Threads And Concurrency Questions Medium
A monitor in thread synchronization refers to a high-level synchronization construct that allows multiple threads to safely access shared resources or critical sections of code. It ensures that only one thread can execute the monitor-protected code at a time, preventing concurrent access and potential data corruption or race conditions.
A monitor typically consists of two main components: a lock and condition variables. The lock is used to control access to the monitor, allowing only one thread to acquire the lock and enter the monitor at a time. This ensures mutual exclusion and prevents multiple threads from executing the protected code simultaneously.
Condition variables, on the other hand, are used to coordinate the execution of threads within the monitor. They allow threads to wait for specific conditions to be met before proceeding, or to signal other threads when certain conditions have been satisfied. Condition variables help in achieving synchronization and efficient thread communication within the monitor.
In addition to mutual exclusion and coordination, monitors also provide a mechanism for thread suspension and resumption. When a thread enters a monitor and encounters a condition that is not yet satisfied, it can voluntarily release the lock and wait on a condition variable. This allows other threads to enter the monitor and potentially satisfy the condition, at which point the waiting thread can be awakened and resume execution.
Overall, monitors provide a higher-level abstraction for thread synchronization, making it easier to write correct and efficient concurrent programs. They encapsulate the low-level details of locks and condition variables, simplifying the synchronization process and reducing the chances of errors or race conditions.