1. tcp、udp使用场景
2. 广播通信流程
3. 广播服务器代码实现
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <arpa/inet.h>
int main(int argc, const char* argv[])
{
// 创建套接字
int fd = socket(AF_INET, SOCK_DGRAM, 0);
if(fd == -1)
{
perror("socket error");
exit(1);
}
// 绑定server的iP和端口
struct sockaddr_in serv;
memset(&serv, 0, sizeof(serv));
serv.sin_family = AF_INET;
serv.sin_port = htons(8787); // server端口
serv.sin_addr.s_addr = htonl(INADDR_ANY);
int ret = bind(fd, (struct sockaddr*)&serv, sizeof(serv));
if(ret == -1)
{
perror("bind error");
exit(1);
}
// 初始化客户端地址信息
struct sockaddr_in client;
memset(&client, 0, sizeof(client));
client.sin_family = AF_INET;
client.sin_port = htons(6767); // 客户端要绑定的端口
// 使用广播地址给客户端发数据
inet_pton(AF_INET, "192.168.123.255", &client.sin_addr.s_addr);
// 给服务器开放广播权限
int flag = 1;
setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &flag, sizeof(flag));
// 通信
while(1)
{
// 一直给客户端发数据
static int num = 0;
char buf[1024] = {0};
sprintf(buf, "hello, udp == %d\n", num++);
int ret = sendto(fd, buf, strlen(buf)+1, 0, (struct sockaddr*)&client, sizeof(client));
if(ret == -1)
{
perror("sendto error");
break;
}
printf("server == send buf: %s\n", buf);
sleep(1);
}
close(fd);
return 0;
}4. 广播客户端代码实现
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <arpa/inet.h>
int main(int argc, const char* argv[])
{
int fd = socket(AF_INET, SOCK_DGRAM, 0);
if(fd == -1)
{
perror("socket error");
exit(1);
}
// 绑定iP和端口
struct sockaddr_in client;
memset(&client, 0, sizeof(client));
client.sin_family = AF_INET;
client.sin_port = htons(6767);
inet_pton(AF_INET, "0.0.0.0", &client.sin_addr.s_addr);
int ret = bind(fd, (struct sockaddr*)&client, sizeof(client));
if(ret == -1)
{
perror("bind error");
exit(1);
}
// 接收数据
while(1)
{
char buf[1024] = {0};
int len = recvfrom(fd, buf, sizeof(buf), 0, NULL, NULL);
if(len == -1)
{
perror("recvfrom error");
break;
}
printf("client == recv buf: %s\n", buf);
}
close(fd);
return 0;
}注：inet_pton函数第二个参数是“0.0.0.0” 时，会自动将其替换为本机的ip地址。
5. 组播通信流程
6. 组播服务器代码实现
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <arpa/inet.h>
#include <net/if.h>
int main(int argc, const char* argv[])
{
// 创建套接字
int fd = socket(AF_INET, SOCK_DGRAM, 0);
if(fd == -1)
{
perror("socket error");
exit(1);
}
// 绑定server的iP和端口
struct sockaddr_in serv;
memset(&serv, 0, sizeof(serv));
serv.sin_family = AF_INET;
serv.sin_port = htons(8787); // server端口
serv.sin_addr.s_addr = htonl(INADDR_ANY);
int ret = bind(fd, (struct sockaddr*)&serv, sizeof(serv));
if(ret == -1)
{
perror("bind error");
exit(1);
}
// 初始化客户端地址信息
struct sockaddr_in client;
memset(&client, 0, sizeof(client));
client.sin_family = AF_INET;
client.sin_port = htons(6767); // 客户端要绑定的端口
// 使用组播地址给客户端发数据
inet_pton(AF_INET, "239.0.0.10", &client.sin_addr.s_addr);
// 给服务器开放组播权限
struct ip_mreqn flag;
// init flag
inet_pton(AF_INET, "239.0.0.10", &flag.imr_multiaddr.s_addr); // 组播地址
inet_pton(AF_INET, "0.0.0.0", &flag.imr_address.s_addr); // 本地IP
flag.imr_ifindex = if_nametoindex("ens33");
setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF, &flag, sizeof(flag));
// 通信
while(1)
{
// 一直给客户端发数据
static int num = 0;
char buf[1024] = {0};
sprintf(buf, "hello, udp == %d\n", num++);
int ret = sendto(fd, buf, strlen(buf)+1, 0, (struct sockaddr*)&client, sizeof(client));
if(ret == -1)
{
perror("sendto error");
break;
}
printf("server == send buf: %s\n", buf);
sleep(1);
}
close(fd);
return 0;
}7. 组播客户端代码实现
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <arpa/inet.h>
#include <net/if.h>
int main(int argc, const char* argv[])
{
int fd = socket(AF_INET, SOCK_DGRAM, 0);
if(fd == -1)
{
perror("socket error");
exit(1);
}
// 绑定iP和端口
struct sockaddr_in client;
memset(&client, 0, sizeof(client));
client.sin_family = AF_INET;
client.sin_port = htons(6767); // ........
