Timeout events in Libevent are managed and maintained using minimal heap. The code is located in <minheap-internal.h>.\
Source: github.com/libevent/li…
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This paper implements Linux network library epoll+ time heap to achieve high performance timer, using C language
One, the original
How to use epoll to implement multiple timer operation is the key of this design. As we know, the last parameter of epoll_wait is the blocking time, in milliseconds. It can be designed like this:
1. If there is no timer in the time heap, the timeout time T of epoll_wait is set to -1, indicating that the user is blocked waiting for the arrival of new users.
When there is a timer in the time heap, the epoll_wait timeout (T) is set to the minimum heap top timeout value to ensure that the most recently triggered timer can be executed.
3. If another user arrives during the epoll_WAIT block, epoll_wait returns n>0 for normal processing, and then resets epoll_WAIT to the top timeout of the small top heap.
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Second, the source
1, CMakeLists. TXT
Cmake_minimum_required (VERSION 2.8) PROJECT(min_heap_libevent_epoll) AUX_SOURCE_DIRECTORY(.src_list) ADD_EXECUTABLE(${PROJECT_NAME} ${SRC_LIST})Copy the code\
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Int (*ev_callback)(void *arg); minheap-event-firecat. I changed the return value to int
#ifndef MINHEAPEVENTFIRECAT_H
#define MINHEAPEVENTFIRECAT_H
#include <sys/time.h>
#include <time.h>
#include <stdio.h>
#include <stdlib.h>/ / last come from https://github.com/libevent/libevent/blob/release-2.1.8-stable/mm-internal.h # define mm_malloc (sz) malloc(sz) #define mm_calloc(n, sz) calloc((n), (sz)) #define mm_strdup(s) strdup(s) #define mm_realloc(p, sz) realloc((p), (sz)) #define mm_free(p) free(p) //come from https://github.com/libevent/libevent/blob/release-2.1.8-stable/include/event2/util.h # define evutil_timercmp (TVP, uvp, cmp) \ (((tvp)->tv_sec == (uvp)->tv_sec) ? \ ((tvp)->tv_usec cmp (uvp)->tv_usec) : \ ((tvp)->tv_sec cmp (uvp)->tv_sec)) #define evutil_timersub(tvp, uvp, vvp) \ do { \ (vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec; \ (vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec; \ if ((vvp)->tv_usec < 0) { \ (vvp)->tv_sec--; \ (vvp)->tv_usec += 1000000; \ } \ } while (0) #define evutil_timeradd(tvp, uvp, vvp) \ do { \ (vvp)->tv_sec = (tvp)->tv_sec + (uvp)->tv_sec; \ (vvp)->tv_usec = (tvp)->tv_usec + (uvp)->tv_usec; \ if ((vvp)->tv_usec >= 1000000) { \ (vvp)->tv_sec++; \ (vvp)->tv_usec -= 1000000; \ } \ } while (0) //come from https://github.com/libevent/libevent/blob/release-2.1.8-stable/include/event2/event_struct.h struct event {/ * for managing timeouts */ union { //TAILQ_ENTRY(event) ev_next_with_common_timeout; int min_heap_idx; } ev_timeout_pos; unsigned int timer_id; struct timeval ev_interval; struct timeval ev_timeout; int ev_exe_num; int (*ev_callback)(void *arg); int ev_arg; int ev_res; /* result passed to event callback */ int ev_flags; }; static inline void gettime(struct timeval *tm); void gettime(struct timeval *tm) { gettimeofday(tm, NULL); } #endif // MINHEAPEVENTFIRECAT_HCopy the code\
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3, 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_ */
Copy the code\
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4. Mytimer.h — Different from the first article, this article uses C language to implement. Timer_add (int timer_id, int arg, etc.)
