mirror of https://github.com/joan2937/pigpio
Address #189 ensuring socket locks are released
The code previous assume exception-free execution of critical blocks between lock acquire() and lock release(); however, in Python exceptions can be thrown in many situations which would then result in a dead-lock of the entire program using pigpio. This is resolved by using the acquire/try/finally/release pattern to ensure that the lock is always released, even when an exception occurs. Also addresses #186, but takes a slightly different approach by using RLock to handle the nested lock requirement, which overall should be safer because it handles additional situations that can cause a deadlock.
This commit is contained in:
Michael
parent
8996b7eaca
commit
fb081b7cf6
326
pigpio.py
326
pigpio.py
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@ -860,7 +860,7 @@ class _socklock:
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"""
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def __init__(self):
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self.s = None
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self.l = threading.Lock()
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self.l = threading.RLock()
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class error(Exception):
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"""pigpio module exception"""
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@ -970,7 +970,7 @@ def _u2i(uint32):
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raise error(error_text(v))
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return v
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def _pigpio_command(sl, cmd, p1, p2, rl=True):
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def _pigpio_command(sl, cmd, p1, p2):
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"""
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Runs a pigpio socket command.
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@ -980,12 +980,14 @@ def _pigpio_command(sl, cmd, p1, p2, rl=True):
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p2:= command parameter 2 (if applicable).
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"""
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sl.l.acquire()
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sl.s.send(struct.pack('IIII', cmd, p1, p2, 0))
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dummy, res = struct.unpack('12sI', sl.s.recv(_SOCK_CMD_LEN))
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if rl: sl.l.release()
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try:
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sl.s.send(struct.pack('IIII', cmd, p1, p2, 0))
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dummy, res = struct.unpack('12sI', sl.s.recv(_SOCK_CMD_LEN))
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finally:
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sl.l.release()
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return res
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def _pigpio_command_ext(sl, cmd, p1, p2, p3, extents, rl=True):
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def _pigpio_command_ext(sl, cmd, p1, p2, p3, extents):
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"""
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Runs an extended pigpio socket command.
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@ -1003,9 +1005,11 @@ def _pigpio_command_ext(sl, cmd, p1, p2, p3, extents, rl=True):
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else:
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ext.extend(x)
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sl.l.acquire()
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sl.s.sendall(ext)
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dummy, res = struct.unpack('12sI', sl.s.recv(_SOCK_CMD_LEN))
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if rl: sl.l.release()
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try:
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sl.s.sendall(ext)
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dummy, res = struct.unpack('12sI', sl.s.recv(_SOCK_CMD_LEN))
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finally:
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sl.l.release()
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return res
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class _event_ADT:
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@ -2854,13 +2858,15 @@ class pi():
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# process read failure
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...
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"""
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# Don't raise exception. Must release lock.
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bytes = u2i(_pigpio_command(self.sl, _PI_CMD_I2CRK, handle, reg, False))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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self.sl.l.release()
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self.sl.l.acquire()
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try:
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bytes = u2i(_pigpio_command(self.sl, _PI_CMD_I2CRK, handle, reg))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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finally:
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self.sl.l.release()
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return bytes, data
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def i2c_block_process_call(self, handle, reg, data):
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@ -2904,14 +2910,16 @@ class pi():
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## extension ##
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# s len data bytes
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# Don't raise exception. Must release lock.
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bytes = u2i(_pigpio_command_ext(
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self.sl, _PI_CMD_I2CPK, handle, reg, len(data), [data], False))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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self.sl.l.release()
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self.sl.l.acquire()
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try:
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bytes = u2i(_pigpio_command_ext(
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self.sl, _PI_CMD_I2CPK, handle, reg, len(data), [data]))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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finally:
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self.sl.l.release()
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return bytes, data
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def i2c_write_i2c_block_data(self, handle, reg, data):
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@ -2982,14 +2990,16 @@ class pi():
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# I count
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extents = [struct.pack("I", count)]
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# Don't raise exception. Must release lock.
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bytes = u2i(_pigpio_command_ext(
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self.sl, _PI_CMD_I2CRI, handle, reg, 4, extents, False))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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self.sl.l.release()
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self.sl.l.acquire()
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try:
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bytes = u2i(_pigpio_command_ext(
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self.sl, _PI_CMD_I2CRI, handle, reg, 4, extentse))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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finally:
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self.sl.l.release()
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return bytes, data
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def i2c_read_device(self, handle, count):
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@ -3013,14 +3023,16 @@ class pi():
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(count, data) = pi.i2c_read_device(h, 12)
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...
