concurrency

问题 How do I do something like $q.all but limiting how many promises are executed concurrently? My question is just like How can I limit Q promise concurrency? I want no more than 5 process spawned at a time The accepted answer for that other question is a library written for promise wrapped to work with Q. But I'm interested specifically in a solution for Angular's $q rather than for Q . Background: The problem being solved: I have a bunch of files to download in 2 steps: a) Get URL b) download

问题 Quite a simple question. In SQL 2008 if I have a stored procedure (see below) do I run the risk of a race condition between the first two statements or does the stored procedure put a lock on the things it touches like transactions do? ALTER PROCEDURE [dbo].[usp_SetAssignedTo] -- Add the parameters for the stored procedure here @Server varchar(50), @User varchar(50), @UserPool varchar(50) AS BEGIN SET NOCOUNT ON; Declare @ServerUser varchar(50) -- Find a Free record SELECT top 1 @ServerUser =

问题 I'm just learning, and really liking, the Actor pattern. I'm using Scala right now, but I'm interested in the architectural style in general, as it's used in Scala, Erlang, Groovy, etc. The case I'm thinking of is where I need to do things concurrently, such as, let's say "run a job". With threading, I would create a thread pool and a blocking queue, and have each thread poll the blocking queue, and process jobs as they came in and out of the queue. With actors, what's the best way to handle

问题 Is there a way I can limit the number of concurrent connections to the Web Application running on my Apache Server. My server version is Apache 2.2.11 回答1: Have a look at limitipconn module. 回答2: I'm not sure if it will useful to you but definitely worth a chance. Maybe you can use the directives MaxClients and ListenBackLog Although they apply to the concurrent access to the entire server, not only your application, and on a resource base. 回答3: We completely built an application layer thing

问题 I have developed an c# web application that has an WCF service. This application is hosted in Windows 10 PRO 64x system. Everything works well so far, except from a "concurrent" requests limitation. I performed a stress test via SOAPUI and the IIS handles only 10 concurrent requests. Is there a limitation in operation system ? Is there any way to overcome this limitation ? Thank you very much, *Screenshot attached below with concurrent requests screenshot enter image description here 来源：

问题 For performance reason I would like to use a forEach loop of a parallel Lambda stream in order to process an instance of a Collection in Java. As this runs in a background Service I would like to use the updateProgress(double,double) method in order to inform the user about the current progress. In order to indicate the current progress I need a certain progress indicator in form of a Integer counter. However, this is not possible as I can only access final variables within the Lambda

问题 I've read a lot of documentation of JBoss Drools but cannot find a definitive answer as to if all rules are executed concurrently (certainly they are fired concurrently). More specifically, for a single input and a rule set of say 1000 rules, do the "when" conditions and the "then" conditions in each rule, execute sequentially one by one, or in parallel at the same time. On the one hand the rete algorithm implies parallelism, certainly when the select nodes are collapsed. However after the

问题 I know you might find this an odd question, but I'm just learning GCD and I want to fully understand all its aspects. So here it is: Is there ever any reason to dispatch a task SYNC on the CURRENT QUEUE? For example: dispatch_queue_t concurrentQueue = dispatch_get_global_queue(...); dispatch_async(concurrentQueue, ^{ //this is work task 0 //first do something here, then suddenly: dispatch_sync(concurrentQueue, ^{ //work task 1 }); //continue work task 0 }); I understand one thing: if instead

问题 I'm planning to use concurrent.futures.ProcessPoolExecutor to parallelize execution of functions. According to the documentation, its executor object can only accept a simple function in map . My actual situation involves initialization (loading of data) prior to execution of the 'to-be-parallelized' function. How do I arrange that? The 'to-be-parallelized' function is called in an iteration for many times. I don't want it to be re-initialized each time. In other words, there's an init

问题 As I understand it, all transactions are Thread-bound (i.e. with the context stored in ThreadLocal). For example if: I start a transaction in a transactional parent method Make database insert #1 in an asynchronous call Make database insert #2 in another asynchronous call Then that will yield two different transactions (one for each insert) even though they shared the same "transactional" parent. For example, let's say I perform two inserts (and using a very simple sample, i.e. not using an