138 lines
3.4 KiB
C
138 lines
3.4 KiB
C
/*
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* Test name: test03.c
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*
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* Objetive: The purpose of this test is to make sure that select works
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* when working with files.
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*
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* Description: This test shows more cases than in test02.c, where every
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* descriptor is ready. Here in one select call only half of the fd's will
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* be ready and in the next one none of them will be ready.
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*
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* Jose M. Gomez
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*/
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#include <sys/types.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <sys/select.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <limits.h>
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#include <sys/time.h>
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void dump_fdset(fd_set *set) {
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int i;
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for (i = 0; i < OPEN_MAX; i++)
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if (FD_ISSET(i, set))
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printf(" %d ", i);
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printf("\n");
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}
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int main(int argc, char *argv[])
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{
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int fd1, fd2, fd3, fd4, fd5, fd6; /* file descriptors of files */
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fd_set fds_read, fds_write; /* bit maps */
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struct timeval timeout; /* timeout */
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int retval; /* ret value */
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/* Creates the dummy files with different modes */
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fd1 = open("dummy1.txt", O_CREAT | O_RDONLY);
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if (fd1 < 0) {
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perror("Error opening file");
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exit(-1);
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}
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fd2 = open("dummy2.txt", O_CREAT | O_RDONLY);
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if (fd2 < 0) {
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perror("Error opening file");
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exit(-1);
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}
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fd3 = open("dummy3.txt", O_CREAT | O_WRONLY);
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if (fd3 < 0) {
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perror("Error opening file");
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exit(-1);
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}
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fd4 = open("dummy4.txt", O_CREAT | O_WRONLY);
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if (fd4 < 0) {
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perror("Error opening file");
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exit(-1);
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}
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fd5 = open("dummy5.txt", O_CREAT | O_RDWR);
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if (fd5 < 0) {
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perror("Error opening file");
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exit(-1);
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}
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fd6 = open("dummy6.txt", O_CREAT | O_RDWR);
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if (fd6 < 0) {
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perror("Error opening file");
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exit(-1);
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}
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/* Create the fd_set structures */
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FD_ZERO(&fds_read);
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FD_ZERO(&fds_write);
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FD_SET(fd1, &fds_write); /* fd1 => O_RDONLY */
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FD_SET(fd2, &fds_write); /* fd2 => O_RDONLY */
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FD_SET(fd3, &fds_read); /* fd3 => O_WRONLY */
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FD_SET(fd4, &fds_read); /* fd4 => O_WRONLY */
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FD_SET(fd5, &fds_read); /* fd5 => O_RDWR */
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FD_SET(fd5, &fds_write); /* fd5 => O_RDWR */
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FD_SET(fd6, &fds_read); /* fd6 => O_RDWR */
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FD_SET(fd6, &fds_write); /* fd6 => O_RDWR */
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printf("* Dump INPUT fds_read:\n");
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dump_fdset(&fds_read);
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printf("* Dump INPUT fds_write:\n");
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dump_fdset(&fds_write);
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retval=select(9, &fds_read, &fds_write, NULL, NULL);
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printf("\n***********************\n");
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printf("After select: \n");
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printf("Return value: %d\n", retval);
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printf("* Dump RESULTING fds_read:\n");
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dump_fdset(&fds_read);
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printf("* Dump RESULTING fds_write:\n");
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dump_fdset(&fds_write);
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/* make a select call where none of them are ready (don't use fd5 and fd6) */
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FD_ZERO(&fds_read);
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FD_ZERO(&fds_write);
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FD_SET(fd1, &fds_write); /* fd1 => O_RDONLY */
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FD_SET(fd2, &fds_write); /* fd2 => O_RDONLY */
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FD_SET(fd3, &fds_read); /* fd3 => O_WRONLY */
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FD_SET(fd4, &fds_read); /* fd4 => O_WRONLY */
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/* make a select call where none of them are ready (don't use fd5 and fd6) */
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/* create a timeout as well */
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timeout.tv_sec = 5;
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timeout.tv_usec = 0;
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retval=select(7, &fds_read, &fds_write, NULL, NULL);
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printf("\n***********************\n");
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printf("After select: \n");
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printf("Return value: %d\n", retval);
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printf("* Dump RESULTING fds_read:\n");
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dump_fdset(&fds_read);
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printf("* Dump RESULTING fds_write:\n");
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dump_fdset(&fds_write);
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/* close and delete dummy files */
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close(fd1);
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close(fd2);
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close(fd3);
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close(fd4);
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close(fd5);
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close(fd6);
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unlink("dummy1.txt");
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unlink("dummy2.txt");
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unlink("dummy3.txt");
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unlink("dummy4.txt");
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unlink("dummy5.txt");
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unlink("dummy6.txt");
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return 0;
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}
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