inet_pton(AF_INET, "0.0.0.0", &client.sin_addr.s_addr);
int ret = bind(fd, (struct sockaddr*)&client, sizeof(client));
if(ret == -1)
{
perror("bind error");
exit(1);
}
// 加入到组播地址
struct ip_mreqn fl;
inet_pton(AF_INET, "239.0.0.10", &fl.imr_multiaddr.s_addr);
inet_pton(AF_INET, "0.0.0.0", &fl.imr_address.s_addr);
fl.imr_ifindex = if_nametoindex("ens33");
setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &fl, sizeof(fl));
// 接收数据
while(1)
{
char buf[1024] = {0};
int len = recvfrom(fd, buf, sizeof(buf), 0, NULL, NULL);
if(len == -1)
{
perror("recvfrom error");
break;
}
printf("client == recv buf: %s\n", buf);
}
close(fd);
return 0;
}8. 本地套接字通信流程
9. 本地套接字服务器端实现
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <arpa/inet.h>
#include <sys/un.h>
int main(int argc, const char* argv[])
{
int lfd = socket(AF_LOCAL, SOCK_STREAM, 0);
if(lfd == -1)
{
perror("socket error");
exit(1);
}
// 如果套接字文件存在, 删除套接字文件
unlink("server.sock");
// 绑定
struct sockaddr_un serv;
serv.sun_family = AF_LOCAL;
strcpy(serv.sun_path, "server.sock");
int ret = bind(lfd, (struct sockaddr*)&serv, sizeof(serv));
if(ret == -1)
{
perror("bind error");
exit(1);
}
// 监听
ret = listen(lfd, 36);
if(ret == -1)
{
perror("listen error");
exit(1);
}
// 等待接收连接请求
struct sockaddr_un client;
socklen_t len = sizeof(client);
int cfd = accept(lfd, (struct sockaddr*)&client, &len);
if(cfd == -1)
{
perror("accept error");
exit(1);
}
printf("======client bind file: %s\n", client.sun_path);
// 通信
while(1)
{
char buf[1024] = {0};
int recvlen = recv(cfd, buf, sizeof(buf), 0);
if(recvlen == -1)
{
perror("recv error");
exit(1);
}
else if(recvlen == 0)
{
printf("clietn disconnect ....\n");
close(cfd);
break;
}
else
{
printf("recv buf: %s\n", buf);
send(cfd, buf, recvlen, 0);
}
}
close(cfd);
close(lfd);
return 0;
}10. 本地套接字客户端实现
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <arpa/inet.h>
#include <sys/un.h>
int main(int argc, const char* argv[])
{
int fd = socket(AF_LOCAL, SOCK_STREAM, 0);
if(fd == -1)
{
perror("socket error");
exit(1);
}
unlink("client.sock");
// ================================
// 给客户端绑定一个套接字文件
struct sockaddr_un client;
client.sun_family = AF_LOCAL;
strcpy(client.sun_path, "client.sock");
int ret = bind(fd, (struct sockaddr*)&client, sizeof(client));
if(ret == -1)
{
perror("bind error");
exit(1);
}
// 初始化server信息
struct sockaddr_un serv;
serv.sun_family = AF_LOCAL;
strcpy(serv.sun_path, "server.sock");
// 连接服务器
connect(fd, (struct sockaddr*)&serv, sizeof(serv));
// 通信
while(1)
{
char buf[1024] = {0};
fgets(buf, sizeof(buf), stdin);
send(fd, buf, strlen(buf)+1, 0);
// 接收数据
recv(fd, buf, sizeof(buf), 0);
printf("recv buf: %s\n", buf);
}
close(fd);
return 0;
}11. 心跳包
12. epoll反应堆工作模式
13. epoll反应堆模型代码实现
/*
* epoll基于非阻塞I/O事件驱动
*/
#include <stdio.h>
#include <sys/socket.h>
#include <sys/epoll.h>
#include <arpa/inet.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#define MAX_EVENTS 1024 //监听上限数
