110 lines
3.6 KiB
C
110 lines
3.6 KiB
C
#ifndef LIBRARIES
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#define LIBRARIES
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#define _GNU_SOURCE
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#include <fcntl.h> ///< For O_* constants *
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#include <stdlib.h>
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#include <stdio.h>
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#include <unistd.h>
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#endif
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#include <string.h>
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#include <sys/mman.h>
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#include <sys/types.h>
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#define BUFF_SHM_NAME "/11777707_buff"
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/**
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* @brief Function that executes shm_open(3) and does error handling.
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* @details The function executes shm_open(3), giving it a name as a param,
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* and handles the errors if any. The same behaviour as shm_open(3) should be expected.
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* Returns a shared memory object file descriptor
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* @param shm_name
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* @return shmfd
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**/
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int create_shmfd(char *shm_name) {
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int shmfd = shm_open(shm_name, O_RDWR | O_CREAT, 0600);
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if(shmfd == -1) {
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fprintf(stderr, "ERROR: Failed creating shared memory object\n");
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exit(EXIT_FAILURE);
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}
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return shmfd;
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}
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/**
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* @brief Function that executes ftruncate(2) and does error handling.
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* @details The function executes ftruncate(2), giving it a file descriptor and size as parameters,
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* and handles the errors if any. The same behaviour as ftruncate(2) should be expected.
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* @param shmfd, shm_size
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* @return none
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**/
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void truncate_shm(int shmfd, size_t shm_size) {
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if(ftruncate(shmfd, shm_size) < 0) {
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fprintf(stderr, "ERROR: Failed truncating shared memory object\n");
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exit(EXIT_FAILURE);
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}
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}
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/**
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* @brief Function that executes mmap(2) and does error handling.
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* @details The function executes mmap(2), giving it a file descriptor and size as parameters,
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* and handles the errors if any. The same behaviour as mmap(2) should be expected.
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* Returns a mapped shared memory object
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* @param shmfd, shm_size
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* @return shm
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**/
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void* open_shm(int shmfd, size_t shm_size) {
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void* shm;
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shm = mmap(NULL, shm_size, PROT_READ | PROT_WRITE, MAP_SHARED, shmfd, 0);
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if(shm == MAP_FAILED) {
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fprintf(stderr, "ERROR: Failed mapping shared memory object\n");
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exit(EXIT_FAILURE);
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}
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return shm;
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}
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/**
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* @brief Function to write a value to shared memory object
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* @details The functions copies the value of a string with a specified size to a shared memory object
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* @param shm, message, message_size
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* @return none
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**/
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void write_to_shm(void* shm, char *message, size_t message_size) {
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memcpy(shm, message, message_size);
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}
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/**
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* @brief Function that executes munmap(2) and does error handling.
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* @details The function executes munmap(2), giving it a shared memory object and size as parameters,
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* and handles the errors if any. The same behaviour as munmap(2) should be expected.
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* Returns a mapped shared memory object
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* @param shmfd, shm_size
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* @return none
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**/
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void close_shm(void* shm, size_t shm_size) {
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if (munmap(shm, shm_size) == -1) {
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fprintf(stderr, "ERROR: Failed unmapping shared memory object\n");
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exit(EXIT_FAILURE);
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}
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}
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/**
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* @brief Function that executes shm_unlink(3) and close(2) and does error handling.
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* @details The function executes shm_unlink(3) and close(2), giving them a shared memory object name
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* and a file descriptor respectively, and handles the errors if any.
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* The same behaviour as shm_unlink(3) and close(2) should be expected.
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* @param shm_name, shmfd
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* @return none
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**/
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void destroy_shm(char *shm_name, int shmfd) {
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if (shm_unlink(shm_name) == -1) {
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fprintf(stderr, "ERROR: Failed unlinking shared memory object\n");
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exit(EXIT_FAILURE);
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}
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if(close(shmfd) < 0) {
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fprintf(stderr, "ERROR: Failed closing file descriptor\n");
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exit(EXIT_FAILURE);
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}
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}
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