Databases
StackOverflow2013
Postsdbo
POWhy doesn't FastBitmap get garbage collected?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POWhy doesn't FastBitmap get garbage collected?
    primarykey
    data
    text
    <p>So I've finally located a problem I have with growing memory consumption. It's the class below, which for some reason doesn't get garbage collected. What would be the problem? The idea of the FastBitmap class is to lock the bitmap data of a bitmap image once to avoid locking/unlocking on each call to GetPixel/SetPixel.</p> <pre><code> public unsafe class FastBitmap { private Bitmap subject; private int subject_width; private BitmapData bitmap_data = null; private Byte* p_base = null; public FastBitmap(Bitmap subject_bitmap) { this.subject = subject_bitmap; try { LockBitmap(); } catch (Exception ex) { throw ex; } } public void Release() { try { UnlockBitmap(); } catch (Exception ex) { throw ex; } } public Bitmap Bitmap { get { return subject; } } public void LockBitmap() { GraphicsUnit unit = GraphicsUnit.Pixel; RectangleF boundsF = subject.GetBounds(ref unit); Rectangle bounds = new Rectangle((int)boundsF.X, (int)boundsF.Y, (int)boundsF.Width, (int)boundsF.Height); subject_width = (int)boundsF.Width * sizeof(int); if (subject_width % 4 != 0) { subject_width = 4 * (subject_width / 4 + 1); } bitmap_data = subject.LockBits(bounds, ImageLockMode.ReadWrite, PixelFormat.Format32bppArgb); p_base = (Byte*)bitmap_data.Scan0.ToPointer(); } private void UnlockBitmap() { if (bitmap_data == null) return; subject.UnlockBits(bitmap_data); bitmap_data = null; p_base = null; } } </code></pre> <p><strong>EDIT</strong></p> <p>Here's how it does get properly collected..</p> <pre><code>public unsafe class FastBitmap : IDisposable { private Bitmap subject; private int subject_width; private BitmapData bitmap_data = null; private Byte* p_base = null; public FastBitmap(Bitmap subject_bitmap) { this.subject = subject_bitmap; try { LockBitmap(); } catch (Exception ex) { throw ex; } } public void Dispose() { Dispose(true); GC.SuppressFinalize(this); } private bool disposed = false; protected virtual void Dispose(bool disposing) { if (!this.disposed) { if (disposing) { UnlockBitmap(); Bitmap.Dispose(); } subject = null; bitmap_data = null; p_base = null; disposed = true; } } ~FastBitmap() { Dispose(false); } public Bitmap Bitmap { get { return subject; } } public void LockBitmap() { GraphicsUnit unit = GraphicsUnit.Pixel; RectangleF boundsF = subject.GetBounds(ref unit); Rectangle bounds = new Rectangle((int)boundsF.X, (int)boundsF.Y, (int)boundsF.Width, (int)boundsF.Height); subject_width = (int)boundsF.Width * sizeof(int); if (subject_width % 4 != 0) { subject_width = 4 * (subject_width / 4 + 1); } bitmap_data = subject.LockBits(bounds, ImageLockMode.ReadWrite, PixelFormat.Format32bppArgb); p_base = (Byte*)bitmap_data.Scan0.ToPointer(); } public void UnlockBitmap() { if (bitmap_data == null) return; subject.UnlockBits(bitmap_data); bitmap_data = null; p_base = null; } } </code></pre>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USAshley Simpson
    1. USAshley Simpson
    plurals
    1. PL
      singulars
      1. LTLinked
    1. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POWhy doesn't FastBitmap get garbage collected?
      1. This table or related slice is empty.
      1. VTUpMod
    1. COYou should definitely read this question, paying special attention to the "DO" and "DO NOT" sections: http://stackoverflow.com/questions/881473/why-catch-and-rethrow-exception-in-c
      singulars
      1. POWhy doesn't FastBitmap get garbage collected?
      1. USSam Harwell
    2. COYour Dispose method is a bit convoluted. Why the bounce to Dispose(bool) ? Why the call to GC.SuppressFinalize ? These are not necessary and are going to confuse you in 1 week. Keep it Simple!
      singulars
      1. POWhy doesn't FastBitmap get garbage collected?
      1. USFrank Krueger
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload