Trying to enable multicore PoW with single core as a fallback when it's a problem.

src/proofofwork.py

@@ -3,20 +3,20 @@
 #from multiprocessing import Pool, cpu_count
 import hashlib
 from struct import unpack, pack
-#import sys
+import sys
 #import os
 
 def _set_idle():
+    if 'linux' in sys.platform:
+      import os
+      os.nice(20)
+    else:
       try:
         sys.getwindowsversion()
         import win32api,win32process,win32con
         pid = win32api.GetCurrentProcessId()
         handle = win32api.OpenProcess(win32con.PROCESS_ALL_ACCESS, True, pid)
         win32process.SetPriorityClass(handle, win32process.IDLE_PRIORITY_CLASS)
-    except:
-        try:
-            #Linux
-            os.nice(20)
       except:
         #Windows 64-bit
         pass
@@ -29,25 +29,29 @@ def _pool_worker(nonce, initialHash, target, pool_size):
         trialValue, = unpack('>Q',hashlib.sha512(hashlib.sha512(pack('>Q',nonce) + initialHash).digest()).digest()[0:8])
     return [trialValue, nonce]
 
-def run(target, initialHash):
+def _doSafePoW(target, initialHash):
     nonce = 0
     trialValue = 99999999999999999999
     while trialValue > target:
         nonce += 1
         trialValue, = unpack('>Q',hashlib.sha512(hashlib.sha512(pack('>Q',nonce) + initialHash).digest()).digest()[0:8])
     return [trialValue, nonce]
-    """try:
+
+def _doFastPoW(target, initialHash):
+    import shared
+    import time
+    from multiprocessing import Pool, cpu_count
+    import os    
+    try:
         pool_size = cpu_count()
     except:
         pool_size = 4
-
     try:
         maxCores = config.getint('bitmessagesettings', 'maxcores')
     except:
         maxCores = 99999
     if pool_size > maxCores:
         pool_size = maxCores
-
     pool = Pool(processes=pool_size)
     result = []
     for i in range(pool_size):
@@ -55,12 +59,17 @@ def run(target, initialHash):
     while True:
         if shared.shutdown:
             pool.terminate()
-            time.sleep(5) #Don't return anything (doing so will cause exceptions because we'll return an unusable response). Sit here and wait for this thread to close.
+            pool.join() #Don't return anything (doing so will cause exceptions because we'll return an unusable response). Sit here and wait for this thread to close.
             return
         for i in range(pool_size):
             if result[i].ready():
                 result = result[i].get()
                 pool.terminate()
                 return result[0], result[1]
-        time.sleep(0.2)"""
+        time.sleep(0.2)
 
+def run(target, initialHash):
+    if linux in sys.platform:
+      return _doFastPoW(target, initialHash)
+    else:
+      return _doSafePoW(target, initialHash)