simple pool

Tags: dbcp connection pool UseDesign of Dbutil Tool class Privatization of construction methods to prevent being new (very important) Exposing some public methods to external calls (very important)After two steps, the tool class is basically finished. • Why use connection pooling?In the application, establish a connection with the data, manipulate the database, and close the connection. This is a very resource-intensive thing. In ord

The production method of billiards is relatively simple. after careful observation, we will find that there are only two sides, one is a large sphere and the other is the label part. You only need to make the selection step by step and add the gradient. Highlight can be properly added to the surface. The production method of billiards is relatively simple. after careful observation, we will find that there

The development of the Android process will encounter at least one main thread, also known as the UI thread, this thread is not allowed to block, or will error, such as the most common access to network resources, read and write files and other operations, these time-consuming operations can no longer use the main thread. Here is a very efficient and very simple and practical way to Executorservice class.The Executorservice class can be understood as

;m_pfreelist = static_castvoid*> (New Char[nSize])); thePlastitem = plastitem->m_pfreelist; + } -Plastitem->m_pfreelist =NULL; $ } $ }; - #endif1#include 2#include 3 using namespacestd;4#include"mempool.h"5 6 7 classctest{8 Public:9 intm;Ten intN; One void*operator New(size_t size) { A void* p = s_pool->Alloc (size); - returnp; - } the void operator Delete(void*p) { -S_pool->Free (p); - return; - } + Static voidNewpool () { -S_pool

xl_thread_pool:boost::noncopyable{public:xl_thread_pool(int thread_num):num_(thread_num), run_(false){}~xl_thread_pool(){if (run_){stop();}}void start(){if (num_ return;int i = 0;run_ = true;for(i=0;i{boost::shared_ptrthread> thread(new boost::thread(boost::BOOST_BIND(xl_thread_pool::run, this)));thread_arr_.push_back(thread);}}void stop(){run_ = false;queue_.notify_all();}void post(const thread_do_func task){if (thread_arr_.size() == 0){task();}else{queue_.put(task);} }private:xl_blocking_queu

, then we re-add the connection to the list, If not, then we will execute the corresponding method on the real connection.It is also important to note that the connection object that is now called createconnection () is not the original connection object, but instead invokes a proxy class that is dynamically generated by the bind () method on the Myconnectionhandler class:Private Connection CreateConnection () throws SQLException {Connection realconn = drivermanager.getconnection ("JDBC: Mysql:/

/1070805 '):BreakElseRes_pic = requests.get (pic_url,headers = head)reg = R ' ' Reg = Re.compile (reg,re. STMP = Re.findall (reg,res_pic.text)Print (TMP)For I in TMP:num = Tmp.index (i)Picture_res = requests.get (i[0],headers = head)string = ' 'If Picture_res:TMP_STR = i[1]For each in TMP_STR:If each in (' \ \ ', '/', ' * ', '? ', ' ', ' | ', ' > ', ' PassElseString = string + eachTmp_str = stringIf i[0][-3:] = = ' jpg ':With open (R './{}/{}-{}{}.jpg '. Format (Page,package_list.index (Pic_url)

What is the concept of a thread pool? In object-oriented programming, it is time-consuming to create and destroy objects because creating an object takes up memory resources or other additional resources. This is especially true in Java, where the virtual machine will attempt to track each object so that it can be garbage collected after the object is destroyed. So one way to improve the efficiency of the service program is to minimize the number of

The use of multithreading and the meaning of the thread pool is needless to say, in order to master the thread pool, the best way is to manually implement it.First, the realization of ideas(Cyber Theft map)In general, all tasks are waiting in the blockingqueue, and the worker is the actual worker.Second, the Code1. Thread Pool classPackage Com.ty.thread;ImportJav

) {if(num> This. Workernum) { Throw NewIllegalArgumentException ("Exceeds actual worker thread"); } intCount=0; while(countnum) {Worker worker=Workers.get (count); if(Workers.remove (worker)) {Worker.shutdown (); Count++; } workernum--; } }} @Override Public intgetjobsize () {//TODO auto-generated Method Stub returnjobs.size (); } //Worker Initialization Private voidInitializeworkers (intnum) { for(inti=0;i) {worker worker=NewWorker ();

