diff --git a/Task_2_1_2/.gitignore b/Task_2_1_2/.gitignore
new file mode 100644
index 0000000..b63da45
--- /dev/null
+++ b/Task_2_1_2/.gitignore
@@ -0,0 +1,42 @@
+.gradle
+build/
+!gradle/wrapper/gradle-wrapper.jar
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### IntelliJ IDEA ###
+.idea/modules.xml
+.idea/jarRepositories.xml
+.idea/compiler.xml
+.idea/libraries/
+*.iws
+*.iml
+*.ipr
+out/
+!**/src/main/**/out/
+!**/src/test/**/out/
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+bin/
+!**/src/main/**/bin/
+!**/src/test/**/bin/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store
\ No newline at end of file
diff --git a/Task_2_1_2/.idea/.gitignore b/Task_2_1_2/.idea/.gitignore
new file mode 100644
index 0000000..26d3352
--- /dev/null
+++ b/Task_2_1_2/.idea/.gitignore
@@ -0,0 +1,3 @@
+# Default ignored files
+/shelf/
+/workspace.xml
diff --git a/Task_2_1_2/.idea/gradle.xml b/Task_2_1_2/.idea/gradle.xml
new file mode 100644
index 0000000..2a65317
--- /dev/null
+++ b/Task_2_1_2/.idea/gradle.xml
@@ -0,0 +1,17 @@
+
+
+
+
+
+
+
\ No newline at end of file
diff --git a/Task_2_1_2/.idea/misc.xml b/Task_2_1_2/.idea/misc.xml
new file mode 100644
index 0000000..d5d5cd9
--- /dev/null
+++ b/Task_2_1_2/.idea/misc.xml
@@ -0,0 +1,7 @@
+
+
+
+
+
+
+
\ No newline at end of file
diff --git a/Task_2_1_2/.idea/vcs.xml b/Task_2_1_2/.idea/vcs.xml
new file mode 100644
index 0000000..6c0b863
--- /dev/null
+++ b/Task_2_1_2/.idea/vcs.xml
@@ -0,0 +1,6 @@
+
+
+
+
+
+
\ No newline at end of file
diff --git a/Task_2_1_2/build.gradle b/Task_2_1_2/build.gradle
new file mode 100644
index 0000000..3b5b6ce
--- /dev/null
+++ b/Task_2_1_2/build.gradle
@@ -0,0 +1,27 @@
+plugins {
+ id 'java'
+ id 'jacoco'
+}
+
+group = 'ru.nsu.nmashkin.task212'
+version = '1.0-SNAPSHOT'
+
+repositories {
+ mavenCentral()
+}
+
+dependencies {
+ testImplementation platform('org.junit:junit-bom:5.10.0')
+ testImplementation 'org.junit.jupiter:junit-jupiter'
+ testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
+}
+
+test {
+ useJUnitPlatform()
+}
+
+jacocoTestReport {
+ reports {
+ xml.required = true
+ }
+}
\ No newline at end of file
diff --git a/Task_2_1_2/gradle/wrapper/gradle-wrapper.jar b/Task_2_1_2/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..249e583
Binary files /dev/null and b/Task_2_1_2/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/Task_2_1_2/gradle/wrapper/gradle-wrapper.properties b/Task_2_1_2/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..cf77dd8
--- /dev/null
+++ b/Task_2_1_2/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,6 @@
+#Sat May 16 12:16:09 NOVT 2026
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.14-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/Task_2_1_2/gradlew b/Task_2_1_2/gradlew
new file mode 100644
index 0000000..1b6c787
--- /dev/null
+++ b/Task_2_1_2/gradlew
@@ -0,0 +1,234 @@
+#!/bin/sh
+
+#
+# Copyright © 2015-2021 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+#
+# Gradle start up script for POSIX generated by Gradle.
+#
+# Important for running:
+#
+# (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+# noncompliant, but you have some other compliant shell such as ksh or
+# bash, then to run this script, type that shell name before the whole
+# command line, like:
+#
+# ksh Gradle
+#
+# Busybox and similar reduced shells will NOT work, because this script
+# requires all of these POSIX shell features:
+# * functions;
+# * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+# «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+# * compound commands having a testable exit status, especially «case»;
+# * various built-in commands including «command», «set», and «ulimit».
+#
+# Important for patching:
+#
+# (2) This script targets any POSIX shell, so it avoids extensions provided
+# by Bash, Ksh, etc; in particular arrays are avoided.
+#
+# The "traditional" practice of packing multiple parameters into a
+# space-separated string is a well documented source of bugs and security
+# problems, so this is (mostly) avoided, by progressively accumulating
+# options in "$@", and eventually passing that to Java.
+#
+# Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+# and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+# see the in-line comments for details.
+#
+# There are tweaks for specific operating systems such as AIX, CygWin,
+# Darwin, MinGW, and NonStop.
