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Subject RE: apr_palloc is not thread safe
Date Fri, 31 May 2013 04:15:53 GMT
Thanks for reply, I got it.  Now the problem is my APIs does not expose apr_pool_t to user
like apr,  so my APIs are not thread safe.

Best Regards
Chunwei Liu

-----Original Message-----
From: Philip Martin [] On Behalf Of Philip Martin
Sent: Thursday, May 30, 2013 17:22 troy
To: TROY.LIU 劉春偉
Subject: Re: apr_palloc is not thread safe


>   In our practice, we found two threads get same address returned by
>   apr_palloc. It will happen about one hour later after our server
>   starts.  We are using apr 1.4.5, the issue still exists in the
>   latest subversion.

From apr_pools.h:

 * Note that most operations on pools are not thread-safe: a single pool
 * should only be accessed by a single thread at any given time. The one
 * exception to this rule is creating a subpool of a given pool: one or more
 * threads can safely create subpools at the same time that another thread
 * accesses the parent pool.

The pool system allows multiple threads to use multiple pools.  There is no point trying to
make apr_palloc "thread-safe" as the API is not designed to work that way.  Even if apr_palloc
was "thread-safe" how would apr_pool_clear work?

A related discussion:


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