100 lines
2.1 KiB
C
100 lines
2.1 KiB
C
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// Producer:
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// Retransfers sinusoidal signal sampled at a frequency of 2kHz
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// Writes to the circular buffer:
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// Write sample into the free buffer position
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// Incremets the free position by one
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// After idx = size go to the beginning
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// Consumers:
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//
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#include <fcntl.h>
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#include <math.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/mman.h>
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#include <sys/types.h>
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#include <unistd.h>
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#include <time.h>
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#define PI 3.14
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// void generate_signal(double *signal, int n_samples) {
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// static double signal[n_samples];
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// double step = 2.*PI/(double)n_samples;
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// for (int i = 0; i < n_samples; ++i) {
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// signal[i] = sin(i*step);
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// }
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// }
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struct CircBuffer {
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union {
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struct {
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int size;
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int rd_idx;
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int wr_idx;
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} info;
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char padding[1024];
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};
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int data[1024];
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};
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void producer(const char * memory_name, int fd) {
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printf("The producer has been called\n");
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double signal[] = {0, 0.7, 1, 0.7, 0};
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struct CircBuffer *buffer;
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buffer = mmap(NULL, 64, PROT_WRITE, MAP_SHARED, fd, 0);
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if (buffer == MAP_FAILED) {
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fprintf(stderr, "mmap: ");
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exit(EXIT_FAILURE);
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}
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}
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int main(int argc, char *argv[]) {
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int buffer_size = 64;
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const char *memory_name = "/dsp";
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int fd = shm_open(memory_name, O_CREAT | O_RDWR, 0777);
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if (fd < 0) {
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fprintf(stderr, "shm_open: ");
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exit(EXIT_FAILURE);
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}
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printf("Shred memory file descriptor: %d\n", fd);
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// double *signal;
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// generate_signal(signal, 100);
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struct CircBuffer *buffer;
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if (ftruncate(fd, sizeof(struct CircBuffer)) < 0) {
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fprintf(stderr, "ftruncate: \n");
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exit(EXIT_FAILURE);
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}
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pid_t pid;
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pid = fork();
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if (pid == -1) {
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perror("fork: ");
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exit(EXIT_FAILURE);
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}
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if (pid == 0) {
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buffer = (struct CircBuffer *)mmap(NULL, sizeof(buffer), PROT_READ, MAP_SHARED, fd, 0);
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if (buffer == MAP_FAILED) {
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fprintf(stderr, "mmap: ");
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exit(EXIT_FAILURE);
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}
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exit(EXIT_SUCCESS);
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} else {
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producer(memory_name, fd);
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}
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return 0;
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}
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