Watchpoints
TLDR: Watchpoints are a specialized type of breakpoint used in debugging to monitor changes to specific variables or memory locations during a program's execution. First introduced in low-level debugging tools like GDB (GNU Debugger), they allow developers to pause execution whenever the monitored value is read or modified. Watchpoints are particularly useful for diagnosing issues related to unexpected changes in state, such as memory corruption or logic errors.
https://en.wikipedia.org/wiki/Watchpoint
Unlike traditional breakpoints that halt execution at specific lines of source code, watchpoints focus on the runtime behavior of variables. For instance, in a C++ program, a watchpoint can be set on a pointer to detect any write operations to the memory it references. Advanced IDEs and debuggers, such as Eclipse CDT and Visual Studio, provide user-friendly interfaces for setting and managing watchpoints. These tools also allow fine-tuning, such as triggering watchpoints only on write operations, read operations, or both.
https://www.gnu.org/software/gdb/documentation/
Watchpoints are essential in debugging scenarios where errors are difficult to trace using static analysis or traditional breakpoints. For example, they are invaluable for detecting concurrency issues like race conditions in multithreaded programs. By pausing execution whenever a shared variable is accessed or modified, developers can pinpoint where conflicts or unexpected behaviors occur. This capability enhances the debugging process, making watchpoints a critical tool for resolving complex runtime issues.