Use TCP_NODELAY if supported; Remove file descriptor ops from the tight loop; Cleanup timeout assignment; Split the threaded test suite in native and c to avoid a large number of active Threads affecting results.Add experimental Mysql#socket_type which typically returns 'socket (x)', but may be helpful for debugging purposes.

ext/mysql.c

@@ -269,11 +269,14 @@ static VALUE real_connect(int argc, VALUE* argv, VALUE klass)
 
     myp->handler.reconnect = 0;
     myp->connection = Qtrue;
-    
+
     my_bool was_blocking;
+
     vio_blocking(myp->handler.net.vio, 0, &was_blocking);    
     myp->blocking = vio_is_blocking( myp->handler.net.vio );
 
+    vio_fastsend( myp->handler.net.vio );
+
     myp->query_with_result = Qtrue;
     rb_obj_call_init(obj, argc, argv);
 
@@ -762,6 +765,14 @@ static VALUE socket(VALUE obj)
     return INT2NUM(m->net.fd);
 }
 
+/* socket_type */
+static VALUE socket_type(VALUE obj)
+{
+    MYSQL* m = GetHandler(obj);
+    VALUE description = vio_description( m->net.vio );
+    return NILorSTRING( description );
+}
+
 /* blocking */
 static VALUE blocking(VALUE obj){
   return ( GetMysqlStruct(obj)->blocking ? Qtrue : Qfalse );
@@ -825,28 +836,27 @@ static VALUE async_query(int argc, VALUE* argv, VALUE obj)
 
   send_query(obj,sql);
 
-  if (NIL_P(timeout)) {
+  timeout = ( NIL_P(timeout) ? m->net.read_timeout : INT2NUM(timeout) );
-    timeout = m->net.read_timeout;
-  }
 
   VALUE args[1];
   args[0] = timeout;
 
   struct timeval tv = { tv_sec: timeout, tv_usec: 0 };
 
+  FD_ZERO(&read);
+  FD_SET(m->net.fd, &read);
+
   for(;;) {
-    FD_ZERO(&read);
-    FD_SET(m->net.fd, &read);
       ret = rb_thread_select(m->net.fd + 1, &read, NULL, NULL, &tv);
       if (ret < 0) {
-        rb_sys_fail(0);
+        rb_raise(eMysql, "query: timeout");
       }
               
       if (ret == 0) {
         continue;
       }
 
-      if (readable(1, (VALUE *)args, obj) == Qtrue) {
+      if ( vio_poll_read( m->net.vio, INT2NUM(timeout) ) == 0 ) {
         break;
       }
   }
@@ -2147,6 +2157,7 @@ void Init_mysql(void)
     rb_define_method(cMysql, "readable?", readable, -1);
     rb_define_method(cMysql, "blocking?", blocking, 0);
     rb_define_method(cMysql, "socket", socket, 0);
+    rb_define_method(cMysql, "socket_type", socket_type, 0);
     rb_define_method(cMysql, "refresh", refresh, 1);
     rb_define_method(cMysql, "reload", reload, 0);
     rb_define_method(cMysql, "select_db", select_db, 1);

mysqlplus.gemspec

@@ -15,7 +15,8 @@ Gem::Specification.new do |s|
 		"Rakefile",
 		"lib/mysqlplus.rb",
 		"test/test_helper.rb",
-		"test/threaded_test.rb",
+		"test/native_threaded_test.rb",
+		"test/c_threaded_test.rb",
 		"test/evented_test.rb",
 		"ext/error_const.h",
 		"ext/extconf.rb",

test/c_threaded_test.rb

@@ -1,26 +1,9 @@
 require File.dirname(__FILE__) + '/test_helper'
 
-ThreadedMysqlTest.new( 10, "Threaded, native Ruby, small overhead"  ) do |test|
+ThreadedMysqlTest.new( 10, "Threaded, C, very small overhead"  ) do |test|
   test.setup{ Mysql.real_connect('localhost','root') }
-  test.per_query_overhead = 0.1
+  test.per_query_overhead = 0.005
-  test.run!
+  test.c_async_query = true
-end
-
-ThreadedMysqlTest.new( 10, "Threaded, native Ruby, medium overhead"  ) do |test|
-  test.setup{ Mysql.real_connect('localhost','root') }
-  test.per_query_overhead = 1
-  test.run!
-end
-
-ThreadedMysqlTest.new( 10, "Threaded, native Ruby, large overhead"  ) do |test|
-  test.setup{ Mysql.real_connect('localhost','root') }
-  test.per_query_overhead = 3
-  test.run!
-end
-
-ThreadedMysqlTest.new( 10, "Threaded, native Ruby, random overhead"  ) do |test|
-  test.setup{ Mysql.real_connect('localhost','root') }
-  test.per_query_overhead = :random
   test.run!
 end
 

test/evented_test.rb

@@ -1,5 +1,11 @@
 require File.dirname(__FILE__) + '/test_helper'
 
+EventedMysqlTest.new( 10, "Evented, very small overhead" ) do |test|
+  test.setup{ Mysql.real_connect('localhost','root') }
+  test.per_query_overhead = 0.005
+  test.run!
+end
+
 EventedMysqlTest.new( 10, "Evented, small overhead" ) do |test|
   test.setup{ Mysql.real_connect('localhost','root') }
   test.per_query_overhead = 0.1

test/native_threaded_test.rb

@@ -0,0 +1,31 @@
+require File.dirname(__FILE__) + '/test_helper'
+
+ThreadedMysqlTest.new( 10, "Threaded, native Ruby, very small overhead"  ) do |test|
+  test.setup{ Mysql.real_connect('localhost','root') }
+  test.per_query_overhead = 0.005
+  test.run!
+end
+
+ThreadedMysqlTest.new( 10, "Threaded, native Ruby, small overhead"  ) do |test|
+  test.setup{ Mysql.real_connect('localhost','root') }
+  test.per_query_overhead = 0.1
+  test.run!
+end
+
+ThreadedMysqlTest.new( 10, "Threaded, native Ruby, medium overhead"  ) do |test|
+  test.setup{ Mysql.real_connect('localhost','root') }
+  test.per_query_overhead = 1
+  test.run!
+end
+
+ThreadedMysqlTest.new( 10, "Threaded, native Ruby, large overhead"  ) do |test|
+  test.setup{ Mysql.real_connect('localhost','root') }
+  test.per_query_overhead = 3
+  test.run!
+end
+
+ThreadedMysqlTest.new( 10, "Threaded, native Ruby, random overhead"  ) do |test|
+  test.setup{ Mysql.real_connect('localhost','root') }
+  test.per_query_overhead = :random
+  test.run!
+end

test/test_helper.rb

@@ -13,7 +13,8 @@ class MysqlTest
                 :start,
                 :done,
                 :c_async_query,
-                :per_query_overhead
+                :per_query_overhead,
+                :timeout
   
   def initialize( queries, context = '' )
     @queries = queries
@@ -21,6 +22,7 @@ class MysqlTest
     @done = []
     @c_async_query = false
     @per_query_overhead = 3
+    @timeout = 20
     yield self if block_given?
   end
   
@@ -186,7 +188,7 @@ class ThreadedMysqlTest < MysqlTest
 
           log "sending query on connection #{conn}"
 
-          c_or_native_async_query( @connections[conn], "select sleep(#{@per_query_overhead})" ).each do |result|
+          c_or_native_async_query( @connections[conn], "select sleep(#{@per_query_overhead})", @timeout ).each do |result|
             log "connection #{conn} done"
           end