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我正在用IDXGIOutputDuplication编写C++/CLI程序。使用DuplicateOutput时CRITICAL_SECTION发生死锁
我想从多个线程获取图像,所以我使用了CriticalSection。但是,包含“AcquireNextFrame()”和“ReleaseFrame()”的代码线程死锁了。
如果从程序中删除了UpdateDesktopImage(),死锁将不会发生。这些函数调用.NET Framework线程(System.Threading.Thread)。我想知道这个原因和解决方案。
HRESULT DesktopDupli::Initialize(int dispno, IDXGIAdapter *adapter, IDXGIOutput *output)
{
HRESULT hr = S_OK;
IDXGIOutput1 *dxgi_op1 = NULL;
DXGI_OUTPUT_DESC desc_op;
hr = output->GetDesc(&desc_op);
sw = desc_op.DesktopCoordinates.right - desc_op.DesktopCoordinates.left;
sh = desc_op.DesktopCoordinates.bottom - desc_op.DesktopCoordinates.top;
D3D_FEATURE_LEVEL FeatureLevels[] =
{
D3D_FEATURE_LEVEL_11_0,
D3D_FEATURE_LEVEL_10_1,
D3D_FEATURE_LEVEL_10_0,
D3D_FEATURE_LEVEL_9_1
};
D3D_FEATURE_LEVEL level;
UINT levels = ARRAYSIZE(FeatureLevels);
hr = D3D11CreateDevice(adapter, D3D_DRIVER_TYPE_UNKNOWN,
NULL, 0, FeatureLevels, levels,
D3D11_SDK_VERSION, &device, &level, &context);
if (FAILED(hr)) goto EXIT;
hr = output->QueryInterface(__uuidof(IDXGIOutput1), (void**)&dxgi_op1);
if (FAILED(hr)) goto EXIT;
hr = dxgi_op1->DuplicateOutput(device, &dupli);
if (FAILED(hr)) goto EXIT;
this->dispno = dispno;
pixelbufLen = sh * sw * 4;
pixelbuf1 = new BYTE[pixelbufLen];
EXIT:
RELEASE(dxgi_op1);
return hr;
}
void DesktopDupli::Remove()
{
EnterCriticalSection(&csec);
// delete some buffer
if (pixelbuf){
delete[]pixelbuf;
pixelbuf = NULL;
}
LeaveCriticalSection(&csec);
}
HRESULT DesktopDupli::UpdateDesktopImage()
{
EnterCriticalSection(&csec);
HRESULT hr = S_OK;
IDXGIResource* res = NULL;
ID3D11Texture2D *deskimage = NULL;
DWORD c = GetTickCount();
if (c >= lastUpdate && c < lastUpdate + 10) goto EXIT;
lastUpdate = c;
if (!dupli/*<-IDXGIOutputDuplication */) {
hr = E_POINTER;
goto EXIT;
}
dupli->ReleaseFrame();
if (FAILED(hr)) goto EXIT;
hr = dupli->AcquireNextFrame(500, &frameinfo, &res);
if (hr == DXGI_ERROR_WAIT_TIMEOUT) {
hr = S_OK;
goto EXIT;
} else if (FAILED(hr)){
goto EXIT;
}
hr = res->QueryInterface(__uuidof(ID3D11Texture2D), (void**)&deskimage);
if (FAILED(hr)) goto EXIT;
if (frameinfo.AccumulatedFrames == 0) {
dupli->ReleaseFrame();
}else {
hr = SetPixel(deskimage); //CopySubresourceRegion
}
EXIT:
RELEASE(deskimage);
RELEASE(res);
LeaveCriticalSection(&csec);
return hr;
}
忘记
dupli->ReleaseFrame()
如果这是在您使用商业性剥削为您锁定的对象只有两个功能,那么我怀疑UpdateDesktopImage要求删除某个地方(ReleaseFrame ?)导致问题 –你能看到它使用调试器死锁的位置吗? –
@ o_weisman:一旦线程获得锁定,就允许线程多次输入关键部分锁。线程一旦锁定后,对EnterCriticalSection()的后续调用就会成功并且不会被阻塞。必须平衡对EnterCriticalSection()和LeaveCriticalSection()的调用,以确保线程放弃锁定。在显示的代码中发生死锁的唯一方法是两个函数是否在单独的线程中调用,其中UpdateDesktopImage()具有锁并执行等待UpdateDesktopImage()的Remove()线程以等待释放锁。 –