+#
+# (3) This script is generated from the Groovy template
+# https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+# within the Gradle project.
+#
+# You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+ APP_HOME=${app_path%"${app_path##*/}"} # leaves a trailing /; empty if no leading path
+ [ -h "$app_path" ]
+do
+ ls=$( ls -ld "$app_path" )
+ link=${ls#*' -> '}
+ case $link in #(
+ /*) app_path=$link ;; #(
+ *) app_path=$APP_HOME$link ;;
+ esac
+done
+
+APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
+
+APP_NAME="Gradle"
+APP_BASE_NAME=${0##*/}
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+ echo "$*"
+} >&2
+
+die () {
+ echo
+ echo "$*"
+ echo
+ exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in #(
+ CYGWIN* ) cygwin=true ;; #(
+ Darwin* ) darwin=true ;; #(
+ MSYS* | MINGW* ) msys=true ;; #(
+ NONSTOP* ) nonstop=true ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+ if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+ # IBM's JDK on AIX uses strange locations for the executables
+ JAVACMD=$JAVA_HOME/jre/sh/java
+ else
+ JAVACMD=$JAVA_HOME/bin/java
+ fi
+ if [ ! -x "$JAVACMD" ] ; then
+ die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+ fi
+else
+ JAVACMD=java
+ which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+ case $MAX_FD in #(
+ max*)
+ MAX_FD=$( ulimit -H -n ) ||
+ warn "Could not query maximum file descriptor limit"
+ esac
+ case $MAX_FD in #(
+ '' | soft) :;; #(
+ *)
+ ulimit -n "$MAX_FD" ||
+ warn "Could not set maximum file descriptor limit to $MAX_FD"
+ esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+# * args from the command line
+# * the main class name
+# * -classpath
+# * -D...appname settings
+# * --module-path (only if needed)
+# * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+ APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+ CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+ JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+ # Now convert the arguments - kludge to limit ourselves to /bin/sh
+ for arg do
+ if
+ case $arg in #(
+ -*) false ;; # don't mess with options #(
+ /?*) t=${arg#/} t=/${t%%/*} # looks like a POSIX filepath
+ [ -e "$t" ] ;; #(
+ *) false ;;
+ esac
+ then
+ arg=$( cygpath --path --ignore --mixed "$arg" )
+ fi
+ # Roll the args list around exactly as many times as the number of
+ # args, so each arg winds up back in the position where it started, but
+ # possibly modified.
+ #
+ # NB: a `for` loop captures its iteration list before it begins, so
+ # changing the positional parameters here affects neither the number of
+ # iterations, nor the values presented in `arg`.
+ shift # remove old arg
+ set -- "$@" "$arg" # push replacement arg
+ done
+fi
+
+# Collect all arguments for the java command;
+# * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
+# shell script including quotes and variable substitutions, so put them in
+# double quotes to make sure that they get re-expanded; and
+# * put everything else in single quotes, so that it's not re-expanded.
+
+set -- \
+ "-Dorg.gradle.appname=$APP_BASE_NAME" \
+ -classpath "$CLASSPATH" \
+ org.gradle.wrapper.GradleWrapperMain \
+ "$@"
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+# readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+# set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+ printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+ xargs -n1 |
+ sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+ tr '\n' ' '
+ )" '"$@"'
+
+exec "$JAVACMD" "$@"
diff --git a/Task_2_1_2/gradlew.bat b/Task_2_1_2/gradlew.bat
new file mode 100644
index 0000000..107acd3
--- /dev/null
+++ b/Task_2_1_2/gradlew.bat
@@ -0,0 +1,89 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/Task_2_1_2/settings.gradle b/Task_2_1_2/settings.gradle
new file mode 100644
index 0000000..891b549
--- /dev/null
+++ b/Task_2_1_2/settings.gradle
@@ -0,0 +1 @@
+rootProject.name = 'Task_2_1_2'
\ No newline at end of file
diff --git a/Task_2_1_2/src/main/java/ru/nsu/nmashkin/task212/Master.java b/Task_2_1_2/src/main/java/ru/nsu/nmashkin/task212/Master.java
new file mode 100644
index 0000000..acf2887
--- /dev/null
+++ b/Task_2_1_2/src/main/java/ru/nsu/nmashkin/task212/Master.java
@@ -0,0 +1,217 @@
+package ru.nsu.nmashkin.task212;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.net.DatagramPacket;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.net.MulticastSocket;
+import java.net.NetworkInterface;
+import java.net.ServerSocket;
+import java.net.Socket;
+import java.net.SocketException;
+import java.nio.charset.StandardCharsets;
+import java.util.Arrays;
+import java.util.List;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/**
+ * Master of Slaves.
