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Simplified algorithm used to generate the preloaded-classes list. Generated a new preloaded-classes file.

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This commit is contained in:
Bob Lee
2009-08-13 14:41:54 -07:00
parent 802527c6a8
commit 9d2d6e14b0
15 changed files with 1073 additions and 1608 deletions
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96
tools/preload/WritePreloadedClassFile.java
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@@ -24,12 +24,18 @@ import java.util.Set;
import java.util.TreeSet;
/**
* Writes /frameworks/base/preloaded-classes. Also updates LoadedClass.preloaded
* fields and writes over compiled log file.
* Writes /frameworks/base/preloaded-classes. Also updates
* {@link LoadedClass#preloaded} fields and writes over compiled log file.
*/
public class WritePreloadedClassFile {
public static void main(String[] args) throws IOException, ClassNotFoundException {
/**
* Preload any class that take longer to load than MIN_LOAD_TIME_MICROS us.
*/
static final int MIN_LOAD_TIME_MICROS = 1250;
public static void main(String[] args) throws IOException,
ClassNotFoundException {
if (args.length != 1) {
System.err.println("Usage: WritePreloadedClassFile [compiled log]");
System.exit(-1);
@@ -44,48 +50,64 @@ public class WritePreloadedClassFile {
// Open preloaded-classes file for output.
Writer out = new BufferedWriter(new OutputStreamWriter(
new FileOutputStream(Policy.getPreloadedClassFileName()),
new FileOutputStream(Policy.PRELOADED_CLASS_FILE),
Charset.forName("US-ASCII")));
out.write("# Classes which are preloaded by com.android.internal.os.ZygoteInit.\n");
out.write("# Automatically generated by /frameworks/base/tools/preload.\n");
out.write("# percent=" + Proc.PERCENTAGE_TO_PRELOAD
+ ", weight=" + ClassRank.SEQUENCE_WEIGHT
+ ", bucket_size=" + ClassRank.BUCKET_SIZE
+ "\n");
out.write("# Classes which are preloaded by"
+ " com.android.internal.os.ZygoteInit.\n");
out.write("# Automatically generated by frameworks/base/tools/preload/"
+ WritePreloadedClassFile.class.getSimpleName() + ".java.\n");
out.write("# MIN_LOAD_TIME_MICROS=" + MIN_LOAD_TIME_MICROS + "\n");
/*
* The set of classes to preload. We preload a class if:
*
* a) it's loaded in the bootclasspath (i.e., is a system class)
* b) it takes > MIN_LOAD_TIME_MICROS us to load, and
* c) it's loaded by more than one process, or it's loaded by an
* application (i.e., not a long running service)
*/
Set<LoadedClass> toPreload = new TreeSet<LoadedClass>();
// Preload all classes that were loaded by at least 2 apps, if both
// apps run at the same time, they'll share memory.
// Preload classes that were loaded by at least 2 processes. Hopefully,
// the memory associated with these classes will be shared.
for (LoadedClass loadedClass : root.loadedClasses.values()) {
if (!loadedClass.isPreloadable()) {
continue;
}
Set<String> appNames = loadedClass.applicationNames();
if (appNames.size() > 3) {
Set<String> names = loadedClass.processNames();
if (shouldPreload(loadedClass) && names.size() > 1) {
toPreload.add(loadedClass);
}
}
// Try to make individual apps start faster by preloading slowest
// classes.
int initialSize = toPreload.size();
System.out.println(initialSize
+ " classses were loaded by more than one app.");
// Preload eligable classes from applications (not long-running
// services).
for (Proc proc : root.processes.values()) {
toPreload.addAll(proc.highestRankedClasses());
if (proc.fromZygote() && !Policy.isService(proc.name)) {
for (Operation operation : proc.operations) {
LoadedClass loadedClass = operation.loadedClass;
if (shouldPreload(loadedClass)) {
toPreload.add(loadedClass);
}
}
}
}
System.out.println(toPreload.size() + " classes will be preloaded.");
System.out.println("Added " + (toPreload.size() - initialSize)
+ " more to speed up applications.");
// Make classes that were already loaded by the zygote explicit.
System.out.println(toPreload.size()
+ " total classes will be preloaded.");
// Make classes that were implicitly loaded by the zygote explicit.
// This adds minimal overhead but avoid confusion about classes not
// appearing in the list.
addAllClassesFor("zygote", root, toPreload);
addAllClassesFrom("zygote", root, toPreload);
for (LoadedClass loadedClass : toPreload) {
out.write(loadedClass.name);
out.write('\n');
out.write(loadedClass.name + "\n");
}
out.close();
@@ -97,18 +119,26 @@ public class WritePreloadedClassFile {
root.toFile(rootFile);
}
private static void addAllClassesFor(String packageName, Root root,
Set<LoadedClass> toPreload) {
private static void addAllClassesFrom(String processName, Root root,
Set<LoadedClass> toPreload) {
for (Proc proc : root.processes.values()) {
if (proc.name.equals(packageName)) {
if (proc.name.equals(processName)) {
for (Operation operation : proc.operations) {
// TODO: I'm not sure how the zygote loaded classes that
// aren't supposed to be preloadable...
if (operation.loadedClass.isPreloadable()) {
boolean preloadable
= Policy.isPreloadable(operation.loadedClass);
if (preloadable) {
toPreload.add(operation.loadedClass);
}
}
}
}
}
/**
* Returns true if the class should be preloaded.
*/
private static boolean shouldPreload(LoadedClass clazz) {
return Policy.isPreloadable(clazz)
&& clazz.medianTimeMicros() > MIN_LOAD_TIME_MICROS;
}
}