diff --git a/DIRECTORY.md b/DIRECTORY.md index 34ded2ceb..774a18601 100644 --- a/DIRECTORY.md +++ b/DIRECTORY.md @@ -530,6 +530,7 @@ * [ScanScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/diskscheduling/ScanScheduling.java) * [SSFScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/diskscheduling/SSFScheduling.java) * [EDFScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/EDFScheduling.java) + * [FairShareScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/FairShareScheduling.java) * [FCFSScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/FCFSScheduling.java) * [HighestResponseRatioNextScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/HighestResponseRatioNextScheduling.java) * [JobSchedulingWithDeadline](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/JobSchedulingWithDeadline.java) @@ -1129,6 +1130,7 @@ * [ScanSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/diskscheduling/ScanSchedulingTest.java) * [SSFSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/diskscheduling/SSFSchedulingTest.java) * [EDFSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/EDFSchedulingTest.java) + * [FairShareSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/FairShareSchedulingTest.java) * [FCFSSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/FCFSSchedulingTest.java) * [HighestResponseRatioNextSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/HighestResponseRatioNextSchedulingTest.java) * [JobSchedulingWithDeadlineTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/JobSchedulingWithDeadlineTest.java) diff --git a/src/main/java/com/thealgorithms/scheduling/FairShareScheduling.java b/src/main/java/com/thealgorithms/scheduling/FairShareScheduling.java new file mode 100644 index 000000000..776fc59c0 --- /dev/null +++ b/src/main/java/com/thealgorithms/scheduling/FairShareScheduling.java @@ -0,0 +1,65 @@ +package com.thealgorithms.scheduling; + +import java.util.HashMap; +import java.util.Map; + +/** + * FairShareScheduling allocates CPU resources equally among users or groups + * instead of individual tasks. Each group gets a proportional share, + * preventing resource hogging by a single user's processes. + * + * Use Case: Multi-user systems where users submit multiple tasks simultaneously, + * such as cloud environments. + * + * @author Hardvan + */ +public final class FairShareScheduling { + + static class User { + String name; + int allocatedResources; + int totalWeight; + + User(String name) { + this.name = name; + this.allocatedResources = 0; + this.totalWeight = 0; + } + + void addWeight(int weight) { + this.totalWeight += weight; + } + } + + private final Map users; // username -> User + + public FairShareScheduling() { + users = new HashMap<>(); + } + + public void addUser(String userName) { + users.putIfAbsent(userName, new User(userName)); + } + + public void addTask(String userName, int weight) { + User user = users.get(userName); + if (user != null) { + user.addWeight(weight); + } + } + + public void allocateResources(int totalResources) { + int totalWeights = users.values().stream().mapToInt(user -> user.totalWeight).sum(); + for (User user : users.values()) { + user.allocatedResources = (int) ((double) user.totalWeight / totalWeights * totalResources); + } + } + + public Map getAllocatedResources() { + Map allocation = new HashMap<>(); + for (User user : users.values()) { + allocation.put(user.name, user.allocatedResources); + } + return allocation; + } +} diff --git a/src/test/java/com/thealgorithms/scheduling/FairShareSchedulingTest.java b/src/test/java/com/thealgorithms/scheduling/FairShareSchedulingTest.java new file mode 100644 index 000000000..7aa6e061c --- /dev/null +++ b/src/test/java/com/thealgorithms/scheduling/FairShareSchedulingTest.java @@ -0,0 +1,60 @@ +package com.thealgorithms.scheduling; + +import static org.junit.jupiter.api.Assertions.assertEquals; + +import java.util.Map; +import org.junit.jupiter.api.BeforeEach; +import org.junit.jupiter.api.Test; + +public class FairShareSchedulingTest { + + private FairShareScheduling scheduler; + + @BeforeEach + public void setup() { + scheduler = new FairShareScheduling(); + } + + @Test + public void testAllocateResourcesSingleUser() { + scheduler.addUser("User1"); + scheduler.addTask("User1", 5); + scheduler.allocateResources(100); + Map expected = Map.of("User1", 100); + assertEquals(expected, scheduler.getAllocatedResources()); + } + + @Test + public void testAllocateResourcesMultipleUsers() { + scheduler.addUser("User1"); + scheduler.addUser("User2"); + scheduler.addUser("User3"); + scheduler.addTask("User1", 2); + scheduler.addTask("User2", 3); + scheduler.addTask("User3", 5); + scheduler.allocateResources(100); + Map expected = Map.of("User1", 20, "User2", 30, "User3", 50); + assertEquals(expected, scheduler.getAllocatedResources()); + } + + @Test + public void testAllocateResourcesZeroWeightUser() { + scheduler.addUser("User1"); + scheduler.addUser("User2"); + scheduler.addTask("User2", 5); + scheduler.allocateResources(100); + Map expected = Map.of("User1", 0, "User2", 100); + assertEquals(expected, scheduler.getAllocatedResources()); + } + + @Test + public void testAllocateResourcesEqualWeights() { + scheduler.addUser("User1"); + scheduler.addUser("User2"); + scheduler.addTask("User1", 1); + scheduler.addTask("User2", 1); + scheduler.allocateResources(100); + Map expected = Map.of("User1", 50, "User2", 50); + assertEquals(expected, scheduler.getAllocatedResources()); + } +}