multithreading - “lock”应用程序的UI线程是什么意思？

Question

我正在使用flkt-rs crate设计GUI。我想知道“锁定”应用程序的UI线程是什么意思。这是否意味着没有CPU分配给该线程？您为什么要锁定UI线程？那么什么时候才想解锁呢？
另外，我看到fltk::app::lock()函数返回了一个结果，这意味着使用它可能存在一些问题。是什么导致您无法成功锁定UI线程？
从fltk-rs docs锁定功能:

pub fn lock() -> Result<(), FltkError>

Answer 1

从FLTK C++ documentation:

In a multithreaded program, drawing of widgets (in the main() thread) happens asynchronously to widgets being updated by worker threads, so no drawing can occur safely whilst a widget is being modified (and no widget should be modified whilst drawing is in progress).

FLTK supports multithreaded applications using a locking mechanism internally. This allows a worker thread to lock the rendering context, preventing any drawing from taking place, whilst it changes the value of its widget.

因此，您不会长时间锁定用户界面；足够的时间来安全地更新小部件的状态，然后再次对其进行解锁。

What could prevent you from succesfully locking the UI thread?

同一文档的下一段可能会解决此问题:

To incorporate the locking mechanism in the library, FLTK must be compiled with –enable-threads set during the configure process. IDE-based versions of FLTK are automatically compiled with the locking mechanism incorporated if possible. Since version 1.3, the configure script that builds the FLTK library also sets –enable-threads by default.

如果将应用程序编译为单线程，则锁定主线程将永久锁定整个应用程序。它没有明确说明，但是在这种情况下出现 FailedToLock错误似乎是合理的。
这种API感觉不太“使用rust ”，可能是这样，因为 fltk-rs crate 是C++库的薄包装。