7、minheap-internal.h
/*
* Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
*
* Copyright (c) 2006 Maxim Yegorushkin <[email protected]>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef MINHEAP_INTERNAL_H_INCLUDED_
#define MINHEAP_INTERNAL_H_INCLUDED_
//come from https://github.com/libevent/libevent/blob/release-2.1.8-stable/minheap-internal.h
/*firecat del
#include "event2/event-config.h"
#include "evconfig-private.h"
#include "event2/event.h"
#include "event2/event_struct.h"
#include "event2/util.h"
#include "util-internal.h"
#include "mm-internal.h"
*/
#include "minheap-event-firecat.h" //firecat add
typedef struct min_heap
{
struct event** p;
unsigned n, a;
} min_heap_t;
static inline void min_heap_ctor_(min_heap_t* s);
static inline void min_heap_dtor_(min_heap_t* s);
static inline void min_heap_elem_init_(struct event* e);
static inline int min_heap_elt_is_top_(const struct event *e);
static inline int min_heap_empty_(min_heap_t* s);
static inline unsigned min_heap_size_(min_heap_t* s);
static inline struct event* min_heap_top_(min_heap_t* s);
static inline int min_heap_reserve_(min_heap_t* s, unsigned n);
static inline int min_heap_push_(min_heap_t* s, struct event* e);
static inline struct event* min_heap_pop_(min_heap_t* s);
static inline int min_heap_adjust_(min_heap_t *s, struct event* e);
static inline int min_heap_erase_(min_heap_t* s, struct event* e);
static inline void min_heap_shift_up_(min_heap_t* s, unsigned hole_index, struct event* e);
static inline void min_heap_shift_up_unconditional_(min_heap_t* s, unsigned hole_index, struct event* e);
static inline void min_heap_shift_down_(min_heap_t* s, unsigned hole_index, struct event* e);
#define min_heap_elem_greater(a, b) \
(evutil_timercmp(&(a)->ev_timeout, &(b)->ev_timeout, >))
void min_heap_ctor_(min_heap_t* s) { s->p = 0; s->n = 0; s->a = 0; }
void min_heap_dtor_(min_heap_t* s) { if (s->p) mm_free(s->p); }
void min_heap_elem_init_(struct event* e) { e->ev_timeout_pos.min_heap_idx = -1; }
int min_heap_empty_(min_heap_t* s) { return 0u == s->n; }
unsigned min_heap_size_(min_heap_t* s) { return s->n; }
struct event* min_heap_top_(min_heap_t* s) { return s->n ? *s->p : 0; }
int min_heap_push_(min_heap_t* s, struct event* e)
{
if (min_heap_reserve_(s, s->n + 1))
return -1;
min_heap_shift_up_(s, s->n++, e);
return 0;
}
struct event* min_heap_pop_(min_heap_t* s)
{
if (s->n)
{
struct event* e = *s->p;
min_heap_shift_down_(s, 0u, s->p[--s->n]);
e->ev_timeout_pos.min_heap_idx = -1;
return e;
}
return 0;
}
int min_heap_elt_is_top_(const struct event *e)
{
return e->ev_timeout_pos.min_heap_idx == 0;
}
int min_heap_erase_(min_heap_t* s, struct event* e)
{
if (-1 != e->ev_timeout_pos.min_heap_idx)
{
struct event *last = s->p[--s->n];
unsigned parent = (e->ev_timeout_pos.min_heap_idx - 1) / 2;
/* we replace e with the last element in the heap. We might need to
shift it upward if it is less than its parent, or downward if it is
greater than one or both its children. Since the children are known
to be less than the parent, it can't need to shift both up and
down. */
if (e->ev_timeout_pos.min_heap_idx > 0 && min_heap_elem_greater(s->p[parent], last))
min_heap_shift_up_unconditional_(s, e->ev_timeout_pos.min_heap_idx, last);
else
min_heap_shift_down_(s, e->ev_timeout_pos.min_heap_idx, last);
