From 15608bcc06a9b549fef3a5a36f07c4e0e6a55f59 Mon Sep 17 00:00:00 2001
From: Jude Nelson <judecn@gmail.com>
Date: Sun, 12 Mar 2017 22:41:12 -0400
Subject: [PATCH] automatic gc collector

---
 blockstack/blockstackd.py | 70 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)

diff --git a/blockstack/blockstackd.py b/blockstack/blockstackd.py
index d25731376..76693d1b9 100644
--- a/blockstack/blockstackd.py
+++ b/blockstack/blockstackd.py
@@ -46,6 +46,7 @@ import blockstack_zones
 import keylib
 import base64
 import urllib2
+import gc
 import jsonschema
 from jsonschema import ValidationError
 
@@ -82,8 +83,11 @@ from blockstack_client.constants import BLOCKSTACK_TEST
 bitcoind = None
 rpc_server = None
 storage_pusher = None
+gc_thread = None
 has_indexer = True
 
+GC_EVENT_THRESHOLD = 20
+
 def get_bitcoind( new_bitcoind_opts=None, reset=False, new=False ):
    """
    Get or instantiate our bitcoind client.
@@ -270,6 +274,9 @@ class BlockstackdRPCHandler(SimpleXMLRPCRequestHandler):
     proper deserialization.
     """
     def _dispatch(self, method, params):
+        global gc_thread
+        gc_thread.gc_event()
+
         try: 
             con_info = {
                 "client_host": self.client_address[0],
@@ -1657,6 +1664,34 @@ class BlockstackdRPCServer( threading.Thread, object ):
             self.rpc_server.shutdown()
 
 
+class GCThread( threading.Thread ):
+    """
+    Optimistic GC thread
+    """
+    def __init__(self, event_threshold=GC_EVENT_THRESHOLD):
+        threading.Thread.__init__(self)
+        self.running = True
+        self.event_count = 0
+        self.event_threshold = event_threshold
+
+    def run(self):
+        deadline = time.time() + 60
+        while self.running:
+            time.sleep(1.0)
+            if time.time() > deadline or self.event_count > self.event_threshold:
+                gc.collect()
+                deadline = time.time() + 60
+                self.event_count = 0
+
+
+    def signal_stop(self):
+        self.running = False
+
+
+    def gc_event(self):
+        self.event_count += 1
+
+
 class BlockstackStoragePusher( threading.Thread ):
     """
     worker thread to push data into storage providers,
@@ -1875,6 +1910,8 @@ class BlockstackStoragePusher( threading.Thread ):
         """
         Push zonefiles and profiles
         """
+        global gc_thread
+
         self.running = True
         while self.running:
           
@@ -1886,6 +1923,9 @@ class BlockstackStoragePusher( threading.Thread ):
                 time.sleep(1.0)
                 continue
 
+            else:
+                gc_thread.gc_event()                
+
         log.debug("StoragePusher thread exit")
         self.running = False
 
@@ -1939,6 +1979,29 @@ def get_storage_queue_path():
    return os.path.join( working_dir, db_filename )
 
 
+def gc_start():
+    """
+    Start a thread to garbage-collect every 30 seconds.
+    """
+    global gc_thread
+
+    gc_thread = GCThread()
+    log.debug("Optimistic GC thread start")
+    gc_thread.start()
+
+
+def gc_stop():
+    """
+    Stop a the optimistic GC thread
+    """
+    global gc_thread
+
+    log.debug("Shutting down GC thread")
+    gc_thread.signal_stop()
+    gc_thread.join()
+    log.debug("GC thread joined")
+
+
 def storage_start( blockstack_opts ):
     """
     Start the global data-pusher thread
@@ -2286,6 +2349,9 @@ def run_server( foreground=False, expected_snapshots=GENESIS_SNAPSHOT, port=None
     # start storage 
     storage_start( blockstack_opts )
 
+    # start GC 
+    gc_start()
+
     # start API server
     rpc_start(port)
     set_running( True )
@@ -2332,6 +2398,10 @@ def run_server( foreground=False, expected_snapshots=GENESIS_SNAPSHOT, port=None
     log.debug("Stopping storage pusher")
     storage_stop()
 
+    # stopping GC 
+    log.debug("Stopping GC worker")
+    gc_stop()
+
     # close logfile
     if logfile is not None:
         logfile.flush()