Waits for a debugging event to occur in a process being debugged.
BOOL WINAPI WaitForDebugEvent( _Out_ LPDEBUG_EVENT lpDebugEvent, _In_ DWORD dwMilliseconds );
- lpDebugEvent [out]
A pointer to a DEBUG_EVENT structure that receives information about the debugging event.
- dwMilliseconds [in]
The number of milliseconds to wait for a debugging event. If this parameter is zero, the function tests for a debugging event and returns immediately. If the parameter is INFINITE, the function does not return until a debugging event has occurred.
If the function succeeds, the return value is nonzero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.
Only the thread that created the process being debugged can call WaitForDebugEvent.
When a CREATE_PROCESS_DEBUG_EVENT occurs, the debugger application receives a handle to the image file of the process being debugged, a handle to the process being debugged, and a handle to the initial thread of the process being debugged in the DEBUG_EVENT structure. The members these handles are returned in are u.CreateProcessInfo.hFile (image file), u.CreateProcessInfo.hProcess (process), and u.CreateProcessInfo.hThread (initial thread). If the system previously reported an EXIT_PROCESS_DEBUG_EVENT debugging event, the system closes the handles to the process and thread when the debugger calls the ContinueDebugEvent function. The debugger should close the handle to the image file by calling the CloseHandle function.
Similarly, when a CREATE_THREAD_DEBUG_EVENT occurs, the debugger application receives a handle to the thread whose creation caused the debugging event in the u.CreateThread.hThread member of the DEBUG_EVENT structure. If the system previously reported an EXIT_THREAD_DEBUG_EVENT debugging event, the system closes the handles to the thread when the debugger calls the ContinueDebugEvent function.
When a LOAD_DLL_DEBUG_EVENT occurs, the debugger application receives a handle to the loaded DLL in the u.LoadDll.hFile member of the DEBUG_EVENT structure. This handle should be closed by the debugger application by calling the CloseHandle function.
Warning Do not queue an asynchronous procedure call (APC) to a thread that calls WaitForDebugEvent.
For an example, see Writing the Debugger's Main Loop.
Minimum supported client
|Windows XP [desktop apps only]|
Minimum supported server
|Windows Server 2003 [desktop apps only]|
- Debugging Events
- Debugging Functions
Build date: 10/26/2012