WaitForMultipleObjects
The WaitForMultipleObjects function returns when one of the following occurs:
Either any one or all of the specified objects are in the signaled state.
The time-out interval elapses.
To enter an alertable wait state, use the WaitForMultipleObjectsEx function.
DWORD WaitForMultipleObjects(
DWORD nCount, // number of handles in array
CONST HANDLE *lpHandles, // object-handle array
BOOL bWaitAll, // wait option
DWORD dwMilliseconds // time-out interval
);
Parameters
nCount
[in] Specifies the number of object handles in the array pointed to by lpHandles. The maximum number of object handles is MAXIMUM_WAIT_OBJECTS.
lpHandles
[in] Pointer to an array of object handles. For a list of the object types whose handles can be specified, see the following Remarks section. The array can contain handles to objects of different types. It may not contain the multiple copies of the same handle.
If one of these handles is closed while the wait is still pending, the function's behavior is undefined.
Windows NT/2000/XP: The handles must have SYNCHRONIZE access. For more information, see Standard Access Rights.
Windows 95/98/Me: No handle may be a duplicate of another handle created using DuplicateHandle.
bWaitAll
[in] Specifies the wait type. If TRUE, the function returns when the state of all objects in the lpHandles array is signaled. If FALSE, the function returns when the state of any one of the objects is set to signaled. In the latter case, the return value indicates the object whose state caused the function to return.
dwMilliseconds
[in] Specifies the time-out interval, in milliseconds. The function returns if the interval elapses, even if the conditions specified by the bWaitAll parameter are not met. If dwMilliseconds is zero, the function tests the states of the specified objects and returns immediately. If dwMilliseconds is INFINITE, the function's time-out interval never elapses.
Return Values
If the function succeeds, the return value indicates the event that caused the function to return. This value can be one of the following.
Value
Meaning
WAIT_OBJECT_0 to (WAIT_OBJECT_0 + nCount – 1)
If bWaitAll is TRUE, the return value indicates that the state of all specified objects is signaled.
If bWaitAll is FALSE, the return value minus WAIT_OBJECT_0 indicates the lpHandles array index of the object that satisfied the wait. If more than one object became signalled during the call, this is the array index of the signalled object with the smallest index value of all the signalled objects.
WAIT_ABANDONED_0 to (WAIT_ABANDONED_0 + nCount – 1)
If bWaitAll is TRUE, the return value indicates that the state of all specified objects is signaled and at least one of the objects is an abandoned mutex object.
If bWaitAll is FALSE, the return value minus WAIT_ABANDONED_0 indicates the lpHandles array index of an abandoned mutex object that satisfied the wait.
WAIT_TIMEOUT
The time-out interval elapsed and the conditions specified by the bWaitAll parameter are not satisfied.
If the function fails, the return value is WAIT_FAILED. To get extended error information, call GetLastError.
Remarks
The WaitForMultipleObjects function determines whether the wait criteria have been met. If the criteria have not been met, the calling thread enters the wait state. It uses no processor time while waiting for the criteria to be met.
When bWaitAll is TRUE, the function's wait operation is completed only when the states of all objects have been set to signaled. The function does not modify the states of the specified objects until the states of all objects have been set to signaled. For example, a mutex can be signaled, but the thread does not get ownership until the states of the other objects are also set to signaled. In the meantime, some other thread may get ownership of the mutex, thereby setting its state to nonsignaled.
The function modifies the state of some types of synchronization objects. Modification occurs only for the object or objects whose signaled state caused the function to return. For example, the count of a semaphore object is decreased by one. When bWaitAll is FALSE, and multiple objects are in the signaled state, the function chooses one of the objects to satisfy the wait; the states of the objects not selected are unaffected.
The WaitForMultipleObjects function can specify handles of any of the following object types in the lpHandles array:
Change notification
Console input
Event
Job
Mutex
Process
Semaphore
Thread
Waitable timer
Use caution when calling the wait functions and code that directly or indirectly creates windows. If a thread creates any windows, it must process messages. Message broadcasts are sent to all windows in the system. A thread that uses a wait function with no time-out interval may cause the system to become deadlocked. Two examples of code that indirectly creates windows are DDE and COM CoInitialize. Therefore, if you have a thread that creates windows, use MsgWaitForMultipleObjects or MsgWaitForMultipleObjectsEx, rather than WaitForMultipleObjects.
HANDLE* threads = new HANDLE[8];
for (int i = 0; i < 8; i++)
{
DWORD dwTmp = 0;
threads[i] = CreateThread(NULL,0,ScanThread,(LPVOID)&i,NULL,&dwTmp);
}
for (int j = 0; j < 8; j++)
ResumeThread(threads[i]);
WaitForMultipleObjects(8, threads, TRUE, INFINITE);
for (j = 0; j < 8; j++)
CloseHandle(threads[j]);
delete[] threads;
ResumeThread
The ResumeThread function decrements a thread's suspend count. When the suspend count is decremented to zero, the execution of the thread is resumed.
DWORD ResumeThread(
HANDLE hThread // handle to thread
);
Parameters
hThread
[in] Handle to the thread to be restarted.
Windows NT/2000/XP: The handle must have THREAD_SUSPEND_RESUME access to the thread. For more information, see Thread Security and Access Rights.
Return Values
If the function succeeds, the return value is the thread's previous suspend count.
If the function fails, the return value is -1. To get extended error information, call GetLastError.
Remarks
The ResumeThread function checks the suspend count of the subject thread. If the suspend count is zero, the thread is not currently suspended. Otherwise, the subject thread's suspend count is decremented. If the resulting value is zero, then the execution of the subject thread is resumed.
If the return value is zero, the specified thread was not suspended. If the return value is 1, the specified thread was suspended but was restarted. If the return value is greater than 1, the specified thread is still suspended.
Note that while reporting debug events, all threads within the reporting process are frozen. Debuggers are expected to use the SuspendThread and ResumeThread functions to limit the set of threads that can execute within a process. By suspending all threads in a process except for the one reporting a debug event, it is possible to "single step" a single thread. The other threads are not released by a continue operation if they are suspended.
Requirements
Windows NT/2000/XP: Included in Windows NT 3.1 and later.
Windows 95/98/Me: Included in Windows 95 and later.
Header: Declared in Winbase.h; include Windows.h.
Library: Use Kernel32.lib.
ps：太懒了，就不翻译了!
