Revert "Allow nested calls to completion handler when using yield_context."

This reverts commit 81242906a5b7dd169667a3a07552d775a7e8662d.

asio/include/asio/impl/spawn.hpp

diff --git a/asio/include/asio/impl/spawn.hpp b/asio/include/asio/impl/spawn.hpp
index 2efc1f9..036b66f 100644
--- a/asio/include/asio/impl/spawn.hpp
+++ b/asio/include/asio/impl/spawn.hpp
@@ -19,7 +19,6 @@
 #include "asio/associated_allocator.hpp"
 #include "asio/associated_executor.hpp"
 #include "asio/async_result.hpp"
-#include "asio/detail/atomic_count.hpp"
 #include "asio/detail/handler_alloc_helpers.hpp"
 #include "asio/detail/handler_cont_helpers.hpp"
 #include "asio/detail/handler_invoke_helpers.hpp"
@@ -42,7 +41,6 @@
       : coro_(ctx.coro_.lock()),
         ca_(ctx.ca_),
         handler_(ctx.handler_),
-        ready_(0),
         ec_(ctx.ec_),
         value_(0)
     {
@@ -52,23 +50,20 @@
     {
       *ec_ = asio::error_code();
       *value_ = ASIO_MOVE_CAST(T)(value);
-      if (--*ready_ == 0)
-        (*coro_)();
+      (*coro_)();
     }
 
     void operator()(asio::error_code ec, T value)
     {
       *ec_ = ec;
       *value_ = ASIO_MOVE_CAST(T)(value);
-      if (--*ready_ == 0)
-        (*coro_)();
+      (*coro_)();
     }
 
   //private:
     shared_ptr<typename basic_yield_context<Handler>::callee_type> coro_;
     typename basic_yield_context<Handler>::caller_type& ca_;
     Handler handler_;
-    atomic_count* ready_;
     asio::error_code* ec_;
     T* value_;
   };
@@ -81,7 +76,6 @@
       : coro_(ctx.coro_.lock()),
         ca_(ctx.ca_),
         handler_(ctx.handler_),
-        ready_(0),
         ec_(ctx.ec_)
     {
     }
@@ -89,22 +83,19 @@
     void operator()()
     {
       *ec_ = asio::error_code();
-      if (--*ready_ == 0)
-        (*coro_)();
+      (*coro_)();
     }
 
     void operator()(asio::error_code ec)
     {
       *ec_ = ec;
-      if (--*ready_ == 0)
-        (*coro_)();
+      (*coro_)();
     }
 
   //private:
     shared_ptr<typename basic_yield_context<Handler>::callee_type> coro_;
     typename basic_yield_context<Handler>::caller_type& ca_;
     Handler handler_;
-    atomic_count* ready_;
     asio::error_code* ec_;
   };
 
@@ -184,10 +175,8 @@
 
   explicit async_result(detail::coro_handler<Handler, T>& h)
     : handler_(h),
-      ca_(h.ca_),
-      ready_(2)
+      ca_(h.ca_)
   {
-    h.ready_ = &ready_;
     out_ec_ = h.ec_;
     if (!out_ec_) h.ec_ = &ec_;
     h.value_ = &value_;
@@ -196,8 +185,7 @@
   type get()
   {
     handler_.coro_.reset(); // Must not hold shared_ptr to coro while suspended.
-    if (--ready_ != 0)
-      ca_();
+    ca_();
     if (!out_ec_ && ec_) throw asio::system_error(ec_);
     return ASIO_MOVE_CAST(type)(value_);
   }
@@ -205,7 +193,6 @@
 private:
   detail::coro_handler<Handler, T>& handler_;
   typename basic_yield_context<Handler>::caller_type& ca_;
-  detail::atomic_count ready_;
   asio::error_code* out_ec_;
   asio::error_code ec_;
   type value_;
@@ -219,10 +206,8 @@
 
   explicit async_result(detail::coro_handler<Handler, void>& h)
     : handler_(h),
-      ca_(h.ca_),
-      ready_(2)
+      ca_(h.ca_)
   {
-    h.ready_ = &ready_;
     out_ec_ = h.ec_;
     if (!out_ec_) h.ec_ = &ec_;
   }
@@ -230,15 +215,13 @@
   void get()
   {
     handler_.coro_.reset(); // Must not hold shared_ptr to coro while suspended.
-    if (--ready_ != 0)
-      ca_();
+    ca_();
     if (!out_ec_ && ec_) throw asio::system_error(ec_);
   }
 
 private:
   detail::coro_handler<Handler, void>& handler_;
   typename basic_yield_context<Handler>::caller_type& ca_;
-  detail::atomic_count ready_;
   asio::error_code* out_ec_;
   asio::error_code ec_;
 };

asio/include/asio/version.hpp

diff --git a/asio/include/asio/version.hpp b/asio/include/asio/version.hpp
index 9def83c..9a32f59 100644
--- a/asio/include/asio/version.hpp
+++ b/asio/include/asio/version.hpp
@@ -18,6 +18,6 @@
 // ASIO_VERSION % 100 is the sub-minor version
 // ASIO_VERSION / 100 % 1000 is the minor version
 // ASIO_VERSION / 100000 is the major version
-#define ASIO_VERSION 101100 // 1.11.0
+#define ASIO_VERSION 101004 // 1.10.4
 
 #endif // ASIO_VERSION_HPP