There's a tension in platform optimization. Whether it's CPUs or runtimes, people who make platforms tend to look at where they can get the biggest wins for existing apps. So if you bend over backwards to do weird things that get you performance, that weirdness will be exactly what prevents you from getting as big a potential win from future platform optimizations.
With GC in particular, that usually means avoiding the creation of objects that die in middle age. Most GCs are optimized for objects that are ephemeral or long-lived. Ephemeral objects have too few references and not long enough of a lifetime to survive multiple GCs. Long-lived objects live too long to be worth collecting for most GCs. Generational GC uses this to split memory into at least 3 logical buckets (survived 0 GCs, survived at least 1 GC, and long-lived).
Working hard to reuse objects means those objects will become part of the long-lived heap. But reusing them means updating their fields, including their references to other objects, which means they still need to be scanned. So they'll increase the cost of what ought to be cheap GCs of the ephemeral objects; writes to them needs to be accounted, and they need to be included as roots.
The situation becomes even worse if you reuse an object for some time, but eventually find some of them surplus to requirements (the middle age problem).
The costs of designing an application to reuse objects are not to be sniffed at either. It's a reinvention of a typed memory allocator, with all the benefits and drawbacks of manual allocation. Best kept to the implementation-side of properly scoped modules. Don't let the approach pervasively infect the entire app.
Look what happened to Minecraft when they stopped caring about allocations: http://what.thedailywtf.com/t/optifine-modder-rips-the-minec... It's allocating 150 MB/second. It's now much slower than it was before.
I've been developing on Android since the 1.x days. Garbage collection has and continues to suck on Android.
People should not be so blind to think that better garbage collection is going to appear soon, and that a real world improved garbage collector will magically make all the GC related performance problems go away.
Google has demonstrated over and over that they are extremely slow to improve things in Android (see Java version support, see audio latency, see NDK, see Eclipse/Gradle transition, etc). And when they do finally improve things, it usually is still lacking.
Garbage collection in general is hard to get right. Even in better environments with highly optimized/tuned GCs, it still causes problems. It is unlikely Android is going to leap frog these.
Not to mention their last Google Play Services update that gets forced to all users automatically is causing wakelocks wanting to update the system, which wrecks havoc on custom ROMs : http://review.cyanogenmod.org/#/c/91021/
Google Android, thank you, not anymore.
Before Google Play Services existed, there was already a mechanism in place that checked for OTA updates. It was in AOSP and could be easily disabled for custom ROMs. Remember those custom ROMs Google was so proud of when they advertised "open source" and how Android was dedicated to it ?
Then in a full "bait and switch" manner they placed everything in the Google Play Services. AOSP doesn't matter anymore, but the proprietary code no one has control of, except the Mountainview mothership. If CyanogenMod didn't disable those services, they would constantly download OTA package to /cache wasting user bandwidth and resources as in wakelocking the device causing battery drain. Is this "responsible programming" ?
My personal experience with the new GPS 7.0 update woes doesn't even include a custom ROM. I had Googles Nexus 5 factory image of Kitkat 4.4.4 installed and blocked the GPS SystemUpdate receivers manually to avoid OTA updates to Lollipop 5.0 .Why ? Because I don't want an update that turns a well working OS to one which leaks memory and has to be rebooted every two days. It's my choice. Other vendors include an option, whether user wants update notifications or not. Not on Googles turf, they want to force you with their beta software, then turn the head away when there are issues without comments when they'll be fixed.
"Can you ask for too many permissions? Short answer is no ... Our personal experience and that of other startups we’ve chatted with suggest any effect is overplayed. Just by browsing the Play store, you can easily find popular apps, including Facebook, WhatsApp, and Candy Crush, that ask for a lot of permissions. Most users scan the permission requests, and a list with 3 vs 5 permissions makes no difference."
Everything wrong with Android permissions in a single paragraph.
When security relies on users making good secure decisions, you've failed. If Internet Explorer taught us anything it's that people will always click YES to punch the monkey, certificates/sandboxes/policies be damned.
And we already DO have OS that caters to that demographic - iOS. I'd like Android to move more in the direction of distinguishing itself apart from Apple way of doing things, not copying the same closed sandbox.
