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Tuning and subprocess spawn for thomaswue (#533)

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* Some clean up, small-scale tuning, and reduce complexity when handling longer names.

* Do actual work in worker subprocess. Main process returns immediately
and OS clean up of the mmap continues in the subprocess.

* Update minor Graal version after CPU release.

* Turn GC back to epsilon GC (although it does not seem to make a
difference).

* Minor tuning for another +1%.
This commit is contained in:
Thomas Wuerthinger
2024-01-21 20:13:48 +01:00
committed by GitHub
parent 6b95ac6113
commit d0a28599c2
2 changed files with 99 additions and 72 deletions
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167
src/main/java/dev/morling/onebrc/CalculateAverage_thomaswue.java
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@@ -15,13 +15,10 @@
*/
package dev.morling.onebrc;
import sun.misc.Unsafe;
import java.io.IOException;
import java.lang.foreign.Arena;
import java.lang.reflect.Field;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.channels.FileChannel;
import java.nio.channels.FileChannel.MapMode;
import java.nio.charset.StandardCharsets;
import java.nio.file.Path;
import java.nio.file.StandardOpenOption;
@@ -39,18 +36,20 @@ import java.util.stream.IntStream;
*/
public class CalculateAverage_thomaswue {
private static final String FILE = "./measurements.txt";
private static final int MIN_TEMP = -999;
private static final int MAX_TEMP = 999;
// Holding the current result for a single city.
private static class Result {
long lastNameLong, secondLastNameLong, nameAddress;
int nameLength, remainingShift;
int min, max, count;
long lastNameLong, secondLastNameLong;
long[] name;
int count;
short min, max;
long sum;
private Result(long nameAddress) {
this.nameAddress = nameAddress;
this.min = Integer.MAX_VALUE;
this.max = Integer.MIN_VALUE;
private Result() {
this.min = MAX_TEMP;
this.max = MIN_TEMP;
}
public String toString() {
@@ -63,18 +62,32 @@ public class CalculateAverage_thomaswue {
// Accumulate another result into this one.
private void add(Result other) {
min = Math.min(min, other.min);
max = Math.max(max, other.max);
if (other.min < min) {
min = other.min;
}
if (other.max > max) {
max = other.max;
}
sum += other.sum;
count += other.count;
}
public String calcName() {
return new Scanner(nameAddress, nameAddress + nameLength).getString(nameLength);
ByteBuffer bb = ByteBuffer.allocate(name.length * Long.BYTES).order(ByteOrder.nativeOrder());
bb.asLongBuffer().put(name);
byte[] array = bb.array();
int i = 0;
while (array[i++] != ';')
;
return new String(array, 0, i - 1, StandardCharsets.UTF_8);
}
}
public static void main(String[] args) throws IOException {
if (args.length == 0 || !("--worker".equals(args[0]))) {
spawnWorker();
return;
}
// Calculate input segments.
int numberOfChunks = Runtime.getRuntime().availableProcessors();
long[] chunks = getSegments(numberOfChunks);
@@ -93,6 +106,22 @@ public class CalculateAverage_thomaswue {
// Final output.
System.out.println(accumulateResults(allResults));
System.out.close();
}
private static void spawnWorker() throws IOException {
ProcessHandle.Info info = ProcessHandle.current().info();
ArrayList<String> workerCommand = new ArrayList<>();
info.command().ifPresent(workerCommand::add);
info.arguments().ifPresent(args -> workerCommand.addAll(Arrays.asList(args)));
workerCommand.add("--worker");
new ProcessBuilder()
.command(workerCommand)
.inheritIO()
.redirectOutput(ProcessBuilder.Redirect.PIPE)
.start()
.getInputStream()
.transferTo(System.out);
}
// Accumulate results sequentially for simplicity.
@@ -115,20 +144,21 @@ public class CalculateAverage_thomaswue {
Result[] results = new Result[1 << 17];
Scanner scanner = new Scanner(chunkStart, chunkEnd);
long word = scanner.getLong();
int pos = findDelimiter(word);
long pos = findDelimiter(word);
while (scanner.hasNext()) {
