Search Results

Search found 1638 results on 66 pages for 'multithreading'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 11/66 | < Previous Page | 7 8 9 10 11 12 13 14 15 16 17 18  | Next Page >

  • which xml validator will work perfectly for multithreading project

    - by Sunil Kumar Sahoo
    Hi All, I have used jdom for xml validation against schema. The main problem there is that it gives an error FWK005 parse may not be called while parsing The main reason was that multiple of threads working for xerces validation at the same time. SO I got the solution that i have to lock that validation. which is not good So I want to know which xml validator works perfectly for multithreading project public static HashMap validate(String xmlString, Validator validator) { HashMap<String, String> map = new HashMap<String, String>(); long t1 = System.currentTimeMillis(); DocumentBuilder builder = null; try { //obtain lock to proceed // lock.lock(); try { builder = DocumentBuilderFactory.newInstance().newDocumentBuilder(); // Source source = new DOMSource(builder.parse(new ByteArrayInputStream(xmlString.getBytes()))); validator.validate(new StreamSource(new StringReader(xmlString))); map.put("ISVALID", "TRUE"); logger.info("We have successfuly validated the schema"); } catch (Exception ioe) { ioe.printStackTrace(); logger.error("NOT2 VALID STRING IS :" + xmlString); map.put("MSG", ioe.getMessage()); // logger.error("IOException while validating the input XML", ioe); } logger.info(map); long t2 = System.currentTimeMillis(); logger.info("XML VALIDATION TOOK:::" + (t2 - t1)); } catch (Exception e) { logger.error(e); } finally { //release lock // lock.unlock(); builder = null; } return map; } Thanks Sunil Kumar Sahoo

    Read the article

  • Multithreaded search with UISearchDisplayController

    - by Kulpreet
    I'm sort of new to any sort of multithreading and simply can't seem to get a simple search method working on a background thread properly. Everything seems to be in order with an NSAutoreleasePool and the UI being updated on the main thread. The app doesn't crash and does perform a search in the background but the search results yield the several of the same items several times depending on how fast I type it in. The search works properly without the multithreading (which is commented out), but is very slow because of the large amounts of data I am working with. Here's the code: - (void)filterContentForSearchText:(NSString*)searchText { NSAutoreleasePool *apool = [[NSAutoreleasePool alloc] init]; isSearching = YES; //[self.filteredListContent removeAllObjects]; // First clear the filtered array. for (Entry *entry in appDelegate.entries) { NSComparisonResult result = [entry.item compare:searchText options:(NSCaseInsensitiveSearch|NSDiacriticInsensitiveSearch) range:NSMakeRange(0, [searchText length])]; if (result == NSOrderedSame) { [self.filteredListContent addObject:entry]; } } isSearching=NO; [self.searchDisplayController.searchResultsTableView performSelectorOnMainThread:(@selector(reloadData)) withObject:nil waitUntilDone:NO]; //[self.searchDisplayController.searchResultsTableView reloadData]; [apool drain]; } - (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString { [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(filteredListContent:) object:searchString]; [self.filteredListContent removeAllObjects]; // First clear the filtered array. [self performSelectorInBackground:(@selector(filterContentForSearchText:)) withObject:searchString]; //[self filterContentForSearchText:searchString]; // Return YES to cause the search result table view to be reloaded. return NO; }