#define BUFLEN 4096
#define SERV_PORT 8080
void recvdata(int fd, int events, void *arg);
void senddata(int fd, int events, void *arg);
/* 描述就绪文件描述符相关信息 */
struct myevent_s {
int fd; //要监听的文件描述符
int events; //对应的监听事件
void *arg; //泛型参数
void (*call_back)(int fd, int events, void *arg); //回调函数
int status; //是否在监听:1->在红黑树上(监听), 0->不在(不监听)
char buf[BUFLEN];
int len;
long last_active; //记录每次加入红黑树 g_efd 的时间值
};
int g_efd; //全局变量, 保存epoll_create返回的文件描述符
struct myevent_s g_events[MAX_EVENTS+1]; //自定义结构体类型数组. +1-->listen fd
/*将结构体 myevent_s 成员变量 初始化*/
void eventset(struct myevent_s *ev, int fd, void (*call_back)(int, int, void *), void *arg)
{
ev->fd = fd;
ev->call_back = call_back;
ev->events = 0;
ev->arg = arg;
ev->status = 0;
//memset(ev->buf, 0, sizeof(ev->buf));
//ev->len = 0;
ev->last_active = time(NULL); //调用eventset函数的时间
return;
}
/* 向 epoll监听的红黑树 添加一个 文件描述符 */
void eventadd(int efd, int events, struct myevent_s *ev)
{
struct epoll_event epv = {0, {0}};
int op;
epv.data.ptr = ev;
epv.events = ev->events = events; //EPOLLIN 或 EPOLLOUT
if (ev->status == 1) { //已经在红黑树 g_efd 里
op = EPOLL_CTL_MOD; //修改其属性
} else { //不在红黑树里
op = EPOLL_CTL_ADD; //将其加入红黑树 g_efd, 并将status置1
ev->status = 1;
}
if (epoll_ctl(efd, op, ev->fd, &epv) < 0) //实际添加/修改
printf("event add failed [fd=%d], events[%d]\n", ev->fd, events);
else
printf("event add OK [fd=%d], op=%d, events[%0X]\n", ev->fd, op, events);
return ;
}
/* 从epoll 监听的 红黑树中删除一个 文件描述符*/
void eventdel(int efd, struct myevent_s *ev)
{
struct epoll_event epv = {0, {0}};
if (ev->status != 1) //不在红黑树上
return ;
epv.data.ptr = ev;
ev->status = 0; //修改状态
epoll_ctl(efd, EPOLL_CTL_DEL, ev->fd, &epv); //从红黑树 efd 上将 ev->fd 摘除
return ;
}
/* 当有文件描述符就绪, epoll返回, 调用该函数 与客户端建立链接 */
// 回调函数 - 监听的文件描述符发送读事件时被调用
void acceptconn(int lfd, int events, void *arg)
{
struct sockaddr_in cin;
socklen_t len = sizeof(cin);
int cfd, i;
if ((cfd = accept(lfd, (struct sockaddr *)&cin, &len)) == -1) {
if (errno != EAGAIN && errno != EINTR) {
/* 暂时不做出错处理 */
}
printf("%s: accept, %s\n", __func__, strerror(errno));
return ;
}
do {
for (i = 0; i < MAX_EVENTS; i++) //从全局数组g_events中找一个空闲元素
if (g_events[i].status == 0) //类似于select中找值为-1的元素
break; //跳出 for
if (i == MAX_EVENTS) {
printf("%s: max connect limit[%d]\n", __func__, MAX_EVENTS);
break; //跳出do while(0) 不执行后续代码
}
int flag = 0;
if ((flag = fcntl(cfd, F_SETFL, O_NONBLOCK)) < 0) { //将cfd也设置为非阻塞
printf("%s: fcntl nonblocking failed, %s\n", __func__, strerror(errno));
break;
}
/* 给cfd设置一个 myevent_s 结构体, 回调函数 设置为 recvdata */
eventset(&g_events[i], cfd, recvdata, &g_events[i]);
eventadd(g_efd, EPOLLIN, &g_events[i]); //将cfd添加到红黑树g_efd中,监听读事件
} while(0);
printf("new connect [%s:%d][time:%ld], pos[%d]\n",
inet_ntoa(cin.sin_addr), ntohs(cin.sin_port), g_events[i].last_active, i);
return ;
}
// 回调函数 - 通信的文件描述符发生读事件时候被调用
void recvdata(int fd, int events, void *arg)
{
struct myevent_s *ev = (struct myevent_s *)arg;
