c语言多线程队列读写

最近用c语言写了个简单的队列服务，记录一下，文件结构为 main.c queue.c queue.h,代码如下:

主函数

#define NUM_THREADS 200     

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <queue.h>
#include <pthread.h>
#include <sys/time.h>
#include <unistd.h>
struct threadArgs
{
    struct queue *q;
    char *c ;
};

void* putArg(void *params)
{
    struct threadArgs *args = params;
    putQueue(args->q, args->c);
}

int main()
{
    pthread_t tids[NUM_THREADS]; //线程id
    struct queue  * g_q;
    g_q = initQueue();
    char c[LENTH] = "test\0";
    char b[LENTH] = "btest\0";
    char a[LENTH] = "atest\0";
    char *h = "";
    int i = 0;
    for( i = 0; i < NUM_THREADS; ++i ) {
        struct threadArgs *args;
        args = (struct threadArgs *)malloc(sizeof(struct threadArgs));
        args->q = g_q;
        args->c   = c;
        pthread_create(&tids[i], NULL, putArg, args);
    }

    while(1) {
        h = getQueue(g_q);
        printf("%s\n", h);
        if (strcmp(h, "0") == 0) {
            printf("queue is empty , sleep for a while");
            sleep(3);
        } else {
            sleep(1);
        }
    }
    return 0;
}

queue.h

#define LENTH 10240
struct node
{
    char * m_content;
    struct node * p_next;
};

struct queue
{
    struct node * p_head;
    struct node * p_tail;
};

struct queue * initQueue();

void putQueue(struct queue *q, char content[LENTH]);
char * getQueue(struct queue *q);
struct node * initNode();

queue.c

#include <stdio.h>
#include <string.h>
#include <queue.h>
#include <stdlib.h>

struct node * initNode(char c[LENTH]){
    struct node *h;
    h=(struct node *)malloc(sizeof(struct node));
    if (h==NULL) {
        printf("can not malloc struct node memory;");
        exit(1);
    }
    h->m_content = (char * )malloc(sizeof(char)*LENTH);
    strcpy(h->m_content, c);
    printf("init success  \n");
    h->p_next    = NULL;
    return h;
}

struct queue * initQueue() {
    struct queue * q;
    q=(struct queue *)malloc(sizeof(struct queue));
    if (q == NULL) {
        printf("can not malloc struct node memory;");
        exit(1);
    }
    q->p_head = NULL;
    q->p_tail = NULL;
    return q;
};

void putQueue(struct queue  *q, char c[LENTH]) {
    struct node * n;
    n = initNode(c);
    if (q->p_tail == NULL) {  // queue is empty
        q->p_head = n;
        q->p_tail = n;
    } else {
        q->p_tail->p_next = n;
        q->p_tail = n;
    }
    printf("put: %s\n", q->p_tail->m_content);
}

char * getQueue(struct queue  *q) {
    char *c;
    if (q->p_head==NULL) {
        c = "0";
        return c;
    }
    struct node * h;
    h = q->p_head;
    c = h->m_content;
    printf("get: %s\n", c);
    q->p_head = q->p_head->p_next;
    free(h);  //这里回收以后  c指针的返回值 会出问题
    return c;
}

//几点收获  指针需要malloc   普通变量不需要， 特别是字符串数组不需要