Android Performance Matters - Ran Nachmany, Google

Performance Matters
+Ran Nachmany
@shed2k

Battery Performance
Hey, do you have a power outlet I can use?

What’s eating your mobile battery?
goo.gl/nMkSE
25-30%Actual work.
70%Analytics
GPS
Ads

QUIT BEING STUPID.
Better Battery Golden Rule

DEFER WORK UNTIL
THE BEST TIME
FOR BATTERY
Better Battery Golden Rule

Active Screen Off
Z
Z
Z
Asleep

Keeping the device awake
goo.gl/uEfy56
Z
Z
Z
Wakelock

Wakelock.aquire(..)
goo.gl/ZNCx6n

AlarmManager.setInexact*(..)
goo.gl/l7m7fb20 minutes
15 minutes

Release Wakelocks.
Batch Wakeups.
#PERFMATTERS TIP

GPS Provider Cell Network Provider
More Accurate
More Power
Less Accurate
Less Power

Better Accuracy Better Battery
PRIORITY_HIGH_ACCURACY
PRIORITY_BALANCED_POWER_ACCURACY PRIORITY_LOW_POWER
PRIORITY_NO_POWER
What’s the best State for
right now?

Z
Z
Z
PRIORITY_HIGH_ACCURACY
PRIORITY_BALANCED_POWER_ACC
URACY
PRIORITY_LOW_POWER
PRIORITY_NO_POWER

GPS
Fetch Totally
steal
Passive Provider

Only use the resolution
you need.
#PERFMATTERS TIP #43

Bandwidth
Power
Idle
DCH
FACH
Tail Time
~10 sec
Tail Time
~60 sec
Wake Up Time
~2 Sec

$$$$$$$$$
User Pays for your requests

LESS RADIO TIME
LESS DATA
NETWORKING Golden Rule

XHR
wait
XHR
wait
XHR
wait
XHR
wait
XHR
wait
XHR
wait
XHR
XHR
XHR
XHR
XHR
XHR
wait
BATCHING!

Do Now Server Response Data Push
Types of networking requests
CAN OPTIMIZE

Length == 10
pending queue
requests

JobInfo uploadJob =
new JobInfo.Buildr(mSomeInt, mServiceComponent)
.setRequiredNetworkCapabilities(JobInfo.NetworkType.UNMETERED)
.setOverrideDeadline(DateUtils.HOUR_IN_MILLIS)
.setRequiresCharging(true)
.build();
JobScheduler API

JobInfo uploadJob =
.build();
JobScheduler API
JobId

JobInfo uploadJob =
.build();
JobScheduler API
Job Endpoint

JobInfo uploadJob =
.build();
JobScheduler API
Network Type

JobInfo uploadJob =
.build();
JobScheduler API
Timing Constraint

JobInfo uploadJob =
.build();
JobScheduler API
Extra Constraint

SyncAdapters
Pre L Batching
GcmNetworkManager

// Schedule a task to occur between five and fifteen minutes from now:
OneoffTask myTask = new OneoffTask.Builder()
.setService(MyGcmTaskService.class)
.setExecutionWindow(
5 * DateUtil.MINUTE_IN_SECONDS, 15 * DateUtil.MINUTE_IN_SECONDS)
.setTag("test-upload")
.build();
GcmNetworkManager.get(this).schedule(myTask);
GcmNetworkManager
GcmNetworkManager
https://goo.gl/hTwIEt

// Implement service logic to be notified when the task elapses:
MyUploadService extends GcmTaskService {
@Override
public int onRunTask(TaskParams params) {
// Do some upload work.
return GcmNetworkManager.RESULT_SUCCESS;
}
}
GcmNetworkManager
GcmNetworkManager

// Implement service logic to be notified when the task elapses:
MyUploadService extends GcmTaskService {
@Override
public int onRunTask(TaskParams params) {
// Do some upload work.
return GcmNetworkManager.RESULT_SUCCESS;
}
}
GcmNetworkManager
adb shell am broadcast -a "com.google.android.gms.gcm.ACTION_TRIGGER_TASK"
-e component -e tag
GcmNetworkManager

Network Technique:
Prefetching

Fetch1MB
Fetch1MB
Fetch1MB
Fetch1MB
Fetch4MB
PRE FETCHING!
wait
wait
wait
wait
wait

How much do we prefetch?
Quality pre-fetch is :
about 1-5mb of data.
about 1-2 minutes of data need

45k
quality : 70
164k
quality : 100

Site JPG Quality
Google Images Thumbnails 74-76
Facebook full-size images 85
Yahoo frontpage JPEGs 69-91
Youtube frontpage JPEGs 70-82
Wikipedia images 80
Windows live background 82
Twitter user JPEG images 30-100

{
"id": 1,
"jsonrpc": "2.0",
"total": 1,
"max_id":276372795494133760,
"result": [
{
"id": 0,
"guid": "2084d344-81fe-4714-9e2a-42c83b46083b",
"isActive": true,
"balance": "$1,507.00",
"picture": "http://placehold.it/32x32",
"age": 24,
"latitude": -85.791587,
"longitude": -64.615557,
"tags": [
"quis",
"est",
"ea",
"velit",
"exercitation",
"quis",
"veniam"
],
"friends": [
{
"id": 0,
"name": "Sanford Patton"
},
Spaces, quotes,
returns, names, are all
verbose data.

