San Mehat | a430b2b | 2014-09-23 08:30:51 -0700 | [diff] [blame] | 1 | #include <sys/types.h> |
| 2 | #include <sys/stat.h> |
| 3 | #include <fcntl.h> |
| 4 | #include <errno.h> |
| 5 | #include <string.h> |
| 6 | #include <unistd.h> |
| 7 | #include <stdio.h> |
| 8 | |
| 9 | typedef struct { |
| 10 | char* filename; /* this file is the pipe (set by user) */ |
| 11 | char is_server; /* this is set by open_control_file */ |
| 12 | int fd; /* this is set by open_control_file */ |
| 13 | } single_instance_struct; |
| 14 | |
| 15 | /* returns fd, is_server is set to -1 if server, 0 if client */ |
| 16 | int open_control_file(single_instance_struct* str) |
| 17 | { |
| 18 | struct stat buf; |
| 19 | |
| 20 | if(stat(str->filename,&buf)) { |
| 21 | mkfifo(str->filename,128|256); |
| 22 | str->is_server=-1; |
| 23 | str->fd=open(str->filename,O_NONBLOCK|O_RDONLY); |
| 24 | } else { |
| 25 | str->fd=open(str->filename,O_NONBLOCK|O_WRONLY); |
| 26 | if(errno==ENXIO) { |
| 27 | str->is_server=-1; |
| 28 | str->fd=open(str->filename,O_NONBLOCK|O_RDONLY); |
| 29 | } else |
| 30 | str->is_server=0; |
| 31 | } |
| 32 | |
| 33 | return(str->fd); |
| 34 | } |
| 35 | |
| 36 | void delete_control_file(single_instance_struct* str) |
| 37 | { |
| 38 | remove(str->filename); |
| 39 | } |
| 40 | |
| 41 | void close_control_file(single_instance_struct* str) |
| 42 | { |
| 43 | close(str->fd); |
| 44 | } |
| 45 | |
| 46 | typedef void (*event_dispatcher)(char* message); |
| 47 | |
| 48 | int get_next_message(char* buffer,int len,single_instance_struct* str,int usecs) |
| 49 | { |
| 50 | struct timeval tv; |
| 51 | fd_set fdset; |
| 52 | int num_fds; |
| 53 | |
| 54 | FD_ZERO(&fdset); |
| 55 | FD_SET(str->fd,&fdset); |
| 56 | tv.tv_sec=0; |
| 57 | tv.tv_usec=usecs; |
| 58 | |
| 59 | num_fds=select(str->fd+1,&fdset,NULL,NULL,&tv); |
| 60 | if(num_fds) { |
| 61 | int reallen; |
| 62 | |
| 63 | reallen=read(str->fd,buffer,len); |
| 64 | if(reallen==0) { |
| 65 | close(str->fd); |
| 66 | str->fd=open(str->filename,O_NONBLOCK|O_RDONLY); |
| 67 | num_fds--; |
| 68 | } |
| 69 | buffer[reallen]=0; |
| 70 | #ifdef DEBUG_1INSTANCE |
| 71 | if(reallen!=0) rfbLog("message received: %s.\n",buffer); |
| 72 | #endif |
| 73 | } |
| 74 | |
| 75 | return(num_fds); |
| 76 | } |
| 77 | |
| 78 | int dispatch_event(single_instance_struct* str,event_dispatcher dispatcher,int usecs) |
| 79 | { |
| 80 | char buffer[1024]; |
| 81 | int num_fds; |
| 82 | |
| 83 | if((num_fds=get_next_message(buffer,1024,str,usecs)) && buffer[0]) |
| 84 | dispatcher(buffer); |
| 85 | |
| 86 | return(num_fds); |
| 87 | } |
| 88 | |
| 89 | int loop_if_server(single_instance_struct* str,event_dispatcher dispatcher) |
| 90 | { |
| 91 | open_control_file(str); |
| 92 | if(str->is_server) { |
| 93 | while(1) |
| 94 | dispatch_event(str,dispatcher,50); |
| 95 | } |
| 96 | |
| 97 | return(str->fd); |
| 98 | } |
| 99 | |
| 100 | void send_message(single_instance_struct* str,char* message) |
| 101 | { |
| 102 | #ifdef DEBUG_1INSTANCE |
| 103 | int i= |
| 104 | #endif |
| 105 | write(str->fd,message,strlen(message)); |
| 106 | #ifdef DEBUG_1INSTANCE |
| 107 | rfbLog("send: %s => %d(%d)\n",message,i,strlen(message)); |
| 108 | #endif |
| 109 | } |
| 110 | |
| 111 | #ifdef DEBUG_MAIN |
| 112 | |
| 113 | #include <stdio.h> |
| 114 | #include <stdlib.h> |
| 115 | |
| 116 | single_instance_struct str1 = { "/tmp/1instance" }; |
| 117 | |
| 118 | void my_dispatcher(char* message) |
| 119 | { |
| 120 | #ifdef DEBUG_1INSTANCE |
| 121 | rfbLog("Message arrived: %s.\n",message); |
| 122 | #endif |
| 123 | if(!strcmp(message,"quit")) { |
| 124 | delete_control_file(str1); |
| 125 | exit(0); |
| 126 | } |
| 127 | } |
| 128 | |
| 129 | int main(int argc,char** argv) |
| 130 | { |
| 131 | int i; |
| 132 | |
| 133 | loop_if_server(str1,my_dispatcher); |
| 134 | |
| 135 | for(i=1;i<argc;i++) |
| 136 | send_event(str1,argv[i]); |
| 137 | |
| 138 | return(0); |
| 139 | } |
| 140 | |
| 141 | #endif |