+ */
+public class Master {
+ private final int port;
+ private final BlockingQueue taskQueue = new LinkedBlockingQueue<>();
+ private final AtomicBoolean globalResult = new AtomicBoolean(false);
+ private final AtomicBoolean isDone = new AtomicBoolean(false);
+ private final List workerHandlers = new CopyOnWriteArrayList<>();
+ private final Object lock = new Object();
+ private volatile MulticastSocket discoverySocket;
+ private int tasksLeft;
+
+ private static final String MULTICAST_ADDRESS = "230.0.0.1";
+ private static final int MULTICAST_PORT = 4446;
+
+ /**
+ * Make a master.
+ *
+ * @param port to listen to.
+ */
+ public Master(int port) {
+ this.port = port;
+ }
+
+ /**
+ * Accept slaves, give them work, return result.
+ */
+ public boolean execute(int[] numbers, int chunkSize, int expectedWorkers) {
+ int taskId = 0;
+ for (int i = 0; i < numbers.length; i += chunkSize) {
+ int end = Math.min(i + chunkSize, numbers.length);
+ int[] chunk = Arrays.copyOfRange(numbers, i, end);
+ taskQueue.add(new Task(taskId++, chunk));
+ }
+
+ tasksLeft = taskQueue.size();
+
+ System.out.println("Master is up and expecting " + expectedWorkers + " slaves...");
+
+ Thread discoveryThread = new Thread(this::searchForSlaves);
+ discoveryThread.setDaemon(true);
+ discoveryThread.start();
+
+ try (ServerSocket serverSocket = new ServerSocket(port)) {
+ Socket[] workerSockets = new Socket[expectedWorkers];
+ for (int i = 0; i < expectedWorkers; i++) {
+ try {
+ workerSockets[i] = serverSocket.accept();
+ System.out.println("Slave detected: "
+ + workerSockets[i].getRemoteSocketAddress());
+ } catch (IOException e) {
+ System.out.println("Not enough slaves: " + e.getMessage());
+ break;
+ }
+ }
+
+ System.out.println("All slaves are ready, " + taskQueue.size() + " works to be done");
+
+ for (var sock : workerSockets) {
+ if (sock != null) {
+ Thread handler = new Thread(new WorkerHandler(sock));
+ workerHandlers.add(handler);
+ handler.start();
+ }
+ }
+
+ synchronized (lock) {
+ while (tasksLeft > 0 && !globalResult.get()) {
+ lock.wait();
+ }
+ }
+
+ } catch (IOException | InterruptedException e) {
+ System.err.println("Error: " + e.getMessage());
+ } finally {
+ isDone.set(true);
+ for (Thread t : workerHandlers) {
+ t.interrupt();
+ }
+
+ if (discoverySocket != null && !discoverySocket.isClosed()) {
+ discoverySocket.close();
+ }
+ }
+
+ return globalResult.get();
+ }
+
+ private void searchForSlaves() {
+ try {
+ discoverySocket = new MulticastSocket(MULTICAST_PORT);
+ InetAddress group = InetAddress.getByName(MULTICAST_ADDRESS);
+ NetworkInterface netIf = NetworkInterface.getByInetAddress(InetAddress.getLocalHost());
+ if (netIf == null) {
+ netIf = NetworkInterface.getNetworkInterfaces().nextElement();
+ }
+ discoverySocket.joinGroup(new InetSocketAddress(group, MULTICAST_PORT), netIf);
+
+ byte[] msgBytes = ("MASTER_START:" + port).getBytes(StandardCharsets.UTF_8);
+ DatagramPacket notification = new DatagramPacket(msgBytes, msgBytes.length,
+ group, MULTICAST_PORT);
+ discoverySocket.send(notification);
+
+ byte[] buffer = new byte[1024];
+ while (!isDone.get()) {
+ DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
+ discoverySocket.receive(packet);
+ String message = new String(packet.getData(), 0,
+ packet.getLength(), StandardCharsets.UTF_8);
+
+ if ("SLAVE_READY".equals(message)) {
+ byte[] responseBytes = ("MASTER_INFO:" + port).getBytes(StandardCharsets.UTF_8);
+ DatagramPacket response = new DatagramPacket(
+ responseBytes, responseBytes.length,
+ group, MULTICAST_PORT
+ );
+ discoverySocket.send(response);
+ }
+ }
+ } catch (SocketException e) {
+ System.out.println("Search ended");
+ } catch (Exception e) {
+ System.err.println("We're screwed: " + e.getMessage());
+ } finally {
+ if (discoverySocket != null && !discoverySocket.isClosed()) {
+ discoverySocket.close();
+ }
+ }
+ }
+
+ private class WorkerHandler implements Runnable {
+ private final Socket socket;
+
+ public WorkerHandler(Socket socket) {
+ this.socket = socket;
+ }
+
+ @Override
+ public void run() {
+ Task currentTask = null;
