diff options
Diffstat (limited to 'jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/SynchronizedBoolean.java')
| -rw-r--r-- | jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/SynchronizedBoolean.java | 284 |
1 files changed, 158 insertions, 126 deletions
diff --git a/jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/SynchronizedBoolean.java b/jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/SynchronizedBoolean.java index 6986617a02..cc4b656752 100644 --- a/jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/SynchronizedBoolean.java +++ b/jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/SynchronizedBoolean.java @@ -15,14 +15,15 @@ import org.eclipse.jpt.utility.Command; /** * This class provides synchronized access to a <code>boolean</code> value. * It also provides protocol for suspending a thread until the - * boolean value is set to true or false, with optional time-outs. + * <code>boolean</code> value is set to <code>true</code> or <code>false</code>, + * with optional time-outs. * * @see BooleanHolder */ public class SynchronizedBoolean implements Cloneable, Serializable { - /** Backing boolean. */ + /** Backing <code>boolean</code>. */ private boolean value; /** Object to synchronize on. */ @@ -34,8 +35,8 @@ public class SynchronizedBoolean // ********** constructors ********** /** - * Create a synchronized <code>boolean</code> with the specified initial value - * and mutex. + * Create a synchronized <code>boolean</code> with the specified + * initial value and mutex. */ public SynchronizedBoolean(boolean value, Object mutex) { super(); @@ -44,7 +45,9 @@ public class SynchronizedBoolean } /** - * Create a synchronized <code>boolean</code> with the specified initial value. + * Create a synchronized <code>boolean</code> with the + * specified initial value. + * The synchronized <code>boolean</code> itself will be the mutex. */ public SynchronizedBoolean(boolean value) { super(); @@ -53,7 +56,8 @@ public class SynchronizedBoolean } /** - * Create a synchronized <code>boolean</code> with an initial value of <code>false</code> + * Create a synchronized <code>boolean</code> + * with an initial value of <code>false</code> * and specified mutex. */ public SynchronizedBoolean(Object mutex) { @@ -61,7 +65,9 @@ public class SynchronizedBoolean } /** - * Create a synchronized <code>boolean</code> with an initial value of <code>false</code>. + * Create a synchronized <code>boolean</code> + * with an initial value of <code>false</code>. + * The synchronized <code>boolean</code> itself will be the mutex. */ public SynchronizedBoolean() { this(false); @@ -71,7 +77,7 @@ public class SynchronizedBoolean // ********** accessors ********** /** - * Return the current boolean value. + * Return the current <code>boolean</code> value. */ public boolean getValue() { synchronized (this.mutex) { @@ -80,7 +86,8 @@ public class SynchronizedBoolean } /** - * Return whether the current boolean value is true. + * Return whether the current <code>boolean</code> + * value is <code>true</code>. */ public boolean isTrue() { synchronized (this.mutex) { @@ -89,7 +96,8 @@ public class SynchronizedBoolean } /** - * Return whether the current boolean value is false. + * Return whether the current <code>boolean</code> + * value is <code>false</code>. */ public boolean isFalse() { synchronized (this.mutex) { @@ -98,7 +106,8 @@ public class SynchronizedBoolean } /** - * Return whether the current boolean value is the specified value. + * Return whether the current <code>boolean</code> + * value is the specified value. */ public boolean is(boolean v) { synchronized (this.mutex) { @@ -107,36 +116,39 @@ public class SynchronizedBoolean } /** - * Set the boolean value. If the value changes, all waiting - * threads are notified. + * Set the <code>boolean</code> value. + * If the value changes, all waiting threads are notified. */ public void setValue(boolean value) { synchronized (this.mutex) { - if (this.value != value) { - this.value = value; - this.mutex.notifyAll(); - } + this.setValue_(value); } } /** - * Set the boolean value to true. If the value changes, all waiting - * threads are notified. + * Pre-condition: synchronized */ - public void setTrue() { - synchronized (this.mutex) { - this.setValue(true); + private void setValue_(boolean value) { + if (this.value != value) { + this.value = value; + this.mutex.notifyAll(); } } /** - * Set the boolean value to false. If the value changes, all waiting - * threads are notified. + * Set the <code>boolean</code> value to <code>true</code>. + * If the value changes, all waiting threads are notified. + */ + public void setTrue() { + this.setValue(true); + } + + /** + * Set the <code>boolean</code> value to <code>false</code>. + * If the value changes, all waiting threads are notified. */ public void setFalse() { - synchronized (this.mutex) { - this.setValue(false); - } + this.setValue(false); } /** @@ -151,176 +163,196 @@ public class SynchronizedBoolean // ********** indefinite waits ********** /** - * Suspend the current thread until the boolean value changes - * to the specified value. If the boolean value is already the + * Suspend the current thread until the <code>boolean</code> value changes + * to the specified value. If the <code>boolean</code> value is already the * specified value, return immediately. */ public void waitUntilValueIs(boolean v) throws InterruptedException { synchronized (this.mutex) { - while (this.value != v) { - this.mutex.wait(); - } + this.waitUntilValueIs_(v); } } /** - * Suspend the current thread until the boolean value changes to true. - * If the boolean value is already true, return immediately. + * Pre-condition: synchronized */ - public void waitUntilTrue() throws InterruptedException { - synchronized (this.mutex) { - this.waitUntilValueIs(true); + private void waitUntilValueIs_(boolean v) throws InterruptedException { + while (this.value != v) { + this.mutex.wait(); } } /** - * Suspend the current thread until the boolean value changes to false. - * If the boolean value is already false, return immediately. + * Suspend the current thread until the <code>boolean</code> value + * changes to <code>true</code>. + * If the <code>boolean</code> value is already <code>true</code>, + * return immediately. + */ + public void waitUntilTrue() throws InterruptedException { + this.waitUntilValueIs(true); + } + + /** + * Suspend the current thread until the <code>boolean</code> value + * changes to <code>false</code>. + * If the <code>boolean</code> value is already <code>false</code>, + * return immediately. */ public void waitUntilFalse() throws InterruptedException { - synchronized (this.mutex) { - this.waitUntilValueIs(false); - } + this.waitUntilValueIs(false); } /** - * Suspend the current thread until the boolean value changes to - * NOT the specified value, then change it back to the specified - * value and continue executing. If the boolean value is already - * NOT the specified value, set the value to the specified value + * Suspend the current thread until the <code>boolean</code> value changes to + * <em>not</em> the specified value, then change it back to the specified + * value and continue executing. If the <code>boolean</code> value is already + * <em>not</em> the specified value, set the value to the specified value * immediately. */ public void waitToSetValue(boolean v) throws InterruptedException { synchronized (this.mutex) { - this.waitUntilValueIs( ! v); - this.setValue(v); + this.waitUntilValueIs_( ! v); + this.setValue_(v); } } /** - * Suspend the current thread until the boolean value changes to false, - * then change it back to true and continue executing. If the boolean - * value is already false, set the value to true immediately. + * Suspend the current thread until the <code>boolean</code> value + * changes to <code>false</code>, + * then change it back to <code>true</code> and continue executing. + * If the <code>boolean</code> value is already <code>false</code>, + * set the value to <code>true</code> immediately. */ public void waitToSetTrue() throws InterruptedException { - synchronized (this.mutex) { - this.waitToSetValue(true); - } + this.waitToSetValue(true); } /** - * Suspend the current thread until the boolean value changes to true, - * then change it back to false and continue executing. If the boolean - * value is already true, set the value to false immediately. + * Suspend the current thread until the <code>boolean</code> value + * changes to <code>true</code>, + * then change it back to <code>false</code> and continue executing. + * If the <code>boolean</code> value is already <code>true</code>, + * set the value to <code>false</code> immediately. */ public void waitToSetFalse() throws InterruptedException { - synchronized (this.mutex) { - this.waitToSetValue(false); - } + this.waitToSetValue(false); } // ********** timed waits ********** /** - * Suspend the current thread