e->ev_timeout_pos.min_heap_idx = -1;
return 0;
}
return -1;
}
int min_heap_adjust_(min_heap_t *s, struct event *e)
{
if (-1 == e->ev_timeout_pos.min_heap_idx) {
return min_heap_push_(s, e);
} else {
unsigned parent = (e->ev_timeout_pos.min_heap_idx - 1) / 2;
/* The position of e has changed; we shift it up or down
* as needed. We can't need to do both. */
if (e->ev_timeout_pos.min_heap_idx > 0 && min_heap_elem_greater(s->p[parent], e))
min_heap_shift_up_unconditional_(s, e->ev_timeout_pos.min_heap_idx, e);
else
min_heap_shift_down_(s, e->ev_timeout_pos.min_heap_idx, e);
return 0;
}
}
int min_heap_reserve_(min_heap_t* s, unsigned n)
{
if (s->a < n)
{
struct event** p;
unsigned a = s->a ? s->a * 2 : 8;
if (a < n)
a = n;
if (!(p = (struct event**)mm_realloc(s->p, a * sizeof *p)))
return -1;
s->p = p;
s->a = a;
}
return 0;
}
void min_heap_shift_up_unconditional_(min_heap_t* s, unsigned hole_index, struct event* e)
{
unsigned parent = (hole_index - 1) / 2;
do
{
(s->p[hole_index] = s->p[parent])->ev_timeout_pos.min_heap_idx = hole_index;
hole_index = parent;
parent = (hole_index - 1) / 2;
} while (hole_index && min_heap_elem_greater(s->p[parent], e));
(s->p[hole_index] = e)->ev_timeout_pos.min_heap_idx = hole_index;
}
void min_heap_shift_up_(min_heap_t* s, unsigned hole_index, struct event* e)
{
unsigned parent = (hole_index - 1) / 2;
while (hole_index && min_heap_elem_greater(s->p[parent], e))
{
(s->p[hole_index] = s->p[parent])->ev_timeout_pos.min_heap_idx = hole_index;
hole_index = parent;
parent = (hole_index - 1) / 2;
}
(s->p[hole_index] = e)->ev_timeout_pos.min_heap_idx = hole_index;
}
void min_heap_shift_down_(min_heap_t* s, unsigned hole_index, struct event* e)
{
unsigned min_child = 2 * (hole_index + 1);
while (min_child <= s->n)
{
min_child -= min_child == s->n || min_heap_elem_greater(s->p[min_child], s->p[min_child - 1]);
if (!(min_heap_elem_greater(e, s->p[min_child])))
break;
(s->p[hole_index] = s->p[min_child])->ev_timeout_pos.min_heap_idx = hole_index;
hole_index = min_child;
min_child = 2 * (hole_index + 1);
}
(s->p[hole_index] = e)->ev_timeout_pos.min_heap_idx = hole_index;
}
#endif /* MINHEAP_INTERNAL_H_INCLUDED_ */
8、mytimer.h
#ifndef MYTIMER_H
#define MYTIMER_H
#include "buffer.h"
#include "minheap-internal.h"
#define LIMIT_TIMER 1 //有限次數定時器
#define CYCLE_TIMER 2 //循環定時器
//typedef enum {false, true} bool;
extern struct min_heap _min_heap;
extern void timer_init();
extern void timer_destroy();
extern struct event* timer_top();
extern unsigned int timer_add(unsigned int timer_id, int interval, int (*fun)(void*), int arg, int flag, int exe_num);//interval:ms
extern int timer_remove(unsigned int timer_id);
extern int timer_process();
#endif // MYTIMER_H 9、mytimer.c
#include "mytimer.h"
struct min_heap _min_heap;
void timer_init()
{
min_heap_ctor_(&_min_heap);
}
void timer_destroy()
{
int i = 0;
for (i = 0; i < _min_heap.n; i++)
{
zfree(_min_heap.p[i]);
}
min_heap_dtor_(&_min_heap);
}
struct event* timer_top()
{
return min_heap_top_(&_min_heap);
}
unsigned int timer_add(unsigned int timer_id, int interval, int(*fun)(void*), int arg,
int flag /* = CYCLE_TIMER */, int exe_num /* = 0 */)//interval:ms
{
struct event * ev = (struct event*) zmalloc(sizeof(struct event));
min_heap_elem_init_(ev);
if (NULL == ev)
return NULL;
