POSIX线程库：
与线程有关的函数构成了一个完整的系列，绝大多数函数的名字都是以“pthread_”打头的
要使用这些函数库，要通过引入头文<pthread.h>
链接这些线程函数库时要使用编译器命令的“-lpthread”选项
pthread_create函数
功能：创建一个新的线程
原型
int pthread_create(pthread_t *thread, const pthread_attr_t *attr, void *(*start_routine)(void*), void *arg);
参数
thread:返回线程ID
attr:设置线程的属性，attr为NULL表示使用默认属性
start_routine:是个函数地址，线程启动后要执行的函数
arg:传给线程启动函数的参数
返回值：成功返回0；失败返回错误码
错误检查
传统的一些函数是，成功返回0，失败返回-1，并且对全局变量errno赋值以指示错误。
pthreads函数出错时不会设置全局变量errno（而大部分其他POSIX函数会这样做）。而是将错误代码通过返回值返回
pthreads同样也提供了线程内的errno变量，以支持其它使用errno的代码。对于pthreads函数的错误，建议通过返回值业判定，因为读取返回值要比读取线程内的errno变量的开销更小
pthread_exit函数
功能：线程终止
原型
void pthread_exit(void *value_ptr);
参数
value_ptr:value_ptr不要指向一个局部变量。
返回值：无返回值，跟进程一样，线程结束的时候无法返回到它的调用者（自身）
pthread_join函数
功能：等待线程结束
原型
int pthread_join(pthread_t thread, void **value_ptr);
参数
thread:线程ID
value_ptr:它指向一个指针，后者指向线程的返回值
返回值：成功返回0；失败返回错误码
pthread_self函数
功能：返回线程ID
原型
pthread_t pthread_self(void);
返回值：成功返回0
pthread_cancel函数
功能：取消一个执行中的线程
原型
int pthread_cancel(pthread_t thread);
参数
thread:线程ID
返回值：成功返回0；失败返回错误码
pthread_detach函数
功能：将一个线程分离
原型
int pthread_detach(pthread_t thread);
参数
thread:线程ID
返回值：成功返回0；失败返回错误码
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <pthread.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#define ERR_EXIT(m) \
do \
{ \
perror(m); \
exit(EXIT_FAILURE); \
} while(0)
void echo_srv(int conn)
{
char recvbuf[1024];
while (1)
{
memset(recvbuf, 0, sizeof(recvbuf));
int ret = read(conn, recvbuf, sizeof(recvbuf));
if (ret == 0)
{
printf("client close\n");
break;
}
else if (ret == -1)
ERR_EXIT("read");
fputs(recvbuf, stdout);
write(conn, recvbuf, ret);
}
}
void* thread_routine(void *arg)
{
pthread_detach(pthread_self());
/*int conn = (int)arg;*/
int conn = *((int*)arg);
free(arg);
echo_srv(conn);
printf("exiting thread ...\n");
return NULL;
}
int main(void)
{
int listenfd;
if ((listenfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
ERR_EXIT("socket");
struct sockaddr_in servaddr;
memset(&servaddr, 0, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons(5188);
servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
int on = 1;
if (setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
ERR_EXIT("setsockopt");
if (bind(listenfd, (struct sockaddr*)&servaddr, sizeof(servaddr)) < 0)
ERR_EXIT("bind");
if (listen(listenfd, SOMAXCONN) < 0)
ERR_EXIT("listen");
struct sockaddr_in peeraddr;
socklen_t peerlen = sizeof(peeraddr);
int conn;
while (1)
{
if ((conn = accept(listenfd, (struct sockaddr*)&peeraddr, &peerlen)) < 0)
ERR_EXIT("accept");
printf("ip=%s port=%d\n", inet_ntoa(peeraddr.sin_addr), ntohs(peeraddr.sin_port));
pthread_t tid;
int ret;
/*pthread_create(&tid, NULL, thread_routine, (void*)&conn);*/
int *p = malloc(sizeof(int));
*p = conn;
pthread_create(&tid, NULL, thread_routine, p);
/*
if ((ret = pthread_create(&tid, NULL, thread_routine, (void*)conn)) != 0)
{