int len;
len = recv(fd, ev->buf, sizeof(ev->buf), 0); //读文件描述符, 数据存入myevent_s成员buf中
eventdel(g_efd, ev); //将该节点从红黑树上摘除
if (len > 0) {
ev->len = len;
ev->buf[len] = '\0'; //手动添加字符串结束标记
printf("C[%d]:%s\n", fd, ev->buf);
eventset(ev, fd, senddata, ev); //设置该 fd 对应的回调函数为 senddata
eventadd(g_efd, EPOLLOUT, ev); //将fd加入红黑树g_efd中,监听其写事件
} else if (len == 0) {
close(ev->fd);
/* ev-g_events 地址相减得到偏移元素位置 */
printf("[fd=%d] pos[%ld], closed\n", fd, ev-g_events);
} else {
close(ev->fd);
printf("recv[fd=%d] error[%d]:%s\n", fd, errno, strerror(errno));
}
return;
}
// 回调函数 - 通信的文件描述符发生写事件时候被调用
void senddata(int fd, int events, void *arg)
{
struct myevent_s *ev = (struct myevent_s *)arg;
int len;
len = send(fd, ev->buf, ev->len, 0); //直接将数据 回写给客户端。未作处理
/*
printf("fd=%d\tev->buf=%s\ttev->len=%d\n", fd, ev->buf, ev->len);
printf("send len = %d\n", len);
*/
if (len > 0) {
printf("send[fd=%d], [%d]%s\n", fd, len, ev->buf);
eventdel(g_efd, ev); //从红黑树g_efd中移除
eventset(ev, fd, recvdata, ev); //将该fd的 回调函数改为 recvdata
eventadd(g_efd, EPOLLIN, ev); //从新添加到红黑树上， 设为监听读事件
} else {
close(ev->fd); //关闭链接
eventdel(g_efd, ev); //从红黑树g_efd中移除
printf("send[fd=%d] error %s\n", fd, strerror(errno));
}
return ;
}
/*创建 socket, 初始化lfd */
void initlistensocket(int efd, short port)
{
int lfd = socket(AF_INET, SOCK_STREAM, 0);
fcntl(lfd, F_SETFL, O_NONBLOCK); //将socket设为非阻塞
/* void eventset(struct myevent_s *ev, int fd, void (*call_back)(int, int, void *), void *arg); */
eventset(&g_events[MAX_EVENTS], lfd, acceptconn, &g_events[MAX_EVENTS]);
/* void eventadd(int efd, int events, struct myevent_s *ev) */
eventadd(efd, EPOLLIN, &g_events[MAX_EVENTS]);
struct sockaddr_in sin;
memset(&sin, 0, sizeof(sin)); //bzero(&sin, sizeof(sin))
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = INADDR_ANY;
sin.sin_port = htons(port);
bind(lfd, (struct sockaddr *)&sin, sizeof(sin));
listen(lfd, 20);
return ;
}
int main(int argc, char *argv[])
{
unsigned short port = SERV_PORT;
if (argc == 2)
port = atoi(argv[1]); //使用用户指定端口.如未指定,用默认端口
g_efd = epoll_create(MAX_EVENTS+1); //创建红黑树,返回给全局 g_efd
if (g_efd <= 0)
printf("create efd in %s err %s\n", __func__, strerror(errno));
initlistensocket(g_efd, port); //初始化监听socket
struct epoll_event events[MAX_EVENTS+1]; //保存已经满足就绪事件的文件描述符数组
printf("server running:port[%d]\n", port);
int checkpos = 0, i;
while (1) {
/* 超时验证，每次测试100个链接，不测试listenfd 当客户端60秒内没有和服务器通信，则关闭此客户端链接 */
long now = time(NULL); //当前时间
for (i = 0; i < 100; i++, checkpos++) { //一次循环检测100个。 使用checkpos控制检测对象
if (checkpos == MAX_EVENTS)
checkpos = 0;
if (g_events[checkpos].status != 1) //不在红黑树 g_efd 上
continue;
long duration = now - g_events[checkpos].last_active; //客户端不活跃的世间
if (duration >= 60) {
close(g_events[checkpos].fd); //关闭与该客户端链接
printf("[fd=%d] timeout\n", g_events[checkpos].fd);
eventdel(g_efd, &g_events[checkpos]); //将该客户端 从红黑树 g_efd移除
}
}
/*监听红黑树g_efd, 将满足的事件的文件描述符加至events数组中, 1秒没有事件满足, 返回 0*/
