1 | #include <stdlib.h> // prototype: rand |
---|
2 | #include <fstream.hfa> |
---|
3 | #include <thread.hfa> |
---|
4 | #include <pthread.h> |
---|
5 | #include <errno.h> |
---|
6 | // tested pthread mutex related routines, pthread cond related routines |
---|
7 | // tested pthread_create/join |
---|
8 | |
---|
9 | enum { BufferSize = 50 }; |
---|
10 | |
---|
11 | volatile int producer_val_total; |
---|
12 | volatile int consumer_val_total; |
---|
13 | |
---|
14 | pthread_mutex_t producer_cnt_lock, consumer_cnt_lock; |
---|
15 | |
---|
16 | |
---|
17 | forall( T ){ |
---|
18 | struct Buffer |
---|
19 | { |
---|
20 | int front, back, count; |
---|
21 | T elements[BufferSize]; |
---|
22 | pthread_mutex_t _mutex; |
---|
23 | pthread_cond_t Full, Empty; // waiting consumers & producers |
---|
24 | }; |
---|
25 | |
---|
26 | void ?{}( Buffer(T) & buffer ) with( buffer ) { |
---|
27 | [front, back, count] = 0; |
---|
28 | pthread_mutex_init(&_mutex, NULL); |
---|
29 | pthread_cond_init(&Full, NULL); |
---|
30 | pthread_cond_init(&Empty, NULL); |
---|
31 | } |
---|
32 | |
---|
33 | void ^?{}( Buffer(T) & buffer ) with( buffer ){ |
---|
34 | pthread_mutex_destroy(&_mutex); |
---|
35 | pthread_cond_destroy(&Full); |
---|
36 | pthread_cond_destroy(&Empty); |
---|
37 | } |
---|
38 | |
---|
39 | int query( Buffer(T) & buffer ) { return buffer.count; } // read-only, no mutual exclusion |
---|
40 | |
---|
41 | void insert( Buffer(T) & buffer, T elem ) with(buffer) { |
---|
42 | pthread_mutex_lock(&_mutex); |
---|
43 | while ( count == 20 ) pthread_cond_wait( &Empty, &_mutex ); // block producer |
---|
44 | elements[back] = elem; |
---|
45 | back = ( back + 1 ) % 20; |
---|
46 | count += 1; |
---|
47 | pthread_cond_signal( &Full ); // unblock consumer |
---|
48 | pthread_mutex_unlock(&_mutex); |
---|
49 | } |
---|
50 | |
---|
51 | T remove(Buffer(T) & buffer) with(buffer) { |
---|
52 | pthread_mutex_lock(&_mutex); |
---|
53 | while ( count == 0 ) pthread_cond_wait( &Full, &_mutex ); // block consumer |
---|
54 | T elem = elements[front]; |
---|
55 | front = ( front + 1 ) % 20; |
---|
56 | count -= 1; |
---|
57 | pthread_cond_signal( &Empty ); // unblock producer |
---|
58 | pthread_mutex_unlock(&_mutex); |
---|
59 | return elem; |
---|
60 | } |
---|
61 | |
---|
62 | } |
---|
63 | |
---|
64 | void *producer( void *arg ) { |
---|
65 | Buffer(int) &buf = *(Buffer(int)*)arg; |
---|
66 | const int NoOfItems = prng(*active_thread(), 40); |
---|
67 | int item; |
---|
68 | for ( int i = 1; i <= NoOfItems; i += 1 ) { // produce a bunch of items |
---|
69 | item = prng(*active_thread(), 1, 101); // produce a random number |
---|
70 | //sout | "Producer:" | pthread_self() | " value:" | item; |
---|
71 | insert( buf,item ); // insert element into queue |
---|
72 | pthread_mutex_lock(&producer_cnt_lock); |
---|
73 | producer_val_total += item; |
---|
74 | pthread_mutex_unlock(&producer_cnt_lock); |
---|
75 | } // for |
---|
76 | //sout | "Producer:" | pthread_self() | " is finished"; |
---|
77 | return NULL; |
---|
78 | } // producer |
---|
79 | |
---|
80 | void *consumer( void *arg ) { |
---|
81 | Buffer(int) &buf = *(Buffer(int) *)arg; |
