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Completed Task 8

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This commit is contained in:
Sergiusz Warga 2021-05-03 20:23:01 +02:00
parent 8744096312
commit fdc21217ee
5 changed files with 197 additions and 59 deletions
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2
Task-8/CircBuffer.h
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@ -6,5 +6,5 @@ struct CircBuffer {
} info; } info;
char padding[1024]; char padding[1024];
}; };
double data[200]; double data[8192];
}; };

28
Task-8/funs.h Normal file
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@ -0,0 +1,28 @@
// From https://github.com/veltzer/demos-linux
const long long NSEC_PER_SEC=1000000000;
static inline unsigned long long timespec_diff_nano(struct timespec* x, struct timespec* y) {
return (x->tv_sec-y->tv_sec)*NSEC_PER_SEC+(x->tv_nsec-y->tv_nsec);
}
static inline void timespec_sub(struct timespec* result, struct timespec* x, struct timespec* y) {
/* Perform the carry for the later subtraction by updating Y. */
if (x->tv_nsec < y->tv_nsec) {
int nsec = (y->tv_nsec - x->tv_nsec) / NSEC_PER_SEC + 1;
y->tv_nsec -= NSEC_PER_SEC * nsec;
y->tv_sec += nsec;
}
if (x->tv_nsec - y->tv_nsec > NSEC_PER_SEC) {
int nsec = (x->tv_nsec - y->tv_nsec) / NSEC_PER_SEC;
y->tv_nsec += NSEC_PER_SEC * nsec;
y->tv_sec -= nsec;
}
/* Compute the time remaining to wait. `tv_nsec' is certainly positive. */
result->tv_sec = x->tv_sec - y->tv_sec;
result->tv_nsec = x->tv_nsec - y->tv_nsec;
/* Check that result is not negative */
// CHECK_ASSERT(x->tv_sec >= y->tv_sec);
}
// END From https://github.com/veltzer/demos-linux

72
Task-8/k_avg.c
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@ -12,59 +12,65 @@
#include <time.h> #include <time.h>
#include "CircBuffer.h" #include "CircBuffer.h"
#include "funs.h"
#define PI 3.14 void handle_arguments(int argc, char *argv[]) {
#define SIG_FREQ 100 if (argc != 3) {
#define SAM_FREQ 2000 fprintf(stderr, "Usage: %s REFRESHING_FREQUENCY ALPHA\n", argv[0]);
exit(EXIT_FAILURE);
}
_Noreturn void k_avg(int fd) { if (strtol(argv[1], NULL, 10) < 2) {
// Exponential Moving Average should be updated with f = 10Hz (i.e. every 200 samples). fprintf(stderr, "Refreshing frequency should be at least 2Hz!\n");
int samples = 200; exit(EXIT_FAILURE);
}
if (strtod(argv[2], NULL) > 1 || strtod(argv[2], NULL) < 0) {
fprintf(stderr, "Alpha coefficient should be in range [0, 1]!\n");
exit(EXIT_FAILURE);
}
}
_Noreturn void k_avg(int fd, int refreshing_frequency, double alpha) {
// Exponential Moving Average
printf("A k_avg has been called\n"); printf("A k_avg has been called\n");
//----- Initialize the buffer -----
struct CircBuffer *buffer; struct CircBuffer *buffer;
buffer = mmap(NULL, sizeof(struct CircBuffer*), PROT_READ, MAP_SHARED, fd, 0); buffer = mmap(NULL, sizeof(struct CircBuffer), PROT_READ, MAP_SHARED, fd, 0);
if (buffer == MAP_FAILED) { if (buffer == MAP_FAILED) {
fprintf(stderr, "mmap: "); fprintf(stderr, "mmap: ");
exit(EXIT_FAILURE); exit(EXIT_FAILURE);
} }
struct timespec delay; struct timespec delay, tic, toc;
delay.tv_sec = 0; delay.tv_sec = 0;
delay.tv_nsec = 100000000ULL*1; // 100ms == 100 000 000ns -> 10Hz delay.tv_nsec = (1./refreshing_frequency * NSEC_PER_SEC); // 1/f in nanoseconds
clock_gettime(CLOCK_REALTIME, &tic);
double alpha = 0.1;
double ema; double ema;
int start_idx = 0; int read_idx;
read_idx = buffer->info.free_idx - 1;
ema = buffer->data[read_idx];
printf("Refreshing period = %ldms\n", delay.tv_nsec/1000000);
while (1) { while (1) {
start_idx = buffer->info.free_idx; clock_gettime(CLOCK_REALTIME, &toc);
ema = buffer->data[start_idx]; if (timespec_diff_nano(&toc, &tic) > delay.tv_nsec) {
printf("start_idx = %d\n", start_idx); printf("EMA = %f\n", ema);
printf("EMA = %lf\n", ema); clock_gettime(CLOCK_REALTIME, &tic);
nanosleep(&delay, NULL); }
while (read_idx == ((buffer->info.free_idx - 1) % buffer->info.size)) {};
read_idx = ++read_idx % buffer->info.size;
ema = alpha * buffer->data[read_idx] + (1 - alpha) * ema;
} }
// while (1) {
// start_idx = (buffer->info.free_idx - samples) % buffer->info.size;
// printf("start_idx = %d\n", start_idx);
// ema = buffer->data[start_idx];
// for (int read_idx = start_idx + 1; read_idx < samples; read_idx = ++read_idx % buffer->info.size) {
// ema = alpha*buffer->data[read_idx] + (1 - alpha) * ema;
// printf("EMA[%d] = %lf\n", read_idx, ema);
// }
// printf("EMA = %lf\n", ema);
// nanosleep(&delay, NULL);
// }
} }
int main(int argc, char *argv[]) { int main(int argc, char *argv[]) {
handle_arguments(argc, argv);
//----- Open a shared memory ----- //----- Open a shared memory -----
const char *memory_name = "/dsp"; const char *memory_name = "/dsp";
int fd = shm_open(memory_name, O_RDONLY, 0777); int fd = shm_open(memory_name, O_RDONLY, 0777);
@ -74,7 +80,7 @@ int main(int argc, char *argv[]) {
} }
printf("Shared memory file descriptor: %d\n", fd); printf("Shared memory file descriptor: %d\n", fd);
k_avg(fd); k_avg(fd, strtol(argv[1], NULL, 10), strtod(argv[2], NULL));
return 0; return 0;
} }