int nfd = epoll_wait(g_efd, events, MAX_EVENTS+1, 1000);
if (nfd < 0) {
printf("epoll_wait error, exit\n");
break;
}
for (i = 0; i < nfd; i++) {
/*使用自定义结构体myevent_s类型指针, 接收 联合体data的void *ptr成员*/
struct myevent_s *ev = (struct myevent_s *)events[i].data.ptr;
if ((events[i].events & EPOLLIN) && (ev->events & EPOLLIN)) { //读就绪事件
ev->call_back(ev->fd, events[i].events, ev->arg);
}
if ((events[i].events & EPOLLOUT) && (ev->events & EPOLLOUT)) { //写就绪事件
ev->call_back(ev->fd, events[i].events, ev->arg);
}
}
}
/* 退出前释放所有资源 */
return 0;
}14. 线程池原理
15. 线程池代码实现
threadpool.h
#ifndef __THREADPOOL_H_
#define __THREADPOOL_H_
typedef struct threadpool_t threadpool_t;
/**
* @function threadpool_create
* @descCreates a threadpool_t object.
* @param thr_num thread num
* @param max_thr_num max thread size
* @param queue_max_size size of the queue.
* @return a newly created thread pool or NULL
*/
threadpool_t *threadpool_create(int min_thr_num, int max_thr_num, int queue_max_size);
/**
* @function threadpool_add
* @desc add a new task in the queue of a thread pool
* @param pool Thread pool to which add the task.
* @param function Pointer to the function that will perform the task.
* @param argument Argument to be passed to the function.
* @return 0 if all goes well,else -1
*/
int threadpool_add(threadpool_t *pool, void*(*function)(void *arg), void *arg);
/**
* @function threadpool_destroy
* @desc Stops and destroys a thread pool.
* @param pool Thread pool to destroy.
* @return 0 if destory success else -1
*/
int threadpool_destroy(threadpool_t *pool);
/**
* @desc get the thread num
* @pool pool threadpool
* @return # of the thread
*/
int threadpool_all_threadnum(threadpool_t *pool);
/**
* desc get the busy thread num
* @param pool threadpool
* return # of the busy thread
*/
int threadpool_busy_threadnum(threadpool_t *pool);
#endifthreadpool.c
#include <stdlib.h>
#include <pthread.h>
#include <unistd.h>
#include <assert.h>
#include <stdio.h>
#include <string.h>
#include <signal.h>
#include <errno.h>
#include "threadpool.h"
#define DEFAULT_TIME 10 /*10s检测一次*/
#define MIN_WAIT_TASK_NUM 10 /*如果queue_size > MIN_WAIT_TASK_NUM 添加新的线程到线程池*/
#define DEFAULT_THREAD_VARY 10 /*每次创建和销毁线程的个数*/
#define true 1
#define false 0
typedef struct {
void *(*function)(void *); /* 函数指针，回调函数 */
void *arg; /* 上面函数的参数 */
} threadpool_task_t; /* 各子线程任务结构体 */
/* 描述线程池相关信息 */
struct threadpool_t {
pthread_mutex_t lock; /* 用于锁住本结构体 */
pthread_mutex_t thread_counter; /* 记录忙状态线程个数de琐 -- busy_thr_num */
pthread_cond_t queue_not_full; /* 当任务队列满时，添加任务的线程阻塞，等待此条件变量 */
pthread_cond_t queue_not_empty; /* 任务队列里不为空时，通知等待任务的线程 */
pthread_t *threads; /* 存放线程池中每个线程的tid。数组 */
pthread_t adjust_tid; /* 存管理线程tid */
threadpool_task_t *task_queue; /* 任务队列 */
int min_thr_num; /* 线程池最小线程数 */
int max_thr_num; /* 线程池最大线程数 */
int live_thr_num; /* 当前存活线程个数 */
int busy_thr_num; /* 忙状态线程个数 */
int wait_exit_thr_num; /* 要销毁的线程个数 */
