Changes from Version 1 of ThreadsAndDelegatesExample

Author:

jcc7 (IP: 192.149.244.9)

Timestamp:

05/22/07 20:35:31 (17 years ago)

Comment:

added example

ThreadsAndDelegatesExample

@@ +1 @@
+= Threads and Delegates =
+
+''Part of'' [StandardLibraryCategory Standard Library Category]
+
+== Example ==
+
+{{{
+#!d
+import std.c.time;
+import std.stdio;
+import std.thread;
+
+class Foo
+{
+   int _v;
+
+   this(int n)
+   {
+      _v = n;
+   }
+
+   public int glob()
+   {
+      return _v;
+   }
+}
+
+class WorkerThread
+{
+   int _v;
+
+   this(int n)
+   {
+      _v = n;
+   }
+
+   // Here's a private member function - we'll call this from the run() method
+   void identify()
+   {
+      writefln("WorkerThread(%d)", _v);
+   }
+
+   // When run is called via the delegate it will have the appropriate this
+   // pointer, and so has access to all the fields and methods of its class.
+   public int run()
+   {
+      for (;;)
+      {
+         sleep(2);
+         identify();
+      }
+      return 0;
+   }
+}
+
+// In the thread 2 case, we override the thread class, and provide the run method
+// explicitly
+class Thread2 : Thread
+{
+   int _v;
+
+   this(int n)
+   {
+      _v = n;
+   }
+   public int run()
+   {
+      for (;;)
+      {
+         sleep(2);
+         writefln("Thread2 %d", _v);;
+      }
+      return 0;
+   }
+}
+
+void bar(int delegate() a)
+{
+   writefln("rv = %d", a());
+}
+
+// In the case of thread 3, this will serve as the run method, and
+// it will be called with the value of the second argument to the
+// thread constructor (the documentation is not correct in this respect).
+int x(void *p)
+{
+   int *ip = cast(int*) p;
+   for (;;)
+   {
+      sleep(2);
+      writefln("Thread3 %d", *ip);
+   }
+   return 0;
+}
+
+
+void main(char[][] args)
+{
+   // Before we get to threads, these first few lines just illustrate the
+   // general ideas of delegates as applied to class member functions.
+   Foo foo = new Foo(42);
+   int delegate() dg = &foo.glob;
+   int n = dg();
+   writefln("n = %d", n);
+   bar(dg);
+   int n3 = 123;
+
+   // Now the different ways of instantiating threads.
+   WorkerThread wt = new WorkerThread(22);
+   dg = &wt.run;
+   Thread t1 = new Thread(dg);
+   t1.start();
+
+   Thread2 t2 = new Thread2(321);
+   t2.start();
+
+   Thread t3 = new Thread(&x, &n3);
+   t3.start();
+
+   sleep(10);
+} 
+}}}
+
+== Sample Batch File ==
+
+{{{
+@echo off
+set pgm=ThreadsAndDelegatesExample
+dmd %pgm%.d 
+%pgm%.exe
+
+pause
+erase *.obj
+erase *.map
+}}}
+
+
+== Tested Environment ==
+
+Tested with Digital Mars D Compiler v1.014 on Windows 2000.
+
+
+== Source ==
+
+Based on "[http://www.dsource.org/forums/viewtopic.php?t=2752 Threads, delegates, and all that]" by teales.