Tag：Semaphore
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Time：2021-10-22
Original address 1 Original address 2 Full text overview [TOC] Why need hystrix Hystrix official website address GitHub Hystrix is also Netfix’s contribution to distributed systems. Similarly, it has entered the non maintenance phase. Not maintaining does not mean being eliminated. It can only show that the new technology is constantly iterative. The brilliant design […]
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Time：2021-9-27
Synchronization mode of process and thread: The synchronization methods of processes and threads are basically the same, mainly locks and semaphores 1. Lock Lock is to use the exclusivity and mutex of resources to ensure the synchronization of processes (threads). In short, a process (thread) obtains a lock on a resource, which is equivalent to […]
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Time：2021-7-21
Concurrency technology, process, thread and lock Part 1. Multitasking At the beginning of computer development, CPU resources were very expensive. If the CPU could only run one program, CPU resources would be wasted when the CPU was idle (such as waiting for I / O). In order to make better use of CPU resources, the […]
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Time：2021-6-10
preface Welcome to the operating system series, using graphic + vernacular form to explain, so that Xiaobai can also understand, help you get started quickly. The last article has introduced the basic knowledge of process and thread. There are multiple threads under the process. Although the communication between multiple threads is very convenient (in the […]
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Time：2021-6-3
@ catalogue Concurrency and contention in kernel Atomic operation Introduction to atomic operation Integer atomic operation function Bit atom operation function Atomic operation routine Spin lock Introduction of spin lock Spin lock operation function Spin lock routines Read write spin lock Read write lock routine Sequence lock Sequential lock operation function Precautions for using spin […]
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Time：2021-5-13
Rwmutex core is based on mutex. If you want to know about mutex, you can take a look at my last mutex article Rwmutex supports concurrent reading. It is suitable for the scene of more reading and less writing. Definition of rwmutex type RWMutex struct { W mutex // mutex Writersem uint32 // semaphore for […]
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Time：2021-5-9
1、 Mutex (synchronous) In a multitasking operating system, multiple tasks running at the same time may need to use the same resource. This process is a bit similar to that in the company department, while I am using the printer to print things (I haven’t finished printing), others are also using the printer to print […]
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Time：2021-5-5
Thread safety When multiple threads try to access the same data at the same time, the data will not be destroyed Thread synchronization construction There are two kinds of construction modes: user mode and kernel mode. User mode construction uses special CPU instruction coordination thread (coordination occurs in hardware), so its construction speed is significantly […]
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Time：2021-4-23
Conditional variable We talked about locks before, but locks are not the only primitives needed in concurrent programming. In many cases, a thread needs to check that a condition is met before it can continue to run. For example, the parent thread needs to check whether the child thread has finished executing. How can this […]
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Time：2021-3-16
When we write @ property (weak) id obj, the compiler will add atomic keyword to obj by default, that is to say, the default setter and getter methods are locked. Atomic locking As mentioned in previous articles in this series, most of the attribute keywords are used in the code implementation of setters and getters. […]
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Time：2021-3-12
Ketcup git address: https://github.com/simple-gr/ketchup What is service governance The process that an enterprise implements in order to ensure the smooth completion of things, including best practices, architectural principles, governance procedures, rules and other decisive factors. What I understand is that service governance is a medicine, which is used to treat all kinds of problems existing […]
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Time：2021-3-8
Automatic completionP109 Automatic completion can be seen everywhere in daily business, which should be regarded as the most common and common function. The actual business scenario must include the case of containing substrings. In fact, to a certain extent, this is converted into the search function, that is, the string containing a certain substring, and […]