int queue_front; /* task_queue队头下标 */
int queue_rear; /* task_queue队尾下标 */
int queue_size; /* task_queue队中实际任务数 */
int queue_max_size; /* task_queue队列可容纳任务数上限 */
int shutdown; /* 标志位，线程池使用状态，true或false */
};
/**
* @function void *threadpool_thread(void *threadpool)
* @desc the worker thread
* @param threadpool the pool which own the thread
*/
void *threadpool_thread(void *threadpool);
/**
* @function void *adjust_thread(void *threadpool);
* @desc manager thread
* @param threadpool the threadpool
*/
void *adjust_thread(void *threadpool);
/**
* check a thread is alive
*/
int is_thread_alive(pthread_t tid);
int threadpool_free(threadpool_t *pool);
threadpool_t *threadpool_create(int min_thr_num, int max_thr_num, int queue_max_size)
{
int i;
threadpool_t *pool = NULL;
do {
if((pool = (threadpool_t *)malloc(sizeof(threadpool_t))) == NULL) {
printf("malloc threadpool fail");
break;/*跳出do while*/
}
pool->min_thr_num = min_thr_num;
pool->max_thr_num = max_thr_num;
pool->busy_thr_num = 0;
pool->live_thr_num = min_thr_num; /* 活着的线程数 初值=最小线程数 */
pool->queue_size = 0; /* 有0个产品 */
pool->queue_max_size = queue_max_size;
pool->queue_front = 0;
pool->queue_rear = 0;
pool->shutdown = false; /* 不关闭线程池 */
/* 根据最大线程上限数， 给工作线程数组开辟空间, 并清零 */
pool->threads = (pthread_t *)malloc(sizeof(pthread_t)*max_thr_num);
if (pool->threads == NULL) {
printf("malloc threads fail");
break;
}
memset(pool->threads, 0, sizeof(pthread_t)*max_thr_num);
/* 队列开辟空间 */
pool->task_queue = (threadpool_task_t *)malloc(sizeof(threadpool_task_t)*queue_max_size);
if (pool->task_queue == NULL) {
printf("malloc task_queue fail");
break;
}
/* 初始化互斥琐、条件变量 */
if (pthread_mutex_init(&(pool->lock), NULL) != 0
|| pthread_mutex_init(&(pool->thread_counter), NULL) != 0
|| pthread_cond_init(&(pool->queue_not_empty), NULL) != 0
|| pthread_cond_init(&(pool->queue_not_full), NULL) != 0)
{
printf("init the lock or cond fail");
break;
}
/* 启动 min_thr_num 个 work thread */
for (i = 0; i < min_thr_num; i++) {
pthread_create(&(pool->threads[i]), NULL, threadpool_thread, (void *)pool);/*pool指向当前线程池*/
printf("start thread 0x%x...\n", (unsigned int)pool->threads[i]);
}
pthread_create(&(pool->adjust_tid), NULL, adjust_thread, (void *)pool);/* 启动管理者线程 */
return pool;
} while (0);
threadpool_free(pool); /* 前面代码调用失败时，释放poll存储空间 */
return NULL;
}
/* 向线程池中 添加一个任务 */
int threadpool_add(threadpool_t *pool, void*(*function)(void *arg), void *arg)
{
pthread_mutex_lock(&(pool->lock));
/* ==为真，队列已经满， 调wait阻塞 */
while ((pool->queue_size == pool->queue_max_size) && (!pool->shutdown)) {
pthread_cond_wait(&(pool->queue_not_full), &(pool->lock));
}
if (pool->shutdown) {
pthread_mutex_unlock(&(pool->lock));
}
/* 清空 工作线程 调用的回调函数 的参数arg */
if (pool->task_queue[pool->queue_rear].arg != NULL) {
free(pool->task_queue[pool->queue_rear].arg);
pool->task_queue[pool->queue_rear].arg = NULL;
}
/*添加任务到任务队列里*/
pool->task_queue[pool->queue_rear].function = function;