long nameAddress = scanner.pos();
long hash = 0;
// Search for ';', one long at a time.
if (pos != 8) {
if (pos != 0) {
pos = Long.numberOfTrailingZeros(pos) >>> 3;
scanner.add(pos);
word = mask(word, pos);
hash = word;
int number = scanNumber(scanner);
long nextWord = scanner.getLong();
int nextPos = findDelimiter(nextWord);
long nextPos = findDelimiter(nextWord);
Result existingResult = results[hashToIndex(hash, results)];
if (existingResult != null && existingResult.lastNameLong == word) {
@@ -142,11 +172,12 @@ public class CalculateAverage_thomaswue {
}
else {
scanner.add(8);
hash ^= word;
hash = word;
long prevWord = word;
word = scanner.getLong();
pos = findDelimiter(word);
if (pos != 8) {
if (pos != 0) {
pos = Long.numberOfTrailingZeros(pos) >>> 3;
scanner.add(pos);
word = mask(word, pos);
hash ^= word;
@@ -166,7 +197,8 @@ public class CalculateAverage_thomaswue {
while (true) {
word = scanner.getLong();
pos = findDelimiter(word);
if (pos != 8) {
if (pos != 0) {
pos = Long.numberOfTrailingZeros(pos) >>> 3;
scanner.add(pos);
word = mask(word, pos);
hash ^= word;
@@ -182,12 +214,7 @@ public class CalculateAverage_thomaswue {
// Save length of name for later.
int nameLength = (int) (scanner.pos() - nameAddress);
scanner.add(1);
long numberWord = scanner.getLong();
int decimalSepPos = Long.numberOfTrailingZeros(~numberWord & 0x10101000);
int number = convertIntoNumber(decimalSepPos, numberWord);
scanner.add((decimalSepPos >>> 3) + 3);
int number = scanNumber(scanner);
// Final calculation for index into hash table.
int tableIndex = hashToIndex(hash, results);
@@ -198,13 +225,16 @@ public class CalculateAverage_thomaswue {
}
// Check for collision.
int i = 0;
int namePos = 0;
for (; i < nameLength + 1 - 8; i += 8) {
if (scanner.getLongAt(existingResult.nameAddress + i) != scanner.getLongAt(nameAddress + i)) {
if (namePos >= existingResult.name.length || existingResult.name[namePos++] != scanner.getLongAt(nameAddress + i)) {
tableIndex = (tableIndex + 31) & (results.length - 1);
continue outer;
}
}
if (((existingResult.lastNameLong ^ scanner.getLongAt(nameAddress + i)) << existingResult.remainingShift) == 0) {
int remainingShift = (64 - (nameLength + 1 - i) << 3);
if (((existingResult.lastNameLong ^ (scanner.getLongAt(nameAddress + i) << remainingShift)) == 0)) {
record(existingResult, number);
break;
}
@@ -230,63 +260,67 @@ public class CalculateAverage_thomaswue {
}
private static void record(Result existingResult, int number) {
existingResult.min = Math.min(existingResult.min, number);
existingResult.max = Math.max(existingResult.max, number);
if (number < existingResult.min) {
existingResult.min = (short) number;
}
if (number > existingResult.max) {
existingResult.max = (short) number;
}
existingResult.sum += number;
existingResult.count++;
}
private static int hashToIndex(long hash, Result[] results) {
int hashAsInt = (int) (hash ^ (hash >>> 28));
int finalHash = (hashAsInt ^ (hashAsInt >>> 15));
int finalHash = (hashAsInt ^ (hashAsInt >>> 17));
return (finalHash & (results.length - 1));
}
private static long mask(long word, int pos) {
return word & (-1L >>> ((8 - pos - 1) << 3));
private static long mask(long word, long pos) {
return (word << ((7 - pos) << 3));
}
// Special method to convert a number in the specific format into an int value without branches created by
// Quan Anh Mai.
// Special method to convert a number in the ascii number into an int without branches created by Quan Anh Mai.
private static int convertIntoNumber(int decimalSepPos, long numberWord) {
int shift = 28 - decimalSepPos;
// signed is -1 if negative, 0 otherwise
long signed = (~numberWord << 59) >> 63;
long designMask = ~(signed & 0xFF);
// Align the number to a specific position and transform the ascii code
// to actual digit value in each byte
// Align the number to a specific position and transform the ascii to digit value
long digits = ((numberWord & designMask) << shift) & 0x0F000F0F00L;