+ try (Socket s = socket;
+ ObjectOutputStream out = new ObjectOutputStream(s.getOutputStream());
+ ObjectInputStream in = new ObjectInputStream(s.getInputStream())) {
+
+ while (!isDone.get() && !globalResult.get()) {
+ currentTask = taskQueue.poll(1, TimeUnit.SECONDS);
+ if (currentTask == null) {
+ if (taskQueue.isEmpty()) {
+ break;
+ }
+ continue;
+ }
+
+ out.writeObject(currentTask);
+ out.flush();
+
+ TaskResult result = (TaskResult) in.readObject();
+
+ synchronized (lock) {
+ if (result.hasNonPrime()) {
+ globalResult.set(true);
+ }
+ System.out.println("Slave has completed work #" + result.taskId()
+ + " with result " + result.hasNonPrime());
+ tasksLeft--;
+
+ if (result.hasNonPrime() || tasksLeft == 0) {
+ lock.notifyAll();
+ }
+ }
+
+ if (!s.isClosed()) {
+ currentTask = null;
+ }
+ }
+
+ if (!s.isClosed()) {
+ out.writeObject(null);
+ out.flush();
+ }
+
+ } catch (Exception e) {
+ System.err.println("Slave is dead: " + socket.getRemoteSocketAddress());
+ } finally {
+ System.out.println(currentTask);
+ if (currentTask != null) {
+ System.out.println("Sun is still up in the sky, returning task to queue: "
+ + currentTask.taskId());
+ taskQueue.add(currentTask);
+ }
+ }
+ }
+ }
+}
\ No newline at end of file
diff --git a/Task_2_1_2/src/main/java/ru/nsu/nmashkin/task212/MultiThreaded.java b/Task_2_1_2/src/main/java/ru/nsu/nmashkin/task212/MultiThreaded.java
new file mode 100644
index 0000000..551ceee
--- /dev/null
+++ b/Task_2_1_2/src/main/java/ru/nsu/nmashkin/task212/MultiThreaded.java
@@ -0,0 +1,50 @@
+package ru.nsu.nmashkin.task212;
+
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/**
+ * Multithreaded implementation for finding a non prime.
+ */
+public class MultiThreaded {
+ /**
+ * Main method.
+ *
+ * @param numbers array of numbers
+ * @return whether there is a non prime among numbers
+ */
+ public static boolean hasNonPrime(int[] numbers, int threadCount) {
+ AtomicBoolean result = new AtomicBoolean(false);
+ Thread[] threads = new Thread[threadCount];
+ int chunkSize = (int) Math.ceil((double) numbers.length / threadCount);
+
+ for (int i = 0; i < threadCount; i++) {
+ final int start = i * chunkSize;
+ final int end = Math.min(start + chunkSize, numbers.length);
+
+ threads[i] = new Thread(() -> {
+ for (int j = start; j < end; j++) {
+ if (result.get()) {
+ break;
+ }
+ if (!PrimeChecker.isPrime(numbers[j])) {
+ result.set(true);
+ break;
+ }
+ }
+ });
+ threads[i].start();
+ }
+
+ for (Thread thread : threads) {
+ try {
+ thread.join();
+ } catch (InterruptedException e) {
+ System.err.println("MultiThreaded.hasNonPrime(): Could not join thread");
+ }
+ }
+
+ return result.get();
+
+ }
+
+}
\ No newline at end of file
diff --git a/Task_2_1_2/src/main/java/ru/nsu/nmashkin/task212/PrimeChecker.java b/Task_2_1_2/src/main/java/ru/nsu/nmashkin/task212/PrimeChecker.java
new file mode 100644
index 0000000..b738dec
--- /dev/null
+++ b/Task_2_1_2/src/main/java/ru/nsu/nmashkin/task212/PrimeChecker.java
@@ -0,0 +1,28 @@
+package ru.nsu.nmashkin.task212;
+
+/**
+ * Check if the number is prime.
+ */
+public class PrimeChecker {
+ /**
+ * Check if the number is prime.
+ *
+ * @param n number
+ * @return is n prime
+ */
+ public static boolean isPrime(int n) {
+ if (n <= 1) {
+ return false;
+ }
+ if (n == 2) {
+ return true;
+ }
+
+ for (int i = 2; i * i <= n; i++) {
+ if (n % i == 0) {
+ return false;
+ }
+ }
+ return true;
+ }
+}
\ No newline at end of file
diff --git a/Task_2_1_2/src/main/java/ru/nsu/nmashkin/task212/Slave.java b/Task_2_1_2/src/main/java/ru/nsu/nmashkin/task212/Slave.java
new file mode 100644
index 0000000..80641a3
--- /dev/null
+++ b/Task_2_1_2/src/main/java/ru/nsu/nmashkin/task212/Slave.java
@@ -0,0 +1,127 @@
+package ru.nsu.nmashkin.task212;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.net.ConnectException;
+import java.net.DatagramPacket;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.net.MulticastSocket;
+import java.net.NetworkInterface;
+import java.net.Socket;
+import java.net.SocketTimeoutException;
+import java.nio.charset.StandardCharsets;
+
+/**
+ * Slave for 300$.
