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Merge pull request #13449 from exaucae/BAEL-2407_project-panama 

Bael 6060: Project Panama
This commit is contained in:
Loredana Crusoveanu 2023-03-05 17:14:06 +02:00 committed by GitHub
parent 5c7bfabbf0 b74bbc518c
commit 19b08b7806
6 changed files with 189 additions and 0 deletions
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49
java-panama/pom.xml Normal file
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<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>${project.model.version}</modelVersion>
<groupId>com.baeldung.java.panama</groupId>
<artifactId>java-panama</artifactId>
<version>${project.version}</version>
<packaging>jar</packaging>
<name>java-panama</name>
<url>https://maven.apache.org</url>
<properties>
<project.model.version>4.0.0</project.model.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.version>1.0</project.version>
<maven.compiler.source>19</maven.compiler.source>
<maven.compiler.target>19</maven.compiler.target>
<maven.compiler.version>3.10.1</maven.compiler.version>
<junit.jupiter.version>5.9.0</junit.jupiter.version>
</properties>
<dependencies>
<dependency>
<groupId>org.junit.jupiter</groupId>
<artifactId>junit-jupiter</artifactId>
<version>${junit.jupiter.version}</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>${maven.compiler.version}</version>
<configuration>
<source>${maven.compiler.source}</source>
<target>${maven.compiler.target}</target>
<compilerArgs>
<arg>--add-opens=java.base/java.lang.foreign=ALL-UNNAMED</arg>
<arg>--enable-preview</arg>
</compilerArgs>
</configuration>
</plugin>
</plugins>
</build>
</project>

40
java-panama/src/main/java/com/baeldung/java/panama/core/Greetings.java Normal file
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package com.baeldung.java.panama.core;
import static java.lang.foreign.ValueLayout.ADDRESS;
import static java.lang.foreign.ValueLayout.JAVA_INT;
import java.lang.foreign.FunctionDescriptor;
import java.lang.foreign.Linker;
import java.lang.foreign.MemorySegment;
import java.lang.foreign.MemorySession;
import java.lang.foreign.SymbolLookup;
import java.lang.invoke.MethodHandle;
public class Greetings {
public static void main(String[] args) throws Throwable {
String symbolName = "printf";
String greeting = "Hello World from Project Panama Baeldung Article";
Linker nativeLinker = Linker.nativeLinker();
SymbolLookup stdlibLookup = nativeLinker.defaultLookup();
SymbolLookup loaderLookup = SymbolLookup.loaderLookup();
FunctionDescriptor descriptor = FunctionDescriptor.of(JAVA_INT, ADDRESS);
MethodHandle methodHandle = loaderLookup.lookup(symbolName)
.or(() -> stdlibLookup.lookup(symbolName))
.map(symbolSegment -> nativeLinker.downcallHandle(symbolSegment, descriptor))
.orElse(null);
if (methodHandle == null) {
throw new NoSuchMethodError("Method Handle was not found");
}
try (MemorySession memorySession = MemorySession.openConfined()) {
MemorySegment greetingSegment = memorySession.allocateUtf8String(greeting);
methodHandle.invoke(greetingSegment);
}
}
}

23
java-panama/src/main/java/com/baeldung/java/panama/core/MemoryAllocation.java Normal file
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package com.baeldung.java.panama.core;
import java.lang.foreign.MemorySegment;
import java.lang.foreign.MemorySession;
import java.lang.foreign.SegmentAllocator;
import java.lang.foreign.ValueLayout;
public class MemoryAllocation {
public static void main(String[] args) throws Throwable {
try (MemorySession session = MemorySession.openConfined()) {
String[] greetingStrings = { "hello", "world", "panama", "baeldung" };
SegmentAllocator allocator = SegmentAllocator.implicitAllocator();
MemorySegment offHeapSegment = allocator.allocateArray(ValueLayout.ADDRESS, greetingStrings.length);
for (int i = 0; i < greetingStrings.length; i++) {
// Allocate a string off-heap, then store a pointer to it
MemorySegment cString = allocator.allocateUtf8String(greetingStrings[i]);
offHeapSegment.setAtIndex(ValueLayout.ADDRESS, i, cString);
}
}
}
}

53
java-panama/src/main/java/com/baeldung/java/panama/core/MemoryLayout.java Normal file
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package com.baeldung.java.panama.core;
import static java.lang.foreign.MemoryLayout.sequenceLayout;
import static java.lang.foreign.MemoryLayout.structLayout;
import static java.lang.foreign.ValueLayout.JAVA_DOUBLE;
import static java.lang.foreign.ValueLayout.JAVA_FLOAT;
import static java.lang.foreign.ValueLayout.PathElement;
import java.lang.foreign.GroupLayout;
import java.lang.foreign.MemorySegment;
import java.lang.foreign.MemorySession;
import java.lang.foreign.SequenceLayout;
import java.lang.invoke.VarHandle;
public class MemoryLayout {
public static void main(String[] args) {
GroupLayout pointLayout = structLayout(JAVA_DOUBLE.withName("x"), JAVA_DOUBLE.withName("y"));
SequenceLayout ptsLayout = sequenceLayout(10, pointLayout);
VarHandle xvarHandle = pointLayout.varHandle(PathElement.groupElement("x"));
VarHandle yvarHandle = pointLayout.varHandle(PathElement.groupElement("y"));
try (MemorySession memorySession = MemorySession.openConfined()) {
MemorySegment pointSegment = memorySession.allocate(pointLayout);
xvarHandle.set(pointSegment, 3d);
yvarHandle.set(pointSegment, 4d);
System.out.println(pointSegment.toString());
}
}
static class ValueLayout {
public static void main(String[] args) {
try (MemorySession memorySession = MemorySession.openConfined()) {
int byteSize = 5;
int index = 3;
float value = 6;
MemorySegment segment = MemorySegment.allocateNative(byteSize, memorySession);
segment.setAtIndex(JAVA_FLOAT, index, value);
float result = segment.getAtIndex(JAVA_FLOAT, index);
System.out.println("Float value is:" + result);
}
}
}
}

19
java-panama/src/main/java/com/baeldung/java/panama/jextract/Greetings.java Normal file
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package com.baeldung.java.panama.jextract;
import java.lang.foreign.MemorySegment;
import java.lang.foreign.MemorySession;
// Generate JExtract bindings before uncommenting
// import static foreign.c.stdio_h.printf;
public class Greetings {
public static void main(String[] args) {
String greeting = "Hello World from Project Panama Baeldung Article, using JExtract!";
try (MemorySession memorySession = MemorySession.openConfined()) {
MemorySegment greetingSegment = memorySession.allocateUtf8String(greeting);
// Generate JExtract bingings before uncommenting
// printf(greetingSegment);
}
}
}

5
java-panama/src/main/resources/hello.c Normal file
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#include <stdio.h>
int main() {
printf("Hello World from Project Panama Baeldung Article");
return 0;
}