Statistics

Note: projects that are considered concurrent have to implements Runnable, or extends Runnable, or extends Threads, or use syncronized keyword (method or block).

Notice that although more than 75% of all projects use, at least, one concurrent construct, only 19% take advantage of java.util.concurrent library. In our opnion, developers are wasting many opportunities to use higher level/more efficient abstractions.

More curious statistics.

The most common used constructs per 100KLoC.

Construct	Median				Mean
	S	M	L	ALL	S	M	L	ALL
Atomic variables	22.89	8.72	1.56	8.05	48.46	17.86	8.17	22.05
extends Runnable	19.32	2.38	0.86	2.37	19.78	4.87	1.58	7.36
extends Thread	25.00	6.05	2.74	13.00	42.54	9.95	5.46	28.93
Executors Constructs	20.93	3.90	11.90	5.13	34.82	13.14	11.74	18.73
implements Runnable	27.45	7.18	3.73	13.85	46.92	12.13	7.43	28.43
sync blocks	73.47	33.22	31.52	55.04	152.29	75.03	71.32	117.60
sync methods	81.43	54.29	47.65	66.75	184.68	99.76	88.50	145.20
notify()	26.26	5.77	2.41	8.69	41.66	10.78	5.64	24.99
notifyAll()	24.00	6.37	2.77	9.09	50.45	11.65	7.22	24.89
volatile	29.95	8.86	3.55	11.73	69.76	31.31	18.92	40.71
wait()	25.60	7.22	3.97	11.51	46.80	14.12	11.24	29.86

Where S, M, L means Small, Medium and Large.