消息隊列的頭文件msgqueue.h

/*

msgqueue.h
/

ifndef MSGQUEUEH
define MSGQUEUEH
include "conn.h"
define MAX_MSG_LENGTH (1024)
typedef struct MSG {
char buf[MAX_MSG_LENGTH];
uint16 buf_len;
CONN c;
struct MSG next;
} MSG;
typedef struct MSG_QUEUE {
MSG head;
MSG tail;
int size;
} MSG_QUEUE;
MSG_QUEUE* create_msg_queue();
extern int push_msg(MSG_QUEUE q,CONN c);
int empty_msg_queue( MSG_QUEUE *q);
int  get_msg(MSG_QUEUE q ,MSG temp_msg);
endif / MSGQUEUEH /
消息隊列的實現文件 * msgqueue.c
/*

msgqueue.c
/

include "msgqueue.h"
MSG_QUEUE* create_msg_queue()
{
MSG_QUEUE qmsg=malloc(sizeof(MSG_QUEUE)); /申請頭尾指針結點/
if(qmsg==NULL){
fprintf(stderr, "create_msg_queue malloc error, errno: %d %m\n", errno);
return NULL;
}
MSG msg=malloc(sizeof(MSG)); /申請鏈隊頭結點/
if(msg==NULL){
fprintf(stderr, "create_head_msg malloc error, errno: %d %m\n", errno);
free(qmsg);
return NULL;
}
msg->next=NULL;
qmsg->head=qmsg->tail=msg;
qmsg->size=0;
return qmsg;
}
int  push_msg(MSG_QUEUE q,CONN c)
{
if(q->size>10240){
fprintf(stderr, "push_msg error,msg_queue size is over %d ,errno: %d %m\n",q->size, errno);
return -1;
}
MSG msg;
msg=malloc(sizeof(MSG)); /申請新結點*/
if(msg==NULL){
fprintf(stderr, "create_new_msg malloc error, errno: %d %m\n", errno);
return -1;
}
memcpy(msg->buf,c->in_buf,c->in_buf_len);
msg->buf_len=c->in_buf_len;
msg->c=c;
msg->next=NULL;
q->tail->next=msg;
q->tail=msg;
q->size++;
return 0;
}
int empty_msg_queue( MSG_QUEUE *q)
{
if (q->head==q->tail)
return 0;
else
return 1;
}
int  get_msg(MSG_QUEUE q ,MSG temp_msg)
{
if (q->head==q->tail){
return -1;
}
MSG *temp=q->head->next;
    if(q->head->next == q->tail) //如果要出隊的結點為最后一個結點,使q->rear指向頭結點防止出現懸空的指針
        q->tail = q->head;
// msg_buf = temp->buf; //將出隊的數據元素存入*e
    temp_msg->c=temp->c;
    memcpy(temp_msg->buf,temp->buf,temp->buf_len);
    temp_msg->buf_len=temp->buf_len;

q->head->next = temp->next; //使下一個結點成為隊頭,如果沒有下一個結點則為NULL

q->size--;
//int buf_len=temp->buf_len;
    free(temp); //刪除要出隊的結點
return 0;
}</pre>