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"""
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# Don't raise exception. Must release lock.
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bytes = u2i(
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_pigpio_command(self.sl, _PI_CMD_I2CRD, handle, count, False))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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self.sl.l.release()
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self.sl.l.acquire()
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try:
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bytes = u2i(
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_pigpio_command(self.sl, _PI_CMD_I2CRD, handle, count))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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finally:
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self.sl.l.release()
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return bytes, data
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def i2c_write_device(self, handle, data):
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@ -3115,14 +3127,16 @@ class pi():
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## extension ##
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# s len data bytes
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# Don't raise exception. Must release lock.
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bytes = u2i(_pigpio_command_ext(
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self.sl, _PI_CMD_I2CZ, handle, 0, len(data), [data], False))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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self.sl.l.release()
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self.sl.l.acquire()
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try:
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bytes = u2i(_pigpio_command_ext(
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self.sl, _PI_CMD_I2CZ, handle, 0, len(data), [data]))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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finally:
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self.sl.l.release()
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return bytes, data
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@ -3284,14 +3298,16 @@ class pi():
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## extension ##
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# s len data bytes
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# Don't raise exception. Must release lock.
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bytes = u2i(_pigpio_command_ext(
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self.sl, _PI_CMD_BSPIX, CS, 0, len(data), [data], False))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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self.sl.l.release()
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self.sl.l.acquire()
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try:
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bytes = u2i(_pigpio_command_ext(
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self.sl, _PI_CMD_BSPIX, CS, 0, len(data), [data]))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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finally:
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self.sl.l.release()
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return bytes, data
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@ -3421,14 +3437,16 @@ class pi():
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## extension ##
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# s len data bytes
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# Don't raise exception. Must release lock.
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bytes = u2i(_pigpio_command_ext(
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self.sl, _PI_CMD_BI2CZ, SDA, 0, len(data), [data], False))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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self.sl.l.release()
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self.sl.l.acquire()
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try:
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bytes = u2i(_pigpio_command_ext(
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self.sl, _PI_CMD_BI2CZ, SDA, 0, len(data), [data]))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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finally:
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self.sl.l.release()
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return bytes, data
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def event_trigger(self, event):
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@ -3551,19 +3569,21 @@ class pi():
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## extension ##
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# s len data bytes
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# Don't raise exception. Must release lock.
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bytes = u2i(_pigpio_command_ext(
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self.sl, _PI_CMD_BSCX, bsc_control, 0, len(data), [data], False))
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if bytes > 0:
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rx = self._rxbuf(bytes)
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status = struct.unpack('I', rx[0:4])[0]
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bytes -= 4
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data = rx[4:]
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else:
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status = bytes
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bytes = 0
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data = bytearray(b'')
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self.sl.l.release()
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self.sl.l.acquire()
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try:
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bytes = u2i(_pigpio_command_ext(
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self.sl, _PI_CMD_BSCX, bsc_control, 0, len(data), [data]))
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if bytes > 0:
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rx = self._rxbuf(bytes)
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status = struct.unpack('I', rx[0:4])[0]
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bytes -= 4
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data = rx[4:]
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else:
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status = bytes
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bytes = 0
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data = bytearray(b'')
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finally:
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self.sl.l.release()
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return status, bytes, data
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def bsc_i2c(self, i2c_address, data=[]):
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@ -3818,14 +3838,16 @@ class pi():
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# error path
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...
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"""
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# Don't raise exception. Must release lock.
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bytes = u2i(_pigpio_command(
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self.sl, _PI_CMD_SPIR, handle, count, False))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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self.sl.l.release()
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self.sl.l.acquire()
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try:
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bytes = u2i(_pigpio_command(
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self.sl, _PI_CMD_SPIR, handle, count))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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finally:
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self.sl.l.release()
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return bytes, data
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def spi_write(self, handle, data):
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@ -3882,14 +3904,16 @@ class pi():
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## extension ##
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# s len data bytes
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# Don't raise exception. Must release lock.
