mac OSX Chrome浏览器中HTML5 Canvas getImageData的javascript内存泄漏
新chrome版本(版本35.0.1916.114)修复了此问题mac OSX Chrome浏览器中HTML5 Canvas getImageData的javascript内存泄漏,javascript,google-chrome,memory-leaks,html5-canvas,getimagedata,Javascript,Google Chrome,Memory Leaks,Html5 Canvas,Getimagedata,新chrome版本(版本35.0.1916.114)修复了此问题 在chrome中,对于mac osx,CanvasRenderingContext2D#getImageData函数将导致内存泄漏,如何避免此问题,这是测试用例和结果,它只发生在chrome浏览器中,safari可以 <!DOCTYPE html> <html> <head> <title>CanvasRenderingContext2D#getImageData bug
在chrome中,对于mac osx,CanvasRenderingContext2D#getImageData函数将导致内存泄漏,如何避免此问题,这是测试用例和结果,它只发生在chrome浏览器中,safari可以
<!DOCTYPE html>
<html>
<head>
<title>CanvasRenderingContext2D#getImageData bug in chrome</title>
<script type="text/javascript">
var g;
function init(){
g = document.getElementById('canvas').getContext('2d');
g.fillStyle = "blue";
g.fillRect(10, 10, 100, 100);
g.fillStyle = "green";
g.fillRect(60, 60, 100, 100);
}
function getImageData(){
var i = 0;
while(i++ < 100){
var c = g.getImageData(0,0,1000, 1000);
delete c;
}
}
function toDataURL(){
var i = 0;
while(i++ < 100){
var c = g.canvas.toDataURL();
delete c;
}
}
</script>
</head>
<body onload="init()">
<button onclick="getImageData()">call getImageData 100 times - then memory will grow, can't GC</button>
<button onclick="toDataURL()">call toDataURL 100 times - it is OK</button><br>
<canvas id='canvas' width='600px' height='500px'/>
</body>
</html>
浏览器中的CanvasRenderingContext2D#getImageData错误
var g;
函数init(){
g=document.getElementById('canvas').getContext('2d');
g、 fillStyle=“蓝色”;
g、 fillRect(10,10,100,100);
g、 fillStyle=“绿色”;
g、 fillRect(60,60,100,100);
}
函数getImageData(){
var i=0;
而(i++<100){
var c=g.getImageData(0,01000,1000);
删除c;
}
}
函数toDataURL(){
var i=0;
而(i++<100){
var c=g.canvas.toDataURL();
删除c;
}
}
调用getImageData 100次-然后内存将增长,GC不能吗
调用toDataURL 100次-一切正常
您的问题不在于
getImageData
函数。保存getImageData
的变量的赋值方式导致了泄漏
问题是delete c
将失败(delete不影响变量名),浏览器会自动返回false
请改用c=null
。尝试在for
循环之外声明c
变量,以避免在循环的每个步骤中重新创建变量
以下是修改后的代码:
function getImageData(){
var i = 0;
var c;
while(i++ < 100){
c = g.getImageData(0,0,1000, 1000);
// c = null; // <= check UPDATE to see why this doesn't work as expected
}
}
function toDataURL(){
var i = 0;
var c;
while(i++ < 100){
c = g.canvas.toDataURL();
// c = null; // <= check UPDATE to see why this doesn't work as expected
}
}
此外,宽度/高度越大,内存泄漏越大。调用
g.getImageData(0,0100009000)使用Google Chrome27.0.1453.94
,code>两次将使Windows 7 SP1上的线程崩溃。谢谢你,但它似乎没用,你曾经测试过吗?chromeI在Chrome 27.0.1453.93、27.0.1453.94和29.0.1518.3 canary中测试的版本是什么。我没有因为那个密码而泄露内存。内存在while
循环期间增长,并在函数结束后由垃圾收集器清除。看来你面临的真正问题不是内存泄漏,而是内存溢出!!!我认为垃圾收集器在函数结束之前不会被触发。因此,在浏览器有机会触发垃圾收集器之前,使用巨大的画布或巨大的循环迭代会使内存溢出。我在windows xp中测试了它,没关系,也许这只发生在chrome中一段时间mac@samsha: . 你有没有试着像我说的那样拨打电话,或者使用类似的设置间隔来进行操作,但还是卡住了?(我无法在osx上测试)如果是这样,请尝试在Chromium项目网站上报告该漏洞,如果您得到了答案,请在这里为我们发布!;)新chrome版本(版本35.0.1916.114)修复了此问题
<!DOCTYPE html>
<html>
<head>
<title>CanvasRenderingContext2D#getImageData bug fixed</title>
<script type="text/javascript">
var g;
function init(){
g = document.getElementById('canvas').getContext('2d');
g.fillStyle = "blue";
g.fillRect(10, 10, 100, 100);
g.fillStyle = "green";
g.fillRect(60, 60, 100, 100);
}
function getImageData(){
var c = g.getImageData(0,0,1000, 1000);
}
var total = 0;
var iterations = 100;
function test(){
var i = 0;
while(i++ < iterations){
setTimeout(function(){
getImageData();
total++;
//console.log(total);
if(total == iterations){
alert("" + total+" getImageData functions were completed!!!")
}
}, 0.01); // defer
}
alert("" + (i-1) + " iterations completed. Wait for the return of all getImageData");
}
</script>
</head>
<body onload="init()">
<button onclick="test()">call getImageData several times</button><br>
<canvas id='canvas' width='600px' height='500px'/>
</body>
</html>