Simple memory pool implementation # Include # Include # Include # Include Using namespace std; class MemPool {struct FreeNode * next;}; private: static const int allocNum = 8; static const int step = 4; static char * head; static char * tail; static unsigned int poolSize; static int allocSize [allocNum]; static FreeNode * FreeList [allocNum]; static void * GetFromPool (int n

Use the Tomcat Jndi data source with spring using the following steps:1. Copy the database driver under the Lib folder of Tomcat2. Configure the Tomcat Server.xml configuration file and add a resource node below the Globalnamingresources node as follows:3. Configure the Context.xml file to add a ResourceLink node below the context node, which is consistent with the name attribute of the resource configured in Server.xml.Global="jdbc/mysql" name="jdbc/mysql" type= " javax.sql.DataSource"/>4. Con

Spider Pond principle, the following excerpt from the online.Hyperlinks can be found on general Web pages, and hyperlinks link up most Web pages on the Internet to form a spider-like structure. One of the spiders ' work is to crawl as many pages as possible, along the hyperlinks, that have not been crawled. To put it another way: the equivalent of artificially created a constantly growing network, the spider trapped inside, let it constantly crawling Web pages within.Let's start with the first s

Workthread - ( ID ) Initwiththreadpoolinner :( threadpoolinner * ) Inner {Self = [Super init]; If (Self ){Self -> _ Inner = Inner;Self -> _ Nativethread = NULL;_ Thread = [[Nsthread alloc] initwithtarget: Self selector: @ selector (run) Object : Nil];_ Isrun = Yes;[_ Thread start];} Return Self;} - ( Void ) Run {NSAID utoreleasepool * Pool = [[NSAID utoreleasepool alloc] init]; If ( ! _ Nativethread ){_ Nativethre

The main function of this component is to process a small number of instances and implement the pooling function. A preparedstatement pool is added on the basis of this component. As long as the classes using this pool are the same as the implementation classes, write the two methods into the package org. koron. db. exchange; import java. SQL. *; import org. koron. db. DBConnection; public class SwanStateme

C + + thread pool, inherit cdoit, implementation of which start and end Header file /* Multithreading Management * */#ifndef cthreadpoolmanage_h #define CTHREADPOOLMANAGE_H #include CPP file * * thread pool, Threading management class */#include "cthreadpoolmanage.h" Cthreadpoolmanage::cthreadpoolmanage () {_minthreads = 5; Minimum number of threads _maxthreads = 5; Can have a maximu

the output order of magnitude The tf.nn.conv2d function has four parameters, the first dimension is the input image, the second dimension is the convolution layer weight, the third dimension is the step of different dimensions (in CNN, the first and fourth dimensions are fixed to 1), and the fourth dimension is filled (same represents full 0 padding, valid is not filled). Depth of the layer: for example, an input image is 28*28*3, where 3 represents the depth, that is (R,G,B) The depth of the c

found that the first three constructors are initialized by the fourth constructor that is called.The following explains the meanings of each parameter in the constructor: Corepoolsize: The size of the core pool, this parameter is very much related to the implementation principle of the thread pool described later. After the thread pool has been created,

For example, there are 10 threads now, but each time you want to run only 3 threads, when any one of these 3 threads finishes running, the 4th thread is then up. This situation can be solved using the thread pool, and the thread pool is quite simple to use, not to believe, you see:Package Com.demo;import Java.util.arraylist;import Java.util.collection;import Java

thread is awakened, it does not exit, but continues to use the delegate execution callback method. While (true) { // Delegate the execution callback Method W (o ); T. Suspend (); } } } } 3. Test. cs Using System; Using System. Threading; Namespace CustomThreadPool { /// /// Test the custom Thread Pool /// Class Test { /// /// Main entry point of the application. /// [STAThread] Static void Main (string [] args) { // // TODO: Add code here to