try to avoid stressing out the cpu by using a proper queue

owrx/wsjt.py

@@ -8,6 +8,7 @@ import os
 from multiprocessing.connection import Pipe
 from owrx.map import Map, LocatorLocation
 import re
+from queue import Queue
 from owrx.config import PropertyManager
 from owrx.bands import Bandplan
 from owrx.metrics import Metrics
@@ -17,6 +18,42 @@ import logging
 logger = logging.getLogger(__name__)
 
 
+class WsjtQueueWorker(threading.Thread):
+    def __init__(self, queue):
+        self.queue = queue
+        self.doRun = True
+        super().__init__(daemon=True)
+
+    def run(self) -> None:
+        while self.doRun:
+            (processor, file) = self.queue.get()
+            logger.debug("processing file %s", file)
+            processor.decode(file)
+            self.queue.task_done()
+
+
+class WsjtQueue(Queue):
+    sharedInstance = None
+
+    @staticmethod
+    def getSharedInstance():
+        if WsjtQueue.sharedInstance is None:
+            WsjtQueue.sharedInstance = WsjtQueue(maxsize=10, workers=2)
+        return WsjtQueue.sharedInstance
+
+    def __init__(self, maxsize, workers):
+        super().__init__(maxsize)
+        self.workers = [self.newWorker() for _ in range(0, workers)]
+
+    def put(self, item):
+        super(WsjtQueue, self).put(item, block=False)
+
+    def newWorker(self):
+        worker = WsjtQueueWorker(self)
+        worker.start()
+        return worker
+
+
 class WsjtChopper(threading.Thread):
     def __init__(self, source):
         self.source = source
@@ -24,7 +61,6 @@ class WsjtChopper(threading.Thread):
         (self.wavefilename, self.wavefile) = self.getWaveFile()
         self.switchingLock = threading.Lock()
         self.scheduler = sched.scheduler(time.time, time.sleep)
-        self.fileQueue = []
         (self.outputReader, self.outputWriter) = Pipe()
         self.doRun = True
         super().__init__()
@@ -67,7 +103,7 @@ class WsjtChopper(threading.Thread):
         self.switchingLock.release()
 
         file.close()
-        self.fileQueue.append(filename)
+        WsjtQueue.getSharedInstance().put((self, filename))
         self._scheduleNextSwitch()
 
     def decoder_commandline(self, file):
@@ -76,23 +112,17 @@ class WsjtChopper(threading.Thread):
         """
         return []
 
-    def decode(self):
-        def decode_and_unlink(file):
-            decoder = subprocess.Popen(self.decoder_commandline(file), stdout=subprocess.PIPE, cwd=self.tmp_dir, preexec_fn=lambda : os.nice(10))
-            while True:
-                line = decoder.stdout.readline()
-                if line is None or (isinstance(line, bytes) and len(line) == 0):
-                    break
-                self.outputWriter.send(line)
-            rc = decoder.wait()
-            if rc != 0:
-                logger.warning("decoder return code: %i", rc)
-            os.unlink(file)
-
-        if self.fileQueue:
-            file = self.fileQueue.pop()
-            logger.debug("processing file {0}".format(file))
-            threading.Thread(target=decode_and_unlink, args=[file]).start()
+    def decode(self, file):
+        decoder = subprocess.Popen(self.decoder_commandline(file), stdout=subprocess.PIPE, cwd=self.tmp_dir, preexec_fn=lambda : os.nice(10))
+        while True:
+            line = decoder.stdout.readline()
+            if line is None or (isinstance(line, bytes) and len(line) == 0):
+                break
+            self.outputWriter.send(line)
+        rc = decoder.wait()
+        if rc != 0:
+            logger.warning("decoder return code: %i", rc)
+        os.unlink(file)
 
     def run(self) -> None:
         logger.debug("WSJT chopper starting up")
@@ -106,7 +136,6 @@ class WsjtChopper(threading.Thread):
                 self.wavefile.writeframes(data)
                 self.switchingLock.release()
 
-            self.decode()
         logger.debug("WSJT chopper shutting down")
         self.outputReader.close()
         self.outputWriter.close()