fprintf(stderr, "pthread_create:%s\n", strerror(ret));
exit(EXIT_FAILURE);
}
*/
}
return 0;
}
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <pthread.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#define ERR_EXIT(m) \
do \
{ \
perror(m); \
exit(EXIT_FAILURE); \
} while(0)
void echo_srv(int conn)
{
char recvbuf[1024];
while (1)
{
memset(recvbuf, 0, sizeof(recvbuf));
int ret = read(conn, recvbuf, sizeof(recvbuf));
if (ret == 0)
{
printf("client close\n");
break;
}
else if (ret == -1)
ERR_EXIT("read");
fputs(recvbuf, stdout);
write(conn, recvbuf, ret);
}
}
void* thread_routine(void *arg)
{
pthread_detach(pthread_self());
/*int conn = (int)arg;*/
int conn = *((int*)arg);
free(arg);
echo_srv(conn);
printf("exiting thread ...\n");
return NULL;
}
int main(void)
{
int listenfd;
if ((listenfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
ERR_EXIT("socket");
struct sockaddr_in servaddr;
memset(&servaddr, 0, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons(5188);
servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
int on = 1;
if (setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
ERR_EXIT("setsockopt");
if (bind(listenfd, (struct sockaddr*)&servaddr, sizeof(servaddr)) < 0)
ERR_EXIT("bind");
if (listen(listenfd, SOMAXCONN) < 0)
ERR_EXIT("listen");
struct sockaddr_in peeraddr;
socklen_t peerlen = sizeof(peeraddr);
int conn;
while (1)
{
if ((conn = accept(listenfd, (struct sockaddr*)&peeraddr, &peerlen)) < 0)
ERR_EXIT("accept");
printf("ip=%s port=%d\n", inet_ntoa(peeraddr.sin_addr), ntohs(peeraddr.sin_port));
pthread_t tid;
int ret;
/*pthread_create(&tid, NULL, thread_routine, (void*)&conn);*/
int *p = malloc(sizeof(int));
*p = conn;
pthread_create(&tid, NULL, thread_routine, p);
/*
if ((ret = pthread_create(&tid, NULL, thread_routine, (void*)conn)) != 0)
{
fprintf(stderr, "pthread_create:%s\n", strerror(ret));
exit(EXIT_FAILURE);
}
*/
}
return 0;
}
echocli.c
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#define ERR_EXIT(m) \
do \
{ \
perror(m); \
exit(EXIT_FAILURE); \
} while(0)
void echo_cli(int sock)
{
char sendbuf[1024] = {0};
char recvbuf[1024] ={0};
while (fgets(sendbuf, sizeof(sendbuf), stdin) != NULL)
{
write(sock, sendbuf, strlen(sendbuf));
read(sock, recvbuf, sizeof(recvbuf));
fputs(recvbuf, stdout);
memset(sendbuf, 0, sizeof(sendbuf));
memset(recvbuf, 0, sizeof(recvbuf));
}
close(sock);
}
int main(void)
{
int sock;
if ((sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
ERR_EXIT("socket");
struct sockaddr_in servaddr;
memset(&servaddr, 0, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons(5188);
servaddr.sin_addr.s_addr = inet_addr("127.0.0.1");
if (connect(sock, (struct sockaddr*)&servaddr, sizeof(servaddr)) < 0)
ERR_EXIT("connect");
echo_cli(sock);
return 0;
}
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#define ERR_EXIT(m) \
do \
{ \
perror(m); \
exit(EXIT_FAILURE); \