# ifNdef MYTIMER_H #define MYTIMER_H #include "minheap-internal.h" #define LIMIT_TIMER 1 // LIMIT_TIMER #define CYCLE_TIMER 2 // Typedef enum {false, true} bool; extern struct min_heap _min_heap; extern void timer_init(); extern void timer_destroy(); extern unsigned int timer_add(unsigned int timer_id, int interval, int (*fun)(void*), int arg, int flag, int exe_num); extern int timer_remove(unsigned int timer_id); extern int timer_process(); #endif // MYTIMER_HCopy the code\
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Mytimer.c — Unlike in Article 1, the int timer_process() function adds a kill timer method
#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++) { free(_min_heap.p[i]); } min_heap_dtor_(&_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 */) { struct event * ev = (struct event*) malloc(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 * e = _min_heap.p[i]; min_heap_erase_(&_min_heap, _min_heap.p[i]); free(e); return 1; } } return 0; } int timer_process() { struct event *event; struct timeval now; int ret = 0; while ((event = min_heap_top_(&_min_heap)) ! = NULL) { gettime(&now); if (evutil_timercmp(&now, &(event->ev_timeout), < )) break; 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 { free(event); } } return 0; }Copy the code\
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Static void do_epoll(int listenfd); static int timerfun_callback(int arg);
#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" #define IPADDRESS "127.0.0.1" #define PORT 8011 #define MAXSIZE 1024 #define LISTENQ 5 #define FDSIZE 50000 #define EPOLLEVENTS 100 #define CONFIG_MIN_RESERVED_FDS 32 //come from redis src #define CONFIG_FDSET_INCR (CONFIG_MIN_RESERVED_FDS+96) int stop_server = 0; Static int socket_bind(const char* IP,int port); static int socket_bind(const char* IP,int port) Epoll static void do_epoll(int listenfd); Static void handle_events(int epollfd,struct epoll_event *events,int num,int listenfd,char *buf); Static void handle_accPET (int epollFD,int listenfd); Static void do_read(int epollfd,int fd,char *buf); Static void do_write(int epollfd,int fd,char *buf); Static void add_event(int epollfd,int fd,int state); Static void modify_event(int epollFD,int fd,int state); 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); Int main(int argc,char *argv[]) {// Set the maximum number of files allowed to open per process,socket if (set_fdlimit() < 0) {return -1; } int background = 0; if (background) { daemonize(); //signal(SIGHUP, SIG_IGN); //signal(SIGHUP, SIG_IGN); // If the terminal window is open, the terminal window will not be closed. That is, the window closes and the process continues. signal(SIGPIPE, SIG_IGN); /* if (argc ! = 2) { fprintf(stderr, "Usage: %s port\n", argv[0]); return 1; } int port = atoi(argv[1]); */ int listenfd; listenfd = socket_bind(IPADDRESS,PORT); listen(listenfd,LISTENQ); printf("start listening... \n"); signal_exit_handler(); timer_init(); do_epoll(listenfd); timer_destroy(); 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; // Create a descriptor int error; epollfd = epoll_create(1024); //1024 is just a hint for the kernel if (epollfd == -1) { return do_error(epollfd, &error); } // Add the listener descriptor event add_event(epollfd,listenfd,EPOLLIN); struct event *event; struct timeval now; struct timeval tv; struct timeval *tvp = NULL; while ( stop_server == 0 ) { if ((event = min_heap_top_(&_min_heap)) ! = 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"); } // Get the prepared descriptor event 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,char *buf) { int i; int fd; For (I = 0; i < num; i++) { fd = events[i].data.fd; If ((fd == listenfd) &&(events[I].events & EPOLLIN)) handle_ACCPET (ePollFD,listenfd); else if (events[i].events & EPOLLIN) do_read(epollfd,fd,buf); else if (events[i].events & EPOLLOUT) do_write(epollfd,fd,buf); } } 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); // Add a customer descriptor and the event add_event(epollfd,clifd,EPOLLIN); //add timer timer_add(clifd, 1000, timerfun_callback, clifd, CYCLE_TIMER, 0); //ms } } static void do_read(int epollfd,int fd,char *buf) { int nread; nread = read(fd,buf,MAXSIZE); if (nread == -1) { perror("read error:"); close(fd); delete_event(epollfd,fd,EPOLLIN); } else if (nread == 0) { fprintf(stderr,"client close,fd=%d\n",fd); close(fd); delete_event(epollfd,fd,EPOLLIN); timer_remove(fd); } else { printf("read message is: %s,fd=%d\n",buf,fd); // Modify_event (epollfd,fd,EPOLLOUT) is changed from read to write; } } static void do_write(int epollfd,int fd,char *buf) { int nwrite; nwrite = write(fd,buf,strlen(buf)); if (nwrite == -1) { perror("write error:"); close(fd); delete_event(epollfd,fd,EPOLLOUT); } else modify_event(epollfd,fd,EPOLLIN); memset(buf,0,MAXSIZE); } 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() {// Set the maximum number of open files per process // this function is equivalent to the Linux terminal command "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); // When CTRL + C is pressed, it sends SIGINT sigAction (SIGTERM, &sa, NULL); //kill pid sigaction(SIGQUIT, &sa, NULL); Sigaction (SIGKILL, &sa, NULL); SIGSTOP (SIGKILL, &sa, NULL); //kill -9 pid sigaction(SIGSTOP, &sa, NULL); //#define SIGKILL 9 //#define SIGKILL 9 // It can cause a puzzling phenomenon. // Run the kill pid command, the system will send a SIGTERM signal to the corresponding program. // Run the kill -9 pid command. The system sends SIGKILL to the corresponding program, that is, exit. The exit signal is not blocked by the system, so kill -9 kills the process smoothly. } static void signal_exit_func(int signo) { printf("exit signo is %d\n", signo); stop_server = 1; } static int timerfun_callback(int arg) { printf("id is %d\n", arg); //return 0; // Kill timer returns 0 to prevent it from joining the heap again. Return 1; }Copy the code
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Reference article:
My personal Linux TCP Server and client test source code, C language (2) (★firecat recommended ★) \
Linux Network programming twenty-three: the time heap of high-performance timer — “Linux high-performance server programming (by You Shuang) 11.4.2” \
High performance timer \ using epoll+ time heap
Epoll timer implementation series article: C language implementation time heap \
IO multiplexing epoll summary – note that there is an error in the source code, which needs to be fixed as: \
static void handle_accpet(int epollfd,int listenfd) { int clifd; struct sockaddr_in cliaddr; socklen_t cliaddrlen = sizeof(cliaddr); \
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