c++ - Windows Metro 模式 (C++) : Waiting on semaphore (WaitForSingleObjectEx): failed with Access Denied [partially solved]

Question

也许这对你来说是个愚蠢的问题..但它对我不起作用! (WinRT 的新手......也可能是 Windows!)只是试图创建信号量并试图获取它......没什么特别的。但它因 WAIT_FAILED 失败:5(拒绝访问)

void MainPage::simple_Sema_test1()
{

    HANDLE p_sema;
    DWORD ret, err;
    p_sema = CreateSemaphoreEx(NULL, 1, MAX_LIMIT, L"sema1", 0, SEMAPHORE_MODIFY_STATE);
    if(p_sema == NULL)
        print_on_textbox("CreateSemaphoreEx Failed!\n");
    ret = WaitForSingleObjectEx(p_sema, 1000, TRUE);
    switch(ret){
    case WAIT_ABANDONED:
        print_on_textbox("WAIT_ABANDONED\n");
    case WAIT_IO_COMPLETION:
        print_on_textbox("WAIT_IO_COMPLETION\n");
    case WAIT_OBJECT_0:
        print_on_textbox("WAIT_OBJECT_0\n");
    case WAIT_TIMEOUT:
        print_on_textbox("WAIT_TIMEOUT\n");
    case WAIT_FAILED:
        print_on_textbox("WAIT_FAILED: " + (GetLastError()).ToString());
}

Edit <<< (Partially solved) Create Semaphore with SEMAPHORE_ALL_ACCESS

即

*sema = CreateSemaphoreEx(NULL, initial, MAX_LIMIT, L"sema1", 0, SEMAPHORE_ALL_ACCESS);

如果有人知道为什么它不能使用修改权限，请解释一下!

Answer 1

要等待一个同步对象，你必须有 SYNCHRONIZE access rights :

SYNCHRONIZE: The right to use the object for synchronization. This enables a thread to wait until the object is in the signaled state.

SEMAPHORE_ALL_ACCESS 值包括 SYNCHRONIZE 标志。