83
Task-8/k_f0.c Normal file
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@ -0,0 +1,83 @@
//
// Written for Computer Networks and Systems lab classes
// AUTHOR : Sergiusz Warga
#include <fcntl.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <unistd.h>
#include <time.h>
#include "CircBuffer.h"
#include "funs.h"
int crosses_zero(double prev, double curr) {
// let's just ignore 0 for now
return (prev > 0 && curr < 0) || (prev < 0 && curr > 0);
}
_Noreturn void k_f0(int fd, int sampling_frequency, int refreshing_frequency) {
printf("A k_f0 has been called\n");
//----- Initialize the buffer -----
struct CircBuffer *buffer;
buffer = mmap(NULL, sizeof(struct CircBuffer), PROT_READ, MAP_SHARED, fd, 0);
if (buffer == MAP_FAILED) {
fprintf(stderr, "mmap: ");
exit(EXIT_FAILURE);
}
struct timespec tic, toc;
// delay.tv_sec = 0;
// delay.tv_nsec = (1./refreshing_frequency * 1000000000L); // 1/f in nanoseconds
unsigned long long delay = NSEC_PER_SEC*1./refreshing_frequency;
clock_gettime(CLOCK_REALTIME, &tic);
int transitions = 0;
int samples = 0;
int read_idx;
read_idx = buffer->info.free_idx - 1;
while (1) {
clock_gettime(CLOCK_REALTIME, &toc);
if (timespec_diff_nano(&toc, &tic) > delay) {
double t_samp = 1./sampling_frequency;
// printf("t_samp = %fs\n", t_samp);
// printf("n_samp = %d\n", samples);
double t_anal = t_samp*samples;
// printf("t_anal = %fs\n", t_anal);
// printf("n_tran = %d\n", transitions);
printf("f = %fHz\n", transitions/(2*t_anal));
transitions = 0;
samples = 0;
clock_gettime(CLOCK_REALTIME, &tic);
}
if (crosses_zero(buffer->data[read_idx-1], buffer->data[read_idx])) {
++transitions;
}
while (read_idx == ((buffer->info.free_idx - 1) % buffer->info.size)) {};
read_idx = ++read_idx % buffer->info.size;
++samples;
}
}
int main(int argc, char *argv[]) {
//----- Open a shared memory -----
const char *memory_name = "/dsp";
int fd = shm_open(memory_name, O_RDONLY, 0777);
if (fd < 0) {
fprintf(stderr, "shm_open: ");
exit(EXIT_FAILURE);
}
printf("Shared memory file descriptor: %d\n", fd);
k_f0(fd, 2000, 1);
return 0;
}

