def preRun_(self):
"""After the fork, but before starting the process loop
"""
super().preRun_()
self.client = ShmemRGBClient(name=self.memname,
n_ringbuffer=self.n_ringbuffer,
width=self.image_dimensions[0],
height=self.image_dimensions[1],
mstimeout=self.mstimeout,
verbose=self.verbose)
class ValkkaShmemRGBProcess(ValkkaProcess):
"""An example process, using the valkka shared memory client for RGB images
"""
incoming_signal_defs = { # each key corresponds to a front- and backend methods
"test_": {
"test_int": int,
"test_str": str
},
"stop_": [],
"ping_": {
"message": str
}
}
outgoing_signal_defs = {"pong_o": {"message": str}}
parameter_defs = {
"image_dimensions": (tuple, (1920 // 4, 1080 // 4)),
"n_ringbuffer": (int, 10), # size of the ringbuffer
"memname": str,
"mstimeout": (int, 1000),
"verbose": (bool, False)
}
def __init__(self, name, affinity=-1, **kwargs):
super().__init__(name, affinity)
# check kwargs agains parameter_defs, attach ok'd parameters to this
# object as attributes
parameterInitCheck(ValkkaShmemRGBProcess.parameter_defs, kwargs, self)
typeCheck(self.image_dimensions[0], int)
typeCheck(self.image_dimensions[1], int)
def preRun_(self):
"""After the fork, but before starting the process loop
"""
super().preRun_()
self.client = ShmemRGBClient(name=self.memname,
n_ringbuffer=self.n_ringbuffer,
width=self.image_dimensions[0],
height=self.image_dimensions[1],
mstimeout=self.mstimeout,
verbose=self.verbose)
def postRun_(self):
"""Just before process exit
"""
print(self.pre, "post: bye!")
def cycle_(self):
index, isize = self.client.pull()
if (index is None): # semaphore timed out
print("Semaphore timeout")
else:
print("Current index, size=", index, isize)
print("Payload=", self.client.shmem_list[index][0:min(isize, 10)])
# *** backend methods corresponding to incoming signals ***
def stop_(self):
self.running = False
def test_(self, test_int=0, test_str="nada"):
print(self.pre, "test_ signal received with", test_int, test_str)
def ping_(self, message="nada"):
print(self.pre, "At backend: ping_ received", message,
"sending it back to front")
self.sendSignal_(name="pong_o", message=message)
# ** frontend methods launching incoming signals
def stop(self):
self.sendSignal(name="stop_")
def test(self, **kwargs):
dictionaryCheck(self.incoming_signal_defs["test_"], kwargs)
kwargs["name"] = "test_"
self.sendSignal(**kwargs)
def ping(self, **kwargs):
dictionaryCheck(self.incoming_signal_defs["ping_"], kwargs)
kwargs["name"] = "ping_"
self.sendSignal(**kwargs)
# ** frontend methods handling received outgoing signals ***
def pong_o(self, message="nada"):
print("At frontend: pong got message", message)