struct timeval now;
gettime(&now);
ev->ev_interval.tv_sec = interval / 1000;
ev->ev_interval.tv_usec = (interval % 1000) * 1000;
evutil_timeradd(&now, &(ev->ev_interval), &(ev->ev_timeout));
ev->ev_flags = flag;
ev->ev_callback = fun;
ev->ev_arg = arg;
ev->ev_exe_num = exe_num;
ev->timer_id = timer_id;
min_heap_push_(&_min_heap, ev);
return ev->timer_id;
}
int timer_remove(unsigned int timer_id)
{
int i = 0;
for (i = 0; i < _min_heap.n; i++)
{
if (timer_id == _min_heap.p[i]->timer_id)
{
struct event * event = _min_heap.p[i];
min_heap_erase_(&_min_heap, _min_heap.p[i]);
zfree(event);
return 1;
}
}
return 0;
}
int timer_process()
{
struct event *event;
struct timeval now;
int ret = 0;
int processed = 0;
while ((event = min_heap_top_(&_min_heap)) != NULL)
{
gettime(&now);
if (evutil_timercmp(&now, &(event->ev_timeout), < ))
break;
processed++;
min_heap_pop_(&_min_heap);
ret = event->ev_callback(event->ev_arg);
if (ret == 0)//kill timer
{
event->ev_flags = LIMIT_TIMER;
event->ev_exe_num = 0;
}
if (event->ev_flags == CYCLE_TIMER
|| (event->ev_flags == LIMIT_TIMER && --event->ev_exe_num > 0))
{
evutil_timeradd(&(event->ev_timeout), &(event->ev_interval), &(event->ev_timeout));
min_heap_push_(&_min_heap, event);
}
else
{
zfree(event);
}
}
return processed;
}
10、main.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/epoll.h>
#include <sys/types.h>
#include <sys/resource.h> /*setrlimit */
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <assert.h>
#include <signal.h>
#include <pthread.h>
#include "mytimer.h"
#include "client.h"
#define IPADDRESS "127.0.0.1"
#define PORT 1883
#define LISTENQ 512
#define FDSIZE 80000
#define EPOLLEVENTS 100
#define CONFIG_MIN_RESERVED_FDS 32 //come from redis src
#define CONFIG_FDSET_INCR (CONFIG_MIN_RESERVED_FDS+96)
#define CLIENT_TIMEOUT 60 * 1000//ms
int stop_server = 0;
int timer_id = 0;
//函數聲明
//建立套接字并進行綁定
static int socket_bind(const char* ip,int port);
//IO多路複用epoll
static void do_epoll(int listenfd);
//事件處理函數
static void handle_events(int epollfd,struct epoll_event *events,int num,int listenfd);
//處理接收到的連接配接
static void handle_accpet(int epollfd,int listenfd);
//讀處理
static void do_read(int epollfd,int fd);
//寫處理
static void do_write(int epollfd,int fd);
//添加事件
static void add_event(int epollfd,int fd,int state);
//修改事件
static void modify_event(int epollfd,int fd,int state);
//删除事件
static void delete_event(int epollfd,int fd,int state);
//other
static int do_error(int fd, int *error);
static int setnonblocking(int fd);
static void daemonize(void);
static int set_fdlimit();
static void signal_exit_handler();
static void signal_exit_func(int signo);
static void handle_timer();
static int timerfun_callback(int arg);
static int user_read(client_t *client, buffer_t *rbuffer);
static int user_write(client_t *client, unsigned char* data, int len);
int main(int argc,char *argv[])
{
//設定每個程序允許打開的最大檔案數,socket
if (set_fdlimit() < 0)
{
return -1;
}
int background = 0;
if (background)
{
daemonize();
}
//設定信号處理,SIG_IGN表示忽略信号,SIG_DFL表示使用信号的預設處理方式
//signal(SIGHUP, SIG_IGN); //開啟的話，就捕獲不到終端視窗關閉的信号了。即視窗關閉，程序仍然進行。
signal(SIGPIPE, SIG_IGN);
/*
if (argc != 2) {
fprintf(stderr, "Usage: %s port\n", argv[0]);
return 1;
}
int port = atoi(argv[1]);*/
create_fileEvent(FDSIZE + CONFIG_FDSET_INCR);
int listenfd;
listenfd = socket_bind(IPADDRESS,PORT);
