critical role

Locate the deadlock caused by the critical section -------- Easy debugging network original welcome reprint, reprint please indicate the source of www.debug-easy.com --------Code in this article (45kb) In the development of multi-threaded programs, criticalsection is usually used as the synchronization mechanism because of the efficiency. Beginners often encounter deadlocks when designing and developing multi-threaded programs. Yesterday I saw a buddy

Critical section (critical area)Only one thread is allowed to access the shared resource at any time. If more than one thread attempts to access the critical section at the same time, all other threads that attempt to access this critical section after one thread has entered will be suspended and continue until the thr

/*Name: The critical path for topological sequencing (depth-first search)Copyright:Author: A clever clumsyDate:17-11-14 21:02Description: The key path of topological sequencingIn a weighted graph, the event is represented by a vertex, an activity is represented by a forward edge, and the weight on the edge represents the cost of the activity, such as the duration of the activity.Then this weighted graph is called the network of activity on edge networ

One: Concept: Before learning the critical path, understand the concept of a AOV and AOE network: as shown in the following figureIf an automobile production plant is to manufacture a car, the approximate event and activity time of the manufacturing process are as follows: AoESo, obviously for the AOE network above, the so-called critical path: Start –> engine complete –> parts in place –> assembly complet

play a very important role in data tables, and an appropriate index can improve the performance of each table, and here's an article that explains how to create indexes and when to create them.15. No transaction mechanism is usedData integrity is important for web systems, and if data consistency is wrong, the entire system crashes and is difficult to repair. Reasonable use of database transaction mechanism will effectively solve this problem. For ex

Operating System-solutions for mutual exclusion between processes-ensure that only one process enters the critical section at a time (2)-Peterson solution, system-peterson This article continues with the previous article about how to allow only one process to enter the critical section at a time. This article mainly introduces the Peterson solution. Summary1. Peterson Solution Based on lock variables and st

The original Published time: 2008-07-30--from my Baidu article [imported by moving tools]Using System;Using System.Data;Using System.Configuration;Using System.Collections;Using System.Web;Using System.Web.Security;Using System.Web.UI;Using System.Web.UI.WebControls;Using System.Web.UI.WebControls.WebParts;Using System.Web.UI.HtmlControls;public partial class Admin_rolegroup:System.Web.UI.Page{protected void Page_Load (object sender, EventArgs e){if (! IsPostBack){Listbox1.datasource = Membershi

Trtlcriticalsection is a struct, defined in a Windows cell; initializecriticalsection, EnterCriticalSection, LeaveCriticalSection, deletecriticalsection and so on these several kernel32.dll in the critical section operation API parameters; Tcriticalsection is the class implemented in the SYNCOBJS unit, It encapsulates the above critical section Operations API functions, simplifying and facilitating the use

be shielded in a critical section; Priority 4~7 interrupts are not affected by the operating system, but in the event of an interrupt, a function of the systems API (operating system in a system-not-administered priority may result in timing confusion, anomalies, etc.).Figure 2 is in the arm-cm3 kernel, such as the Stm32f2xx and STM32F1 series microcontroller, the kernel uses 4bit priority, priority 0 highest, priority 15 lowest. If you set configmax

Thank blogger Http://blog.csdn.net/speedme/article/details/17595821 1. Background First of all, for example, the process p1,p2 a variable count, with an initial value of 0 Because the order of execution of the P1,P2 two processes is random, possible sequential execution may also be concurrent, visible by the diagram, different execution order, the value of count will be different, which is not allowed. In this case, multiple processes concurrently access and manipulate the same data and the ex

I. Concurrency and CompetitionConcurrency means that multiple execution units are executed at the same time and concurrently, while the access of concurrent execution units to shared resources (global variables, static variables) is prone to competition.Scenarios: 1. multiple CPUs of symmetric multi-processor (SMP)2. single CPU process and preemption Process3. Process interruptionThe Code area used to access the shared resource area is called the critical