until the boolean value changes + * Suspend the current thread until the <code>boolean</code> value changes * to the specified value or the specified time-out occurs. - * The time-out is specified in milliseconds. Return true if the specified - * value was achieved; return false if a time-out occurred. - * If the boolean value is already the specified value, return true - * immediately. + * The time-out is specified in milliseconds. Return <code>true</code> if the specified + * value was achieved; return <code>false</code> if a time-out occurred. + * If the <code>boolean</code> value is already the specified value, + * return <code>true</code> immediately. + * If the time-out is zero, wait indefinitely. */ public boolean waitUntilValueIs(boolean v, long timeout) throws InterruptedException { synchronized (this.mutex) { - if (timeout == 0L) { - this.waitUntilValueIs(v); // wait indefinitely until notified - return true; // if it ever comes back, the condition was met - } - - long stop = System.currentTimeMillis() + timeout; - long remaining = timeout; - while ((this.value != v) && (remaining > 0L)) { - this.mutex.wait(remaining); - remaining = stop - System.currentTimeMillis(); - } - return (this.value == v); + return this.waitUntilValueIs_(v, timeout); } } /** - * Suspend the current thread until the boolean value changes - * to true or the specified time-out occurs. - * The time-out is specified in milliseconds. Return true if the specified - * value was achieved; return false if a time-out occurred. - * If the boolean value is already true, return true immediately. + * Pre-condition: synchronized */ - public boolean waitUntilTrue(long timeout) throws InterruptedException { - synchronized (this.mutex) { - return this.waitUntilValueIs(true, timeout); + private boolean waitUntilValueIs_(boolean v, long timeout) throws InterruptedException { + if (timeout == 0L) { + this.waitUntilValueIs_(v); // wait indefinitely until notified + return true; // if it ever comes back, the condition was met } + + long stop = System.currentTimeMillis() + timeout; + long remaining = timeout; + while ((this.value != v) && (remaining > 0L)) { + this.mutex.wait(remaining); + remaining = stop - System.currentTimeMillis(); + } + return (this.value == v); } /** - * Suspend the current thread until the boolean value changes - * to false or the specified time-out occurs. - * The time-out is specified in milliseconds. Return true if the specified - * value was achieved; return false if a time-out occurred. - * If the boolean value is already true, return true immediately. + * Suspend the current thread until the <code>boolean</code> value changes + * to <code>true</code> or the specified time-out occurs. + * The time-out is specified in milliseconds. Return <code>true</code> if the specified + * value was achieved; return <code>false</code> if a time-out occurred. + * If the <code>boolean</code> value is already <code>true</code>, + * return <code>true</code> immediately. + * If the time-out is zero, wait indefinitely. + */ + public boolean waitUntilTrue(long timeout) throws InterruptedException { + return this.waitUntilValueIs(true, timeout); + } + + /** + * Suspend the current thread until the <code>boolean</code> value changes + * to <code>false</code> or the specified time-out occurs. + * The time-out is specified in milliseconds. Return <code>true</code> if the specified + * value was achieved; return <code>false</code> if a time-out occurred. + * If the <code>boolean</code> value is already <code>true</code>, + * return <code>true</code> immediately. + * If the time-out is zero, wait indefinitely. */ public boolean waitUntilFalse(long timeout) throws InterruptedException { - synchronized (this.mutex) { - return this.waitUntilValueIs(false, timeout); - } + return this.waitUntilValueIs(false, timeout); } /** - * Suspend the current thread until the boolean value changes to NOT the - * specified value, then change it back to the specified value and continue - * executing. If the boolean value does not change to false before the - * time-out, simply continue executing without changing the value. - * The time-out is specified in milliseconds. Return true if the value was - * set to the specified value; return false if a time-out occurred. - * If the boolean value is already NOT the specified value, set the value - * to the specified value immediately and return true. + * Suspend the current thread until the <code>boolean</code> value