所以我正在为使用基本 GNU 随机数生成器的分配制作一个数字生成器。理想情况下，我需要输出处于这个发展阶段
On loop 0, just produced...1804289383
On loop 0, I just consumed...1804289383.
等等，但现在，我的输出是：
On loop 0, just produced...1804289383
On loop 1, just produced...846930886
On loop 2, just produced...1681692777
On loop 3, just produced...1714636915
On loop 4, just produced...1957747793
On loop 5, just produced...424238335
On loop 6, just produced...719885386
On loop 7, just produced...1649760492
On loop 8, just produced...596516649
On loop 9, just produced...1189641421
On loop 0, I just consumed...1804289383
On loop 1, I just consumed...846930886
On loop 2, I just consumed...1681692777
On loop 3, I just consumed...1714636915
On loop 4, I just consumed...1957747793
On loop 5, I just consumed...424238335
On loop 6, I just consumed...719885386
On loop 7, I just consumed...1649760492
On loop 8, I just consumed...596516649
On loop 9, I just consumed...1189641421
直到它创造了一堆数字之后，它才打动了消费者。
这里发生了什么？我一直在将它与另一段执行类似功能的代码进行比较，并且完成了我需要做的事情，这两段代码非常相似。我只需要第二双眼睛，也许我错过了一些简单的东西？
我的代码：
#include <pthread.h>
#include <time.h>
#include <stdio.h>
#include <math.h>
#define MAX_LOOP 10 //how many times the loop is allowed to go
#define MAX_VALUE 10 //how hig the random number can be
#define TRUE 1 //boolean value
#define FALSE 0 // ""
#define BUFFER_SIZE 10
#define DEBUG TRUE //debug variable. if on 1, it checks for bugs and stuff
pthread_cond_t cond; // conditional variable global
pthread_mutex_t the_mutex;
int bufferRandomFirst[BUFFER_SIZE]; //shared buffer array
int numOfItemsInQueue = 0;//number of items in the array
void *producerRandom(void *ptr)
{
/*
*
* Random() Producer function:
* Creates numbers for the consumer to process using gcc random()
*
*/
int i = 0;
int rand_num = 0;
int rear = 0; //beginning of queue
srandom((unsigned int)0) ; //make some random seeds
for (i = 0; i< BUFFER_SIZE; i++){
rand_num =random(); //make a random number
pthread_mutex_lock(&the_mutex); //get access to the buffer
while (numOfItemsInQueue ==BUFFER_SIZE) {
pthread_cond_wait(&cond, &the_mutex); //if the buffer is not empty, producer must stop
}//end of while
bufferRandomFirst[rear] = rand_num; //store the number in the buffer
if (DEBUG){
printf("On loop %d, just produced...%d\n", i, bufferRandomFirst[rear]);
}
rear = (rear + 1) % BUFFER_SIZE; //does the ciruclar queue loop
numOfItemsInQueue +=1;
pthread_cond_signal(&cond); //fires up the consumer process
pthread_mutex_unlock(&the_mutex); // unlocks the mutex
}//end of for loop
pthread_exit(0); //exit the thread
}//end producer
void *consumerRandom(void *ptr)
{
/*
*
* Random() Consumer Function
* consumes the numbers that the producer makes
*
*/
int front = 0; //front of the queue
int lastDigit = 0; //last digit of random number (thanks Nathan)
int i = 0; //counting variable for for loops
for (i = 0; i < BUFFER_SIZE; i++){
pthread_mutex_lock(&the_mutex); //get exclusive access to buffer
while(numOfItemsInQueue == 0){
pthread_cond_wait(&cond, &the_mutex);
}//end of while
if (DEBUG){
printf("On loop %d, I just consumed...%d\n", i, bufferRandomFirst[i]);
}
lastDigit = bufferRandomFirst[front] % 10; //steals the last digit from the random number
//for example, if the number was 100, 100 mod 10
//is 0, so you get 0. if it was 101, you would get 1
front = (front + 1) % BUFFER_SIZE; //wrap around the array
numOfItemsInQueue -= 1;
pthread_cond_signal(&cond);//wake up producer
pthread_mutex_unlock(&the_mutex);
}//end of for loop
pthread_exit(0); //exit the loop
}//end of consumer
int main(int argc){
pthread_t thread_one, thread_two; //create two threads for Random() Function
printf("Random GNU numbers inbound!\n");
//Random GCC pthread handing/
pthread_mutex_init(&the_mutex,0); //set up the mutex
pthread_cond_init(&cond, 0); //set up the condition
//makes a thread
pthread_create(&thread_one, 0, producerRandom, 0);
//makes a thread
pthread_create(&thread_two, 0, consumerRandom, 0);
pthread_join(thread_one, 0); //wait on this thread
pthread_join(thread_two, 0); //wait on this one too. =)
pthread_cond_destroy(&cond); //condition destroy
pthread_mutex_destroy(&the_mutex); //destroy the mutex resources
printf("And that is all for those numbers\n\n");
}//end of main