http://android.git.kernel.org/?p=platform/frameworks/base.git;a=blob;f=core/java/android/util/Pools.java;h=8edb3e60405ed70f0b97b477b48c53fcab88c631;hb=donut
On Sat, Jul 18, 2009 at 4:38 AM, Fred Grott(shareme)<[email protected]> wrote: > > Romain, was it renamed cannot find it by your link.. > > On Jul 15, 3:55 pm, Romain Guy <[email protected]> wrote: >> We have an efficient implementation for you: use thePools.java file >> fromhttp://android.git.kernel.org/?p=platform/frameworks/base.git;a=tree;... >> (and the associated classes.) These are not public APIs so just copy >> the code in your application. >> >> Here's an example of a Poolable object with this API: >> static class InvalidateInfo implements Poolable<InvalidateInfo> { >> private static final int POOL_LIMIT = 10; >> private static final Pool<InvalidateInfo> sPool >> =Pools.synchronizedPool( >> Pools.finitePool(new PoolableManager<InvalidateInfo>() { >> public InvalidateInfo newInstance() { >> return new InvalidateInfo(); >> } >> >> public void onAcquired(InvalidateInfo element) { >> } >> >> public void onReleased(InvalidateInfo element) { >> } >> }, POOL_LIMIT) >> ); >> >> private InvalidateInfo mNext; >> >> public void setNextPoolable(InvalidateInfo element) { >> mNext = element; >> } >> >> public InvalidateInfo getNextPoolable() { >> return mNext; >> } >> >> static InvalidateInfo acquire() { >> return sPool.acquire(); >> } >> >> void release() { >> sPool.release(this); >> } >> } >> >> >> >> On Wed, Jul 15, 2009 at 1:48 PM, Brad Larson<[email protected]> wrote: >> >> > At Google I/O and in the forums, it has been clear that if you need >> > optimal performance, you must avoid memory allocation inside tight >> > loops. I'm curious about the best way to handle this in my use-case, >> > which I think must be fairly common. I need to access at most n >> > objects of type MyObject, I need to iterate over them during every >> > screen refresh, and I need to remove them and put them back in the >> > object pool randomly. >> >> > The object pool seems pretty straight-forward, just use a >> > Vector<MyObject>(n), add n copies of MyObject at bootup, and add/ >> > remove from the end to avoid any memcpy or allocation. >> >> > The iterating is a little more difficult. I can use for(MyObject m : >> > myObjects), but this will allocate memory to create the iterator. I >> > could create a static final Iterator at bootup, but there is no good >> > way to get back to the start of the List. For now, I'm using another >> > Vector for active MyObjects, and a for loop with an int to get() the >> > objects and avoid allocating an iterator. get() runs in constant time >> > for a Vector, so this works well. >> >> > However, when an object is done, I need to remove it and send it back >> > to the pool. If I use Vector.remove(i), it has to memcpy everything >> > after i. I could use an Iterator on a LinkedList, which can remove() >> > in constant time, but I don't think there is a good way to get the >> > Iterator back to the start of the list without allocating memory. I >> > could use an int to loop through a LinkedList, but LinkedList.get(n) >> > runs in O(n) time. >> >> > Any tips on the optimal way to solve this? Worst-case, I assume the >> > memcpy called during Vector.remove() is a better bet over allocating >> > an Iterator inside my app loop, correct? >> >> > Thanks! >> > Brad >> >> -- >> Romain Guy >> Android framework engineer >> [email protected] >> >> Note: please don't send private questions to me, as I don't have time >> to provide private support. All such questions should be posted on >> public forums, where I and others can see and answer them > > > -- Romain Guy Android framework engineer [email protected] Note: please don't send private questions to me, as I don't have time to provide private support. All such questions should be posted on public forums, where I and others can see and answer them --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -~----------~----~----~----~------~----~------~--~---