} while(0)
void echo_cli(int sock)
{
char sendbuf[1024] = {0};
char recvbuf[1024] ={0};
while (fgets(sendbuf, sizeof(sendbuf), stdin) != NULL)
{
write(sock, sendbuf, strlen(sendbuf));
read(sock, recvbuf, sizeof(recvbuf));
fputs(recvbuf, stdout);
memset(sendbuf, 0, sizeof(sendbuf));
memset(recvbuf, 0, sizeof(recvbuf));
}
close(sock);
}
int main(void)
{
int sock;
if ((sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
ERR_EXIT("socket");
struct sockaddr_in servaddr;
memset(&servaddr, 0, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons(5188);
servaddr.sin_addr.s_addr = inet_addr("127.0.0.1");
if (connect(sock, (struct sockaddr*)&servaddr, sizeof(servaddr)) < 0)
ERR_EXIT("connect");
echo_cli(sock);
return 0;
}
01thread.c
#include <unistd.h>
#include <sys/types.h>
#include <pthread.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#define ERR_EXIT(m) \
do \
{ \
perror(m); \
exit(EXIT_FAILURE); \
} while(0)
void* thread_routine(void *arg)
{
int i;
for (i=0; i<20; i++)
{
printf("B");
fflush(stdout);
usleep(20);
/*
if (i==3)
pthread_exit("ABC");
*/
}
sleep(3);
return "DEF";
}
int main(void)
{
pthread_t tid;
int ret;
if ((ret = pthread_create(&tid, NULL, thread_routine, NULL)) != 0)
{
fprintf(stderr, "pthread_create:%s\n", strerror(ret));
exit(EXIT_FAILURE);
}
int i;
for (i=0; i<20; i++)
{
printf("A");
fflush(stdout);
usleep(20);
}
void *value;
if ((ret = pthread_join(tid, &value)) != 0)
{
fprintf(stderr, "pthread_join:%s\n", strerror(ret));
exit(EXIT_FAILURE);
}
printf("\n");
printf("return msg=%s\n", (char*)value);
return 0;
}
#include <sys/types.h>
#include <pthread.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#define ERR_EXIT(m) \
do \
{ \
perror(m); \
exit(EXIT_FAILURE); \
} while(0)
void* thread_routine(void *arg)
{
int i;
for (i=0; i<20; i++)
{
printf("B");
fflush(stdout);
usleep(20);
/*
if (i==3)
pthread_exit("ABC");
*/
}
sleep(3);
return "DEF";
}
int main(void)
{
pthread_t tid;
int ret;
if ((ret = pthread_create(&tid, NULL, thread_routine, NULL)) != 0)
{
fprintf(stderr, "pthread_create:%s\n", strerror(ret));
exit(EXIT_FAILURE);
}
int i;
for (i=0; i<20; i++)
{
printf("A");
fflush(stdout);
usleep(20);
}
void *value;
if ((ret = pthread_join(tid, &value)) != 0)
{
fprintf(stderr, "pthread_join:%s\n", strerror(ret));
exit(EXIT_FAILURE);
}
printf("\n");
printf("return msg=%s\n", (char*)value);
return 0;
}
makefile:
.PHONY:clean all
CC=gcc
CFLAGS=-Wall -g
BIN=01thread echosrv echocli
all:$(BIN)
%.o:%.c
$(CC) $(CFLAGS) -c $< -o $@
01thread:01thread.o
$(CC) $(CFLAGS) $^ -o $@ -lpthread
echosrv:echosrv.o
$(CC) $(CFLAGS) $^ -o $@ -lpthread
clean:
rm -f *.o $(BIN)
CC=gcc
CFLAGS=-Wall -g
BIN=01thread echosrv echocli
all:$(BIN)
%.o:%.c
$(CC) $(CFLAGS) -c $< -o $@
01thread:01thread.o
$(CC) $(CFLAGS) $^ -o $@ -lpthread
echosrv:echosrv.o
$(CC) $(CFLAGS) $^ -o $@ -lpthread
clean:
rm -f *.o $(BIN)