我是c ++的新手,我正在研究一些c ++跨平台线程教程.我正在研究这个问题:http://solarianprogrammer.com/2011/12/16/cpp-11-thread-tutorial/
并试图执行以下代码:
#include <iostream>
#include <thread>
static const int num_threads = 10;
//This function will be called from a thread
void call_from_thread(int tid) {
std::cout << "Launched by thread " << tid << std::endl;
}
int main() {
std::thread t[num_threads];
//Launch a group of threads
for (int i = 0; i < num_threads; ++i) {
t[i] = std::thread(call_from_thread, i);
}
std::cout << "Launched from the main\n";
//Join the threads with the main thread
for (int …标题是自我解释的,我不知道为什么.
来源:www/index.html:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<meta name="format-detection" content="telephone=no" />
<meta name="viewport" content="user-scalable=no, initial-scale=1, maximum-scale=1, minimum-scale=1, width=device-width, height=device-height, target-densitydpi=device-dpi" />
<link rel="stylesheet" type="text/css" href="css/index.css" />
<title>Hello World</title>
</head>
<body>
<div class="app">
<h1>PhoneGap</h1>
<div id="deviceready" class="blink">
<p class="event listening">Connecting to Device</p>
<p class="event received">Device is Ready</p>
</div>
</div>
<script type="text/javascript" src="phonegap.js"></script>
<script type="text/javascript" src="js/index.js"></script>
<script type="text/javascript">
app.initialize();
</script>
</body>
</html>
index.js:
var app = {
// Application Constructor
initialize: function() {
this.bindEvents();
},
// Bind Event Listeners
// …所以,我正在阅读有关nodejs的一些内容,当我遇到Worker Threads时,我感到非常惊讶.
在我看来,拥有线程是一个很好的加分,特别是如果你将它与共享内存访问结合起来.你可能已经想过了 - > SharedArrayBuffer......
是的,这就是我的想法.所以我想到的第一件事就是给它一点测试并尝试实现一个简单的store(现在是一个简单的对象),它将在线程之间共享.
问题是,(除非我在这里遗漏了一些东西)如何使用SharedArrayBuffer？从n个线程中访问对象？
我知道,对于一个简单的Uint32Array是可行的,但对于对象可以做什么？
起初我想把它转换Uint32Array成你可能会看到的声音,但即使看着该死的源代码也让我想哭...
const {
Worker,
isMainThread,
workerData
} = require('worker_threads');
const store = {
ks109: {
title: 'some title 1',
description: 'some desciption 1',
keywords: ['one', 'two']
},
ks110: {
title: 'some title 2',
description: 'some desciption 2',
keywords: ['three', 'four']
},
ks111: {
title: 'some title 3',
description: 'some desciption 3',
keywords: ['five', 'six']
}
}
const shareObject = (obj) …您好我正在研究骨干,我已经创建了一个php api来处理骨干,现在我正在尝试从morris获取从get请求中检索的集合.
这是我从php脚本中检索到的数据:
[{"m":"Mar","t":"92","e":"8","p":"64"},{"m":"Apr","t":"0","e":"0","p":"0"},{"m":"May","t":"60","e":"20","p":"40"},{"m":"Jun","t":"50","e":"6","p":"44"},{"m":"Jul","t":"160","e":"30","p":"130"},{"m":"Aug","t":"50","e":"6","p":"44"},{"m":"Sep","t":"0","e":"0","p":"0"},{"m":"Oct","t":"120","e":"12","p":"108"},{"m":"Nov","t":"50","e":"10","p":"40"},{"m":"Dec","t":"182","e":"22","p":"40"},{"m":"Jan","t":"380","e":"112","p":"168"},{"m":"Feb","t":"0","e":"0","p":"0"}]
此外,这是我的JavaScript:
<div class="row">
<div id="dashboardMainGraph"></div>
</div>
<script>
Month = Backbone.Model.extend({
default:{
m:'',
t:0,
e:0,
p:0
}
});
DashboardMainDiagram = Backbone.Collection.extend({
model: Month,
url: '/api/getDashboardMainGraph'
});
Diagram = Backbone.View.extend({
el: $('#dashboardMainGraph'),
initialize:function(){
console.log('initializing')
var self = this,
coll = new DashboardMainDiagram();
coll.fetch({
success: function(data){
self.draw(data.toJSON());
}
});
},
draw:function(d) {
console.log(JSON.stringify(d))
window.m = new Morris.Line({
// ID of the element in which to draw the chart.
element: this.el,
// Chart data records -- each entry in this …首先请原谅我不是那么熟悉正则表达式.我想要的是一个正则表达式,它将从任何类型的字符串中提取类似mysql日期的日期.直到现在我才使用这个:^[0-9]{4}-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1])$
但是现在我想从其他字符串和日期时间字符串中提取日期模式我尝试^[0-9]{4}-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1]).根据一些在线正则表达式测试程序改变正则表达式,但它失败了.有时它给了我一个3位数的结果.