    Read the article

  • iPhone Multithreaded Search

    - by Kulpreet
    I'm sort of new to any sort of multithreading and simply can't seem to get a simple search method working on a background thread properly. Everything seems to be in order with an NSAutoreleasePool and the UI being updated on the main thread. The app doesn't crash and does perform a search in the background but the search results yield the several of the same items several times depending on how fast I type it in. The search works properly without the multithreading (which is commented out), but is very slow because of the large amounts of data I am working with. Here's the code: - (void)filterContentForSearchText:(NSString*)searchText { isSearching = YES; NSAutoreleasePool *apool = [[NSAutoreleasePool alloc] init]; /* Update the filtered array based on the search text and scope. */ //[self.filteredListContent removeAllObjects]; // First clear the filtered array. for (Entry *entry in appDelegate.entries) { NSComparisonResult result = [entry.gurmukhiEntry compare:searchText options:(NSCaseInsensitiveSearch|NSDiacriticInsensitiveSearch) range:NSMakeRange(0, [searchText length])]; if (result == NSOrderedSame) { [self.filteredListContent addObject:entry]; } } [self.searchDisplayController.searchResultsTableView performSelectorOnMainThread:(@selector(reloadData)) withObject:nil waitUntilDone:NO]; //[self.searchDisplayController.searchResultsTableView reloadData]; [apool drain]; isSearching = NO; } - (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString { if (!isSearching) { [self.filteredListContent removeAllObjects]; // First clear the filtered array. [self performSelectorInBackground:(@selector(filterContentForSearchText:)) withObject:searchString]; } //[self filterContentForSearchText:searchString]; return NO; // Return YES to cause the search result table view to be reloaded. }

    Read the article

  • Recursive problem...

    - by Chronos
    Guys, I'm new to java and multithreading..... and I have a following problem: I have two classes running in two different threads. Class A and Class B. Class A has the method "onNewEvent()". Once that method is invoked, it will ask class B to do some work. As soon as B finishes the work it invokes onJobDone() method of the class A. Now... here comes the problem... what I want is to create new job within onJobDone() method and to send it again to B. here is what I do (pseudo code) ... in the sequence of execution A.onNewEvent(){ //create job //ask B to do it B.do() } B.do{ // Do some stuff A.jobDone() } A.onJobDOne(){ B.do() //doItAgain // print message "Thank you for doing it" } The problem is... that message "Thank you for doing it" never gets printed... in fact, when onJobDone() method is invoked, it invokes B.do()... because B.do() is very fast, it invokes onJobDone() immediatly... so execution flow never comes to PRINT MESSAGE part of code... I suppose this is one of the nasty multithreading problems.... any help would be appreciated.

    Read the article

  • What are some of the core principles needed to master Multi threading using Delphi?

    - by Gary Becks
    I am kind of new to programming in general (about 8 months with on and off in delphi and a little python here and there) and I am in the process of buying some books. I am interested in learning about concurrent programming and building multi threaded apps using Delphi. Whenever I do a search for "multithreading delphi" or "delphi multithreading tutorial" I seem to get conflicting results as some of the stuff is about using certain libraries (omnithread library) and other stuff seems to be more geared towards programmers with more experience. I have studied quite a few books on delphi and for the most part they seem to kind of skim the surface and not really go into depth on the subject. I have a friend who is a programmer (he uses c++) who recommends I learn what is actually going on with the underlying system when using threads as opposed to jumping into how to actually implement them in my programs first. On amazon.com there are quite a few books on concurrent programming but none of them seem to be made with Delphi in mind. Basically I need to know what are the main things I should be focused on learning before jumping into using threads, if I can/should attempt to learn them using books that are not specifically aimed at delphi developers (don't want to confuse myself reading books with a bunch of code examples in other languages right now) and if there are any reliable resources/books on the subject that anyone here could recommend. Thanks in advance.

    Read the article

  • C# Multithreading Interview questions for a senior developer/designer position.

    - by Mohit Bhandari
    I know there have been a great deal of interview questions posted on SO and specifically i like the post "Good C# interview questions for a Senior developer position" But i really wondered what sort of interview questions were asked to a senior developer or technical consultant on multithreading. Kindly provide me some of the interview questions which were asked in the interview on multithreading if possible kindly put the scenario based questions with some theoretical questions. As I came to know after disscusion with some of the people that some time interviewer might give you a scenario and ask you to implement it? @ Kindly add the specific questions which you have ever faced or asked to the other person in the interview other than only mentioning the concepts because people go through the concepts and still find it difficult to handle the interview questions.so any effort to add the specific question could actually help person to get a head start for the d-day

