diff options
Diffstat (limited to 'docs/tutorials/007/page07.html')
| -rw-r--r-- | docs/tutorials/007/page07.html | 119 |
1 files changed, 0 insertions, 119 deletions
diff --git a/docs/tutorials/007/page07.html b/docs/tutorials/007/page07.html deleted file mode 100644 index 7b31b7d09e7..00000000000 --- a/docs/tutorials/007/page07.html +++ /dev/null @@ -1,119 +0,0 @@ -<HTML> -<HEAD> - <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> - <META NAME="GENERATOR" CONTENT="Mozilla/4.04 [en] (X11; I; Linux 2.0.32 i486) [Netscape]"> - <META NAME="Author" CONTENT="James CE Johnson"> - <META NAME="Description" CONTENT="A first step towards using ACE productively"> - <TITLE>ACE Tutorial 007</TITLE> -</HEAD> -<BODY TEXT="#000000" BGCOLOR="#FFFFFF" LINK="#000FFF" VLINK="#FF0F0F"> - -<CENTER><B><FONT SIZE=+2>ACE Tutorial 007</FONT></B></CENTER> - -<CENTER><B><FONT SIZE=+2>Creating a thread-pool server</FONT></B></CENTER> -<HR> -<P>Two new files this time. The first is <A HREF="thread_pool.h">thread_pool.h</A> -where we declare our Thread_Pool object. This is responsible for -abstracting away the thread pool implementation details and allowing us -to make so few changes to the rest of the code. - -<P> -<HR WIDTH="100%"><FONT FACE="Arial,Helvetica"></FONT> - -<PRE> -<font color=red>// $Id$</font> - -<font color=blue>#ifndef</font> <font color=purple>THREAD_POOL_H</font> -<font color=blue>#define</font> <font color=purple>THREAD_POOL_H</font> - -<font color=red>/* In order to implement a thread pool, we have to have an object that - can create a thread. The ACE_Task<> is the basis for doing just - such a thing. */</font> -<font color=blue>#include</font> "<A HREF="../../../ace/Task.h">ace/Task.h</A>" - -<font color=blue>#if !defined</font> (<font color=purple>ACE_LACKS_PRAGMA_ONCE</font>) -<font color=blue># pragma</font> <font color=purple>once</font> -<font color=blue>#endif</font> <font color=red>/* ACE_LACKS_PRAGMA_ONCE */</font> - -<font color=red>/* We need a forward reference for ACE_Event_Handler so that our - enqueue() method can accept a pointer to one. */</font> -class ACE_Event_Handler; - -<font color=red>/* Although we modified the rest of our program to make use of the - thread pool implementation, if you look closely you'll see that the - changes were rather minor. The "<font color=green>ACE way</font>" is generally to create a - helper object that abstracts away the details not relevant to your - application. That's what I'm trying to do here by creating the - Thread_Pool object. */</font> -class Thread_Pool : public ACE_Task<ACE_MT_SYNCH> -{ -public: - typedef ACE_Task<ACE_MT_SYNCH> inherited; - - <font color=red>/* Provide an enumeration for the default pool size. By doing this, - other objects can use the value when they want a default. */</font> - enum size_t - { - default_pool_size_ = 5 - }; - - <font color=red>// Basic constructor</font> - Thread_Pool (void); - - <font color=red>/* Opening the thread pool causes one or more threads to be - activated. When activated, they all execute the svc() method - declared below. */</font> - int open (int pool_size = default_pool_size_); - - <font color=red>/* Some compilers will complain that our open() above attempts to - override a virtual function in the baseclass. We have no - intention of overriding that method but in order to keep the - compiler quiet we have to add this method as a pass-thru to the - baseclass method. */</font> - virtual int open (void *void_data) - { - return <font color=#008888>inherited::open</font> (void_data); - } - - <font color=red>/* - */</font> - virtual int close (u_long flags = 0); - - <font color=red>/* To use the thread pool, you have to put some unit of work into - it. Since we're dealing with event handlers (or at least their - derivatives), I've chosen to provide an enqueue() method that - takes a pointer to an ACE_Event_Handler. The handler's - handle_input() method will be called, so your object has to know - when it is being called by the thread pool. */</font> - int enqueue (ACE_Event_Handler *handler); - - <font color=red>/* Another handy ACE template is ACE_Atomic_Op<>. When - parameterized, this allows is to have a thread-safe counting - object. The typical arithmetic operators are all internally - thread-safe so that you can share it across threads without - worrying about any contention issues. */</font> - typedef ACE_Atomic_Op<ACE_Mutex, int> counter_t; - -protected: - - <font color=red>/* Our svc() method will dequeue the enqueued event handler objects - and invoke the handle_input() method on each. Since we're likely - running in more than one thread, idle threads can take work from - the queue while other threads are busy executing handle_input() on - some object. */</font> - int svc (void); - - <font color=red>/* We use the atomic op to keep a count of the number of threads in - which our svc() method is running. This is particularly important - when we want to close() it down! */</font> - counter_t active_threads_; -}; - -<font color=blue>#endif</font> <font color=red>/* THREAD_POOL_H */</font> -</PRE> -<HR WIDTH="100%"> - -<P>Well, that doesn't look too complex. What about the implementation? - -<P><HR WIDTH="100%"> -<CENTER>[<A HREF="../online-tutorials.html">Tutorial Index</A>] [<A HREF="page08.html">Continue This Tutorial</A>]</CENTER> |