发布IOSurface [英] Releasing an IOSurface

问题描述

此问题扩展为：

Link-1：从ios表面创建并保存图像
Link-2：从iOS应用程序获取屏幕截图 - 模拟显示记录器（内部查询）

（参考链接-1）我有在后台工作时截取屏幕截图的代码。但如上所述，它需要2秒的睡眠才能不间断地工作，否则操作系统会暂停应用程序。我想出原因可能是我没有明确发布我创建的IOSurface。

原因 - 使用链接 http://pastie.org/pastes/3734430我尝试在每次写入图像后使用CFRelease释放destSurf（我创建的目标表面），但这不起作用。

(Refer Link-1) I have the code for taking screenshots in the background working. But as stated, it requires a sleep of 2 sec to work uninterruptedly, otherwise the OS suspends the app. I figured out the reason could be that I am not explicitly releasing the IOSurface I create.
Reason - Using the link http://pastie.org/pastes/3734430 given by Victor Ronin, the capture works fine even without the sleep. I tried releasing the destSurf (destination surface that I have created) using CFRelease after I write the image each time, but that doesn't work.

任何帮助何时，如何以及是否发布创建的IOSurface，将非常有用。谢谢。


更新

所以，这就是确切发生的事情。 （参考链接-1）

Any help on when, how and whether or not to release a created IOSurface, will be really useful. Thanks.

Update
So, this is what exactly happens. (Referring Link-1)

IOSurfaceRef destSurf = IOSurfaceCreate(dict);
IOSurfaceAcceleratorRef outAcc;
IOSurfaceAcceleratorCreate(NULL, 0, &outAcc);

CFDictionaryRef ed = (__bridge CFDictionaryRef)[NSDictionary dictionaryWithObjectsAndKeys: nil];
IOSurfaceAcceleratorTransferSurface(outAcc, screenSurface, destSurf, ed, NULL);

IOSurfaceUnlock(screenSurface, kIOSurfaceLockReadOnly, &aseed);

CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, IOSurfaceGetBaseAddress(destSurf), (width*height*4), NULL);
CGImageRef cgImage=CGImageCreate(width, height, 8, 8*4, IOSurfaceGetBytesPerRow(destSurf), CGColorSpaceCreateDeviceRGB(), kCGImageAlphaNoneSkipFirst | kCGBitmapByteOrder32Little, provider, NULL, YES, kCGRenderingIntentDefault);
UIImage *image = [UIImage imageWithCGImage: cgImage];
CGImageRelease(cgImage);
UIImageWriteToSavedPhotosAlbum(image, self, nil, nil);
CFRelease(destSurf);

1. 调用CFRelease并发生应用程序崩溃。没有保存图像。但是，如果您在发布前1-2秒进行睡眠，则可以正常工作。
   
2. 如果你跳过对UIImageWriteToSavePhotosAlbum（）的调用，一切正常，捕获不会中断。
   
   我仍​​然不清楚究竟是什么问题以及如何解决问题。任何帮助都非常感谢。

推荐答案

我认为你需要释放表面。它由API IOSurfaceCreate创建，不受autorelease的管理。

I think you need to release surface. It's create by API IOSurfaceCreate which isn't managed by autorelease's.

作为示例，我发现以下代码已经发布：

As example I found following code where it's released:

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=8&cad=rja& VED = 0CF0QFjAH&安培; URL = HTTP％3A％2F％2Fcode.google.com％2FP％2Fsyphon-框架％2Fsource％2Fbrowse％2Ftags％2Fpublic-β-1％2FSyphonServer.m％3FR％3D3&安培; EI = i_zRUMWQDMqw0AHs7IHYDA&安培; USG = AFQjCNG9yO3sUf-ZQy-W_h_Q9WJMm4hqgw

http：// w ww.opensource.apple.com/source/WebCore/WebCore-7536.24/platform/graphics/surfaces/mac/GraphicsSurfaceMac.cpp?txt

会发生什么如果你试图用CFRelease释放它？它会崩溃还是有相同的2秒问题？

What happens if you try to release it with CFRelease? Does it crash or does it have the same 2 secs problem?

这篇关于发布IOSurface的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！