{
"id": 1,
"jsonrpc": "2.0",
"total": 1,
"max_id":276372795494133760,
"result": [
{
"id": 0,
"guid": "2084d344-81fe-4714-9e2a-42c83b46083b",
"isActive": true,
"balance": "$1,507.00",
"picture": "http://placehold.it/32x32",
"age": 24,
"latitude": -85.791587,
"longitude": -64.615557,
"tags": [
"quis",
"est",
"ea",
"velit",
"exercitation",
"quis",
"veniam"
],
"friends": [
{
"id": 0,
"name": "Sanford Patton"
},
Copied into memory,
must determine if
string, int, date, etc.

FlatBuffers
Scheme Compiler
.java
.cpp
.go
FlatBuffers
http://goo.gl/r9xTXK

Smaller data
wins the Internet.
#PERFMATTERS TIP #9

Memory Performance
WHY IS EVERYTHING SLOW????? I FORGET……...

GC Event!
Allocatedmemory
Memory Threshold

Fib3(..) GC Fib3(..)Main
function
FIB3 fcn haulted
FIB3 fcn Resume

16ms
DRAW!DRAW! DRAW!
16ms 16ms
UPDATE GC

GC events eat
kittens
framerate
MEMORY Golden Rule

Smaller Pixel
Formats
Down-Scale
ImagesBitmap Re-use

Glide
goo.gl/flNbyf
Picasso
goo.gl/tpTc1

Bitmaps are big
Make them smaller

KEY
Hash-to-index
Allocated, but unused
Allocated, but unused
Stored Value

ArrayMap.java
goo.gl/SCeQEL
ArrayMap
HASH #1
HASH #2
HASH #3
Hashes of keys
sorted
VALUE 2
KEY 3
VALUE 3
KEY 1
VALUE 1
KEY 2
Interwoven
key / value

ArrayMap.java
goo.gl/SCeQEL
HASH #8
HASH #9
HASH #10
KEY HASH #5
HASH #6
HASH #7
HASH #1
VALUE 7
KEY 8
VALUE 8
KEY 1
VALUE 1
KEY 7
Key Index
= (hashIndex *2) + 1
binary search
HASH #7

collision
search
VALUE 7
KEY 8
VALUE 8
KEY 1
VALUE 1
KEY 7
Key Index
= (hashIndex *2) + 1
HASH #8
HASH #9
HASH #10
KEY HASH #5
HASH #6
HASH #7
HASH #1
binary search

Empty
But array still allocated
Empty
nothing allocated
HashMap ArrayMap

<1000
objects
Maps
containing maps

Use ArrayMap
in the right places.

Primitive sizes
boolean 8 bits
int
float 32 bits
32 bits
boolean java.lang.Boolean
int
float java.lang.Float
java.lang.Integer

Integer value = 0
Primitive int
Integer Object
Autoboxing

// Primitive version
int total = 0;
for (int i = 0; i < 100; i++)
total += i;
// Generic version
Integer total = 0;
for (int i = 0; i < 100; i++)
total += i;

// Primitive version
int total = 0;
for (int i = 0; i < 100; i++)
total += i;
// Generic version
Integer total = 0;
for (int i = 0; i < 100; i++)
//total += i;
Allocates 83 new objects!
(yea, i know, it’s confusing..)
Allocates 0 new objects!
// create new Integer(),
// push in new value
// add to total

HashMap <Primitive,Object>
put update get
autoboxing autoboxing
autoboxing

HashMap <obj, obj>
SparseBoolMap <bool,obj>
SparseIntMap <int,obj>
SparseLongMap <long,obj>
LongSparseMap <long,obj>
NoAutoboxing

LotsofGenerics
Single Call Site
AllocationTracker
Memory Profiling 101
goo.gl/h1Cl9k

Avoid Autoboxing

public static final int VALUE1 = 1;
int func(int value) {
switch (value) {
case VALUE1:
return -1;
case VALUE2:
return -2;
case VALUE3:
return -3;
}
return 0;
}
Bytes
2680
+124 bytes

public static enum Value {
VALUE1,
VALUE2,
VALUE3
}
int func(Value value) {
switch (value) {
case VALUE1:
return -1;
case VALUE2:
return -2;
case VALUE3:
return -3;
}
return 0;
} Bytes
4188
13x more
than int version

public static enum Value {
VALUE1,
VALUE2,
VALUE3
}
12-16 bytes
for the array
20+ bytes (each)

If you’re using ENUMS
STOP.

QUIT BEING STUPID.
#PerfMatters Golden Rule

Android Performance Matters - Ran Nachmany, Google

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