8000 tools: Add locking to pyboard.py serial port for linux and OSX by dhylands · Pull Request #2256 · micropython/micropython · GitHub
[go: up one dir, main page]
Skip to content

tools: Add locking to pyboard.py serial port for linux and OSX #2256

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 1 commit into from
Closed

tools: Add locking to pyboard.py serial port for linux and OSX #2256

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
92 changes: 92 additions & 0 deletions tools/pyboard.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -116,13 +116,101 @@ def inWaiting(self):
else:
return n_waiting

plat = sys.platform.lower()
if plat[:5] == 'linux':
import os

class SerialFileLock:
LOCK_DIR = '/var/lock'

def __init__(self, dev_name):
self._dev_name = dev_name
self._lockname = self.lockname()

def lockname(self):
os.stat(SerialFileLock.LOCK_DIR) # throws an exception if the directory doesn't exist
dev_name = self._dev_name
if dev_name.startswith('/dev/'):
dev_name = dev_name[5:]
return '{}/LCK..{}'.format(SerialFileLock.LOCK_DIR, dev_name.replace('/', '_'))

def lock(self):
try:
with open(self._lockname, 'rb') as file:
data = file.read(16)
if len(data) == 4:
# old-style - pid is binary
pid = struct.unpack('@i', data)[0]
else:
try:
pid = int(data)
except:
pid = 0
if pid > 0:
try:
os.kill(pid, 0)
self._lockname = None
raise PyboardError("{} is already open by pid {}".format(self._dev_name, pid))
except OSError:
# Process doesn't exist - stale lock file
print('Removing stale lock:', self._lockname)
time.sleep(1)
os.unlink(self._lockname)
except IOError:
# This is the normal path - the lockfile doesn't exist
pass
with open(self._lockname, 'w') as file:
file.write('{}\n'.format(os.getpid()))

def unlock(self):
if self._lockname:
os.unlink(self._lockname)

else:
class SerialFileLock:
def __init__(self, dev_name):
pass
def lock(self):
pass
def unlock(self):
pass

if plat[:6] == 'darwin':
import fcntl

class SerialFlock:

def __init__(self, file, dev_name):
self.file = file
self.dev_name = dev_name

def lock(self):
try:
fcntl.flock(self.file.fileno(), fcntl.LOCK_EX | fcntl.LOCK_NB)
except IOError:
raise PyboardError("{} is already open".format(self.dev_name))

def unlock(self):
fcntl.flock(self.file.fileno(), fcntl.LOCK_UN)
else:
class SerialFlock:
def __init__(self, file, dev_name):
pass
def lock(self):
pass
def unlock(self):
pass


class Pyboard:
def __init__(self, device, baudrate=115200, user='micro', password='python', wait=0):
if device and device[0].isdigit() and device[-1].isdigit() and device.count('.') == 3:
# device looks like an IP address
self.serial = TelnetToSerial(device, user, password, read_timeout=10)
else:
import serial
self.file_lock = SerialFileLock(device)
self.file_lock.lock()
delayed = False
for attempt in range(wait + 1):
try:
Expand All @@ -143,9 +231,13 @@ def __init__(self, device, baudrate=115200, user='micro', password='python', wai
raise PyboardError('failed to access ' + device)
if delayed:
print('')
self.flock = SerialFlock(self.serial, device)
self.flock.lock()

def close(self):
self.flock.unlock()
self.serial.close()
self.file_lock.unlock()

def read_until(self, min_num_bytes, ending, timeout=10, data_consumer=None):
data = self.serial.read(min_num_bytes)
Expand Down
0