pool->task_queue[pool->queue_rear].arg = arg;
pool->queue_rear = (pool->queue_rear + 1) % pool->queue_max_size; /* 队尾指针移动, 模拟环形 */
pool->queue_size++;
/*添加完任务后，队列不为空，唤醒线程池中 等待处理任务的线程*/
pthread_cond_signal(&(pool->queue_not_empty));
pthread_mutex_unlock(&(pool->lock));
return 0;
}
/* 线程池中各个工作线程 */
void *threadpool_thread(void *threadpool)
{
threadpool_t *pool = (threadpool_t *)threadpool;
threadpool_task_t task;
while (true) {
/* Lock must be taken to wait on conditional variable */
/*刚创建出线程，等待任务队列里有任务，否则阻塞等待任务队列里有任务后再唤醒接收任务*/
pthread_mutex_lock(&(pool->lock));
/*queue_size == 0 说明没有任务，调 wait 阻塞在条件变量上, 若有任务，跳过该while*/
while ((pool->queue_size == 0) && (!pool->shutdown)) {
printf("thread 0x%x is waiting\n", (unsigned int)pthread_self());
pthread_cond_wait(&(pool->queue_not_empty), &(pool->lock));
/*清除指定数目的空闲线程，如果要结束的线程个数大于0，结束线程*/
if (pool->wait_exit_thr_num > 0) {
pool->wait_exit_thr_num--;
/*如果线程池里线程个数大于最小值时可以结束当前线程*/
if (pool->live_thr_num > pool->min_thr_num) {
printf("thread 0x%x is exiting\n", (unsigned int)pthread_self());
pool->live_thr_num--;
pthread_mutex_unlock(&(pool->lock));
pthread_exit(NULL);
}
}
}
/*如果指定了true，要关闭线程池里的每个线程，自行退出处理*/
if (pool->shutdown) {
pthread_mutex_unlock(&(pool->lock));
printf("thread 0x%x is exiting\n", (unsigned int)pthread_self());
pthread_exit(NULL); /* 线程自行结束 */
}
/*从任务队列里获取任务, 是一个出队操作*/
task.function = pool->task_queue[pool->queue_front].function;
task.arg = pool->task_queue[pool->queue_front].arg;
pool->queue_front = (pool->queue_front + 1) % pool->queue_max_size; /* 出队，模拟环形队列 */
pool->queue_size--;
/*通知可以有新的任务添加进来*/
pthread_cond_broadcast(&(pool->queue_not_full));
/*任务取出后，立即将 线程池琐 释放*/
pthread_mutex_unlock(&(pool->lock));
/*执行任务*/
printf("thread 0x%x start working\n", (unsigned int)pthread_self());
pthread_mutex_lock(&(pool->thread_counter)); /*忙状态线程数变量琐*/
pool->busy_thr_num++; /*忙状态线程数+1*/
pthread_mutex_unlock(&(pool->thread_counter));
(*(task.function))(task.arg); /*执行回调函数任务*/
//task.function(task.arg); /*执行回调函数任务*/
/*任务结束处理*/
printf("thread 0x%x end working\n", (unsigned int)pthread_self());
pthread_mutex_lock(&(pool->thread_counter));
pool->busy_thr_num--; /*处理掉一个任务，忙状态数线程数-1*/
pthread_mutex_unlock(&(pool->thread_counter));
}
pthread_exit(NULL);
}
/* 管理线程 */
void *adjust_thread(void *threadpool)
{
int i;
threadpool_t *pool = (threadpool_t *)threadpool;
while (!pool->shutdown) {
sleep(DEFAULT_TIME); /*定时 对线程池管理*/
pthread_mutex_lock(&(pool->lock));
int queue_size = pool->queue_size; /* 关注 任务数 */
int live_thr_num = pool->live_thr_num; /* 存活 线程数 */
pthread_mutex_unlock(&(pool->lock));
pthread_mutex_lock(&(pool->thread_counter));
int busy_thr_num = pool->busy_thr_num; /* 忙着的线程数 */
pthread_mutex_unlock(&(pool->thread_counter));
/* 创建新线程 算法： 任务数大于最小线程池个数, 且存活的线程数少于最大线程个数时 如：30>=10 && 40<100*/
if (queue_size >= MIN_WAIT_TASK_NUM && live_thr_num < pool->max_thr_num) {
pthread_mutex_lock(&(pool->lock));
int add = 0;