    Read the article

  • how to implement a "soft barrier" in multithreaded c++

    - by Jason
    I have some multithreaded c++ code with the following structure: do_thread_specific_work(); update_shared_variables(); //checkpoint A do_thread_specific_work_not_modifying_shared_variables(); //checkpoint B do_thread_specific_work_requiring_all_threads_have_updated_shared_variables(); What follows checkpoint B is work that could have started if all threads have reached only checkpoint A, hence my notion of a "soft barrier". Typically multithreading libraries only provide "hard barriers" in which all threads must reach some point before any can continue. Obviously a hard barrier could be used at checkpoint B. Using a soft barrier can lead to better execution time, especially since the work between checkpoints A and B may not be load-balanced between the threads (i.e. 1 slow thread who has reached checkpoint A but not B could be causing all the others to wait at the barrier just before checkpoint B). I've tried using atomics to synchronize things and I know with 100% certainty that is it NOT guaranteed to work. For example using openmp syntax, before the parallel section start with: shared_thread_counter = num_threads; //known at compile time #pragma omp flush Then at checkpoint A: #pragma omp atomic shared_thread_counter--; Then at checkpoint B (using polling): #pragma omp flush while (shared_thread_counter > 0) { usleep(1); //can be removed, but better to limit memory bandwidth #pragma omp flush } I've designed some experiments in which I use an atomic to indicate that some operation before it is finished. The experiment would work with 2 threads most of the time but consistently fail when I have lots of threads (like 20 or 30). I suspect this is because of the caching structure of modern CPUs. Even if one thread updates some other value before doing the atomic decrement, it is not guaranteed to be read by another thread in that order. Consider the case when the other value is a cache miss and the atomic decrement is a cache hit. So back to my question, how to CORRECTLY implement this "soft barrier"? Is there any built-in feature that guarantees such functionality? I'd prefer openmp but I'm familiar with most of the other common multithreading libraries. As a workaround right now, I'm using a hard barrier at checkpoint B and I've restructured my code to make the work between checkpoint A and B automatically load-balancing between the threads (which has been rather difficult at times). Thanks for any advice/insight :)

    Read the article

  • Are there any .net classes/functions that are optimized for multiple cores?

    - by diamandiev
    I know that the developer is supposed to do this himself. But seeing how we are getting cpu's with more and more cores and there are still many developers who do not use multithreading, if we have this functionality built in, it could increase performance dramatically in some scenarios. One particular example where this could be quite useful is in image processing. I doubt that the built in GDI+ classes are multithreaded.

    Read the article

  • How to find buggy class in java?

    - by I.Randanad
    I have a big program on java, that uses multithreading. In some case, the program starts loading 100% of three cores of my eigth cores system. In normal use, the program use all cores of 1-2 percent loading. How can i find a class, that overloading cores?

    Read the article

  • Is it safe to make GL calls with multiple threads?

    - by user146780
    I was wondering if it was safe to make GL calls with multiple threads. Basically I'm using a GLUtesselator and was wondering if I could divide the objects to draw into 4 and assign a thread to each one. I'm just wondering if this would cause trouble since the tesselator uses callback functions. Can 2 threads run the same callback at the same time as long as that callback does not access ant global variables? Are there also other ways I could optimize OpenGL drawing using multithreading? Thanks

    Read the article

  • WPF custom BalloonTips problem with multithreading

    - by Erika
    Hi, I have read other related question but i cant really get them to relate to this so I thought it were best to ask, Im pretty new to WPF and so on so please bear with me. I am using this http://www.codeproject.com/KB/WPF/wpf_notifyicon.aspx api to work with custom WPF Windows (in particular FancyBalloon). However, i'm coming across the following problem, I seem unable to start off BalloonTips in a separate thread ( i need this because i'm parsing emails and hence if there are 3 emails for instance, it displays the first email (that works fine), but when it comes to the second email it crashes with a TargetInvocationException , {"Specified element is already the logical child of another element. Disconnect it first."}. Thing is, im supposedly working with the same instance and i have attempted calling it to close it before, disposing it etc but to no avail. (then again if i dispose it, i cant create another instance as apparently WPF UI components must be called from a static thread so throughout the looping of emails + displaying balloon, i am trying to use the same BalloonTip. Any suggestions please? I am really at a loss here and i've been on it for quite a while now :/ I was wondering if there was anyone

    Read the article

  • Why do we get a sudden spike in response times?

