstall.
lockfile = pathjoin(vdir, ESKY_CONTROL_DIR, "bootstrap-manifest.txt")
_locked_version_dirs.setdefault(vdir, []).append(os_open(lockfile, 0, 0))
else:
# On posix platforms we take a shared flock on esky-files/lockfile.txt.
# While fcntl.fcntl locks are apparently the new hotness, they have
# unfortunate semantics that we don't want for this application:
# * not inherited across fork()
# * released when closing *any* fd associated with that file
# fcntl.flock doesn't have these problems, but may fail on NFS.
# To complicate matters, python sometimes emulates flock with fcntl!
# We therefore use a separate lock file to avoid unpleasantness.
lockfile = pathjoin(vdir, ESKY_CONTROL_DIR, "lockfile.txt")
f = os_open(lockfile, 0, 0)
_locked_version_dirs.setdefault(vdir, []).append(f)
fcntl.flock(f, fcntl.LOCK_SH)
def lock_version_dir(vdir):
"""Lock the given version dir so it cannot be uninstalled."""
if sys.platform == "win32":
# On win32, we just hold bootstrap file open for reading.
# This will prevent it from being renamed during uninstall.
lockfile = pathjoin(vdir,ESKY_CONTROL_DIR,"bootstrap-manifest.txt")
_locked_version_dirs.setdefault(vdir,[]).append(os_open(lockfile,0,0))
else:
# On posix platforms we take a shared flock on esky-files/lockfile.txt.
# While fcntl.fcntl locks are apparently the new hotness, they have
# unfortunate semantics that we don't want for this application:
# * not inherited across fork()
# * released when closing *any* fd associated with that file
# fcntl.flock doesn't have these problems, but may fail on NFS.
# To complicate matters, python sometimes emulates flock with fcntl!
# We therefore use a separate lock file to avoid unpleasantness.
lockfile = pathjoin(vdir,ESKY_CONTROL_DIR,"lockfile.txt")
f = os_open(lockfile,0,0)
_locked_version_dirs.setdefault(vdir,[]).append(f)
fcntl.flock(f,fcntl.LOCK_SH)