/*一次增加 DEFAULT_THREAD 个线程*/
for (i = 0; i < pool->max_thr_num && add < DEFAULT_THREAD_VARY
&& pool->live_thr_num < pool->max_thr_num; i++) {
if (pool->threads[i] == 0 || !is_thread_alive(pool->threads[i])) {
pthread_create(&(pool->threads[i]), NULL, threadpool_thread, (void *)pool);
add++;
pool->live_thr_num++;
}
}
pthread_mutex_unlock(&(pool->lock));
}
/* 销毁多余的空闲线程 算法：忙线程X2 小于 存活的线程数 且 存活的线程数 大于 最小线程数时*/
if ((busy_thr_num * 2) < live_thr_num && live_thr_num > pool->min_thr_num) {
/* 一次销毁DEFAULT_THREAD个线程, 隨機10個即可 */
pthread_mutex_lock(&(pool->lock));
pool->wait_exit_thr_num = DEFAULT_THREAD_VARY; /* 要销毁的线程数 设置为10 */
pthread_mutex_unlock(&(pool->lock));
for (i = 0; i < DEFAULT_THREAD_VARY; i++) {
/* 通知处在空闲状态的线程, 他们会自行终止*/
pthread_cond_signal(&(pool->queue_not_empty));
}
}
}
return NULL;
}
int threadpool_destroy(threadpool_t *pool)
{
int i;
if (pool == NULL) {
return -1;
}
pool->shutdown = true;
/*先销毁管理线程*/
pthread_join(pool->adjust_tid, NULL);
for (i = 0; i < pool->live_thr_num; i++) {
/*通知所有的空闲线程*/
pthread_cond_broadcast(&(pool->queue_not_empty));
}
for (i = 0; i < pool->live_thr_num; i++) {
pthread_join(pool->threads[i], NULL);
}
threadpool_free(pool);
return 0;
}
int threadpool_free(threadpool_t *pool)
{
if (pool == NULL) {
return -1;
}
if (pool->task_queue) {
free(pool->task_queue);
}
if (pool->threads) {
free(pool->threads);
pthread_mutex_lock(&(pool->lock));
pthread_mutex_destroy(&(pool->lock));
pthread_mutex_lock(&(pool->thread_counter));
pthread_mutex_destroy(&(pool->thread_counter));
pthread_cond_destroy(&(pool->queue_not_empty));
pthread_cond_destroy(&(pool->queue_not_full));
}
free(pool);
pool = NULL;
return 0;
}
int threadpool_all_threadnum(threadpool_t *pool)
{
int all_threadnum = -1;
pthread_mutex_lock(&(pool->lock));
all_threadnum = pool->live_thr_num;
pthread_mutex_unlock(&(pool->lock));
return all_threadnum;
}
int threadpool_busy_threadnum(threadpool_t *pool)
{
int busy_threadnum = -1;
pthread_mutex_lock(&(pool->thread_counter));
busy_threadnum = pool->busy_thr_num;
pthread_mutex_unlock(&(pool->thread_counter));
return busy_threadnum;
}
int is_thread_alive(pthread_t tid)
{
int kill_rc = pthread_kill(tid, 0); //发0号信号，测试线程是否存活
if (kill_rc == ESRCH) {
return false;
}
return true;
}
/*测试*/
#if 1
/* 线程池中的线程，模拟处理业务 */
void *process(void *arg)
{
printf("thread 0x%x working on task %d\n ",(unsigned int)pthread_self(),*(int *)arg);
sleep(1);
printf("task %d is end\n",*(int *)arg);
return NULL;
}
int main(void)
{
/*threadpool_t *threadpool_create(int min_thr_num, int max_thr_num, int queue_max_size);*/
threadpool_t *thp = threadpool_create(3,100,100);/*创建线程池，池里最小3个线程，最大100，队列最大100*/
printf("pool inited");
//int *num = (int *)malloc(sizeof(int)*20);
int num[20], i;
for (i = 0; i < 20; i++) {
num[i]=i;
printf("add task %d\n",i);
threadpool_add(thp, process, (void*)&num[i]); /* 向线程池中添加任务 */
}
sleep(10); /* 等子线程完成任务 */
threadpool_destroy(thp);
return 0;
}
#endif