我收到一个错误,我不知道如何解决。我正在尝试使用自旋锁解决“生产者-消费者”问题。我创建了一个类似“队列”的数据结构作为共享资源来放入“生产”项目,并删除要“消费”的项目。这是我的主程序的样子:
#include <pthread.h>
#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include "Queue.h"
#define DEBUG 1
Queue_t* global_queue; // create a global queue
/* thread procedure for the producer thread */
void* producer_func(void* arg)
{
while(1) // loops infinitely
{
int datum = rand() % global_queue->maximum_count;
// spin while the queue is full
while ((global_queue->current_count) ==
(global_queue->maximum_count));
enqueue(global_queue, datum);
display(global_queue);
}
}
/* thread procedure for the consumer thread */
void* consumer_func(void* arg)
{
while(1) // loops infinitely
{
int datum = 0;
// spin while there are no items in the queue
while(global_queue->current_count == 0);
datum = dequeue(global_queue);
printf("The number consumed is %d\n");
}
}
/* Main */
int main(int argc, char** argv)
{
if(argc != 2)
{
printf("Error: wrong number of command-line arguments\n");
printf("Usage: %s <integer>\n", argv[0]);
exit(1);
}
pthread_t producer; // create producer thread
pthread_t consumer; // create consumer thread
// create the queue object, get the max queue size
//int max_count = atoi(argv[1]);
global_queue = construct(10);
display(global_queue);
// intialize the random seed generator
srand((unsigned)time(NULL));
// create the threads and have them execute their routines
pthread_create(&producer, NULL, &producer_func, NULL);
pthread_create(&consumer, NULL, &consumer_func, NULL);
// join the threads to finish
pthread_join(producer, NULL);
pthread_join(consumer, NULL);
// deallocate the queue from memory
//destruct(global_queue);
return 0;
}
然而,当我在主程序中调用 pthread_create 时,我在 malloc.c 中得到一个奇怪的错误:
queue_demo: malloc.c:3096: sYSMALLOc: Assertion `(old_top == (((mbinptr) (((char *) &((av)->bins[((1) - 1) * 2])) - __builtin_offsetof (struct malloc_chunk, fd)))) && old_size == 0) || ((unsigned long) (old_size) >= (unsigned long)((((__builtin_offsetof (struct malloc_chunk, fd_nextsize))+((2 * (sizeof(size_t))) - 1)) & ~((2 * (sizeof(size_t))) - 1))) && ((old_top)->size & 0x1) && ((unsigned long)old_end & pagemask) == 0)' failed.
Aborted
这是我的“队列”数据结构头文件:
#ifndef QUEUE_H
#define QUEUE_H
typedef struct Queue
{
int current_count;
int maximum_count;
int buffer[]; // queue uses an array
} Queue_t;
// routines to implement Queue-like functionality (FIFO)
// TODO: somehow encapsulate all these features in the struct itself.
//
Queue_t* construct(int buff_size);
void destruct (Queue_t* queue);
void display (Queue_t* queue);
int dequeue (Queue_t* queue);
void enqueue (Queue_t* queue, const int datum);
#endif
和实施:
#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
#include "Queue.h"
Queue_t* construct(int buff_size)
{
Queue_t* queue = malloc(sizeof(Queue_t));
assert(queue != NULL);
queue->maximum_count = buff_size;
queue->current_count = 0;
int i = 0;
for(; i < queue->maximum_count; ++i)
queue->buffer[i] = 0;
return queue;
}
void destruct(Queue_t* queue)
{
assert(queue != NULL);
free(queue);
printf("Queue destroyed!\n");
}
void display(Queue_t* queue)
{
int i = 0;
for(; i < queue->maximum_count; ++i)
printf("%d ", queue->buffer[i]);
printf("\n");
}
void enqueue(Queue_t* queue, const int datum)
{
assert(queue->current_count < queue->maximum_count);
queue->buffer[queue->current_count] = datum;
++queue->current_count;
}
int dequeue(Queue_t* queue)
{
int i = 1;
int datum = queue->buffer[0];
assert(queue->current_count > 0);
for(; i < queue->maximum_count; ++i)
{
queue->buffer[i-1] = queue->buffer[i];
queue->buffer[i] = 0;
}
--queue->current_count;
return datum;
}
显然,我做错了什么。但我不知道那到底是什么。我怀疑它可能与全局声明结构有关,但我不确定。任何想法将不胜感激。