1. socket的TIMEOUT
#include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <stdlib.h> #include <assert.h> #include <stdio.h> #include <errno.h> #include <fcntl.h> #include <unistd.h> #include <string.h> int timeout_connect( const char* ip, int port, int time ) { int ret = 0; struct sockaddr_in address; bzero( &address, sizeof( address ) ); address.sin_family = AF_INET; inet_pton( AF_INET, ip, &address.sin_addr ); address.sin_port = htons( port ); int sockfd = socket( PF_INET, SOCK_STREAM, 0 ); assert( sockfd >= 0 ); int flags = fcntl(sockfd, F_GETFL, 0); if (flags < 0) { fprintf(stderr, "Get flags error:%s ", strerror(errno)); close(sockfd); return -1; } flags |= O_NONBLOCK; // if (fcntl(sockfd, F_SETFL, flags) < 0) { // fprintf(stderr, "Set flags error:%s ", strerror(errno)); // close(sockfd); // return -1; // } struct timeval timeout; timeout.tv_sec = time; timeout.tv_usec = 0; socklen_t len = sizeof( timeout ); ret = setsockopt( sockfd, SOL_SOCKET, SO_SNDTIMEO, &timeout, len ); assert( ret != -1 ); ret = connect( sockfd, ( struct sockaddr* )&address, sizeof( address ) ); if ( ret == -1 ) { if( errno == EINPROGRESS ) { printf( "connecting timeout " ); return -1; } printf( "error occur when connecting to server:%d. ", errno); return -1; } return sockfd; } int main( int argc, char* argv[] ) { if( argc <= 2 ) { printf( "usage: %s ip_address port_number ", basename( argv[0] ) ); return 1; } const char* ip = argv[1]; int port = atoi( argv[2] ); int sockfd = timeout_connect( ip, port, 5 ); if ( sockfd < 0 ) { return 1; } return 0; }
2. SIGALRM信号
lst_timer.h
#ifndef LST_TIMER #define LST_TIMER #include <time.h> #define BUFFER_SIZE 64 class util_timer; struct client_data { sockaddr_in address; int sockfd; char buf[ BUFFER_SIZE ]; util_timer* timer; }; class util_timer { public: util_timer() : prev( NULL ), next( NULL ){} public: time_t expire; void (*cb_func)( client_data* ); client_data* user_data; util_timer* prev; util_timer* next; }; class sort_timer_lst { public: sort_timer_lst() : head( NULL ), tail( NULL ) {} ~sort_timer_lst() { util_timer* tmp = head; while( tmp ) { head = tmp->next; delete tmp; tmp = head; } } void add_timer( util_timer* timer ) { if( !timer ) { return; } if( !head ) { head = tail = timer; return; } if( timer->expire < head->expire ) { timer->next = head; head->prev = timer; head = timer; return; } add_timer( timer, head ); } void adjust_timer( util_timer* timer ) { if( !timer ) { return; } util_timer* tmp = timer->next; if( !tmp || ( timer->expire < tmp->expire ) ) { return; } if( timer == head ) { head = head->next; head->prev = NULL; timer->next = NULL; add_timer( timer, head ); } else { timer->prev->next = timer->next; timer->next->prev = timer->prev; add_timer( timer, timer->next ); } } void del_timer( util_timer* timer ) { if( !timer ) { return; } if( ( timer == head ) && ( timer == tail ) ) { delete timer; head = NULL; tail = NULL; return; } if( timer == head ) { head = head->next; head->prev = NULL; delete timer; return; } if( timer == tail ) { tail = tail->prev; tail->next = NULL; delete timer; return; } timer->prev->next = timer->next; timer->next->prev = timer->prev; delete timer; } void tick() { if( !head ) { return; } printf( "timer tick " ); time_t cur = time( NULL ); util_timer* tmp = head; while( tmp ) { if( cur < tmp->expire ) { break; } tmp->cb_func( tmp->user_data ); head = tmp->next; if( head ) { head->prev = NULL; } delete tmp; tmp = head; } } private: void add_timer( util_timer* timer, util_timer* lst_head ) { util_timer* prev = lst_head; util_timer* tmp = prev->next; while( tmp ) { if( timer->expire < tmp->expire ) { prev->next = timer; timer->next = tmp; tmp->prev = timer; timer->prev = prev; break; } prev = tmp; tmp = tmp->next; } if( !tmp ) { prev->next = timer; timer->prev = prev; timer->next = NULL; tail = timer; } } private: util_timer* head; util_timer* tail; }; #endif
11-1connect_timeout.cpp
#include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <assert.h> #include <stdio.h> #include <signal.h> #include <unistd.h> #include <errno.h> #include <string.h> #include <fcntl.h> #include <stdlib.h> #include <sys/epoll.h> #include <pthread.h> #include "lst_timer.h" #define FD_LIMIT 65535 #define MAX_EVENT_NUMBER 1024 #define TIMESLOT 5 static int pipefd[2]; static sort_timer_lst timer_lst; static int epollfd = 0; 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; } void addfd( int epollfd, int fd ) { epoll_event event; event.data.fd = fd; event.events = EPOLLIN | EPOLLET; epoll_ctl( epollfd, EPOLL_CTL_ADD, fd, &event ); setnonblocking( fd ); } void sig_handler( int sig ) { int save_errno = errno; int msg = sig; send( pipefd[1], ( char* )&msg, 1, 0 ); errno = save_errno; } void addsig( int sig ) { struct sigaction sa; memset( &sa, '