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Process Pool: When the number of sub processes to be created is small, you can directly use the Process in multiprocessing to dynamically generate multiple processes, but if it is hundreds of Process goals, the workload of manual creation will be very huge. At this time, you can use the Pool class in the multiprocessing module. When initializ ...

What is a queue A queue is a linear data structure. Different from the stack with the same linear data structure, the elements in the queue follow the First In First Out rule. Like queuing in reality, it pays attention to the principle of first come, first served. The exit end of the queue is called the front, and the entrance end of the queue ...

Concept: Heap is also called priority queue. When entering the queue, it is the same as ordinary queue, but when leaving the queue, the elements with higher priority are given priority. When the priority is the same, it is carried out in the way of first in first out. The essence of heap is actually a binary tree, and this binary tree needs to ...

Main differences between Set and List Duplicate elements are allowed to be inserted in the List, while duplicate elements are not allowed in the Set.Related to the storage order of elements, List is an ordered Set, which will retain the order in which elements are inserted, and Set is an unordered Set.List can be accessed by subscript, but Set ...

Fair lock and unfair lock Fair lock It refers to that multiple threads acquire locks according to the order of applying for locks, and follow the principle of first come, first serve. Its implementation can use queues. Unfair lock The method of multiple threads acquiring locks is not in the order of applying for locks. The thread that ap ...

In the previous section, I learned how consumers get messages So when consumers get the message and find that the message should not be solved by themselves, or an exception occurs during processing, how should they deal with it This is the message rejection in this section 1, Message reject There are also two ways to Reject messages: Rejec ...

environment The process in php is completed in the form of extension. Through these extensions, we can easily complete a series of actions of the process. pcntl extension: the main process extension, which completes the process creation in the waiting operation. posix extension: complete the general api of posix compatible machine, such as ob ...

Title Description Give you an integer matrix isWater with the size of m x n, which represents a map composed of land and water cells. If i s W a t e ...

Recognize stacks and queues What is stack, JVM virtual machine stack and stack frame? ✌️ Stack: a linear table with limited operation, which is limited to linear tables with insertion and deletion operations only at the end of the table. This end is called the top of the stack, and the other end is called the bottom of the stack. Inserting a ...

Interrupt the tasklet below tasklet related knowledge points What is a tasklet? tasklet is a commonly used method for interrupt processing. tasklet is a special soft interrupt. The following mechanisms for handling interrupts include work queues and soft interrupts. How to use tasklet s to design interrupts? Interrupt occurrence, dealing w ...