From f4404d7b5bed29972d7977ef60f305842a740c8a Mon Sep 17 00:00:00 2001
From: Simon <simon@bitcartel.com>
Date: Fri, 11 Nov 2016 14:39:28 -0800
Subject: [PATCH] Closes #1680, temporary fix for rpc deadlock inherited from
 upstream.

---
 qa/rpc-tests/httpbasics.py | 25 ++++++++++---------------
 src/init.cpp               |  5 ++++-
 src/rpcserver.cpp          |  6 ++++++
 3 files changed, 20 insertions(+), 16 deletions(-)

diff --git a/qa/rpc-tests/httpbasics.py b/qa/rpc-tests/httpbasics.py
index 64ba49df6..21c7b1f8b 100755
--- a/qa/rpc-tests/httpbasics.py
+++ b/qa/rpc-tests/httpbasics.py
@@ -38,13 +38,9 @@ class HTTPBasicsTest (BitcoinTestFramework):
         conn.request('POST', '/', '{"method": "getbestblockhash"}', headers)
         out1 = conn.getresponse().read();
         assert_equal('"error":null' in out1, True)
-        assert_equal(conn.sock!=None, True) #according to http/1.1 connection must still be open!
-        
-        #send 2nd request without closing connection
-        conn.request('POST', '/', '{"method": "getchaintips"}', headers)
-        out2 = conn.getresponse().read();
-        assert_equal('"error":null' in out1, True) #must also response with a correct json-rpc message
-        assert_equal(conn.sock!=None, True) #according to http/1.1 connection must still be open!
+
+        # TODO #1856: Re-enable support for persistent connections.
+        assert_equal(conn.sock!=None, False)
         conn.close()
         
         #same should be if we add keep-alive because this should be the std. behaviour
@@ -55,13 +51,9 @@ class HTTPBasicsTest (BitcoinTestFramework):
         conn.request('POST', '/', '{"method": "getbestblockhash"}', headers)
         out1 = conn.getresponse().read();
         assert_equal('"error":null' in out1, True)
-        assert_equal(conn.sock!=None, True) #according to http/1.1 connection must still be open!
-        
-        #send 2nd request without closing connection
-        conn.request('POST', '/', '{"method": "getchaintips"}', headers)
-        out2 = conn.getresponse().read();
-        assert_equal('"error":null' in out1, True) #must also response with a correct json-rpc message
-        assert_equal(conn.sock!=None, True) #according to http/1.1 connection must still be open!
+
+        # TODO #1856: Re-enable support for persistent connections.
+        assert_equal(conn.sock!=None, False)
         conn.close()
         
         #now do the same with "Connection: close"
@@ -96,7 +88,10 @@ class HTTPBasicsTest (BitcoinTestFramework):
         conn.request('POST', '/', '{"method": "getbestblockhash"}', headers)
         out1 = conn.getresponse().read();
         assert_equal('"error":null' in out1, True)
-        assert_equal(conn.sock!=None, True) #connection must be closed because bitcoind should use keep-alive by default
+
+        # TODO #1856: Re-enable support for persistent connections.
+        assert_equal(conn.sock!=None, False)
+        conn.close()
         
 if __name__ == '__main__':
     HTTPBasicsTest ().main ()
diff --git a/src/init.cpp b/src/init.cpp
index 3e1a22373..5163db5de 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -425,7 +425,10 @@ std::string HelpMessage(HelpMessageMode mode)
     strUsage += HelpMessageOpt("-rpcport=<port>", strprintf(_("Listen for JSON-RPC connections on <port> (default: %u or testnet: %u)"), 8232, 18232));
     strUsage += HelpMessageOpt("-rpcallowip=<ip>", _("Allow JSON-RPC connections from specified source. Valid for <ip> are a single IP (e.g. 1.2.3.4), a network/netmask (e.g. 1.2.3.4/255.255.255.0) or a network/CIDR (e.g. 1.2.3.4/24). This option can be specified multiple times"));
     strUsage += HelpMessageOpt("-rpcthreads=<n>", strprintf(_("Set the number of threads to service RPC calls (default: %d)"), 4));
-    strUsage += HelpMessageOpt("-rpckeepalive", strprintf(_("RPC support for HTTP persistent connections (default: %d)"), 1));
+
+    // TODO #1856: Re-enable support for persistent connections.
+    // Disabled to avoid rpc deadlock #1680, until we backport upstream changes which replace boost::asio with libevent, or another solution is implemented.
+    //strUsage += HelpMessageOpt("-rpckeepalive", strprintf(_("RPC support for HTTP persistent connections (default: %d)"), 1));
 
     // Disabled until we can lock notes and also tune performance of libsnark which by default uses multiple threads
     //strUsage += HelpMessageOpt("-rpcasyncthreads=<n>", strprintf(_("Set the number of threads to service Async RPC calls (default: %d)"), 1));
diff --git a/src/rpcserver.cpp b/src/rpcserver.cpp
index b990f2040..0418d7519 100644
--- a/src/rpcserver.cpp
+++ b/src/rpcserver.cpp
@@ -1025,9 +1025,15 @@ void ServiceConnection(AcceptedConnection *conn)
         // Read HTTP message headers and body
         ReadHTTPMessage(conn->stream(), mapHeaders, strRequest, nProto, MAX_SIZE);
 
+        // TODO #1856: Re-enable support for persistent connections.
+        // We have disabled support for HTTP Keep-Alive until resolution of #1680, upstream rpc deadlock.
+        // Close connection immediately.
+        fRun = false;
+        /*
         // HTTP Keep-Alive is false; close connection immediately
         if ((mapHeaders["connection"] == "close") || (!GetBoolArg("-rpckeepalive", true)))
             fRun = false;
+        */
 
         // Process via JSON-RPC API
         if (strURI == "/") {