信号驱动的IO，信号驱动IO

信号驱动的IO，信号驱动IO

（1）client1，基于SIGIO的写法：

1 #include <sys/types.h> 2 #include <sys/stat.h> 3 #include <fcntl.h> 4 #include <unistd.h> 5 #include <signal.h> 6 7 #include <stdio.h> 8 #include <stdlib.h> 9 #include <errno.h> 10 11 #define BUFSIZE 128 12 13 static int fdr; 14 static int fdw; 15 16 static void handler(int unuse) 17 { 18 int ret; 19 char buf[BUFSIZE]; 20 21 ret = read(fdr, buf, BUFSIZE); 22 if (ret == -1) { 23 return; 24 } 25 if (ret == 0) { 26 exit(0); 27 } 28 write(1, "\033[31m", 5); 29 write(1, buf, ret); 30 write(1, "\033[0m", 4); 31 } 32 33 int main(void) 34 { 35 int ret; 36 char buf[BUFSIZE]; 37 long flags; 38 39 signal(SIGIO, handler); 40 41 fdr = open("f1", O_RDONLY); 42 if (fdr == -1) { 43 perror("f1"); 44 goto open_fdr_err; 45 } 46 47 fdw = open("f2", O_WRONLY); 48 if (fdw == -1) { 49 perror("f2"); 50 goto open_fdw_err; 51 } 52 53 flags = fcntl(fdr, F_GETFL); 54 flags |= O_ASYNC; 55 fcntl(fdr, F_SETFL, flags); 56 57 fcntl(fdr, F_SETOWN, getpid()); 58 59 while (1) { 60 ret = read(0, buf, BUFSIZE); 61 if (ret == -1) { 62 if (errno == EINTR) { 63 continue; 64 } 65 perror("read()"); 66 break; 67 } 68 if (ret == 0) { 69 break; 70 } 71 write(fdw, buf, ret); 72 } 73 74 close(fdw); 75 close(fdr); 76 77 return 0; 78 79 80 close(fdw); 81 open_fdw_err: 82 close(fdr); 83 open_fdr_err: 84 return 1; 85 } View Code

client1，基于自定义信号的写法：

1 #define _GNU_SOURCE 2 3 #include <sys/types.h> 4 #include <sys/stat.h> 5 #include <fcntl.h> 6 #include <unistd.h> 7 #include <signal.h> 8 9 #include <stdio.h> 10 #include <stdlib.h> 11 #include <errno.h> 12 13 #define BUFSIZE 128 14 15 static int fdr; 16 static int fdw; 17 18 static void handler(int unuse) 19 { 20 int ret; 21 char buf[BUFSIZE]; 22 23 ret = read(fdr, buf, BUFSIZE); 24 if (ret == -1) { 25 return; 26 } 27 if (ret == 0) { 28 exit(0); 29 } 30 write(1, "\033[31m", 5); 31 write(1, buf, ret); 32 write(1, "\033[0m", 4); 33 } 34 35 int main(void) 36 { 37 int ret; 38 char buf[BUFSIZE]; 39 long flags; 40 41 signal(SIGUSR1, handler); 42 43 fdr = open("f1", O_RDONLY); 44 if (fdr == -1) { 45 perror("f1"); 46 goto open_fdr_err; 47 } 48 49 fdw = open("f2", O_WRONLY); 50 if (fdw == -1) { 51 perror("f2"); 52 goto open_fdw_err; 53 } 54 55 flags = fcntl(fdr, F_GETFL); 56 flags |= O_ASYNC; 57 fcntl(fdr, F_SETFL, flags); 58 59 fcntl(fdr, F_SETOWN, getpid()); 60 fcntl(fdr, F_SETSIG, SIGUSR1); 61 62 while (1) { 63 ret = read(0, buf, BUFSIZE); 64 if (ret == -1) { 65 if (errno == EINTR) { 66 continue; 67 } 68 perror("read()"); 69 break; 70 } 71 if (ret == 0) { 72 break; 73 } 74 write(fdw, buf, ret); 75 } 76 77 close(fdw); 78 close(fdr); 79 80 return 0; 81 82 83 close(fdw); 84 open_fdw_err: 85 close(fdr); 86 open_fdr_err: 87 return 1; 88 } View Code

（2）client2：

1 #include <sys/types.h> 2 #include <sys/stat.h> 3 #include <fcntl.h> 4 #include <signal.h> 5 #include <unistd.h> 6 7 #include <stdio.h> 8 #include <stdlib.h> 9 #include <errno.h> 10 11 #define BUFSIZE 128 12 13 static int fdr; 14 static int fdw; 15 16 static void handler(int unuse) 17 { 18 int ret; 19 char buf[BUFSIZE]; 20 21 ret = read(fdr, buf, BUFSIZE); 22 if (ret == -1) { 23 return; 24 } 25 if (ret == 0) { 26 exit(0); 27 } 28 write(1, "\033[31m", 5); 29 write(1, buf, ret); 30 write(1, "\033[0m", 4); 31 } 32 33 int main(void) 34 { 35 int ret; 36 char buf[BUFSIZE]; 37 long flags; 38 39 signal(SIGIO, handler); 40 41 fdw = open("f1", O_WRONLY); 42 if (fdw == -1) { 43 perror("f1"); 44 goto open_fdw_err; 45 } 46 47 fdr = open("f2", O_RDONLY); 48 if (fdr == -1) { 49 perror("f2"); 50 goto open_fdr_err; 51 } 52 53 flags = fcntl(fdr, F_GETFL); 54 flags |= O_ASYNC; 55 fcntl(fdr, F_SETFL, flags); 56 57 fcntl(fdr, F_SETOWN, getpid()); 58 59 while (1) { 60 ret = read(0, buf, BUFSIZE); 61 if (ret == -1) { 62 if (errno == EINTR) { 63 continue; 64 } 65 perror("read()"); 66 break; 67 } 68 if (ret == 0) { 69 break; 70 } 71 write(fdw, buf, ret); 72 } 73 74 close(fdr); 75 close(fdw); 76 77 return 0; 78 79 80 close(fdr); 81 open_fdr_err: 82 close(fdw); 83 open_fdw_err: 84 return 1; 85 } View Code