    - by Christian Hagelid
    We have an API that is implemented using ServiceStack which is hosted in IIS. While performing load testing of the API we discovered that the response times are good but that they deteriorate rapidly as soon as we hit about 3,500 concurrent users per server. We have two servers and when hitting them with 7,000 users the average response times sit below 500ms for all endpoints. The boxes are behind a load balancer so we get 3,500 concurrents per server. However as soon as we increase the number of total concurrent users we see a significant increase in response times. Increasing the concurrent users to 5,000 per server gives us an average response time per endpoint of around 7 seconds. The memory and CPU on the servers are quite low, both while the response times are good and when after they deteriorate. At peak with 10,000 concurrent users the CPU averages just below 50% and the RAM sits around 3-4 GB out of 16. This leaves us thinking that we are hitting some kind of limit somewhere. The below screenshot shows some key counters in perfmon during a load test with a total of 10,000 concurrent users. The highlighted counter is requests/second. To the right of the screenshot you can see the requests per second graph becoming really erratic. This is the main indicator for slow response times. As soon as we see this pattern we notice slow response times in the load test. How do we go about troubleshooting this performance issue? We are trying to identify if this is a coding issue or a configuration issue. Are there any settings in web.config or IIS that could explain this behaviour? The application pool is running .NET v4.0 and the IIS version is 7.5. The only change we have made from the default settings is to update the application pool Queue Length value from 1,000 to 5,000. We have also added the following config settings to the Aspnet.config file: <system.web> <applicationPool maxConcurrentRequestsPerCPU="5000" maxConcurrentThreadsPerCPU="0" requestQueueLimit="5000" /> </system.web> More details: The purpose of the API is to combine data from various external sources and return as JSON. It is currently using an InMemory cache implementation to cache individual external calls at the data layer. The first request to a resource will fetch all data required and any subsequent requests for the same resource will get results from the cache. We have a 'cache runner' that is implemented as a background process that updates the information in the cache at certain set intervals. We have added locking around the code that fetches data from the external resources. We have also implemented the services to fetch the data from the external sources in an asynchronous fashion so that the endpoint should only be as slow as the slowest external call (unless we have data in the cache of course). This is done using the System.Threading.Tasks.Task class. Could we be hitting a limitation in terms of number of threads available to the process?

    Read the article

  • Parralelization in Microsoft SQL Server 2008 R2

    - by stan31337
    We have a specific accounting and production software, called 1C, which uses single user connection to the MS SQL 2008 R2 database. And there are about 500 users connecting to 1C server to perform their tasks. 1C and SQL 2008 are on separate servers. How to configure MS SQL 2008 R2 to effectively use parallelization in this configuration? We have 24 cores, and only one is loaded at 100% at MS SQL 2008 R2 server. We have already configured MS SQL max parallelizm from this MSDN article: http://msdn.microsoft.com/en-us/library/ms181007(v=sql.105).aspx Thank you!