listen(listenfd,LISTENQ);
printf("start listening...\n");
signal_exit_handler();
timer_init();
do_epoll(listenfd);
timer_destroy();
destroy_fileEvent(FDSIZE + CONFIG_FDSET_INCR);
return 0;
}
static int socket_bind(const char* ip,int port)
{
int listenfd;
struct sockaddr_in servaddr;
listenfd = socket(AF_INET,SOCK_STREAM,0);
if (listenfd == -1)
{
perror("socket error:");
exit(1);
}
bzero(&servaddr,sizeof(servaddr));
servaddr.sin_family = AF_INET;
//inet_pton(AF_INET,ip,&servaddr.sin_addr);
servaddr.sin_port = htons(port);
servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
int error;
int reuse = 1;
int ret = setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse));
if (ret == -1)
{
return do_error(listenfd, &error);
}
if (bind(listenfd,(struct sockaddr*)&servaddr,sizeof(servaddr)) == -1)
{
perror("bind error: ");
exit(1);
}
return listenfd;
}
static void do_epoll(int listenfd)
{
int epollfd;
struct epoll_event events[EPOLLEVENTS];
int ret;
//建立一個描述符
int error;
epollfd = epoll_create(1024);//1024 is just a hint for the kernel
if (epollfd == -1)
{
return do_error(epollfd, &error);
}
//添加監聽描述符事件
add_event(epollfd,listenfd,EPOLLIN);
struct event *event;
//struct timeval now;
struct timeval tv;
struct timeval *tvp = NULL;
while ( stop_server == 0 )
{
if ((event = timer_top()) != NULL)
{
long now_sec, now_ms;//come from redis src "ae.c", int aeProcessEvents(aeEventLoop *eventLoop, int flags)
aeGetTime(&now_sec, &now_ms);
tvp = &tv;
/* How many milliseconds we need to wait for the next
* time event to fire? */
long long ms = (event->ev_timeout.tv_sec - now_sec) * 1000 +
(event->ev_timeout.tv_usec / 1000 - now_ms);
if (ms > 0) {
tvp->tv_sec = ms / 1000;
tvp->tv_usec = (ms % 1000) * 1000;
} else {
tvp->tv_sec = 0;
tvp->tv_usec = 0;
}
/* maybe error
gettime(&now);
tv.tv_sec = event->ev_timeout.tv_sec - now.tv_sec;;
tv.tv_usec = event->ev_timeout.tv_usec - now.tv_usec;
if ( tv.tv_usec < 0 )
{
tv.tv_usec += 1000000;
tv.tv_sec--;
printf("tv.tv_usec < 0\n");
}
tvp = &tv;
*/
}
else
{
tvp = NULL;
printf("tvp == NULL\n");
}
//擷取已經準備好的描述符事件
if (tvp == NULL)
{
ret = epoll_wait(epollfd, events, EPOLLEVENTS, -1);
}
else
{
printf("timer_wait:%d\n", tvp->tv_sec*1000 + tvp->tv_usec/1000);//ms
ret = epoll_wait(epollfd, events, EPOLLEVENTS, tvp->tv_sec*1000 + tvp->tv_usec/1000);//ms
}
handle_events(epollfd,events,ret,listenfd);
handle_timer();
}
close(epollfd);
}
static void handle_events(int epollfd,struct epoll_event *events,int num,int listenfd)
{
int i;
int fd;
//進行選好周遊
for (i = 0;i < num;i++)
{
fd = events[i].data.fd;
//根據描述符的類型和事件類型進行處理
if ((fd == listenfd) &&(events[i].events & EPOLLIN))
handle_accpet(epollfd,listenfd);
else if (events[i].events & EPOLLIN)
do_read(epollfd,fd);
else if (events[i].events & EPOLLOUT)
do_write(epollfd,fd);
}
}
static void handle_timer()
{
timer_process();
}
static void handle_accpet(int epollfd,int listenfd)
{
int clifd;
struct sockaddr_in cliaddr;
socklen_t cliaddrlen = sizeof(cliaddr);
clifd = accept(listenfd,(struct sockaddr*)&cliaddr,&cliaddrlen);
if (clifd == -1)
perror("accpet error:");
else
{
printf("accept a new client: %s:%d\n",inet_ntoa(cliaddr.sin_addr),cliaddr.sin_port);
client_t *client = alloc_client();
if (!client) {
printf("alloc client error...close socket\n");
close(clifd);
return;
}
