c**t
发帖数: 2744 | 1 Easy to test:
var links = new ConcurrentQueue(); //and populate with links
Parallel.For(0, link.Count, delegate(int i){
string url;
if( links.TryDeQueue(out url) )
{ Download(url); }
});
...
private void Download(string url)
{
using(WebClient wc = new WebClient())
{
wc.DownloadFile(url, somefilename);
}
} |
a9
发帖数: 21638 | 2 这叫异步执行吧？
【在 c**t 的大作中提到】
: Easy to test:
: var links = new ConcurrentQueue(); //and populate with links
: Parallel.For(0, link.Count, delegate(int i){
: string url;
: if( links.TryDeQueue(out url) )
: { Download(url); }
: });
: ...
: private void Download(string url)
: {
|
c**d
发帖数: 579 | 3 This is not thread safety. And what issue does WebClient have? |
c**t
发帖数: 2744 | 4 Only two links were downloaded, app doesn't stop, doesn't download more
links either.
【在 c**d 的大作中提到】
: This is not thread safety. And what issue does WebClient have?
|
d****d
发帖数: 133 | 5 you create one instace of wc per task, wc doesn't need to be thread-safe.
【在 c**t 的大作中提到】
: Only two links were downloaded, app doesn't stop, doesn't download more
: links either.
|
c**t
发帖数: 2744 | 6 read my code, each task has its own wc (using)
【在 d****d 的大作中提到】
: you create one instace of wc per task, wc doesn't need to be thread-safe.
|
v******n
发帖数: 421 | 7 how many cpu's (cores) in your machine? It is possible that TPL only
schedules
two threads
【在 c**t 的大作中提到】
: Only two links were downloaded, app doesn't stop, doesn't download more
: links either.
|
d****d
发帖数: 133 | 8 that's what I meant. wc doesn't need to be thread-safe if you write code
like
this. If it doesn't work, it has nothing to do with wc's thread-safety.
【在 c**t 的大作中提到】
: read my code, each task has its own wc (using)
|
d****d
发帖数: 133 | 9 I just wrote a test app. I have no problem downloading multiple urls at all.
At peak I have 6 downloading simultaneously.
Something else is wrong in your project. But as I said, it shouldn't have
anything to do with wc's thread safety.
【在 d****d 的大作中提到】
: that's what I meant. wc doesn't need to be thread-safe if you write code
: like
: this. If it doesn't work, it has nothing to do with wc's thread-safety.
|
s*****w
发帖数: 215 | 10 I also tested the above code,
multiple files are downloaded,
wc.DownloadFile(url, filename); the second parameter is the filename you are
going to download to. For each thread, they should have their own file
names.
【在 c**t 的大作中提到】
: Only two links were downloaded, app doesn't stop, doesn't download more
: links either.
|
