From fa0a61b5d72b70cc7bc3447bc6e40a4ebfa8381f Mon Sep 17 00:00:00 2001
From: Tom Ritchford <tom@swirly.com>
Date: Tue, 28 Jul 2015 13:04:37 -0400
Subject: [PATCH] Revert "Always use co-routines:"

This reverts commit 3d6e76046cfae9f310d5a1ac18f6437d03a98753.
---
 src/ripple/rpc/Yield.h                      |  5 +++++
 src/ripple/rpc/impl/Yield.cpp               |  3 +++
 src/ripple/server/impl/ServerHandlerImp.cpp | 24 +++++++++++++++------
 3 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/src/ripple/rpc/Yield.h b/src/ripple/rpc/Yield.h
index f7e0aaa9e..73dffafbc 100644
--- a/src/ripple/rpc/Yield.h
+++ b/src/ripple/rpc/Yield.h
@@ -78,10 +78,15 @@ private:
 struct YieldStrategy
 {
     enum class Streaming {no, yes};
+    enum class UseCoroutines {no, yes};
 
     /** Is the data streamed, or generated monolithically? */
     Streaming streaming = Streaming::no;
 
+    /** Are results generated in a coroutine?  If this is no, then the code can
+        never yield. */
+    UseCoroutines useCoroutines = UseCoroutines::no;
+
     /** How many bytes do we emit before yielding?  0 means "never yield due to
         number of bytes sent". */
     std::size_t byteYieldCount = 0;
diff --git a/src/ripple/rpc/impl/Yield.cpp b/src/ripple/rpc/impl/Yield.cpp
index c7f3b3fcc..4f4d3a289 100644
--- a/src/ripple/rpc/impl/Yield.cpp
+++ b/src/ripple/rpc/impl/Yield.cpp
@@ -71,6 +71,9 @@ YieldStrategy makeYieldStrategy (Section const& s)
     ys.streaming = get<bool> (s, "streaming") ?
             YieldStrategy::Streaming::yes :
             YieldStrategy::Streaming::no;
+    ys.useCoroutines = get<bool> (s, "use_coroutines") ?
+            YieldStrategy::UseCoroutines::yes :
+            YieldStrategy::UseCoroutines::no;
     ys.byteYieldCount = get<std::size_t> (s, "byte_yield_count");
     ys.accountYieldCount = get<std::size_t> (s, "account_yield_count");
     ys.transactionYieldCount = get<std::size_t> (s, "transaction_yield_count");
diff --git a/src/ripple/server/impl/ServerHandlerImp.cpp b/src/ripple/server/impl/ServerHandlerImp.cpp
index 565bef5f8..c63e3249b 100644
--- a/src/ripple/server/impl/ServerHandlerImp.cpp
+++ b/src/ripple/server/impl/ServerHandlerImp.cpp
@@ -180,12 +180,24 @@ ServerHandlerImp::onRequest (HTTP::Session& session)
 
     auto detach = session.detach();
 
-    RPC::SuspendCallback suspend (
-        [this, detach] (RPC::Suspend const& suspend) {
-            processSession (detach, suspend);
-        });
-    RPC::Coroutine coroutine (suspend);
-    coroutine.run();
+    if (setup_.yieldStrategy.useCoroutines ==
+        RPC::YieldStrategy::UseCoroutines::yes)
+    {
+        RPC::SuspendCallback suspend (
+            [this, detach] (RPC::Suspend const& suspend) {
+                processSession (detach, suspend);
+            });
+        RPC::Coroutine coroutine (suspend);
+        coroutine.run();
+    }
+    else
+    {
+        getApp().getJobQueue().addJob (
+            jtCLIENT, "RPC-Client",
+            [=] (Job&) {
+                processSession (detach, RPC::Suspend());
+            });
+    }
 }
 
 void