我是否可以在OpenGL 2.1的多个共享上下文中同时从同一缓冲区对象进行渲染？

我们还遇到了“ gleLookupHashObject”崩溃问题，并做了一个小巧的假货（非常类似于您的假货），并在“事件”中发布给Apple支持。经过调查，Apple DTS工程师返回了以下信息，并引用：

“引起我注意的是，在主线程和绑定位置数据的辅助线程上都调用了glFlush（）。这确实会引入问题，尽管有些微妙，但实际上确实表明我们对线程和GL施加了约束上下文没有得到充分尊重。在这一点上，您应该进一步调查您的实现以确保避免这种情况，或者更好的是，使用显式同步机制（例如我们为GCD提供的功能）扩展您的实现。”

因此，如果遇到此崩溃，您将需要在应用程序端进行显式同步（在驱动程序端进行修复）。

Apple官方文档中与“ OpenGL，上下文和线程”相关的摘要摘要：

[0] Section: "Use Multiple OpenGL Contexts"
If your application has multiple scenes that can be rendered in parallel, you can use a context for each scene you need to render. Create one context for each scene and assign each context to an operation or task. Because each task has its own context, all can submit rendering commands in parallel.
https://developer.apple.com/library/mac/documentation/GraphicsImaging/Conceptual/OpenGL-MacProgGuide/opengl_threading/opengl_threading.html#//apple_ref/doc/uid/TP40001987-CH409-SW6

[1] Section: Guidelines for Threading OpenGL Applications
(a) Use only one thread per context. OpenGL commands for a specific context are not thread safe. You should never have more than one thread accessing a single context simultaneously.
(b) Contexts that are on different threads can share object resources. For example, it is acceptable for one context in one thread to modify a texture, and a second context in a second thread to modify the same texture. The shared object handling provided by the Apple APIs automatically protects against thread errors. And, your application is following the "one thread per context" guideline.
https://developer.apple.com/library/mac/documentation/GraphicsImaging/Conceptual/OpenGL-MacProgGuide/opengl_threading/opengl_threading.html

[2] OpenGL Restricts Each Context to a Single Thread
Each thread in an OS X process has a single current OpenGL rendering context. Every time your application calls an OpenGL function, OpenGL implicitly looks up the context associated with the current thread and modifies the state or objects associated with that context.
OpenGL is not reentrant. If you modify the same context from multiple threads simultaneously, the results are unpredictable. Your application might crash or it might render improperly. If for some reason you decide to set more than one thread to target the same context, then you must synchronize threads by placing a mutex around all OpenGL calls to the context, such as gl* and CGL*. OpenGL commands that blockâsuch as fence commandsâdo not synchronize threads.
https://developer.apple.com/library/mac/documentation/GraphicsImaging/Conceptual/OpenGL-MacProgGuide/opengl_threading/opengl_threading.html