calling concurrently Graphics.Draw and new Bitmap from memory in thread take long time
Posted
by Abdul jalil
on Stack Overflow
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or by Abdul jalil
Published on 2009-10-20T15:20:21Z
Indexed on
2010/05/08
9:18 UTC
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Example1
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
pro = new Thread(new ThreadStart(Producer));
con = new Thread(new ThreadStart(Consumer));
}
private AutoResetEvent m_DataAvailableEvent = new AutoResetEvent(false);
Queue<Bitmap> queue = new Queue<Bitmap>();
Thread pro;
Thread con ;
public void Producer()
{
MemoryStream[] ms = new MemoryStream[3];
for (int y = 0; y < 3; y++)
{
StreamReader reader = new StreamReader("image"+(y+1)+".JPG");
BinaryReader breader = new BinaryReader(reader.BaseStream);
byte[] buffer=new byte[reader.BaseStream.Length];
breader.Read(buffer,0,buffer.Length);
ms[y] = new MemoryStream(buffer);
}
while (true)
{
for (int x = 0; x < 3; x++)
{
Bitmap bmp = new Bitmap(ms[x]);
queue.Enqueue(bmp);
m_DataAvailableEvent.Set();
Thread.Sleep(6);
}
}
}
public void Consumer()
{
Graphics g= pictureBox1.CreateGraphics();
while (true)
{
m_DataAvailableEvent.WaitOne();
Bitmap bmp = queue.Dequeue();
if (bmp != null)
{
// Bitmap bmp = new Bitmap(ms);
g.DrawImage(bmp,new Point(0,0));
bmp.Dispose();
}
}
}
private void pictureBox1_Click(object sender, EventArgs e)
{
con.Start();
pro.Start();
}
}
when Creating bitmap and Drawing to picture box are in seperate thread then Bitmap bmp = new Bitmap(ms[x]) take 45.591 millisecond and g.DrawImage(bmp,new Point(0,0)) take 41.430 milisecond
when i make bitmap from memoryStream and draw it to picture box in one thread then Bitmap bmp = new Bitmap(ms[x]) take 29.619 and g.DrawImage(bmp,new Point(0,0)) take 35.540 the code is for Example 2 is
why it take more time to draw and bitmap take time in seperate thread and how to reduce the time when processing in seperate thread. i am using ANTS performance profiler 4.3
public Form1()
{
InitializeComponent();
pro = new Thread(new ThreadStart(Producer));
con = new Thread(new ThreadStart(Consumer));
}
private AutoResetEvent m_DataAvailableEvent = new AutoResetEvent(false);
Queue<MemoryStream> queue = new Queue<MemoryStream>();
Thread pro;
Thread con ;
public void Producer()
{
MemoryStream[] ms = new MemoryStream[3];
for (int y = 0; y < 3; y++)
{
StreamReader reader = new StreamReader("image"+(y+1)+".JPG");
BinaryReader breader = new BinaryReader(reader.BaseStream);
byte[] buffer=new byte[reader.BaseStream.Length];
breader.Read(buffer,0,buffer.Length);
ms[y] = new MemoryStream(buffer);
}
while (true)
{
for (int x = 0; x < 3; x++)
{
// Bitmap bmp = new Bitmap(ms[x]);
queue.Enqueue(ms[x]);
m_DataAvailableEvent.Set();
Thread.Sleep(6);
}
}
}
public void Consumer()
{
Graphics g= pictureBox1.CreateGraphics();
while (true)
{
m_DataAvailableEvent.WaitOne();
//Bitmap bmp = queue.Dequeue();
MemoryStream ms= queue.Dequeue();
if (ms != null)
{
Bitmap bmp = new Bitmap(ms);
g.DrawImage(bmp,new Point(0,0));
bmp.Dispose();
}
}
}
private void pictureBox1_Click(object sender, EventArgs e)
{
con.Start();
pro.Start();
}
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