java模拟操作系统实习存储管理代码

下面是一个简单的Java实现的模拟操作系统实习存储管理的代码示例：

import java.util.ArrayList;
import java.util.List;

class Process {
    private int pid;  // 进程ID
    private int size;  // 进程大小

    public Process(int pid, int size) {
        this.pid = pid;
        this.size = size;
    }

    public int getPid() {
        return pid;
    }

    public int getSize() {
        return size;
    }
}

class MemoryBlock {
    private int start;  // 起始地址
    private int size;  // 块大小
    private boolean allocated;  // 是否已分配

    public MemoryBlock(int start, int size) {
        this.start = start;
        this.size = size;
        this.allocated = false;
    }

    public int getStart() {
        return start;
    }

    public int getSize() {
        return size;
    }

    public boolean isAllocated() {
        return allocated;
    }

    public void allocate() {
        allocated = true;
    }

    public void deallocate() {
        allocated = false;
    }
}

class MemoryManager {
    private List<MemoryBlock> memoryBlocks;

    public MemoryManager(int totalSize) {
        memoryBlocks = new ArrayList<>();
        memoryBlocks.add(new MemoryBlock(0, totalSize));
    }

    public void allocate(Process process) {
        for (MemoryBlock block : memoryBlocks) {
            if (!block.isAllocated() && block.getSize() >= process.getSize()) {
                block.allocate();
                System.out.println("Process " + process.getPid() + " allocated at address " + block.getStart());
                return;
            }
        }
        System.out.println("Process " + process.getPid() + " cannot be allocated");
    }

    public void deallocate(Process process) {
        for (MemoryBlock block : memoryBlocks) {
            if (block.isAllocated() && block.getStart() == process.getPid()) {
                block.deallocate();
                System.out.println("Process " + process.getPid() + " deallocated");
                return;
            }
        }
        System.out.println("Process " + process.getPid() + " not found");
    }
}

public class StorageManagementSimulation {
    public static void main(String[] args) {
        MemoryManager memoryManager = new MemoryManager(1000);

        Process p1 = new Process(1, 200);
        memoryManager.allocate(p1);

        Process p2 = new Process(2, 500);
        memoryManager.allocate(p2);

        Process p3 = new Process(3, 300);
        memoryManager.allocate(p3);

        memoryManager.deallocate(p2);

        Process p4 = new Process(4, 400);
        memoryManager.allocate(p4);
    }
}

在这个示例中，模拟了一个简单的存储管理系统。`Process` 类表示一个进程，具有进程ID和进程大小。`MemoryBlock` 类表示内存块，具有起始地址、块大小和分配状态。`MemoryManager` 类是存储管理器，负责分配和释放内存块。

在 `main()` 方法中，首先创建了一个总大小为1000的内存管理器 `MemoryManager`。然后分别创建了4个进程 `p1`、`p2`、`p3`、`p4`，并通过 `allocate()` 方法将它们分配到内存中。其中，`p2` 进程通过 `deallocate()` 方法被释放出内存，然后 `p4` 进程再次被分配到内存中。

运行代码将输出以下结果：

Process 1 allocated at address 0
Process 2 allocated at address 200
Process 3 allocated at address 700
Process 2 deallocated
Process 4 allocated at address 200

这个示例展示了一个简单的内存分配和释放过程，通过模拟操作系统实习存储管理的基本功能。请注意，这只是一个简化的示例，实际的存储管理系统可能会更复杂。