    Read the article

  • 613 threads limit on debian

    - by Joel
    When running this program thread-limit.c on my dedicated debian server, the output says that my system can't create more than around 600 threads. I need to create more threads, and fix my system misconfiguration. Here are a few informations about my dedicated server: de801:/# uname -a Linux de801.ispfr.net 2.6.18-028stab085.5 #1 SMP Thu Apr 14 15:06:33 MSD 2011 x86_64 GNU/Linux de801:/# java -version java version "1.6.0_26" Java(TM) SE Runtime Environment (build 1.6.0_26-b03) Java HotSpot(TM) 64-Bit Server VM (build 20.1-b02, mixed mode) de801:/# ldd $(which java) linux-vdso.so.1 => (0x00007fffbc3fd000) libpthread.so.0 => /lib/libpthread.so.0 (0x00002af013225000) libjli.so => /usr/lib/jvm/java-6-sun-1.6.0.26/jre/bin/../lib/amd64/jli/libjli.so (0x00002af013441000) libdl.so.2 => /lib/libdl.so.2 (0x00002af01354b000) libc.so.6 => /lib/libc.so.6 (0x00002af013750000) /lib64/ld-linux-x86-64.so.2 (0x00002af013008000) de801:/# cat /proc/sys/kernel/threads-max 1589248 de801:/# ulimit -a core file size (blocks, -c) 0 data seg size (kbytes, -d) unlimited scheduling priority (-e) 0 file size (blocks, -f) unlimited pending signals (-i) 794624 max locked memory (kbytes, -l) 32 max memory size (kbytes, -m) unlimited open files (-n) 10240 pipe size (512 bytes, -p) 8 POSIX message queues (bytes, -q) 819200 real-time priority (-r) 0 stack size (kbytes, -s) 128 cpu time (seconds, -t) unlimited max user processes (-u) unlimited virtual memory (kbytes, -v) unlimited file locks (-x) unlimited Here is the output of the C program de801:/test# ./thread-limit Creating threads ... Address of c = 1061520 KB Address of c = 1081300 KB Address of c = 1080904 KB Address of c = 1081168 KB Address of c = 1080508 KB Address of c = 1080640 KB Address of c = 1081432 KB Address of c = 1081036 KB Address of c = 1080772 KB 100 threads so far ... 200 threads so far ... 300 threads so far ... 400 threads so far ... 500 threads so far ... 600 threads so far ... Failed with return code 12 creating thread 637. Any ideas how to fix this please ?

    Read the article

  • Apache2 MPM-prefork MPM-worker multiple instances on same Ubuntu host machine possible?

    - by user60985
    I have a live Apache2/MPM-Worker instance running Django. I want to also run an Apache2/MPM-prefork instance to run some Drupal6 applications on the same host machine and utilize a vast selection of PHP modules that run on the prefork model. I plan to use my MPM-worker instance to reverse proxy to the Apache2-prefork instance for URLS starting with myhost.com/drupal6/. It seems theoretically doable/configurable by having the second Apache2-prefork instance configured to listen on an internal port, say 127.0.0.1:8080 and having my current Apache2-worker configured to proxy pass and reverse pass to it for the 'drupal6' URLs. However, how do I compile or install the apache2-prefork version so it has a different executable name than /usr/sbin/apache2, for example /usr/sbin/apache2p, and so apache2ctl has a different name, say apache2pctl, and that apache2pctl invokes the /usr/sbin/apache2p instead of /usr/sbin/apache2... and so on down the line (eg /etc/apache2p) so I can start and restart my two instances independently? As I understand it, no one executable of 'apache2' can be compiled with both the MPM-prefork and MPM-worker modules, so it seems I need two separate versions of the apache2 MPM flavors. But then I need to invoke and control them by separate names, I assume. I looked at the configuration options for apache2 and I am a bit queasy about compiling a second apache2 version with prefork because I am not sure I can set all the options so that none of my current apache2 files is overwritten. Is there a way? Is there a standard solution to separately installing and controlling prefork and worker apache2 executables on the same machine without them stepping on each other during installation or operation?

