What are Python thread locks and global locks?

Thread Lock is a mechanism used to protect access to shared resources in a multi-threading environment. Once a thread acquires the lock, other threads are unable to access the protected shared resource until the thread releases the lock. This helps prevent race conditions that may arise from multiple threads simultaneously modifying shared resources.

In Python, thread locking can be implemented using the Lock class in the threading module. A thread can acquire a lock before accessing shared resources by calling the acquire() method. If the lock is already acquired by another thread, the thread will be blocked until the lock is released. After finishing accessing the shared resources, the thread can release the lock by calling the release() method.

A Global Lock is a special type of thread lock that is a shared lock object among multiple threads. It can be used to protect a critical section, allowing only one thread to enter this section at any given time. Global Locks are considered heavyweight locks as they can block the execution of the entire program.

In Python, a global lock can be implemented using the Lock class in the threading module. By creating a global lock object and calling the acquire() and release() methods within the critical section of code that needs protection, the critical section can be safeguarded. The global lock ensures that at any given time, only one thread can execute the critical section of code, thereby preventing race conditions.