线程队列队列很常见，但是如果我们考虑在多线程环境中，那么可能就要注意同步互斥了。这里使用读写锁，可以在
线程队列
队列很常见，但是如果我们考虑在多线程环境中，那么可能就要注意同步互斥了。
这里使用读写锁，可以在读的时候不需要锁住整个队列。但是添加到队列就必须用互斥的锁了。
这里就介绍一下读写锁。pthread_rwlock_t lock定义一个读写锁lock，同样注意要初始化。
用 pthread_rwlock_init(&lock) 来初始化 lock。
下面来看一个列子，使用双向链表实现队列。可以从头添加或者从尾添加。
th_queue.h
$gcc -g -c th_queue.c$gcc -g -c test_th_queue.c$gcc -g -lpthread -o test_th_queue th_queue.o test_th_queue.o
来看看结果吧。
add task 0 to tail, queue count=1
add task 1 to tail, queue count=2
add task 2 to tail, queue count=3
add task 3 to tail, queue count=4
add task 4 to tail, queue count=5
add task 5 to tail, queue count=6
add task 6 to tail, queue count=7
add task 7 to tail, queue count=8
add task 8 to tail, queue count=9
add task 9 to tail, queue count=10
add task 10 to tail, queue count=11
add task 11 to tail, queue count=12
add task 12 to tail, queue count=13
add task 13 to tail, queue count=14
add task 14 to tail, queue count=15
add task 15 to tail, queue count=16
add task 16 to tail, queue count=17
add task 17 to tail, queue count=18
add task 18 to tail, queue count=19
add task 19 to tail, queue count=20
add task 20 to tail, queue count=21
add task 21 to tail, queue count=22
add task 22 to tail, queue count=23
add task 23 to tail, queue count=24
add task 24 to tail, queue count=25
add task 25 to tail, queue count=26
add task 26 to tail, queue count=27
add task 27 to tail, queue count=28
add task 28 to tail, queue count=29
add task 29 to tail, queue count=30
add task 30 to tail, queue count=31
add task 31 to tail, queue count=32
add task 32 to tail, queue count=33
add task 33 to tail, queue count=34
add task 34 to tail, queue count=35
add task 35 to tail, queue count=36
add task 36 to tail, queue count=37
add task 37 to tail, queue count=38
add task 38 to tail, queue count=39
add task 39 to tail, queue count=40
add task 40 to tail, queue count=41
add task 41 to tail, queue count=42
add task 42 to tail, queue count=43
add task 43 to tail, queue count=44
add task 44 to tail, queue count=45
add task 45 to tail, queue count=46
add task 46 to tail, queue count=47
add task 47 to tail, queue count=48
add task 48 to tail, queue count=49
add task 49 to tail, queue count=50
add task 50 to head, queue count=51
add task 51 to head, queue count=52
add task 52 to head, queue count=53
add task 53 to head, queue count=54
add task 54 to head, queue count=55
add task 55 to head, queue count=56
add task 56 to head, queue count=57
add task 57 to head, queue count=58
add task 58 to head, queue count=59
add task 59 to head, queue count=60
add task 60 to head, queue count=61
add task 61 to head, queue count=62
add task 62 to head, queue count=63
add task 63 to head, queue count=64
add task 64 to head, queue count=65
add task 65 to head, queue count=66
add task 66 to head, queue count=67
add task 67 to head, queue count=68
add task 68 to head, queue count=69
add task 69 to head, queue count=70
add task 70 to head, queue count=71
add task 71 to head, queue count=72
add task 72 to head, queue count=73
add task 73 to head, queue count=74
add task 74 to head, queue count=75
add task 75 to head, queue count=76
rm task 0 ,queue count=75
rm task 1 ,queue count=74
rm task 2 ,queue count=73
rm task 3 ,queue count=72
rm task 4 ,queue count=71
rm task 5 ,queue count=70
rm task 6 ,queue count=69
rm task 7 ,queue count=68
rm task 8 ,queue count=67
rm task 9 ,queue count=66
rm task 10 ,queue count=65
rm task 11 ,queue count=64
rm task 12 ,queue count=63
rm task 13 ,queue count=62
rm task 14 ,queue count=61
rm task 15 ,queue count=60
rm task 16 ,queue count=59
rm task 17 ,queue count=58
rm task 18 ,queue count=57
rm task 19 ,queue count=56
rm task 20 ,queue count=55
rm task 21 ,queue count=54
rm task 22 ,queue count=53
rm task 23 ,queue count=52
简单吧。。。
