Date: Sun, 23 May 2004 00:20:09 +0300 From: Alex Keahan <alex@hightemplar.com> To: "Cole" <cole@opteqint.net>, <freebsd-hackers@freebsd.org> Subject: Re: Pthread_create and memory issues. Message-ID: <200405230020.09482.alex@hightemplar.com> In-Reply-To: <000701c44034$89dbffb0$4206000a@stalker> References: <000701c44034$89dbffb0$4206000a@stalker>
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On Saturday 22 May 2004 10:39 pm, Cole wrote: > Hi > > Ok this is just a more direct question that the thread Memory Leak. > > I have a program using pthread_create, and it runs fine, no compile errors > or warnings, it all works fine, not a single issue, but it very very slowly > uses up memory. The program creates a fixed number of threads, and after > each one has run to completion it stores them for a while for use again if > needed soon, else it destroys them after a specified amount of time. Cole, Are you certain it's not a bug in your code? A thread's resources are not immediately released at termination, unless the thread was created with the detachstate attribute set to PTHREAD_CREATE_DETACHED, or if pthread_detach has been called for its pthread_t. An undetached thread remains in the terminated state until its identifier is passed to pthread_join or pthread_detach. At a minimum, a terminated thread retains its pthread_t identifier and the return value that was returned from the thread's run function (or the value specified in a call to pthread_exit). To sum it up, you have three options: 1) create your threads detached (PTHREAD_CREATE_DETACHED attribute), 2) detach them after creation (pthread_detach), or 3) join with the terminated threads to recycle them (pthread_join). Alex Keahan > > Now i have tried to use ElectricFence to try track down the program, and it > created cores all pointing round about to pthread_create. So then i tried > to use mpatrol, and it either doesnt even crash, or cause errors, or it > creates a core file that is so large with so many instructions, that is > well over 1000 instruction calls, but as far as i can see they both seem to > be pointing to pthread_create. With mpatrol i set > MPATROL_OPTIONS=LEAKTABLE, but it never produces any output and crashes > before i can even test the program. It also uses up close to 100% of the > cpu before crashing. > > I was just wondering if anyone else has had any other memory debugging > program suggestions, or has had any issues with pthread_create. > > If you want i can post the code or at the very least my pthread_create > call. > > Thanks > /Cole
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