Implement deadlock prevention logic and parallel Taylor series calculation #1

Open
AmirAli_Amiri wants to merge 1 commits from develop into master
4 changed files with 61 additions and 33 deletions
@@ -20,17 +20,18 @@ public class DeadlockPreventionWorkshop {
} }
public static void useResources(Resource r1, Resource r2) { public static void useResources(Resource r1, Resource r2) {
// TODO: Prevent deadlock by enforcing a consistent lock acquisition order // برای جلوگیری از ددلاک، بر اساس id منابع رو مرتب می‌کنیم تا همه تردها قفل‌ها رو با یک ترتیب ثابت بگیرن
// Hint: Compare resource IDs and always synchronize on the resource with the smaller ID first. Resource first = r1.getId() < r2.getId() ? r1 : r2;
Resource second = r1.getId() < r2.getId() ? r2 : r1;
System.out.println(Thread.currentThread().getName() + " is attempting to lock " + r1.getName()); System.out.println(Thread.currentThread().getName() + " is attempting to lock " + first.getName());
synchronized (r1) { synchronized (first) {
System.out.println("+ " + Thread.currentThread().getName() + " locked " + r1.getName()); System.out.println("+ " + Thread.currentThread().getName() + " locked " + first.getName());
try { Thread.sleep(100); } catch (InterruptedException ignored) {} try { Thread.sleep(100); } catch (InterruptedException ignored) {}
System.out.println(Thread.currentThread().getName() + " is attempting to lock " + r2.getName()); System.out.println(Thread.currentThread().getName() + " is attempting to lock " + second.getName());
synchronized (r2) { synchronized (second) {
System.out.println("+ " + Thread.currentThread().getName() + " locked " + r2.getName()); System.out.println("+ " + Thread.currentThread().getName() + " locked " + second.getName());
System.out.println(Thread.currentThread().getName() + " using " + r1.getName() + " and " + r2.getName()); System.out.println(Thread.currentThread().getName() + " using " + r1.getName() + " and " + r2.getName());
} }
} }
@@ -6,15 +6,22 @@ import java.util.concurrent.locks.ReentrantLock;
public class LockWorkshop { public class LockWorkshop {
public static int counter = 0; public static int counter = 0;
// TODO: Create a ReentrantLock instance to protect the critical section // تعریف شیء قفل ReentrantLock برای محافظت از محدوده بحرانی
private static final Lock lock = new ReentrantLock();
public static class MyRunnable implements Runnable { public static class MyRunnable implements Runnable {
@Override @Override
public void run() { public void run() {
int i; int i;
for (i = 0; i < 1_000_000; i++) { for (i = 0; i < 1_000_000; i++) {
// TODO: Acquire the lock, increment the counter, and release the lock safely in a finally block // گرفتن قفل قبل از تغییر دادن مقدار کانتر مشترک
lock.lock();
try {
counter += 1; counter += 1;
} finally {
// آزاد کردن قطعی قفل در بلوک finally برای امنیت بیشتر
lock.unlock();
}
} }
System.out.println("Increments completed by " + Thread.currentThread().getName() + ": " + i); System.out.println("Increments completed by " + Thread.currentThread().getName() + ": " + i);
} }
@@ -3,16 +3,19 @@ package workshop.exercises;
public class SynchronizedWorkshop { public class SynchronizedWorkshop {
public static int counter = 0; public static int counter = 0;
// TODO: Define a lock object to prevent race condition // تعریف یک شیء قفل برای جلوگیری از تداخل داده‌ها در مانیتور اینتزینزیک
private static final Object lock = new Object();
public static class MyRunnable implements Runnable { public static class MyRunnable implements Runnable {
@Override @Override
public void run() { public void run() {
int i; int i;
for (i = 0; i < 1_000_000; i++) { for (i = 0; i < 1_000_000; i++) {
// TODO: Use a synchronized block to protect the counter increment // استفاده از بلوک synchronized روی شیء قفل برای محافظت از کانتر
synchronized (lock) {
counter += 1; counter += 1;
} }
}
System.out.println("Increments completed by " + Thread.currentThread().getName() + ": " + i); System.out.println("Increments completed by " + Thread.currentThread().getName() + ": " + i);
} }
} }
@@ -21,14 +21,30 @@ public class TaylorSeries {
@Override @Override
public void run() { public void run() {
// TODO: Calculate the n-th term of the Taylor series for sin(x): // محاسبه فرمول: term = (-1)^n * (x^(2n+1)) / (2n+1)!
// term = (-1)^n * (x^(2n+1)) / (2n+1)! int exponent = 2 * n + 1;
// Add the term to the global sum ensuring thread-safety. BigDecimal num = x.pow(exponent, mc);
BigDecimal den = factorial(exponent);
BigDecimal term = num.divide(den, mc);
// اگه n فرد باشه جمله منفی میشه
if (n % 2 == 1) {
term = term.negate();
} }
// TODO: Implement factorial(k) using BigDecimal // اضافه کردن به sum سراسری به صورت ایمن و Thread-safe
synchronized (TaylorSeries.class) {
sum = sum.add(term, mc);
}
}
// پیاده‌سازی فاکتوریل با BigDecimal
private BigDecimal factorial(int k) { private BigDecimal factorial(int k) {
return BigDecimal.ZERO; BigDecimal fact = BigDecimal.ONE;
for (int i = 2; i <= k; i++) {
fact = fact.multiply(BigDecimal.valueOf(i));
}
return fact;
} }
} }
@@ -41,7 +57,8 @@ public class TaylorSeries {
// Submit tasks to calculate terms // Submit tasks to calculate terms
for (int i = 0; i < 100; i++) { for (int i = 0; i < 100; i++) {
// TODO: Submit task to the thread pool // فرستادن تسک‌های محاسبه به ترد پول
threadPool.submit(new CalculateSin(x, i));
} }
threadPool.shutdown(); threadPool.shutdown();