Files to test triggering the main loop with a periodic signal

loop.py

+import signal, time
+from abc import ABCMeta, abstractmethod
+
+## Code copied from mlp to avoid large dependency. Should be put in smaller package instead
+
+
+class Loop(metaclass=ABCMeta):
+    """
+    Astract Class to allow users to execute self.loop at a given frequency
+    with a timer while self.run can do something else.
+    """
+    def __init__(self, period):
+        self.period = period
+        signal.signal(signal.SIGALRM, self.loop)
+        signal.setitimer(signal.ITIMER_REAL, period, period)
+        self.run()
+
+    def stop(self):
+        signal.setitimer(signal.ITIMER_REAL, 0)
+        raise KeyboardInterrupt  # our self.run is waiting for this.
+
+    def run(self):
+        # Default implementation: don't do anything
+        try:
+            time.sleep(1e9)
+        except KeyboardInterrupt:
+            pass
+
+    @abstractmethod
+    def loop(self, signum, frame):
+        ...

test_loop.py

+import numpy as np
+import time
+from loop import Loop
+
+
+class SimulatorLoop(Loop):
+    """
+    Class used to call pybullet at a given frequency
+    """
+    def __init__(self, period, t_max):
+        """
+        Constructor
+        :param period: the time step
+        :param t_max: maximum simulation time
+        """
+        self.t = 0.0
+        self.t_max = t_max
+        self.period = period
+
+    def trigger(self):
+        super().__init__(self.period)
+
+    def loop(self, signum, frame):
+        self.t += self.period
+        if self.t > self.t_max:
+            self.stop()
+
+        print("- Start loop -")
+        print("- End loop -")
+
+
+if __name__ == "__main__":
+
+    # Start the control loop:
+    sim_loop = SimulatorLoop(1.0, 10.0)
+    sim_loop.trigger()
+
+    print("-- FINAL --")