Try Semaphore

I check Semaphore.

It's allow sample

Semaphore sem = new Semaphore(1); //allow  only 1 member .
Log.d("test", "constructure");
sem.drainPermits(); // No permit.
Log.d("test", "drainPermits");

sem.release(); //release semaphore and 1 permit.

Log.d("test", "release");

try {
 sem.acquire(); //require permit.
} catch (InterruptedException e) {
 e.printStackTrace();
}

Log.d("test", "acquire"); //allowed

Up program log:

constructure
drainPermits
release
acquire

up program source code



Other allow sample.

Semaphore sem = new Semaphore(1); //allow  only 1 member .

Log.d("test", "constructure. and first time, 1 member permit");

try {
 sem.acquire(); //require permit.
} catch (InterruptedException e) {
 e.printStackTrace();
}

Log.d("test", "acquire. and now 0 member permit."); //allowed

try {
 sem.acquire(); //require permit.
} catch (InterruptedException e) {
 e.printStackTrace();
}

Log.d("test", "May not reach"); //allowed

Up program log:

constructure. and first time, 1 member permit
acquire. and now 0 member permit.

up program source code

reject sample.

Semaphore sem = new Semaphore(1); //allow  only 1 member .
Log.d("test", "constructure");
sem.drainPermits(); // No permit.
Log.d("test", "drainPermits");

Log.d("test", "May be reject to acquire");

try {
 sem.acquire(); //require permit.
} catch (InterruptedException e) {
 e.printStackTrace();
}

Log.d("test", "May not reach"); //allowed

Up program log:

constructure
drainPermits
May be reject to acquire

up program source code