deadlock prevention

which the process is running is inappropriate. (3) Improper allocation of resources and so on. If the system resources are sufficient, the resource request of the process can be satisfied, the probability of deadlock is very low, otherwise it will be locked into a deadlock because of contention for limited resources. Second, the process is run in a different order and speed, and may also produce a

request for resources, the acquired resources are persisted.(3) No deprivation condition: the resources that this process (thread) has obtained cannot be forcibly stripped until the end of use.(4) Cyclic wait condition: a cyclic waiting resource relationship between multiple processes (threads) is formed.These four conditions are necessary for the deadlock, as long as the system has a deadlock, these condi

over a limited resource. Second, the process is run in a different order and speed, and may also produce a deadlock. the four necessary conditions for creating a deadlock:(1) Mutex condition: A resource can only be used by one process at a time. (2) Request and hold condition: When a process is blocked by a request for resources, it remains in place for the resources that have been obtained. (3) Conditions

1. definition : Competing for shared resources and allocating resources in an inappropriate order. 2. Prerequisites(1) Mutual exclusion: When a process accesses a resource, other processes cannot access the resource. This causes blocking until the resource is freed by the process.(2) Request and hold conditions: The process has maintained at least one resource, and new resource requirements have been raised, and the newly requested resources have been occupied by other processes, where the proce

Dog Planing Learning Network reported/yesterday, the Dog planing Learning Network has been "[under the Dome]" brush screen who to do a haze theme hand tour? "Report. Also yesterday, the First Air defense disaster prevention electronic game "absolute Tribe" was developed by the Fujian provincial Civil Defense office, which was formally accepted by the National Civil Defense office, and began to be tested and run in Fujian province. The game is currentl

Disable deadlock detection to improve MySQL performance with high concurrency bitsCN.com On a high-concurrency MySQL server, transactions will recursively detect deadlocks. when the depth is exceeded, the performance decline will become unacceptable. FACEBOOK has long proposed a deadlock prevention test. We conducted an experiment to greatly improve the TPS aft

, these conditions must be established, and as long as the above conditionsif not satisfied, there will be no deadlock. release and prevention of deadlocks:Understanding the causes of deadlocks, especially the four necessary conditions that generate deadlocks, can be avoided, prevented, andunlock the deadlock. Therefore, in the system design, process scheduling a

In the previous blog (http://cloudapps.blog.51cto.com/3136598/1708539), we described how to use Apache's module Mod_evasive to set up anti-DDoS attacks, in which The main prevention is the HTTP volume attack, but the DDOS attack way, a lot of tools, a random search to know, we look back, what is called Dos/ddos, see Wikipedia:"Denial of Service Attacks (denial of servicesAttack, abbreviation:DoS), also known as flood attacks , is a network attack tech

According to statistics, in all hacker attacks, SYN attacks are the most common and most easily exploited one of the attack methods. I believe many people still remember the 2000 Yahoo site attack case, the hacker was using a simple and effective SYN attack, some network worm with SYN attack caused greater damage. This paper introduces the basic principle, tools and detection methods of SYN attack, and probes into the technology of SYN attack prevention