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How do you implement a bounded FIFO buffer in C-Linda? Assume the buffer contains integers (to make life a little easier). There are a number of producers and a number of consumer. Assume that the functions consume and produce have already been defined. Now consider the functions consumer and producer.
void consumer() { int data; while (1) { data = get(); consume(data); } } void producer() { int data; while (1) { data = produce(); put(data); } }
A single consumer and producer can be created as follows.
void real_main() { eval("consumer", consumer()); eval("producer", producer()); }
How can the above be extended to create multiple consumers and producers?
It remains to define the functions get and put.
int get() { int data; return data; } void put(int data) { }
How should get and put be completed?
A try for comment:
<code c>
void down_mutex() {
in("mutex", 1);
out("mutex", 0);
}
void up_mutex() {
in("mutex", 0);
out("mutex", 1);
}
int get() {
int i, data;
in("full");
down_mutex();
rd("size",?i);
in("head",?j);
in("buffer",j,?data);
j=(j+1)%i;
out("head",j);
up_mutex();
out("empty")
return data;
}
void put(int data) {
int i,j;
in("empty");
down_mutex();
rd("size",?i);
in("tail",?j)
j=(j+1)%i;
out("tail",j);
out("buffer",j,?data);
up_mutex();
out("full");
return;
}
void consumer() {
int data;
while (1)
{
data = get();
consume(data);
}
}
void producer() {
int data;
while (1)
{
data = produce();
put(data);
}
} void real_main() {
#define Len 10
#define Run 5
for (int i =0 ; i<Len; i++)
out("empty");
out("head",1);
out("tail", 1);
out("size",len);
out("mutex",1);
for (int i =0 ; i<5; i++){
eval("consumer", consumer());
eval("producer", producer());
} </code c>