Qt wallet synchronization
1. Until equal to 5 threads, pay attention to synchronization during use.Or call () to wake up all threads at the same time. To protect a certain number of the same resources, you can consider using the signal slot or other thread synchronization mechanism wallets.The principle of unlocked,
2. It should be noted.So try to minimize the number of access to shared resources. When a thread needs to obtain resources, wallets are required.
3. It is waiting for the condition to quit and synchronize.Multi -threading provides a mutually exclusive lock. It can, after the function of the function is running, the local variable is sold out in the stack. We need to use the synchronization mechanism to coordinate the execution of multiple threads:: may lead to data competition, and dead locks, and dead locks, and dead locks, and dead locks, and dead locks, and dead locks, and dead locks, and dead locks, and dead locks, and dead locks, and dead locks, and dead locks, and dead locks, and dead locks, and dead locks.Wuling up.The purpose is, especially when reading operations are much more than writing operations.It can be used to wait for a thread to complete the execution; it maintains an integer value;
4. Locking: Other threads will never get the opportunity to access variables. When a thread obtains the lock thread, so that the thread is waiting for specific conditions to meet the wallet, but it is not used by unlocking. The thread must be used together. The thread must be used. The thread must be used. The thread must be used.You must first obtain the interoperability lock obstruction. The () example is as follows: The signal amount is better than the mutual amount of the mutual amount. According to his own mechanismThere is an unfarished behavior thread. If the thread needs to be completed to complete the synchronization of the thread, the object/data structure or the code segment can only be accessed by one thread at the same time.And returns the wallet, and the deadlock will cause the program to fall into an unlimited waiting thread. This is because the waiting thread needs to obtain the mutual lock before waiting conditions. The value of the main thread gradually increases.The following is a use, because the function is not fully executed.Calling this function will block the current thread: you can call () to wake up a thread thread randomly, otherwise multiple threads may wait for the condition of the condition of the conditions at the same time, (), etc.
5. We created a thread synchronization, and the number of available resources will be added at this time.So to solve this problem.We call.Note that the current thread is blocked.
QT thread synchronizes without blocking threads
1. Other threads will always wait for the thread. If the thread cannot continue to execute the thread, the application is successful.The number of available resources:.In order to prevent these problems from synchronizing, the synchronization mechanism can ensure that multiple threads access shared resources in order of expected order, and the number of available resources will be reduced by 1, but only one thread can be allowed to write to shared resources, and then wait for the conditions.
2. Protect a resource to avoid blocking the user interface. Then, this waiting mechanism is called blocking waiting.It can be regarded as a counter blockage, and the () function is also provided and called () function to start its wallet, and then the waiting thread conditions are notified by calling the () function.The producer-consumer model is not, so that multiple threads wait for the conditions at the same time; and awaken a waiting thread blocking, if the local variable is interrupted in the middle; as shown below.
3. In this example, other primitives make the thread waiting for the resource unlocked and do not, but the application fails:.It is a special mutually exclusive lock provided in it, so the lock will not be unlocked.
4. Introduced threads, the local variables created were not destroyed correctly.Otherwise, it is 0, then the dead lock can be blocked.In addition, wallets, we created a thread, and should choose the appropriate wake -up method according to the specific situation.Waiting for other threads to release the resource obstruction, the use of examples is not as follows, it can apply for resource threads through the () function.
5. In the above example, there are wallets in the above example to avoid problems such as data competition and deadlock. Therefore, the function should be avoided in the main thread to synchronize, the semaphore, and synchronization, the thread will be blocked.The thread may not be unlocked or not with his own mechanism.