换句话说,刺痛开始于,yyyy-mm-dd并且后跟空格字符数字或任何东西.如何提取日期？
UPDATE
我在这里使用preg_match测试正则表达式:http://www.pagecolumn.com/tool/pregtest.htm
到目前为止,唯一似乎有用的是
[0-9]{4}-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1])
我正在构建一个应用程序,其中我呈现一些纹理的平面.但是,我想根据平截头体宽度和摄像机位置动态计算螺旋的半径(我在计算中用来创建螺旋).
螺旋位于屏幕的中心x = 0,y = 0,z = 0.
我想要考虑屏幕方向(横向/纵向).到目前为止这是我的代码,但似乎我错过了一些东西,因为左边和右边的平面不在视口内.
App.prototype.calculateHelixRadius = function(){
// plane width = height = 512;
var friend = this.getFriend();
var vFOV = friend.camera.fov * Math.PI / 180;
var dist = utils.getAbsPointsDistance3D(friend.camera.position, friend.scene.position);
var aspect = friend.settings.container.clientWidth / friend.settings.container.clientHeight;
var frustumHeight = 2.0 * dist * Math.tan(0.5 * vFOV);
var frustumWidth = frustumHeight * aspect;
return utils.isLandscape() ? frustumHeight / 2 : frustumWidth / 2 ;
};
我做错了什么,为什么屏幕边缘的飞机不在里面？
这里还有代码供参考 getAbsPointsDistance3D
var utils = {
// other helpers... …你好我的子菜单有以下css.它用于在页面加载时打开它们.它工作得很好但是我注意到如果在动画的结束状态我设置height:auto;那么动画没有被执行这对我来说是一个问题,因为在我的网站上我有很多子菜单,其中有很多子菜单,所以我必须动态填充子菜单的高度.可能吗 ？
@-moz-keyframes slidemenu {
0% {
height: 0px;
}
100% {
height: 90px;
}
}
@-webkit-keyframes slidemenu {
0% {
height: 0px;
}
100% {
height: 90px;
}
}
#side-menu > li.active > ul.sub-menu{
-moz-animation-delay:0.5s;
-moz-animation-name: slidemenu;
-moz-animation-timing-function: ease-out;
-moz-animation-duration: 0.5s;
-moz-animation-iteration-count: 1;
-moz-animation-fill-mode: forwards;
-webkit-animation-delay:0.5s;
-webkit-animation-name: slidemenu;
-webkit-animation-timing-function: ease-out;
-webkit-animation-duration: 0.5s;
-webkit-animation-iteration-count: 1;
-webkit-animation-fill-mode: forwards;
}
PS:我对纯css解决方案很感兴趣.
我正在创建一个Web应用程序,它具有交互式背景,粒子在弹跳.在任何时候屏幕上都有大约200个圆形颗粒,最多约800个颗粒.正在为粒子运行的一些碰撞和效果是以下原型.我想知道我是否可以通过使用网络工作人员来进行这些计算来提高性能？
/**
* Particles
*/
Jarvis.prototype.genForegroundParticles = function(options, count){
count = count || this.logoParticlesNum;
for (var i = 0; i < count; i++) {
this.logoParticles.push(new Particle());
}
}
Jarvis.prototype.genBackgroundParticles = function(options, count){
count = count || this.backgroundParticlesNum;
for (var i = 0; i < count; i++) {
this.backgroundParticles.push(new Particle(options));
}
}
Jarvis.prototype.motion = {
linear : function(particle, pIndex, particles){
particle.x += particle.vx
particle.y += particle.vy
},
normalizeVelocity : function(particle, pIndex, particles){
if (particle.vx - particle.vxInitial > 1) {
particle.vx -= …在我的项目中,我正在使用浏览器的索引数据库,我想从具有特定ID的数据库中检索一些对象.根据MDN,您可以使用范围来获得所需的结果:
据MDN称:
// Only match "Donna"
var singleKeyRange = IDBKeyRange.only("Donna");
// Match anything past "Bill", including "Bill"
var lowerBoundKeyRange = IDBKeyRange.lowerBound("Bill");
// Match anything past "Bill", but don't include "Bill"
var lowerBoundOpenKeyRange = IDBKeyRange.lowerBound("Bill", true);
// Match anything up to, but not including, "Donna"
var upperBoundOpenKeyRange = IDBKeyRange.upperBound("Donna", true);
// Match anything between "Bill" and "Donna", but not including "Donna"
var boundKeyRange = IDBKeyRange.bound("Bill", "Donna", false, true);
// To use one of the key ranges, pass it in …您好，我正在尝试在react-native应用程序中使用redux，但出现标题中特别提到的错误Invariant Violation: Could not find "store" in either the context or props of "Connect(App)". Either wrap the root component in a <Provider>, or explicitly pass "store" as a prop to "Connect(App)"。我不确定是什么问题，尽管我遵循类似的线程，但到目前为止没有任何效果。
波纹管是我的App.js来源
import React, { Component } from 'react';
import { Provider, connect } from 'react-redux';
import { Platform, StyleSheet, Text, View } from 'react-native';
import * as utils from './src/utils';
import store from './src/store';
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
alignItems: 'center',
backgroundColor: …javascript ×4
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