Solve the problem of multi-threaded reading and writing the same file.

When multiple threads share an object Code Similarly, the lock keyword should not be used for this problem. Here we need to use system. threading.
A Class of Monitor, which can be called a monitor, provides a solution to share resources with threads.
The monitor class can lock an object. A thread can operate on this object only when this lock is obtained. The object lock mechanism ensures the next time in the case of confusion
Only one thread can access this object. Monitor must be associated with a specific object, but because it is a static class, it cannot be used to define the object, and it
All methods are static and cannot be referenced by objects. The following code uses monitor to lock an object:

......
Queue oqueue = new Queue ();
......
Monitor. Enter (oqueue );
... // Now the oqueue object can only be manipulated by the current thread
Monitor. Exit (oqueue); // release the lock

As shown above, when a thread calls the monitor. Enter () method to lock an object, this object will be owned by it. Other threads want to access this object, only waiting for it to make
Use the monitor. Exit () method to release the lock. To ensure that the thread can finally release the lock, you can write the monitor. Exit () method into the finally code block in the try-catch-Finally structure.
. For any monitor-locked object, some information related to it is stored in the memory. One is the reference of the thread currently holding the lock, and the other is a reserve team column.
The column stores the thread that is ready to get the lock. The third is a waiting queue, which stores the reference of the queue that is currently waiting for this object to change its status. If you have an object lock
When the thread is preparing to release the lock, it uses the monitor. Pulse () method to notify the first thread in the waiting queue, so the thread is transferred to the reserve queue column. When the object lock is released
The thread in the standby queue can immediately obtain the object lock.