+ */
+public record Slave(int threadCount) {
+ private static final String MULTICAST_ADDRESS = "230.0.0.1";
+ private static final int MULTICAST_PORT = 4446;
+
+ /**
+ * Start the work day.
+ */
+ public void start() {
+ System.out.println("Slave ready. Initiating Master discovery...");
+
+ while (true) {
+ InetSocketAddress masterAddress = discoverMaster();
+ if (masterAddress == null) {
+ System.out.println("Discovery failed. Retrying...");
+ continue;
+ }
+
+ try {
+ System.out.println("Connecting to discovered Master at " + masterAddress);
+
+ try (Socket socket = new Socket(masterAddress.getAddress(),
+ masterAddress.getPort());
+ ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
+ ObjectInputStream in = new ObjectInputStream(socket.getInputStream())) {
+
+ System.out.println("Master detected");
+
+ while (true) {
+ Object input = in.readObject();
+ if (input == null) {
+ System.out.println("Work is over");
+ return;
+ }
+
+ Task task = (Task) input;
+ System.out.println("Work received: #" + task.taskId()
+ + ", size: " + task.numbers().length);
+
+ boolean result = MultiThreaded.hasNonPrime(task.numbers(), threadCount);
+
+ TaskResult taskResult = new TaskResult(task.taskId(), result);
+ out.writeObject(taskResult);
+ out.flush();
+ System.out.println("Work #" + task.taskId()
+ + " is done, result: " + result);
+ }
+ }
+ } catch (ConnectException e) {
+ System.err.println("Master found but unavailable (Connection refused).");
+ } catch (IOException | ClassNotFoundException e) {
+ System.err.println("Connection with Master broken: " + e.getMessage());
+ System.out.println("Work is over");
+ return;
+ }
+
+ try {
+ Thread.sleep(3000);
+ } catch (InterruptedException ie) {
+ System.out.println("Slave interrupted, stopping loop.");
+ Thread.currentThread().interrupt();
+ break;
+ }
+ }
+ }
+
+ private InetSocketAddress discoverMaster() {
+ try (MulticastSocket multicastSocket = new MulticastSocket(MULTICAST_PORT)) {
+ InetAddress group = InetAddress.getByName(MULTICAST_ADDRESS);
+ NetworkInterface netIf = NetworkInterface.getByInetAddress(InetAddress.getLocalHost());
+ if (netIf == null) {
+ netIf = NetworkInterface.getNetworkInterfaces().nextElement();
+ }
+ multicastSocket.joinGroup(new InetSocketAddress(group, MULTICAST_PORT), netIf);
+
+ byte[] msgBytes = "SLAVE_READY".getBytes(StandardCharsets.UTF_8);
+ DatagramPacket readyPacket = new DatagramPacket(msgBytes, msgBytes.length,
+ group, MULTICAST_PORT);
+ multicastSocket.send(readyPacket);
+ multicastSocket.setSoTimeout(3000);
+
+ byte[] buffer = new byte[1024];
+ while (true) {
+ try {
+ DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
+ multicastSocket.receive(packet);
+ String response = new String(packet.getData(), 0,
+ packet.getLength(), StandardCharsets.UTF_8);
+
+ if (response.startsWith("MASTER_INFO:")
+ || response.startsWith("MASTER_START:")) {
+ int port = Integer.parseInt(response.split(":")[1]);
+ InetAddress masterIp = packet.getAddress();
+
+ if (masterIp.isLoopbackAddress() || masterIp.isAnyLocalAddress()) {
+ masterIp = InetAddress.getLocalHost();
+ }
+ return new InetSocketAddress(masterIp, port);
+ }
+ } catch (SocketTimeoutException e) {
+ System.out.println("No Master answered. Re-broadcasting/waiting...");
+ multicastSocket.send(readyPacket);
+ }
+ }
+ } catch (Exception e) {
+ System.err.println("Discovery exception: " + e.getMessage());
+ return null;
+ }
+ }
+}
\ No newline at end of file
diff --git a/Task_2_1_2/src/main/java/ru/nsu/nmashkin/task212/Task.java b/Task_2_1_2/src/main/java/ru/nsu/nmashkin/task212/Task.java
new file mode 100644
index 0000000..b5fd0db
--- /dev/null
+++ b/Task_2_1_2/src/main/java/ru/nsu/nmashkin/task212/Task.java
@@ -0,0 +1,15 @@
+package ru.nsu.nmashkin.task212;
+
+import java.io.Serial;
+import java.io.Serializable;
+
+/**
+ * Slave's work.
+ *
+ * @param taskId .
+ * @param numbers .
