[Boost-commit] svn:boost r54845 - trunk/boost/asio/detail

Subject: [Boost-commit] svn:boost r54845 - trunk/boost/asio/detail
From: chris_at_[hidden]
Date: 2009-07-09 18:58:26

Author: chris_kohlhoff
Date: 2009-07-09 18:58:26 EDT (Thu, 09 Jul 2009)
New Revision: 54845
URL: http://svn.boost.org/trac/boost/changeset/54845

Log:
Don't write to /dev/poll descriptor when there are no pending changes.

Text files modified: 
   trunk/boost/asio/detail/dev_poll_reactor.hpp |    29 ++++++++++++++++-------------           
   1 files changed, 16 insertions(+), 13 deletions(-)

Modified: trunk/boost/asio/detail/dev_poll_reactor.hpp
==============================================================================
--- trunk/boost/asio/detail/dev_poll_reactor.hpp	(original)
+++ trunk/boost/asio/detail/dev_poll_reactor.hpp	2009-07-09 18:58:26 EDT (Thu, 09 Jul 2009)
@@ -366,23 +366,26 @@
 
     // Write the pending event registration changes to the /dev/poll descriptor.
     std::size_t events_size = sizeof(::pollfd) * pending_event_changes_.size();
-    errno = 0;
-    int result = ::write(dev_poll_fd_,
-        &pending_event_changes_[0], events_size);
-    if (result != static_cast<int>(events_size))
+    if (events_size > 0)
     {
-      for (std::size_t i = 0; i < pending_event_changes_.size(); ++i)
+      errno = 0;
+      int result = ::write(dev_poll_fd_,
+          &pending_event_changes_[0], events_size);
+      if (result != static_cast<int>(events_size))
       {
-        int descriptor = pending_event_changes_[i].fd;
-        boost::system::error_code ec = boost::system::error_code(
-            errno, boost::asio::error::get_system_category());
-        read_op_queue_.perform_all_operations(descriptor, ec);
-        write_op_queue_.perform_all_operations(descriptor, ec);
-        except_op_queue_.perform_all_operations(descriptor, ec);
+        for (std::size_t i = 0; i < pending_event_changes_.size(); ++i)
+        {
+          int descriptor = pending_event_changes_[i].fd;
+          boost::system::error_code ec = boost::system::error_code(
+              errno, boost::asio::error::get_system_category());
+          read_op_queue_.perform_all_operations(descriptor, ec);
+          write_op_queue_.perform_all_operations(descriptor, ec);
+          except_op_queue_.perform_all_operations(descriptor, ec);
+        }
       }
+      pending_event_changes_.clear();
+      pending_event_change_index_.clear();
     }
-    pending_event_changes_.clear();
-    pending_event_change_index_.clear();
 
     int timeout = block ? get_timeout() : 0;
     wait_in_progress_ = true;