client->fd = clifd;
client->epollfd = epollfd;
client->timerId = timer_id;
fileev[clifd].clientData = client;
//添加一個客戶描述符和事件
add_event(epollfd,clifd,EPOLLIN);
//add timer
timer_add(timer_id, 1000, timerfun_callback, clifd, CYCLE_TIMER, 0);//ms
timer_id++;
}
}
static void do_read(int epollfd,int fd)
{
client_t *client = fileev[fd].clientData;
buffer_t *rbuffer = client->read_buffer;
check_buffer_size(rbuffer, DEFAULT_BUFF_SIZE / 2);
size_t avlid_size = rbuffer->size - rbuffer->write_idx;
//ssize_t readn = anetRead(fd, rbuffer->buff + rbuffer->write_idx, avlid_size);
//不能調用anetRead這個函數
//1.用戶端下線不好判斷
//2.該函數适合linux epoll是邊緣模式（ET），資料一定要一次性收完，anetRead裡面有while循環
//3.redis源碼自身也沒有調用anetRead
//把讀到的網絡資料寫入活塞緩存
ssize_t readn = read(fd, rbuffer->buff + rbuffer->write_idx, avlid_size);
if (readn > 0)
{
rbuffer->write_idx += readn;
user_read(client, rbuffer);
client->last_recv_tick = get_tick_count();
}
else if (readn == 0)
{
printf("fd=%d, client disconnect, close it.\n", client->fd);
delete_event(epollfd,fd,EPOLLIN);
delete_event(epollfd,fd,EPOLLOUT);
timer_remove(client->timerId);
free_client(client);
}
else if (readn == -1)
{
if (errno == EAGAIN) {
return;
} else {
printf("read error,%s.\n", strerror(errno));
delete_event(epollfd,fd,EPOLLIN);
delete_event(epollfd,fd,EPOLLOUT);
timer_remove(client->timerId);
free_client(client);
}
}
}
static void do_write(int epollfd,int fd)
{
client_t *client = fileev[fd].clientData;
buffer_t *wbuffer = client->write_buffer;
int data_size = (int)get_readable_size(wbuffer);
if (data_size == 0) {
delete_event(epollfd,fd,EPOLLOUT);
return;
}
//int writen = anetWrite(client->fd, (char *)wbuffer->buff + wbuffer->read_idx, data_size);
int writen = write(client->fd, (char *)wbuffer->buff + wbuffer->read_idx, data_size);
if (writen > 0) {
wbuffer->read_idx += writen;
} else if (writen == 0) {
printf("Writing 0\n");
} else { //-1
if (errno != EWOULDBLOCK) {
printf("Writing error: %s\n", strerror(errno));
} else {
printf("Writing EWOULDBLOCK\n");
}
}
if (get_readable_size(wbuffer) == 0) {
delete_event(epollfd,fd,EPOLLOUT);
}
}
static int user_read(client_t *client, buffer_t *rbuffer)
{
size_t len = get_readable_size(rbuffer);
unsigned char data[DEFAULT_BUFF_SIZE];
if (len > DEFAULT_BUFF_SIZE)
{
len = DEFAULT_BUFF_SIZE;
}
//把活塞緩存讀取出來，作為使用者資料
memcpy(data, rbuffer->buff + rbuffer->read_idx, len);
rbuffer->read_idx += len;
int i = 0;
for (i = 0; i < len; i++)
{
printf("%c", data[i]);
}
printf("\n");
user_write(client, data, len);//echo
return 0;
}
static int user_write(client_t *client, unsigned char* data, int len)
{
//把使用者資料寫入活塞緩存
buffer_t *wbuffer = client->write_buffer;
check_buffer_size(wbuffer, len);
memcpy((char *)wbuffer->buff + wbuffer->write_idx, data, len);
wbuffer->write_idx += len;
//把活塞緩存的有效資料通過網絡發送出去
//int writen = anetWrite(client->fd, (char *)wbuffer->buff + wbuffer->read_idx, (int)get_readable_size(wbuffer));
int writen = write(client->fd, (char *)wbuffer->buff + wbuffer->read_idx, (int)get_readable_size(wbuffer));
if (writen > 0) {
wbuffer->read_idx += writen;
} else if (writen == 0) {
printf("Writing 0\n");
} else { //-1
if (errno != EWOULDBLOCK) {
printf("Writing error: %s\n", strerror(errno));
} else {
printf("Writing EWOULDBLOCK\n");
}
}
//如果writen==-1，表示目前tcp視窗容量不夠，需要等待下次機會再發,errno == EWOULDBLOCK
//因為活塞緩存的有效資料沒有發完，遺留部分需要再給機會
