PoW can sometimes be shutdown-able

Python and OpenCL PoW now stop when PyBitmessage shutdowns. C PoW needs
additional support in C so it doesn't work there yet.

src/class_singleWorker.py

@@ -89,15 +89,30 @@ class singleWorker(threading.Thread, StoppableThread):
         while shared.shutdown == 0:
             command, data = shared.workerQueue.get()
             if command == 'sendmessage':
+                try:
                     self.sendMsg()
+                except:
+                    pass
             elif command == 'sendbroadcast':
+                try:
                     self.sendBroadcast()
+                except:
+                    pass
             elif command == 'doPOWForMyV2Pubkey':
+                try:
                     self.doPOWForMyV2Pubkey(data)
+                except:
+                    pass
             elif command == 'sendOutOrStoreMyV3Pubkey':
+                try:
                     self.sendOutOrStoreMyV3Pubkey(data)
+                except:
+                    pass
             elif command == 'sendOutOrStoreMyV4Pubkey':
+                try:
                     self.sendOutOrStoreMyV4Pubkey(data)
+                except:
+                    pass
             elif command == 'stopThread':
                 return
             else:

src/openclpow.py

@@ -5,7 +5,7 @@ import hashlib
 import random
 import os
 
-from shared import codePath, safeConfigGetBoolean
+from shared import codePath, safeConfigGetBoolean, shutdown
 from debug import logger
 
 libAvailable = True
@@ -69,7 +69,7 @@ def do_opencl_pow(hash, target):
 	progress = 0
 	globamt = worksize*2000
 
-	while output[0][0] == 0:
+	while output[0][0] == 0 and shutdown == 0:
 		kernel.set_arg(2, pack("<Q", progress))
 		cl.enqueue_nd_range_kernel(queue, kernel, (globamt,), (worksize,))
 		cl.enqueue_read_buffer(queue, dest_buf, output)
@@ -77,6 +77,8 @@ def do_opencl_pow(hash, target):
 		progress += globamt
 		sofar = time.time() - start
 #		logger.debug("Working for %.3fs, %.2f Mh/s", sofar, (progress / sofar) / 1000000)
+	if shutdown != 0:
+		raise Exception ("Interrupted")
 	taken = time.time() - start
 #	logger.debug("Took %d tries.", progress)
 	return output[0][0]

src/proofofwork.py

@@ -29,7 +29,7 @@ def _set_idle():
 def _pool_worker(nonce, initialHash, target, pool_size):
     _set_idle()
     trialValue = float('inf')
-    while trialValue > target:
+    while trialValue > target and shutdown == 0:
         nonce += pool_size
         trialValue, = unpack('>Q',hashlib.sha512(hashlib.sha512(pack('>Q',nonce) + initialHash).digest()).digest()[0:8])
     return [trialValue, nonce]
@@ -38,9 +38,11 @@ def _doSafePoW(target, initialHash):
     logger.debug("Safe PoW start")
     nonce = 0
     trialValue = float('inf')
-    while trialValue > target:
+    while trialValue > target and shutdown == 0:
         nonce += 1
         trialValue, = unpack('>Q',hashlib.sha512(hashlib.sha512(pack('>Q',nonce) + initialHash).digest()).digest()[0:8])
+    if shutdown != 0:
+        raise Exception("Interrupted")
     logger.debug("Safe PoW done")
     return [trialValue, nonce]
 
@@ -65,9 +67,7 @@ def _doFastPoW(target, initialHash):
     while True:
         if shutdown >= 1:
             pool.terminate()
-            while True:
+            raise Exception("Interrupted")
-                time.sleep(10) # Don't let this thread return here; it will return nothing and cause an exception in bitmessagemain.py
-            return
         for i in range(pool_size):
             if result[i].ready():
                 result = result[i].get()
@@ -85,6 +85,8 @@ def _doCPoW(target, initialHash):
     logger.debug("C PoW start")
     nonce = bmpow(out_h, out_m)
     trialValue, = unpack('>Q',hashlib.sha512(hashlib.sha512(pack('>Q',nonce) + initialHash).digest()).digest()[0:8])
+    if shutdown != 0:
+        raise Exception("Interrupted")
     logger.debug("C PoW done")
     return [trialValue, nonce]
 
@@ -99,6 +101,8 @@ def _doGPUPoW(target, initialHash):
         logger.error("Your GPUs (%s) did not calculate correctly, disabling OpenCL. Please report to the developers.", deviceNames)
         openclpow.ctx = False
         raise Exception("GPU did not calculate correctly.")
+    if shutdown != 0:
+        raise Exception("Interrupted")
     logger.debug("GPU PoW done")
     return [trialValue, nonce]
     
@@ -138,11 +142,15 @@ def run(target, initialHash):
         try:
             return _doGPUPoW(target, initialHash)
         except:
+            if shutdown != 0:
+                raise
             pass # fallback
     if bmpow:
         try:
             return _doCPoW(target, initialHash)
         except:
+            if shutdown != 0:
+                raise
             pass # fallback
     if frozen == "macosx_app" or not frozen:
         # on my (Peter Surda) Windows 10, Windows Defender
@@ -152,8 +160,15 @@ def run(target, initialHash):
         try:
             return _doFastPoW(target, initialHash)
         except:
+            if shutdown != 0:
+                raise
             pass #fallback
+    try:
         return _doSafePoW(target, initialHash)
+    except:
+        if shutdown != 0:
+            raise
+        pass #fallback
 
 # init
 bitmsglib = 'bitmsghash.so'