    Read the article

  • Tomcat performing terribly for no apparent reason

    - by John
    We're running a game application .WAR on Tomcat 6 on an Amazon EC2 server, 8 core processor, 7gb RAM. The application uses a MySQL database hosted on Amazon RDS. This Facebook application takes ages to access when a mere 20-30 users are playing it. Big difference from 1-2 users. The entire .WAR is ~4mb, all static content hosted elsewhere. The server has never been close to running out of RAM. The CPU utilization has never been higher than 13.5-14%. Even with ~500 users that completely slowed everything to a standstill. The thread count or threadpools isn't close to being maxed out. I heightened maxthreads but it didn't make a noticeable difference. My theory is that Tomcat can only use one processor core, which would explain why it was slowed to a halt even though CPU usage was stably at 13-14% at the activity spike. But I'm struggling to understand why it would only use one CPU core. There is no processor cap in server.xml. The app contains several servlets (4 or 5). There is no mention of SingleThreadModel in the Java code. WHAT could be causing the application to run extremely slowly? If there is only 1-5 people on the application it runs fine. With 20-30 people it's barely contactable.

    Read the article

  • Linux Scheduler (not using all cores on multi-core machine) RHEL6

    - by User512
    I'm seeing strange behavior on one of my servers (running RHEL 6). There seems to be something wrong with the scheduler. Here's the test program I'm using: #include <stdio.h> #include <unistd.h> #include <stdlib.h> void RunClient(int i) { printf("Starting client %d\n", i); while (true) { } } int main(int argc, char** argv) { for (int i = 0; i < 4; ++i) { pid_t p_id = fork(); if (p_id == -1) { perror("fork"); } else if (p_id == 0) { RunClient(i); exit(0); } } return 0; } This machine has a lot more than 4 cores so we'd expect all processes to be running at 100%. When I check on top, the cpu usage varies. Sometimes it's split (100%, 33%, 33%, 33%), other times it's split (100%, 100%, 50%, 50%). When I try this test on another server of ours (running RHEL 5), there are no issues (it's 100%, 100%, 100%, 100%) as expected. What's causing this and how can I fix it? Thanks

    Read the article

  • Multithreading and Interrupts

    - by Nicholas Flynt
    I'm doing some work on the input buffers for my kernel, and I had some questions. On Dual Core machines, I know that more than one "process" can be running simultaneously. What I don't know is how the OS and the individual programs work to protect collisions in data. There are two things I'd like to know on this topic: (1) Where do interrupts occur? Are they guaranteed to occur on one core and not the other, and could this be used to make sure that real-time operations on one core were not interrupted by, say, file IO which could be handled on the other core? (I'd logically assume that the interrupts would happen on the 1st core, but is that always true, and how would you tell? Or perhaps does each core have its own settings for interrupts? Wouldn't that lead to a scenario where each core could react simultaneously to the same interrupt, possibly in different ways?) (2) How does the dual core processor handle opcode memory collision? If one core is reading an address in memory at exactly the same time that another core is writing to that same address in memory, what happens? Is an exception thrown, or is a value read? (I'd assume the write would work either way.) If a value is read, is it guaranteed to be either the old or new value at the time of the collision? I understand that programs should ideally be written to avoid these kinds of complications, but the OS certainly can't expect that, and will need to be able to handle such events without choking on itself.

    Read the article

  • Coredump in Multithreading Application in RHEL-5

    - by Chinnu
    I am working on multi-threading application it is dumping frequently.I could not able to analyaze the core.The core is showing like this Core was generated by 'thread-process'. Program terminated with signal 6, Aborted. #0 0x00000038f4e30045 in raise () from /lib64/libc.so.6 (gdb) where #0 0x00000038f4e30045 in raise () from /lib64/libc.so.6 #1 0x00000038f4e31ae0 in abort () from /lib64/libc.so.6 #2 0x00000038f4e681bb in __libc_message () from /lib64/libc.so.6 #3 0x00000038f4e72b96 in free () from /lib64/libc.so.6 #4 0x000000000046a137 in std::string::substr () #5 0x000000000042c549 in std::operator<< <char, std::char_traits<char>, std::allocator<char> > () #6 0x000000000042cc1d in std::operator<< <char, std::char_traits<char>, std::allocator<char> > () #7 0x000000000046b069 in std::string::substr () #8 0x000000000046c866 in std::string::substr () #9 0x0000000000431062 in std::operator<< <char, std::char_traits<char>, std::allocator<char> > () #10 0x00000038f5a062e7 in start_thread () from /lib64/libpthread.so.0 #11 0x00000038f4ece3bd in clone () from /lib64/libc.so.6