changes + * to <em>not</em> the specified value, then change it back to the specified + * value and continue executing. If the <code>boolean</code> value does not + * change to <code>false</code> before the time-out, simply continue + * executing without changing the value. + * The time-out is specified in milliseconds. Return <code>true</code> + * if the value was set to the specified value; return <code>false</code> + * if a time-out occurred. If the <code>boolean</code> value is already + * <em>not</em> the specified value, set the value to the specified value + * immediately and return <code>true</code>. + * If the time-out is zero, wait indefinitely. */ public boolean waitToSetValue(boolean v, long timeout) throws InterruptedException { synchronized (this.mutex) { - boolean success = this.waitUntilValueIs( ! v, timeout); + boolean success = this.waitUntilValueIs_( ! v, timeout); if (success) { - this.setValue(v); + this.setValue_(v); } return success; } } /** - * Suspend the current thread until the boolean value changes to false, - * then change it back to true and continue executing. If the boolean - * value does not change to false before the time-out, simply continue - * executing without changing the value. The time-out is specified in - * milliseconds. Return true if the value was set to true; return false - * if a time-out occurred. If the boolean value is already false, set the - * value to true immediately and return true. + * Suspend the current thread until the <code>boolean</code> value changes + * to <code>false</code>, then change it back to <code>true</code> and + * continue executing. If the <code>boolean</code> value does not change to + * <code>false</code> before the time-out, simply continue executing without + * changing the value. The time-out is specified in milliseconds. Return + * <code>true</code> if the value was set to <code>true</code>; + * return <code>false</code> if a time-out occurred. If the + * <code>boolean</code> value is already <code>false</code>, set the + * value to <code>true</code> immediately and return <code>true</code>. + * If the time-out is zero, wait indefinitely. */ public boolean waitToSetTrue(long timeout) throws InterruptedException { - synchronized (this.mutex) { - return this.waitToSetValue(true, timeout); - } + return this.waitToSetValue(true, timeout); } /** - * Suspend the current thread until the boolean value changes to true, - * then change it back to false and continue executing. If the boolean - * value does not change to true before the time-out, simply continue - * executing without changing the value. The time-out is specified in - * milliseconds. Return true if the value was set to false; return false - * if a time-out occurred. If the boolean value is already true, set the - * value to false immediately and return true. + * Suspend the current thread until the <code>boolean</code> value changes + * to <code>true</code>, then change it back to <code>false</code> and + * continue executing. If the <code>boolean</code> value does not change to + * <code>true</code> before the time-out, simply continue executing without + * changing the value. The time-out is specified in milliseconds. Return + * <code>true</code> if the value was set to <code>false</code>; + * return <code>false</code> if a time-out occurred. If the + * <code>boolean</code> value is already <code>true</code>, set the + * value to <code>false</code> immediately and return <code>true</code>. + * If the time-out is zero, wait indefinitely. */ public boolean waitToSetFalse(long timeout) throws InterruptedException { - synchronized (this.mutex) { - return this.waitToSetValue(false, timeout); - } + return this.waitToSetValue(false, timeout); } @@ -328,7 +360,7 @@ public class SynchronizedBoolean /** * If the current thread is not interrupted, execute the specified command - * with the mutex locked. This is useful for initializing the value in another + * with the mutex locked. This is useful for initializing the value from another * thread. */ public void execute(Command command) throws InterruptedException { @@ -344,10 +376,10 @@ public class SynchronizedBoolean // ********** standard methods ********** @Override - public Object clone() { + public SynchronizedBoolean clone() { try { synchronized (this.mutex) { - return super.clone(); + return (SynchronizedBoolean) super.clone(); } } catch (CloneNotSupportedException ex) { throw new InternalError(); |