+ */
+public record Task(int taskId, int[] numbers) implements Serializable {
+ @Serial
+ private static final long serialVersionUID = 1L;
+}
\ No newline at end of file
diff --git a/Task_2_1_2/src/main/java/ru/nsu/nmashkin/task212/TaskResult.java b/Task_2_1_2/src/main/java/ru/nsu/nmashkin/task212/TaskResult.java
new file mode 100644
index 0000000..57aa70b
--- /dev/null
+++ b/Task_2_1_2/src/main/java/ru/nsu/nmashkin/task212/TaskResult.java
@@ -0,0 +1,15 @@
+package ru.nsu.nmashkin.task212;
+
+import java.io.Serial;
+import java.io.Serializable;
+
+/**
+ * Slave's work report.
+ *
+ * @param taskId .
+ * @param hasNonPrime .
+ */
+public record TaskResult(int taskId, boolean hasNonPrime) implements Serializable {
+ @Serial
+ private static final long serialVersionUID = 1L;
+}
\ No newline at end of file
diff --git a/Task_2_1_2/src/test/java/ru/nsu/nmashkin/task212/EndToEndTest.java b/Task_2_1_2/src/test/java/ru/nsu/nmashkin/task212/EndToEndTest.java
new file mode 100644
index 0000000..29f9b28
--- /dev/null
+++ b/Task_2_1_2/src/test/java/ru/nsu/nmashkin/task212/EndToEndTest.java
@@ -0,0 +1,45 @@
+package ru.nsu.nmashkin.task212;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.Test;
+
+class EndToEndTest {
+
+ @Test
+ public void e2e() {
+ int port = 8004;
+ int[] numbers = {11, 13, 17, 19, 23, 29};
+ Master master = new Master(port);
+
+ Thread slaveThread = new Thread(() -> {
+ Slave slave = new Slave(2);
+ slave.start();
+ });
+ slaveThread.start();
+
+ boolean result = master.execute(numbers, 2, 1);
+ assertFalse(result);
+
+ slaveThread.interrupt();
+ }
+
+ @Test
+ public void e2e_allPrime() {
+ int port = 8005;
+ int[] numbers = {11, 13, 15, 17, 19};
+ Master master = new Master(port);
+
+ Thread slaveThread = new Thread(() -> {
+ Slave slave = new Slave(2);
+ slave.start();
+ });
+ slaveThread.start();
+
+ boolean result = master.execute(numbers, 2, 1);
+ assertTrue(result);
+
+ slaveThread.interrupt();
+ }
+}
\ No newline at end of file
diff --git a/Task_2_1_2/src/test/java/ru/nsu/nmashkin/task212/MasterTest.java b/Task_2_1_2/src/test/java/ru/nsu/nmashkin/task212/MasterTest.java
new file mode 100644
index 0000000..1a055da
--- /dev/null
+++ b/Task_2_1_2/src/test/java/ru/nsu/nmashkin/task212/MasterTest.java
@@ -0,0 +1,230 @@
+package ru.nsu.nmashkin.task212;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.net.DatagramPacket;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.net.MulticastSocket;
+import java.net.NetworkInterface;
+import java.net.Socket;
+import java.net.SocketTimeoutException;
+import java.nio.charset.StandardCharsets;
+import java.util.concurrent.atomic.AtomicBoolean;
+import org.junit.jupiter.api.Test;
+
+class MasterTest {
+
+ @Test
+ public void execute_allPrime() throws Exception {
+ int port = 8011;
+ int[] numbers = {2, 3, 5, 7, 11, 13, 17, 19};
+ int chunkSize = 3;
+ int expectedWorkers = 1;
+
+ Master master = new Master(port);
+
+ Thread slaveSimulator = new Thread(() -> {
+ try {
+ Thread.sleep(200);
+ try (Socket socket = new Socket("localhost", port);
+ ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
+ ObjectInputStream in = new ObjectInputStream(socket.getInputStream())) {
+
+ while (true) {
+ Object obj = in.readObject();
+ if (obj == null) {
+ break;
+ }
+ Task task = (Task) obj;
+ out.writeObject(new TaskResult(task.taskId(), false));
+ out.flush();
+ }
+ }
+ } catch (Exception e) {
+ e.printStackTrace();
+ }
+ });
+ slaveSimulator.start();
+
+ boolean result = master.execute(numbers, chunkSize, expectedWorkers);
+ assertFalse(result);
+ slaveSimulator.join();
+ }
+
+ @Test
+ public void execute() throws Exception {
+ int port = 8012;
+ int[] numbers = {2, 3, 4, 5, 7};
+ int chunkSize = 2;
+ int expectedWorkers = 1;
+
+ Master master = new Master(port);
+
+ Thread slaveSimulator = new Thread(() -> {
+ try {
+ Thread.sleep(200);
+ try (Socket socket = new Socket("localhost", port);
+ ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
