pool

问题 I want to create Oracle UCP using this code: import oracle.ucp.jdbc.PoolDataSource; import oracle.ucp.jdbc.PoolDataSourceFactory; System.out.println("***** OracleDS_UCP -> start init of PoolDataSource"); PoolDataSource pool = PoolDataSourceFactory.getPoolDataSource(); pool.setConnectionFactoryClassName("oracle.jdbc.pool.OracleDataSource"); pool.setURL("jdbc:oracle:thin:@localhost:1521:XE"); pool.setUser("test"); pool.setPassword("test"); pool.setMaxStatements(10); // the maximum number of

问题 I know that Java and C# both use a string pool to save memory when dealing with string literals. Does Objective-C use any such mechanism? If not, why not? 回答1: Yes, string literals like @"Hello world" are never released and they point to the same memory which means that pointer comparison is true. NSString *str1 = @"Hello world"; NSString *str2 = @"Hello world"; if (str1 == str2) // Is true. It also means that a weak string pointer won't change to nil (which happens for normal objects) since

问题 This question may be a duplicate. However, I read lot of stuff around on this topic, and I didn't find one that matches my case - or at least, I didn't understood it. Sorry for the inconvenance. What I'm trying to do is fairly common, passing a list of kwargs to pool.starmap(), to achieve multiprocessing. Here's my reduced case: def compute(firstArg, **kwargs): # A function that does things # Fancy computing stuff... # Saving to disk... return True if __name__ == '__main__': args = [{

问题 I need to manage long running TCP socket connections to an external server from my Java application. I'm looking for a good socket pool so I will be able to re-use the sockets. There is another solution than org.apache.commons.pool2 ? 回答1: Here are some object pool implementations you may try: Vibur Object Pool fast-object-pool I suggest you to benchmark the object pool implementations in order to find the most appropriate one for your project. 来源： https://stackoverflow.com/questions/43735067

问题 I have a Python program that takes around 10 minutes to execute. So I use Pool from multiprocessing to speed things up: from multiprocessing import Pool p = Pool(processes = 6) # I have an 8 thread processor results = p.map( function, argument_list ) # distributes work over 6 processes! It runs much quicker, just from that. God bless Python! And so I thought that would be it. However I've noticed that each time I do this, the processes and their considerably sized state remain, even when p

问题 I am trying some performance benchmark regarding String Pool. However, the outcome is not expected. I made 3 static methods perform0() method ... creates a new object every time perform1() method ... String literal "Test" perform2() method ... String constant expression "Te"+"st" My expectation was (1. fastest -> 3. slowest) "Test" because of string pooling "Te"+"st" because of string pooling but bit slower than 1 because of + operator new String(..) because of no string pooling. But the

问题 I notice this behavior in python for the pool allocation. Even though I have 20 processes in the pool, when I do a map_async for say 8 processes, instead of throwing all the processes to execute, I get only 4 executing. when those 4 finish, it sends two more, and then when those two finish is sends one. When I throw more than 20 at it, it runs all 20, until it starts to get less than 20 in the queue, when the above behavior repeats. I assume this is done on purpose, but it looks weird. My

问题 I use a Pool to run several commands simultaneously. I would like to don't print the stack-trace when the user interrupt the script. Here is my script structure: def worker(some_element): try: cmd_res = Popen(SOME_COMMAND, stdout=PIPE, stderr=PIPE).communicate() except (KeyboardInterrupt, SystemExit): pass except Exception, e: print str(e) return #deal with cmd_res... pool = Pool() try: pool.map(worker, some_list, chunksize = 1) except KeyboardInterrupt: pool.terminate() print 'bye!' By

问题 I am making a condensed (only upper right) distance matrix. The calculation of the distance takes some time, so I want to paralelise the for loop. The unparelalised loop looks like spectra_names, condensed_distance_matrix, index_0 = [], [], 0 for index_1, index_2 in itertools.combinations(range(len(clusters)), 2): if index_0 == index_1: index_0 += 1 spectra_names.append(clusters[index_1].get_names()[0]) try: distance = 1/float(compare_clusters(clusters[index_1], clusters[index_2],maxiter=50))

问题 I'm using GlassFish 3 and I can't seem to get it to recognize the MySql connector. The admin console always says: Ping Connection Pool for --- is Failed. Ping failed Exception - Class name is wrong or classpath is not set for : com.mysql.jdbc.jdbc2.optional.MysqlDataSource Please check the server.log for more details. However, JPA can connect even with the error. The only downside is that I get resize pool exceptions (null). I've even placed the connector in the following folders: %GLASSFISH%