---|
82 | int item; |
---|
83 | for ( ;; ) { // consume until a negative element appears |
---|
84 | item = remove(buf); // remove from front of queue |
---|
85 | //sout | "Consumer:" | pthread_self() | " value:" | item; |
---|
86 | if ( item == -1 ) break; |
---|
87 | pthread_mutex_lock(&consumer_cnt_lock); |
---|
88 | consumer_val_total += item; |
---|
89 | pthread_mutex_unlock(&consumer_cnt_lock); |
---|
90 | } // for |
---|
91 | //sout | "Consumer:" | pthread_self() | " is finished"; |
---|
92 | return NULL; |
---|
93 | } // consumer |
---|
94 | |
---|
95 | int main() { |
---|
96 | const int NoOfCons = 20, NoOfProds = 30; |
---|
97 | Buffer(int) buf; // create a buffer monitor |
---|
98 | pthread_t cons[NoOfCons]; // pointer to an array of consumers |
---|
99 | pthread_t prods[NoOfProds]; // pointer to an array of producers |
---|
100 | pthread_mutex_init(&producer_cnt_lock, NULL); |
---|
101 | pthread_mutex_init(&consumer_cnt_lock, NULL); |
---|
102 | // parallelism |
---|
103 | set_seed( 1003 ); |
---|
104 | |
---|
105 | processor p[5]; |
---|
106 | { |
---|
107 | // create/join and mutex/condition test |
---|
108 | //sout | "create/join and mutex/condition test"; |
---|
109 | for ( int i = 0; i < NoOfCons; i += 1 ) { // create consumers |
---|
110 | if ( pthread_create( &cons[i], NULL, consumer, (void*)&buf ) != 0 ) { |
---|
111 | sout | "create thread failure, errno:" | errno; |
---|
112 | exit( EXIT_FAILURE ); |
---|
113 | } // if |
---|
114 | } // for |
---|
115 | for ( int i = 0; i < NoOfProds; i += 1 ) { // create producers |
---|
116 | if ( pthread_create( &prods[i], NULL, producer, (void*)&buf ) != 0 ) { |
---|
117 | sout | "create thread failure"; |
---|
118 | exit( EXIT_FAILURE ); |
---|
119 | } // if |
---|
120 | } // for |
---|
121 | |
---|
122 | void *result; |
---|
123 | for ( int i = 0; i < NoOfProds; i += 1 ) { // wait for producers to end |
---|
124 | if ( pthread_join( prods[i], &result ) != 0 ) { |
---|
125 | sout | " producers join thread failure"; |
---|
126 | exit( EXIT_FAILURE ); |
---|
127 | } // if |
---|
128 | if ( (uint64_t)result != 0 ) { |
---|
129 | sout | "producers" | prods[i] |" bad return value " | result; |
---|
130 | exit( EXIT_FAILURE ); |
---|
131 | } // if |
---|
132 | //sout | "join prods[" | i | "]:" | prods[i] | " result:" | result; |
---|
133 | } // for |
---|
134 | |
---|
135 | for ( int i = 0; i < NoOfCons; i += 1 ) { // terminate each consumer |
---|
136 | insert(buf, -1 ); |
---|
137 | } // for |
---|
138 | |
---|
139 | for ( int i = 0; i < NoOfCons; i += 1 ) { // wait for consumer to end |
---|
140 | if ( pthread_join( cons[i], &result ) != 0 ) { |
---|
141 | sout| "consumers join thread failure" ; |
---|
142 | exit( EXIT_FAILURE ); |
---|
143 | } // if |
---|
144 | if ( (uint64_t)result != 0 ) { |
---|
145 | sout| "consumers bad return value" | result; |
---|
146 | exit( EXIT_FAILURE ); |
---|
147 | } // if |
---|
148 | } // for |
---|
149 | sout | "producer total value is " | producer_val_total; |
---|
150 | sout | "consumer total value is " | consumer_val_total; |
---|
151 | } |
---|
152 | |
---|
153 | |
---|
154 | |
---|
155 | |
---|
156 | } |
---|