追踪点（Tracepoint）被当成断点(breakpoint)的一种，但有两个不同点需要注意：
1. 当一个追踪点在一个调试会话中被创建时，它并不种入到二进制代码中，直到用户显式地开始追踪实验。这意味着，创建/修改/删除追踪点并不影响程序，直到追踪真正开始。
2. 简单的创建一个追踪点并不是非常有价值，因为它默认不会收集任何信息。重要的是，把操作(Actions)添加到Tracepoint，这样tracepoint被触发的时候，前面自定义的Action就大有用处了。
来自CDT官网的原文：
Create Tracepoints
Tracepoints are handled as a type of breakpoint. There are two differences to note:
- When a tracepoint is created in a debug session, it is not actually planted in the binary code until the user explicitly starts the tracing experiment. This means that creating/modifying/deleting tracepoints does not affect the program until tracing is actually started.
- Simply creating a Tracepoint has very limited value as it won't collect any information by default. It is important to add Actions to the Tracepoint to tell it what to do. This will be explained below.
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