[Mono-bugs] [Bug 44438][Wis] New - WebClient.DownloadData() returns only partial page

[bugzilla-daemon@rocky.ximian.com]

Please do not reply to this email- if you want to comment on the bug, go to the
URL shown below and enter your comments there.

Changed by monobugzilla@lojic.com.

http://bugzilla.ximian.com/show_bug.cgi?id=44438

--- shadow/44438	Tue Jun 10 14:56:59 2003
+++ shadow/44438.tmp.23904	Tue Jun 10 14:56:59 2003
@@ -0,0 +1,142 @@
+Bug#: 44438
+Product: Mono/Class Libraries
+Version: unspecified
+OS: other
+OS Details: Redhat 7.3
+Status: NEW   
+Resolution: 
+Severity: 
+Priority: Wishlist
+Component: System
+AssignedTo: mono-bugs@ximian.com                            
+ReportedBy: monobugzilla@lojic.com               
+QAContact: mono-bugs@ximian.com
+TargetMilestone: ---
+URL: 
+Cc: 
+Summary: WebClient.DownloadData() returns only partial page
+
+The following program was originally part of a test case to demonstrate a
+memory leak in the MS .NET v1.1 garbage collector.  When attempting to
+reproduce the results on Linux using Mono, I discovered a problem in which
+WebClient.DownloadData() doesn't return the entire web page, but only a
+portion (4096 bytes coincidentally :).
+
+The results are very dependent on the URL you supply to the program, so you
+may have to try several before you reproduce the results.  The page I found
+that demonstrated the problem is on our intranet, so I can't supply the URL.
+
+The program is multi-threaded, so that may have something to do with it.
+
+Brian Adkins
+
+--- snip ---
+using System;
+using System.Collections;
+using System.Net;
+using System.Text;
+using System.Threading;
+
+class MemLeak
+{
+    private const int NUM_THREADS   = 3;
+    private const int SLEEP_MS      = 250;
+
+    private Queue       _pageQueue = new Queue();
+    private Thread[]    _threads;
+    private string      _url;
+
+    [STAThread]
+    static void Main (string[] args)
+    {
+        if (args.Length != 1)
+        {
+            Console.WriteLine("You must supply a URL as an argument.");
+            return;
+        }
+        MemLeak x = new MemLeak(args[0]);
+        x.Init();
+    }
+
+    public MemLeak (string url)
+    {
+        _url = url;
+    }
+
+    public void Init ()
+    {
+        CreateThreads(NUM_THREADS);
+
+        while (true)
+        {
+            try
+            {
+                string page = DequeuePageElement();
+                Console.WriteLine("Page length is {0}", page.Length);
+                Console.WriteLine(page);
+                Console.WriteLine("=====");
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine(ex.Message);
+                Console.WriteLine(ex.StackTrace);
+            }
+        }
+    }
+
+    private void CreateThreads (int numThreads)
+    {
+        _threads = new Thread[numThreads];
+
+        for (int i = 0; i < _threads.Length; ++i)
+        {
+            _threads[i] = new Thread(new ThreadStart(ProducerThread));
+            _threads[i].Start();
+        }
+    }
+
+    private string DequeuePageElement ()
+    {
+        while (true)
+        {
+            lock (this)
+            {
+                if (_pageQueue.Count > 0)
+                {
+                    return (string) _pageQueue.Dequeue();
+                }
+            }
+
+            Thread.Sleep(SLEEP_MS);
+        }
+    }
+
+    private void ProducerThread ()
+    {
+        UTF8Encoding    encoding = new UTF8Encoding();
+        WebClient       webClient = new WebClient();
+        string          page;
+
+        while (true)
+        {
+            try
+            {
+                byte[] bytes = webClient.DownloadData(_url);
+                page = encoding.GetString(bytes);
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine(ex.Message);
+                Console.WriteLine(ex.StackTrace);
+                page = "";
+                Thread.Sleep(SLEEP_MS);
+            }
+
+            lock (this)
+            {
+                _pageQueue.Enqueue(page);
+            }
+        }
+    }
+}
+--- snip ---