diff --git a/src/main/java/workshop/exercises/DeadlockPreventionWorkshop.java b/src/main/java/workshop/exercises/DeadlockPreventionWorkshop.java index 91ba6a8..5c2026c 100644 --- a/src/main/java/workshop/exercises/DeadlockPreventionWorkshop.java +++ b/src/main/java/workshop/exercises/DeadlockPreventionWorkshop.java @@ -20,17 +20,18 @@ public class DeadlockPreventionWorkshop { } public static void useResources(Resource r1, Resource r2) { - // TODO: Prevent deadlock by enforcing a consistent lock acquisition order - // Hint: Compare resource IDs and always synchronize on the resource with the smaller ID first. - - System.out.println(Thread.currentThread().getName() + " is attempting to lock " + r1.getName()); - synchronized (r1) { - System.out.println("+ " + Thread.currentThread().getName() + " locked " + r1.getName()); + // برای جلوگیری از ددلاک، بر اساس id منابع رو مرتب می‌کنیم تا همه تردها قفل‌ها رو با یک ترتیب ثابت بگیرن + 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 " + first.getName()); + synchronized (first) { + System.out.println("+ " + Thread.currentThread().getName() + " locked " + first.getName()); try { Thread.sleep(100); } catch (InterruptedException ignored) {} - - System.out.println(Thread.currentThread().getName() + " is attempting to lock " + r2.getName()); - synchronized (r2) { - System.out.println("+ " + Thread.currentThread().getName() + " locked " + r2.getName()); + + System.out.println(Thread.currentThread().getName() + " is attempting to lock " + second.getName()); + synchronized (second) { + System.out.println("+ " + Thread.currentThread().getName() + " locked " + second.getName()); System.out.println(Thread.currentThread().getName() + " using " + r1.getName() + " and " + r2.getName()); } } @@ -47,4 +48,4 @@ public class DeadlockPreventionWorkshop { t1.start(); t2.start(); } -} +} \ No newline at end of file diff --git a/src/main/java/workshop/exercises/LockWorkshop.java b/src/main/java/workshop/exercises/LockWorkshop.java index ec24ecf..79f69eb 100644 --- a/src/main/java/workshop/exercises/LockWorkshop.java +++ b/src/main/java/workshop/exercises/LockWorkshop.java @@ -5,16 +5,23 @@ import java.util.concurrent.locks.ReentrantLock; public class LockWorkshop { 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 { @Override public void run() { int 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 - counter += 1; + // گرفتن قفل قبل از تغییر دادن مقدار کانتر مشترک + lock.lock(); + try { + 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); } @@ -25,13 +32,13 @@ public class LockWorkshop { Thread thread1 = new Thread(new MyRunnable(), "Thread-1"); Thread thread2 = new Thread(new MyRunnable(), "Thread-2"); - + thread1.start(); thread2.start(); thread1.join(); thread2.join(); - + System.out.println("Final counter value (expected 2000000): " + counter); } -} +} \ No newline at end of file diff --git a/src/main/java/workshop/exercises/SynchronizedWorkshop.java b/src/main/java/workshop/exercises/SynchronizedWorkshop.java index 9259d8e..e8319ae 100644 --- a/src/main/java/workshop/exercises/SynchronizedWorkshop.java +++ b/src/main/java/workshop/exercises/SynchronizedWorkshop.java @@ -2,16 +2,19 @@ package workshop.exercises; public class SynchronizedWorkshop { 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 { @Override public void run() { int i; for (i = 0; i < 1_000_000; i++) { - // TODO: Use a synchronized block to protect the counter increment - counter += 1; + // استفاده از بلوک synchronized روی شیء قفل برای محافظت از کانتر + synchronized (lock) { + counter += 1; + } } System.out.println("Increments completed by " + Thread.currentThread().getName() + ": " + i); } @@ -22,13 +25,13 @@ public class SynchronizedWorkshop { Thread thread1 = new Thread(new MyRunnable(), "Thread-1"); Thread thread2 = new Thread(new MyRunnable(), "Thread-2"); - + thread1.start(); thread2.start(); thread1.join(); thread2.join(); - + System.out.println("Final counter value (expected 2000000): " + counter); } -} +} \ No newline at end of file diff --git a/src/main/java/workshop/exercises/TaylorSeries.java b/src/main/java/workshop/exercises/TaylorSeries.java index d63a18e..7299651 100644 --- a/src/main/java/workshop/exercises/TaylorSeries.java +++ b/src/main/java/workshop/exercises/TaylorSeries.java @@ -8,7 +8,7 @@ import java.util.concurrent.Executors; import java.util.concurrent.TimeUnit; public class TaylorSeries { - + public static class CalculateSin implements Runnable { private final MathContext mc = new MathContext(1000); private final BigDecimal x; @@ -21,14 +21,30 @@ public class TaylorSeries { @Override public void run() { - // TODO: Calculate the n-th term of the Taylor series for sin(x): - // term = (-1)^n * (x^(2n+1)) / (2n+1)! - // Add the term to the global sum ensuring thread-safety. + // محاسبه فرمول: term = (-1)^n * (x^(2n+1)) / (2n+1)! + int exponent = 2 * n + 1; + 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(); + } + + // اضافه کردن به sum سراسری به صورت ایمن و Thread-safe + synchronized (TaylorSeries.class) { + sum = sum.add(term, mc); + } } - // TODO: Implement factorial(k) using BigDecimal + // پیاده‌سازی فاکتوریل با BigDecimal 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 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(); @@ -72,4 +89,4 @@ public class TaylorSeries { System.out.println("Accurate Value: " + accurateValue.toPlainString()); System.out.println("Difference: " + accurateValue.subtract(sum).abs().toPlainString()); } -} +} \ No newline at end of file