if (get_readable_size(wbuffer) != 0) {
/*
if (aeCreateFileEvent(client->loop, client->fd,
AE_WRITABLE, writeEventHandler, client) == AE_ERR) {
printf("create socket writeable event error, close it.\n");
free_client(client);
}*/
//modify_event(client->epollfd,client->fd,EPOLLOUT);
add_event(client->epollfd,client->fd,EPOLLOUT);
}
return 0;
}
static void add_event(int epollfd,int fd,int state)
{
struct epoll_event ev;
ev.events = state;
ev.data.fd = fd;
epoll_ctl(epollfd,EPOLL_CTL_ADD,fd,&ev);
setnonblocking(fd);
}
static void delete_event(int epollfd,int fd,int state)
{
struct epoll_event ev;
ev.events = state;
ev.data.fd = fd;
epoll_ctl(epollfd,EPOLL_CTL_DEL,fd,&ev);
}
static void modify_event(int epollfd,int fd,int state)
{
struct epoll_event ev;
ev.events = state;
ev.data.fd = fd;
epoll_ctl(epollfd,EPOLL_CTL_MOD,fd,&ev);
}
static int do_error(int fd, int *error)
{
fprintf(stderr, "error: %s\n", strerror(errno));
*error = errno;
while ((close(fd) == -1) && (errno == EINTR));
errno = *error;
return 1;
}
static int setnonblocking(int fd)
{
int old_option = fcntl(fd, F_GETFL);
int new_option = old_option | O_NONBLOCK;
fcntl(fd, F_SETFL, new_option);
return old_option;
}
static void daemonize(void) { //come from /redis/server.c/daemonize()
int fd;
if (fork() != 0) exit(0); /* parent exits */
setsid(); /* create a new session */
/* Every output goes to /dev/null. If Redis is daemonized but
* the 'logfile' is set to 'stdout' in the configuration file
* it will not log at all. */
if ((fd = open("/dev/null", O_RDWR, 0)) != -1) {
dup2(fd, STDIN_FILENO);
dup2(fd, STDOUT_FILENO);
dup2(fd, STDERR_FILENO);
if (fd > STDERR_FILENO) close(fd);
}
}
static int set_fdlimit()
{
//設定每個程序允許打開的最大檔案數
//這項功能等價于linux終端指令 "ulimit -n 102400"
struct rlimit rt;
rt.rlim_max = rt.rlim_cur = FDSIZE + CONFIG_FDSET_INCR;
if (setrlimit(RLIMIT_NOFILE, &rt) == -1)
{
perror("setrlimit error");
return -1;
}
return 0;
}
static void signal_exit_handler()
{
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
sa.sa_handler = signal_exit_func;
sigaction(SIGINT, &sa, NULL);//當按下ctrl+c時，它的效果就是發送SIGINT信号
sigaction(SIGTERM, &sa, NULL);//kill pid
sigaction(SIGQUIT, &sa, NULL);//ctrl+\代表退出SIGQUIT
//SIGSTOP和SIGKILL信号是不可捕獲的,是以下面兩句話寫了等于沒有寫
sigaction(SIGKILL, &sa, NULL);//kill -9 pid
sigaction(SIGSTOP, &sa, NULL);//ctrl+z代表停止
//#define SIGTERM 15
//#define SIGKILL 9
//kill和kill -9，兩個指令在linux中都有殺死程序的效果，然而兩指令的執行過程卻大有不同，在程式中如果用錯了，可能會造成莫名其妙的現象。
//執行kill pid指令，系統會發送一個SIGTERM信号給對應的程式。
//執行kill -9 pid指令，系統給對應程式發送的信号是SIGKILL，即exit。exit信号不會被系統阻塞，是以kill -9能順利殺掉程序。
}
static void signal_exit_func(int signo)
{
printf("exit signo is %d\n", signo);
stop_server = 1;
}
static int timerfun_callback(int arg)
{
client_t *client = fileev[arg].clientData;
assert(arg == client->fd);
printf("timer_id=%d, fd=%d\n", client->timerId, client->fd);
//心跳機制：定時檢測，如果沒有資料來則踢除用戶端
uint64_t curr_tick = get_tick_count();
if (curr_tick > client->last_recv_tick + CLIENT_TIMEOUT)
{
printf("timeout, fd=%d\n", client->fd);
//timer_remove(arg);//不能在這裡删除timer，因為是回調函數，timer其實已經先pop掉了，我們要做的是不讓它再次加入堆
delete_event(client->epollfd, client->fd, EPOLLIN);
delete_event(client->epollfd, client->fd, EPOLLOUT);
free_client(client);
return 0;//kill timer，傳回值為0，目的是不讓它再次加入堆
}
return 1;
}
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