[Boost-bugs] [Boost C++ Libraries] #2696: max_size for boost pool

Subject: [Boost-bugs] [Boost C++ Libraries] #2696: max_size for boost pool
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2009-01-29 16:06:27

#2696: max_size for boost pool
--------------------------+-------------------------------------------------
 Reporter:  nikiml        |       Owner:         
     Type:  Bugs          |      Status:  new    
Milestone:  Boost 1.38.0  |   Component:  None   
  Version:  Boost 1.37.0  |    Severity:  Problem
 Keywords:                |  
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 The malloc_needs_resize, ordered_malloc_needs_resize and ordered_malloc
 members of the pool class double the size of the chunk requested from the
 operating system every time they cannot satisfy request.

 Consider a scenario in which the client allocates about 900Mb before
 releases the initial size of the pool is 128Mb.
 on the 1st request from the client the pool will request 128 MB from the
 OS
 when the client uses 128M -> 256MB will be requested from the os
 when the client uses 384M -> 512MB will be requested from the os
 when the client uses 896M -> 1GB will be requested from the os (which is
 already likely to fail)

 when the client reaches 900M the pool will have close to 2Gb memory
 allocated from the OS.

 But the client will be perfectly happy if the pool just allocates 128M
 from the OS when it is exhausted, provided 128Mb is large enough to
 satisfy any single request from the client.

 The supplied patch allow for a cap on the chunks the pool is allocating
 from the OS.
 This is done by adding a default last parameter max_size which when left
 at the default of 0 leads to the uncapped behavior.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/2696>
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