Looking at the code, by 1st guess would be that you have a race condition. tObj->runthread() is getting executed before tObj->createthead() has finished its business and the worker thread has actually entered the mutex. Meaning that tObj->runthread() calls the notify_one() BEFORE the actual worker thread does a wait. Thus when your threadproc does a lock and then a wait, it will wait forever because nothing will do the notify_one() again. Race conditions are funny things, may work perfectly on one box forever, then change one line of code, or take it to another system and bad things happen. May also behave differently under different OS's - mutexes are a prime examle of this, under Windows they seem to be recursive by default, but not under LINUX. A down and dirty way to see if my theory is correct, put in a delay between the tObj->createthread() and tObj->runthread() lines. Hope this helps - if it does praise me with thanx, if it doesn't it was a crackpot theory or I haven't had sufficient coffee yet to make an intelligent analysis - you pick. :-) good luck, - Patrick -----Original Message----- From: boost-users-bounces@lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Michael Glassford Sent: Wednesday, February 11, 2004 7:40 AM To: Boost Users mailing list Subject: [Boost-users] Re: Re: Thread creation state What I meant was, can you post a complete sample that you have actually compiled and run and that has actually demonstrated the problem? That obviously isn't the case with the code you posted because it contains syntax errors and the main() function in your second post doesn't match the definition of the testCommand class in your first post. Having said that, I fixed the errors the best I could and don't see the problem. It would help if you could: 1) Tell me what compiler and compiler version you're using. 2) Tell me what Boost version you're using. 3) Post a complete code sample that demonstrates the problem. 4) Specify what compile and link options you're using (perhaps you could attach a make file or project file?) Sorry; I'm trying to help, but if you want me to be able to figure out the problem you'll have to help me out. Mike ----- Original Message ----- From: <janardhan.guptha@efi.com> Newsgroups: gmane.comp.lib.boost.user Sent: Tuesday, February 10, 2004 11:32 PM Subject: RE: Re: Thread creation state
The rest of the applicatin is just creating the object and preparing
it
for execution. I am using Win32 version of boost.Thread implementation.
The creation code snipet is
void main() { testCommand *tObj = new testCommand(11); tObj->createthread(); tObj->runthread(); }
-----Original Message----- From: boost-users-bounces@lists.boost.org [mailto:boost-users-bounces@lists.boost.org]On Behalf Of Michael Glassford Sent: Wednesday, February 11, 2004 12:17 AM To: boost-users@lists.boost.org Subject: [Boost-users] Re: Thread creation state
It would be a lot easier to help if you could post a complete, compilable example that demonstrates the problem. Also, it would be useful to know whether you are using the Win32, pthread, or Mac implementation of Boost.Thread.
Thanks,
Mike
<janardhan.guptha@efi.com> wrote in message news:433CFA26BCA852438922F929E3D07955AE53A7@blraddc02.efi.internal...
I am creating a boost thread, how to know in which state it is created. I have a code snippet that is waiting always in the thread creatin functon istelf. Where as i tried with some boost samples, they are working amazingly perfect. This is how my code snippet looks like
typedef boost::mutex::scoped_lock lock; class testCommand { static void threadfunc() { testCommand *testObj = mMapCommand[mObjID]; testObj->processthread(); };
static map< int mObjID, testCommand*> mMapCommand; private: void createthread() { mThread = new boost::thread(&testCommand::threadfunc); } void processthread() { lock lk(mMutex); mCondition.wait(lk); //// Some Action };
void runthread() { lock lk(mMutex); mCondition.notify_one(); };
public: static int mObjID; boost::thread *mThread; boost::condition mCondition; boost::mutex mMutex; };
The newly created thread is waiting at the following location forever, by the time i get a chance to execute the new thread is greatly delayed.
NTDLL! 77f8856e() boost::detail::thread::lock_ops<boost::mutex>::unlock(boost::mutex & {...}) line 49 boost::detail::thread::scoped_lock<boost::mutex>::unlock() line 85 + 11 bytes
boost::detail::thread::scoped_lock<boost::mutex>::~scoped_lock<boost:: mutex>
() line 74 `anonymous namespace'::thread_param::started() line 47 + 15 bytes thread_proxy(void * 0x0012fd74) line 71 _threadstartex(void * 0x00961040) line 212 + 13 bytes KERNEL32! 7c57b382()
It sounds like i am missing something here. The queries here are 1. why it is waiting at the above specified line forever ? 2. Where can i get few worth thread samples done using boost::thread
Regards Janardhan
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