Simple "Flag" class (thread-safe flagging!) [1000782]

< > BotCompany Repo | #1000782 // Simple "Flag" class (thread-safe flagging!)

JavaX fragment (include) [tags: archive]

/** this class is fully thread-safe */
class Flag {
  private boolean up;

  /** returns true if flag was down before */
  public synchronized boolean raise() {
    return doRaise();
  }

  private synchronized boolean doRaise() {
    if (!up) {
      up = true;
      notifyAll();
      return true;
    } else
      return false;
  }

  public synchronized void waitUntilUp() {
    if (!up) {
      try {
        wait();
      } catch (InterruptedException e) {
        e.printStackTrace();
      }
    }
  }

  public synchronized boolean isUp() {
    return up;
  }

  public String toString() {
    return isUp() ? "up" : "down";
  }

  // currently does a semi-active wait with latency = 50 ms
  public void waitForThisOr(Flag otherFlag) ctex {
    while (!isUp() && !otherFlag.isUp())
      Thread.sleep(50);
  }
}

Author comment

Began life as a copy of #1000781

Travelled to 2 computer(s): cfunsshuasjs, mqqgnosmbjvj

Snippet ID:

#1000782

Snippet name:

Simple "Flag" class (thread-safe flagging!)

Eternal ID of this version:

#1000782/1

Text MD5:

d4ed5418a5fde2cc3629ea0cddca98f7

Author:

stefan

Category:

Type:

JavaX fragment (include)

Public (visible to everyone):

Yes

Archived (hidden from active list):

Yes

Created/modified:

2015-08-27 02:00:08

Source code size:

862 bytes / 42 lines

Pitched / IR pitched:

No / Yes

Views / Downloads:

762 / 953

Referenced in:

[show references]

1	/** this class is fully thread-safe */
2	class Flag {
3	private boolean up;
4
5	/** returns true if flag was down before */
6	public synchronized boolean raise() {
7	return doRaise();
8	}
9
10	private synchronized boolean doRaise() {
11	if (!up) {
12	up = true;
13	notifyAll();
14	return true;
15	} else
16	return false;
17	}
18
19	public synchronized void waitUntilUp() {
20	if (!up) {
21	try {
22	wait();
23	} catch (InterruptedException e) {
24	e.printStackTrace();
25	}
26	}
27	}
28
29	public synchronized boolean isUp() {
30	return up;
31	}
32
33	public String toString() {
34	return isUp() ? "up" : "down";
35	}
36
37	// currently does a semi-active wait with latency = 50 ms
38	public void waitForThisOr(Flag otherFlag) ctex {
39	while (!isUp() && !otherFlag.isUp())
40	Thread.sleep(50);
41	}
42	}