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bytes = u2i(_pigpio_command_ext(
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self.sl, _PI_CMD_SPIX, handle, 0, len(data), [data], False))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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self.sl.l.release()
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self.sl.l.acquire()
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try:
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bytes = u2i(_pigpio_command_ext(
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self.sl, _PI_CMD_SPIX, handle, 0, len(data), [data]))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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finally:
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self.sl.l.release()
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return bytes, data
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def serial_open(self, tty, baud, ser_flags=0):
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@ -3988,14 +4012,16 @@ class pi():
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# process read data
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...
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"""
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# Don't raise exception. Must release lock.
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bytes = u2i(
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_pigpio_command(self.sl, _PI_CMD_SERR, handle, count, False))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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self.sl.l.release()
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self.sl.l.acquire()
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try:
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bytes = u2i(
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_pigpio_command(self.sl, _PI_CMD_SERR, handle, count))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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finally:
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self.sl.l.release()
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return bytes, data
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def serial_write(self, handle, data):
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@ -4217,18 +4243,20 @@ class pi():
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(s, pars) = pi.script_status(sid)
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...
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"""
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# Don't raise exception. Must release lock.
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bytes = u2i(
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_pigpio_command(self.sl, _PI_CMD_PROCP, script_id, 0, False))
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if bytes > 0:
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data = self._rxbuf(bytes)
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pars = struct.unpack('11i', _str(data))
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status = pars[0]
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params = pars[1:]
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else:
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status = bytes
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params = ()
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self.sl.l.release()
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self.sl.l.acquire()
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try:
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bytes = u2i(
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_pigpio_command(self.sl, _PI_CMD_PROCP, script_id, 0))
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if bytes > 0:
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data = self._rxbuf(bytes)
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pars = struct.unpack('11i', _str(data))
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status = pars[0]
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params = pars[1:]
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else:
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status = bytes
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params = ()
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finally:
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self.sl.l.release()
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return status, params
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def stop_script(self, script_id):
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@ -4308,14 +4336,16 @@ class pi():
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(count, data) = pi.bb_serial_read(4)
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...
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"""
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# Don't raise exception. Must release lock.
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bytes = u2i(
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_pigpio_command(self.sl, _PI_CMD_SLR, user_gpio, 10000, False))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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self.sl.l.release()
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self.sl.l.acquire()
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try:
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bytes = u2i(
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_pigpio_command(self.sl, _PI_CMD_SLR, user_gpio, 10000))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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finally:
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self.sl.l.release()
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return bytes, data
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|
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@ -4410,14 +4440,16 @@ class pi():
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## extension ##
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# s len argx bytes
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# Don't raise exception. Must release lock.
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bytes = u2i(_pigpio_command_ext(
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self.sl, _PI_CMD_CF2, arg1, retMax, len(argx), [argx], False))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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self.sl.l.release()
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self.sl.l.acquire()
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try:
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bytes = u2i(_pigpio_command_ext(
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self.sl, _PI_CMD_CF2, arg1, retMax, len(argx), [argx]))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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finally:
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self.sl.l.release()
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return bytes, data
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def get_pad_strength(self, pad):
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|
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@ -4610,14 +4642,16 @@ class pi():
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# process read data
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...
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"""
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# Don't raise exception. Must release lock.
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bytes = u2i(
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_pigpio_command(self.sl, _PI_CMD_FR, handle, count, False))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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self.sl.l.release()
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self.sl.l.acquire()
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try:
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bytes = u2i(
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_pigpio_command(self.sl, _PI_CMD_FR, handle, count))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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finally:
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self.sl.l.release()
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return bytes, data
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def file_write(self, handle, data):
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|
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@ -4716,14 +4750,16 @@ class pi():
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## extension ##
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# s len data bytes
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# Don't raise exception. Must release lock.
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bytes = u2i(_pigpio_command_ext(
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self.sl, _PI_CMD_FL, 60000, 0, len(fpattern), [fpattern], False))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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self.sl.l.release()
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self.sl.l.acquire()
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try:
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bytes = u2i(_pigpio_command_ext(
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self.sl, _PI_CMD_FL, 60000, 0, len(fpattern), [fpattern]))
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if bytes > 0:
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data = self._rxbuf(bytes)
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else:
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data = ""
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finally:
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self.sl.l.release()
|
||||
return bytes, data
|
||||
|
||||
def shell(self, shellscr, pstring=""):
|
||||
|
|
|
|||
Loading…
Reference in New Issue