+ ObjectInputStream in = new ObjectInputStream(socket.getInputStream())) {
+
+ while (true) {
+ Object obj = in.readObject();
+ if (obj == null) {
+ break;
+ }
+ Task task = (Task) obj;
+ boolean hasNonPrime = false;
+ for (int n : task.numbers()) {
+ if (n == 4) {
+ hasNonPrime = true;
+ break;
+ }
+ }
+ out.writeObject(new TaskResult(task.taskId(), hasNonPrime));
+ out.flush();
+ }
+ }
+ } catch (Exception e) {
+ e.printStackTrace();
+ }
+ });
+ slaveSimulator.start();
+
+ boolean result = master.execute(numbers, chunkSize, expectedWorkers);
+ assertTrue(result);
+ slaveSimulator.join();
+ }
+
+ @Test
+ public void masterRespondsToSlaveReady() throws Exception {
+ int port = 8030;
+ Master master = new Master(port);
+ AtomicBoolean responseReceived = new AtomicBoolean(false);
+
+ Thread slaveSimulator = new Thread(() -> {
+ try {
+ Thread.sleep(1000);
+ } catch (InterruptedException e) {
+ e.printStackTrace();
+ }
+
+ try {
+ try (MulticastSocket multicastSocket = new MulticastSocket(4446)) {
+ InetAddress group = InetAddress.getByName("230.0.0.1");
+ NetworkInterface netIf = NetworkInterface.getByInetAddress(
+ InetAddress.getLocalHost());
+ if (netIf == null) {
+ netIf = NetworkInterface.getNetworkInterfaces().nextElement();
+ }
+ multicastSocket.joinGroup(new InetSocketAddress(group, 4446), netIf);
+ multicastSocket.setSoTimeout(3000);
+
+ byte[] msgBytes = "SLAVE_READY".getBytes(StandardCharsets.UTF_8);
+ DatagramPacket readyPacket = new DatagramPacket(msgBytes, msgBytes.length,
+ group, 4446);
+ multicastSocket.send(readyPacket);
+
+ byte[] buffer = new byte[1024];
+ while (true) {
+ try {
+ DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
+ multicastSocket.receive(packet);
+ String response = new String(packet.getData(), 0,
+ packet.getLength(), StandardCharsets.UTF_8);
+
+ System.err.println(response);
+ if (response.startsWith("MASTER_INFO:")) {
+ responseReceived.set(true);
+ break;
+ }
+ } catch (SocketTimeoutException e) {
+ System.out.println("No Master answered. Re-broadcasting/waiting...");
+ multicastSocket.send(readyPacket); // Повторяем запрос
+ }
+ }
+ } catch (Exception e) {
+ System.err.println("Discovery exception: " + e.getMessage());
+ return;
+ }
+
+ try (Socket socket = new Socket("localhost", port);
+ ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
+ ObjectInputStream in = new ObjectInputStream(socket.getInputStream())) {
+
+ Task task = (Task) in.readObject();
+ out.writeObject(new TaskResult(task.taskId(), false));
+ out.flush();
+ in.readObject();
+ }
+ } catch (Exception e) {
+ e.printStackTrace();
+ }
+ });
+
+ slaveSimulator.start();
+
+ master.execute(new int[]{1}, 1, 1);
+
+ slaveSimulator.join(5000);
+ assertTrue(responseReceived.get());
+ }
+
+
+ @Test
+ public void workerCrash_returnsTaskToQueue() throws Exception {
+ int port = 8040;
+ int[] numbers = {2, 3, 5, 7};
+ Master master = new Master(port);
+
+ Thread badSlave = new Thread(() -> {
+ try {
+ Thread.sleep(1000);
+ } catch (InterruptedException e) {
+ e.printStackTrace();
+ }
+
+ try (Socket socket = new Socket("localhost", port);
+ ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
+ ObjectInputStream in = new ObjectInputStream(socket.getInputStream())) {
+ in.readObject();
+ } catch (Exception e) {
+ e.printStackTrace();
+ }
+ });
+
+ AtomicBoolean success = new AtomicBoolean(false);
+ Thread goodSlave = new Thread(() -> {
+ try {
+ Thread.sleep(1000);
+ } catch (InterruptedException e) {
+ e.printStackTrace();
+ }
+ try (Socket socket = new Socket("localhost", port);
+ ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
+ ObjectInputStream in = new ObjectInputStream(socket.getInputStream())) {
+
+ for (int i = 0; i < 2; i++) {
+ Task task = (Task) in.readObject();
+ out.writeObject(new TaskResult(task.taskId(), false));
+ out.flush();
+ }
+ success.set(true);
+ } catch (Exception e) {
+ e.printStackTrace();
+ }
+ });
+
+ badSlave.start();
+ goodSlave.start();
+
