RE: cleaning of memory in pthread_create

RE: cleaning of memory in pthread_create

[Bossom, John]

Not calling pthread_join on an undetached thread will
leak resources on ALL platforms.

John.

-----Original Message-----
From: Ross Johnson [mailto:rpj@ise.canberra.edu.au]
Sent: September 10, 2002 8:14 AM
To: pankaj bathwal
Cc: pthreads-win32@sources.redhat.com
Subject: Re: cleaning of memory in pthread_create


pankaj bathwal wrote:
> Hi,
> This is regarding freeing of resource and cleaning of
> memory allocated when "pthread_create" is called.
> Most of my memory leaks tool says 'memory leak of 120
> bytes allocated by calloc in "ptw32_new.c"'.
> Is there any call that will free memory and resources?
> Or there is some other way?

Hi Pankaj,

In your code below you have the comment about pthread_join(). Can you 
elaborate?

All threads are joinable by default, so your thread's struct won't be 
freed unless you either join the thread, or make the thread detached 
before it exits.

See the PTHREAD_CREATE_DETACHED attribute and the 
pthread_attr_setdetachstate() function.

Regards.
Ross

> 
> Regards
> 
> Pankaj
> 
> 
> This is my sample code.
> 
> 
> static int washere = 0;
> 
> void * func(void * arg)
> {
>   washere = 1;
>   std::cout<<"Inside The THREAD "<<std::endl;
>   return 0; 
> }
>  
> int main()
> {
>   pthread_t t;
> 
>   assert(pthread_create(&t, NULL, func, NULL) == 0);
> 
>   /* A dirty hack, but we cannot rely on pthread_join
> in this
>      primitive test. */
>   Sleep(2000);
>   assert(washere == 1);
>   std::cout<<"Out side the THREAD "<<std::endl;
>   return 0;
> }
> 
> 
> __________________________________________________
> Yahoo! - We Remember
> 9-11: A tribute to the more than 3,000 lives lost
> http://dir.remember.yahoo.com/tribute



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Re: cleaning of memory in pthread_create

[Ross Johnson]

pankaj bathwal wrote:
> Hi,
> This is regarding freeing of resource and cleaning of
> memory allocated when "pthread_create" is called.
> Most of my memory leaks tool says 'memory leak of 120
> bytes allocated by calloc in "ptw32_new.c"'.
> Is there any call that will free memory and resources?
> Or there is some other way?

Hi Pankaj,

In your code below you have the comment about pthread_join(). Can you 
elaborate?

All threads are joinable by default, so your thread's struct won't be 
freed unless you either join the thread, or make the thread detached 
before it exits.

See the PTHREAD_CREATE_DETACHED attribute and the 
pthread_attr_setdetachstate() function.

Regards.
Ross

> 
> Regards
> 
> Pankaj
> 
> 
> This is my sample code.
> 
> 
> static int washere = 0;
> 
> void * func(void * arg)
> {
>   washere = 1;
>   std::cout<<"Inside The THREAD "<<std::endl;
>   return 0; 
> }
>  
> int main()
> {
>   pthread_t t;
> 
>   assert(pthread_create(&t, NULL, func, NULL) == 0);
> 
>   /* A dirty hack, but we cannot rely on pthread_join
> in this
>      primitive test. */
>   Sleep(2000);
>   assert(washere == 1);
>   std::cout<<"Out side the THREAD "<<std::endl;
>   return 0;
> }
> 
> 
> __________________________________________________
> Yahoo! - We Remember
> 9-11: A tribute to the more than 3,000 lives lost
> http://dir.remember.yahoo.com/tribute

cleaning of memory in pthread_create

[pankaj bathwal]

Hi,
This is regarding freeing of resource and cleaning of
memory allocated when "pthread_create" is called.
Most of my memory leaks tool says 'memory leak of 120
bytes allocated by calloc in "ptw32_new.c"'.
Is there any call that will free memory and resources?
Or there is some other way?

Regards

Pankaj


This is my sample code.


static int washere = 0;

void * func(void * arg)
{
  washere = 1;
  std::cout<<"Inside The THREAD "<<std::endl;
  return 0; 
}
 
int main()
{
  pthread_t t;

  assert(pthread_create(&t, NULL, func, NULL) == 0);

  /* A dirty hack, but we cannot rely on pthread_join
in this
     primitive test. */
  Sleep(2000);
  assert(washere == 1);
  std::cout<<"Out side the THREAD "<<std::endl;
  return 0;
}


__________________________________________________
Yahoo! - We Remember
9-11: A tribute to the more than 3,000 lives lost
http://dir.remember.yahoo.com/tribute