The synchronized block in j**a is a multi-threaded synchronization mechanism that allows the programmer to specify a piece of ** that can only be accessed by one thread at a time. Synchronization blocks are defined using the synchronized keyword and require an object that is shared across all threads as a lock. When a thread enters a synchronous block, it needs to acquire a lock, and if the lock is already held by another thread, the thread will be blocked until the lock is released.
What the synchronization block does:
Atomicity: Ensure that only one thread can execute the synchronization of the ** within the block at a time.
Visibility: Ensures that when a thread changes the value of a shared variable, other threads can see the change immediately.
Orderliness: Ensure the order of execution by prohibiting the reordering of instructions.
Syntax for sync blocks:
synchronized (lockobject)
public int getcount()
public static void main(string args) ,"thread-" + i).start();
Wait for all threads to finish executing (the way to do this is simple, just for demonstration).
try catch (interruptedexception e)
system.out.println("final count is: " + counter.getcount())
The synchronized block in j**a is a multi-threaded synchronization mechanism that allows the programmer to specify a piece of ** that can only be accessed by one thread at a time. Synchronization blocks are defined using the synchronized keyword and require an object that is shared across all threads as a lock. When a thread enters a synchronous block, it needs to acquire a lock, and if the lock is already held by another thread, the thread will be blocked until the lock is released.
What the synchronization block does:
Atomicity: Ensure that only one thread can execute the synchronization of the ** within the block at a time.
Visibility: Ensures that when a thread changes the value of a shared variable, other threads can see the change immediately.
Orderliness: Ensure the order of execution by prohibiting the reordering of instructions.
Syntax for sync blocks:
j**a copy.
synchronized (lockobject)
public int getcount()
public static void main(string args) ,"thread-" + i).start();
Wait for all threads to finish executing (the way to do this is simple, just for demonstration).
try catch (interruptedexception e)
system.out.println("final count is: " + counter.getcount())
In this example, the counter class has an increment method, which contains a synchronization block to protect access to the count variable. We create a lock object lock and use it in the sync block. The main method creates 5 threads, and each thread calls the increment method to increment the value of count by 100 times. Due to the existence of synchronous blocks, only one thread can increase the counter at a time, thus avoiding the problem of data inconsistency caused by multi-threaded concurrent access.
Notice that the thread. in this examplesleep(2000) was added just for the sake of simple demonstrations, and it made the main thread wait 2 seconds to allow other threads time to complete their tasks. In practice, a more reliable thread synchronization mechanism such as countdownlatch, cyclicbarrier, or semaphore should be used to wait for all threads to complete.