+ boolean result = master.execute(numbers, 2, 2);
+
+ assertFalse(result);
+ goodSlave.join(2000);
+ assertTrue(success.get());
+ }
+}
\ No newline at end of file
diff --git a/Task_2_1_2/src/test/java/ru/nsu/nmashkin/task212/SlaveTest.java b/Task_2_1_2/src/test/java/ru/nsu/nmashkin/task212/SlaveTest.java
new file mode 100644
index 0000000..53181f8
--- /dev/null
+++ b/Task_2_1_2/src/test/java/ru/nsu/nmashkin/task212/SlaveTest.java
@@ -0,0 +1,140 @@
+package ru.nsu.nmashkin.task212;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+import java.net.InetAddress;
+import java.net.ServerSocket;
+import java.net.Socket;
+import java.nio.charset.StandardCharsets;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+import org.junit.jupiter.api.Test;
+
+class SlaveTest {
+
+ private void masterSim(int port, CountDownLatch stopLatch) {
+ Thread advertiser = new Thread(() -> {
+ try (DatagramSocket udpSocket = new DatagramSocket()) {
+ InetAddress group = InetAddress.getByName("230.0.0.1");
+ byte[] msgBytes = ("MASTER_START:" + port).getBytes(StandardCharsets.UTF_8);
+ DatagramPacket packet = new DatagramPacket(msgBytes, msgBytes.length, group, 4446);
+
+ while (stopLatch.getCount() > 0) {
+ udpSocket.send(packet);
+ Thread.sleep(500);
+ }
+ } catch (Exception e) {
+ e.printStackTrace();
+ }
+ });
+ advertiser.setDaemon(true);
+ advertiser.start();
+ }
+
+ @Test
+ public void start() throws Exception {
+ int port = 8003;
+ AtomicBoolean resultReceived = new AtomicBoolean(false);
+ CountDownLatch stopAdvertiser = new CountDownLatch(1);
+
+ Thread masterSimulator = new Thread(() -> {
+ try (ServerSocket server = new ServerSocket(port)) {
+ masterSim(port, stopAdvertiser);
+
+ try (Socket socket = server.accept();
+ ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
+ ObjectInputStream in = new ObjectInputStream(socket.getInputStream())) {
+
+ stopAdvertiser.countDown();
+
+ out.writeObject(new Task(99, new int[]{2, 4, 6}));
+ out.flush();
+
+ TaskResult result = (TaskResult) in.readObject();
+ if (result != null && result.taskId() == 99) {
+ resultReceived.set(result.hasNonPrime());
+ }
+
+ out.writeObject(null);
+ out.flush();
+ }
+ } catch (Exception e) {
+ e.printStackTrace();
+ } finally {
+ stopAdvertiser.countDown();
+ }
+ });
+ masterSimulator.start();
+
+ Thread.sleep(200);
+
+ Slave slave = new Slave(2);
+ slave.start();
+
+ masterSimulator.join();
+ assertTrue(resultReceived.get());
+ }
+
+ @Test
+ public void start_reconnect() throws Exception {
+ int port = 8025;
+ AtomicBoolean taskProcessedAfterReconnect = new AtomicBoolean(false);
+ CountDownLatch masterStartedLatch = new CountDownLatch(1);
+ CountDownLatch taskDoneLatch = new CountDownLatch(1);
+ CountDownLatch stopAdvertiser = new CountDownLatch(1);
+
+ Thread slaveThread = new Thread(() -> {
+ Slave slave = new Slave(2);
+ slave.start();
+ });
+
+ slaveThread.start();
+ Thread.sleep(5000);
+
+ Thread masterDelayedThread = new Thread(() -> {
+ masterStartedLatch.countDown();
+ try (ServerSocket server = new ServerSocket(port)) {
+ masterSim(port, stopAdvertiser);
+
+ try (Socket socket = server.accept();
+ ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
+ ObjectInputStream in = new ObjectInputStream(socket.getInputStream())) {
+
+ stopAdvertiser.countDown();
+
+ out.writeObject(new Task(42, new int[]{4, 6, 8}));
+ out.flush();
+
+ TaskResult result = (TaskResult) in.readObject();
+ if (result != null && result.taskId() == 42) {
+ taskProcessedAfterReconnect.set(true);
+ }
+
+ out.writeObject(null);
+ out.flush();
+ taskDoneLatch.countDown();
+
+ }
+ } catch (Exception e) {
+ e.printStackTrace();
+ } finally {
+ stopAdvertiser.countDown();
+ }
+ });
+
+ masterDelayedThread.start();
+
+ assertTrue(masterStartedLatch.await(2, TimeUnit.SECONDS));
+ assertTrue(taskDoneLatch.await(5, TimeUnit.SECONDS));
+
+ slaveThread.interrupt();
+ slaveThread.join(1000);
+
+ assertTrue(taskProcessedAfterReconnect.get());
+ }
+}
\ No newline at end of file