Code becomes asynchronous on await – we wouldn’t know what to return What await does in addition to waiting for the promise to resolve is that it immediately returns the code execution to the caller. All code inside the function after await is asynchronous. async is syntatic sugar for returning a promise. If you don’t … Read more
The result of both calls is the same. The difference is that var stream = file.readAsStream() will block the calling thread until the operation completes. If the call was made in a GUI app from the UI thread, the application will freeze until the IO completes. If the call was made in a server application, … Read more
I’ve done something similar at https://github.com/JamesDunne/Aardwolf and have done some extensive testing on this. See the code at https://github.com/JamesDunne/aardwolf/blob/master/Aardwolf/HttpAsyncHost.cs#L107 for the core event loop’s implementation. I find that using a Semaphore to control how many concurrent GetContextAsync requests are active is the best approach. Essentially, the main loop continues running until the semaphore blocks the … Read more
My question: does anybody know of a good pattern to deal with acquiring exclusive access in the presence of thread switching due to async/await? Yes, you can use AsyncLock, which is also available as part of my AsyncEx library. If you want to have a “TryLock” kind of operation, then you may have to create … Read more
Example code with progress from the article public async Task<int> UploadPicturesAsync(List<Image> imageList, IProgress<int> progress) { int totalCount = imageList.Count; int processCount = await Task.Run<int>(() => { int tempCount = 0; foreach (var image in imageList) { //await the processing and uploading logic here int processed = await UploadAndProcessAsync(image); if (progress != null) { progress.Report((tempCount * … Read more
That’s because compiler generates state machine from your async method, and that state machine class (named <Do>d__0 in this case) contains field of type Disposable but does not itself implements IDisposable interface. It doesn’t make much sense for analyzer to analyze compiler generated code (and this <Do>d__0 class is marked with CompilerGenerated attribute). Fortunately, there … Read more
Assuming that you don’t want to call the Stop method on the TcpListener class, there’s no perfect solution here. If you’re alright with being notified when the operation doesn’t complete within a certain time frame, but allowing the original operation to complete, then you can create an extension method, like so: public static async Task<T> … Read more
Change this: getProducts({commit}, type) { axios.get(`/api/products/${type}`) .then(res => { let products = res.data; commit(‘SET_PRODUCTS’, {products, type}) }).catch(err => { console.log(err); }) }, To this: getProducts({commit}, type) { return axios.get(`/api/products/${type}`) .then(res => { let products = res.data; commit(‘SET_PRODUCTS’, {products, type}) }).catch(err => { console.log(err); }) }, Should work. axios.get returns a promise. You would need to … Read more
The async function will return a Promise, so you need to await the call to demo const sleep = (ms) => new Promise(resolve => setTimeout(resolve, ms)) const demo = async() => { console.log(‘2…’) await sleep(2000) console.log(‘3…’) } const blah = async() => { console.log(‘1…’) await demo() console.log(‘4.’) } blah()
Let’s consider how to apply two aggregate functions to the same iterator, which we can only exhaust once. The initial attempt (which hardcodes sum and max for brevity, but is trivially generalizable to an arbitrary number of aggregate functions) might look like this: def max_and_sum_buffer(it): content = list(it) p = sum(content) m = max(content) return … Read more