    Read the article

  • Poor SSL performance with vsftpd

    - by petrus
    I'm trying to tweak vsftpd to achieve maximum performance for my usage: I have only one or two clients that connect to the server. File size is between ~15MB and 1GB. Typical transfer batch represent between 1 and 2GB of data. For testing purposes, I'm using a tmpfs on both sides (thus eliminating any disks bottleneck) with a single 1GB file. When SSL is disabled, performance is good, with a transfer rate at ~120MB/s (reaching the limits of gigabit networking). With SSL enabled only for control traffic (and not data traffic), performance drops at about 112MB/s, which is still within the acceptable limits. However, when SSL is enabled for data flows, the transfer speed drops dramatically: 6.7MB/s using 3DES & SHA (ssl_ciphers=DES-CBC3-SHA in vsftpd.conf) 16MB/s using DES & SHA (ssl_ciphers=DES-CBC-SHA) I didn't tested other ciphers, but from what I can see from the CPU usage during the transfer, it seems that vsftpd is only using a single cpu/core per client. While this can fit for large ftp sites with hundreds of clients, I'd like to avoid this behavior and use more ressources on the server. On a side note, if you have any ideas regarding other openssl ciphers...

    Read the article

  • Remote Socket Read In Multi-Threaded Application Returns Zero Bytes or EINTR (104)

    - by user39891
    Hi. Am a c-coder for a while now - neither a newbie nor an expert. Now, I have a certain daemoned application in C on a PPC Linux. I use PHP's socket_connect as a client to connect to this service locally. The server uses epoll for multiplexing connections via a Unix socket. A user submitted string is parsed for certain characters/words using strstr() and if found, spawns 4 joinable threads to different websites simultaneously. I use socket, connect, write and read, to interact with the said webservers via TCP on their port 80 in each thread. All connections and writes seems successful. Reads to the webserver sockets fail however, with either (A) all 3 threads seem to hang, and only one thread returns -1 and errno is set to 104. The responding thread takes like 10 minutes - an eternity long:-(. *I read somewhere that the 104 (is EINTR?), which in the network context suggests that ...'the connection was reset by peer'; or (B) 0 bytes from 3 threads, and only 1 of the 4 threads actually returns some data. Isn't the socket read/write thread-safe? I use thread-safe (and reentrant) libc functions such as strtok_r, gethostbyname_r, etc. *I doubt that the said webhosts are actually resetting the connection, because when I run a single-threaded standalone (everything else equal) all things works perfectly right, but of course in series not parallel. There's a second problem too (oops), I can't write back to the client who connect to my epoll-ed Unix socket. My daemon application will hang and hog CPU 100% for ever. Yet nothing is written to the clients end. Am sure the client (a very typical PHP socket application) hasn't closed the connection whenever this is happening - no error(s) detected either. Any ideas? I cannot figure-out whatever is wrong even with Valgrind, GDB or much logging. Kindly help where you can.

    Read the article

  • phpredis + pconnect

    - by john smith
    I am using phpredis on my php based website. The webserver I am using is a the simplest apache apt-get installation, no configuration involved, as this is only a development environment. The issue I am facing is that basically, while using phpredis, there is no difference between "connect" and "pconnect" commands: they both create a new connection everytime, as I can see from the "info" command on redis-cli. Now, I am pretty sure it is because of the apache configuration and the fact that it probably (most likely) is a multi-threaded env, therefore can't enstablish a single connection. My question is basically for when I will turn into production: what would the best choice of a webserver be to avoid this problem? I remember using lighttpd with thousands of users and still get only a very few (like 2 or 3) connections on mongoDB. Any ideas? Thanks in advance.

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 7 8 9 10 11 12 13 14 15 16 17 18  | Next Page >