// Now digits is in the form 0xUU00TTHH00 (UU: units digit, TT: tens digit, HH: hundreds digit)
// 0xUU00TTHH00 * (100 * 0x1000000 + 10 * 0x10000 + 1) =
// 0x000000UU00TTHH00 +
// 0x00UU00TTHH000000 * 10 +
// 0xUU00TTHH00000000 * 100
// Now TT * 100 has 2 trailing zeroes and HH * 100 + TT * 10 + UU < 0x400
// This results in our value lies in the bit 32 to 41 of this product
// That was close :)
// 0x000000UU00TTHH00 + 0x00UU00TTHH000000 * 10 + 0xUU00TTHH00000000 * 100
long absValue = ((digits * 0x640a0001) >>> 32) & 0x3FF;
long value = (absValue ^ signed) - signed;
return (int) value;
}
private static int findDelimiter(long word) {
private static long findDelimiter(long word) {
long input = word ^ 0x3B3B3B3B3B3B3B3BL;
long tmp = (input - 0x0101010101010101L) & ~input & 0x8080808080808080L;
return Long.numberOfTrailingZeros(tmp) >>> 3;
return tmp;
}
private static Result newEntry(Result[] results, long nameAddress, int hash, int nameLength, Scanner scanner) {
Result r = new Result(nameAddress);
Result r = new Result();
results[hash] = r;
long[] name = new long[(nameLength / Long.BYTES) + 1];
int pos = 0;
int i = 0;
for (; i < nameLength + 1 - 8; i += 8) {
r.secondLastNameLong = (scanner.getLongAt(nameAddress + i));
for (; i < nameLength + 1 - Long.BYTES; i += Long.BYTES) {
name[pos++] = scanner.getLongAt(nameAddress + i);
}
r.remainingShift = (64 - (nameLength + 1 - i) << 3);
r.lastNameLong = (scanner.getLongAt(nameAddress + i) & (-1L >>> r.remainingShift));
r.nameLength = nameLength;
if (pos > 0) {
r.secondLastNameLong = name[pos - 1];
}
int remainingShift = (64 - (nameLength + 1 - i) << 3);
long lastWord = (scanner.getLongAt(nameAddress + i) << remainingShift);
r.lastNameLong = lastWord;
name[pos] = lastWord >> remainingShift;
r.name = name;
return r;
}
@@ -295,16 +329,15 @@ public class CalculateAverage_thomaswue {
long fileSize = fileChannel.size();
long segmentSize = (fileSize + numberOfChunks - 1) / numberOfChunks;
long[] chunks = new long[numberOfChunks + 1];
long mappedAddress = fileChannel.map(MapMode.READ_ONLY, 0, fileSize, Arena.global()).address();
long mappedAddress = fileChannel.map(FileChannel.MapMode.READ_ONLY, 0, fileSize, java.lang.foreign.Arena.global()).address();
chunks[0] = mappedAddress;
long endAddress = mappedAddress + fileSize;
Scanner s = new Scanner(mappedAddress, mappedAddress + fileSize);
for (int i = 1; i < numberOfChunks; ++i) {
long chunkAddress = mappedAddress + i * segmentSize;
// Align to first row start.
while (chunkAddress < endAddress && (s.getLongAt(chunkAddress++) & 0xFF) != '\n') {
// nop
}
while (chunkAddress < endAddress && (s.getLongAt(chunkAddress++) & 0xFF) != '\n')
;
chunks[i] = Math.min(chunkAddress, endAddress);
}
chunks[numberOfChunks] = endAddress;
@@ -314,13 +347,13 @@ public class CalculateAverage_thomaswue {
private static class Scanner {
private static final Unsafe UNSAFE = initUnsafe();
private static final sun.misc.Unsafe UNSAFE = initUnsafe();
private static Unsafe initUnsafe() {
private static sun.misc.Unsafe initUnsafe() {
try {
Field theUnsafe = Unsafe.class.getDeclaredField("theUnsafe");
java.lang.reflect.Field theUnsafe = sun.misc.Unsafe.class.getDeclaredField("theUnsafe");
theUnsafe.setAccessible(true);
return (Unsafe) theUnsafe.get(Unsafe.class);
return (sun.misc.Unsafe) theUnsafe.get(sun.misc.Unsafe.class);
}
catch (NoSuchFieldException | IllegalAccessException e) {
throw new RuntimeException(e);
@@ -342,7 +375,7 @@ public class CalculateAverage_thomaswue {
return pos;
}
void add(int delta) {
void add(long delta) {
pos += delta;
}
@@ -354,13 +387,7 @@ public class CalculateAverage_thomaswue {
return UNSAFE.getLong(pos);
}
public String getString(int nameLength) {
byte[] bytes = new byte[nameLength];
UNSAFE.copyMemory(null, pos, bytes, Unsafe.ARRAY_BYTE_BASE_OFFSET, nameLength);
return new String(bytes, StandardCharsets.UTF_8);
}
public void setPos(long l) {
void setPos(long l) {
this.pos = l;
}
}