67
Task-8/producer.c
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@ -7,53 +7,74 @@
#include <stdio.h> #include <stdio.h>
#include <stdlib.h> #include <stdlib.h>
#include <sys/mman.h> #include <sys/mman.h>
#include <sys/types.h> // #include <sys/types.h>
#include <unistd.h> #include <unistd.h>
#include <time.h> #include <time.h>
#include "CircBuffer.h" #include "CircBuffer.h"
#include "funs.h"
#define PI 3.14 #define PI 3.14
#define SIG_FREQ 100 #define SIG_FREQ 100
#define SAM_FREQ 2000
double get_sample(int signal_frequeuncy, int sampling_frequency, int sample_no) { void handle_arguments(int argc, char *argv[]) {
if (argc != 2) {
fprintf(stderr, "Usage: %s SAMPLING_FREQUENCY\n", argv[0]);
exit(EXIT_FAILURE);
}
if (strtol(argv[1], NULL, 10) < 400) {
fprintf(stderr, "Sampling frequency should be at least 400Hz!\n");
exit(EXIT_FAILURE);
}
}
double get_sample(int signal_frequeuncy, int sampling_frequency, unsigned int sample_no) {
// TODO: Just a sketch, gotta rewrite // TODO: Just a sketch, gotta rewrite
double step = 2.*PI/200; double step = 2.*PI/((double)sampling_frequency/signal_frequeuncy); // Step in radians
return sin(sample_no*step); return sin(sample_no*step);
} }
_Noreturn void producer(int fd) { // That's something new I've learned and I think that _Noreturn void producer(int fd, int sampling_frequency) { // That's something new I've learned and I think that
// function specifiers are cute. // function specifiers are cute.
printf("The producer has been called\n"); printf("The producer has been called\n");
//----- Initialize the buffer -----
struct CircBuffer *buffer; struct CircBuffer *buffer;
buffer = mmap(NULL, sizeof(struct CircBuffer), PROT_WRITE, MAP_SHARED, fd, 0); buffer = mmap(NULL, sizeof(struct CircBuffer), PROT_WRITE, MAP_SHARED, fd, 0);
if (buffer == MAP_FAILED) { if (buffer == MAP_FAILED) {
fprintf(stderr, "mmap: "); fprintf(stderr, "mmap: ");
exit(EXIT_FAILURE); exit(EXIT_FAILURE);
} }
unsigned int i = 0;
int i = 0; int free_idx;
int free_idx = 0; struct timespec delay, tic, toc;
struct timespec delay;
delay.tv_sec = 0; delay.tv_sec = 0;
delay.tv_nsec = 500000ULL*1; // 0.5ms == 500 000ns -> 2kHz delay.tv_nsec = (int) (1./sampling_frequency * NSEC_PER_SEC); // 1/f in nanoseconds
clock_gettime(CLOCK_REALTIME, &tic);
clock_gettime(CLOCK_REALTIME, &toc);
printf("Starting to sampling the signal at %dHz with t_s = %ldns\n", sampling_frequency, delay.tv_nsec);
//----- Fill the buffer -----
while (1) { while (1) {
free_idx = buffer->info.free_idx; // For more readable code clock_gettime(CLOCK_REALTIME, &toc);
buffer->data[free_idx] = get_sample(SIG_FREQ, SAM_FREQ, i+1); // Put a sample into the buffer free_idx = buffer->info.free_idx;
buffer->info.free_idx = (free_idx + 1 ) % buffer->info.size; // Increase the free-cell index buffer->data[free_idx] = get_sample(SIG_FREQ, sampling_frequency, i);
printf("CircBuffer[%d] = \t %lf\n", free_idx, buffer->data[free_idx]); // printf("CircBuffer[%d] = \t %lf\n", free_idx, buffer->data[free_idx]);
i = ++i % 200; buffer->info.free_idx = (free_idx + 1 ) % buffer->info.size;
nanosleep(&delay, NULL); ++i;
while (timespec_diff_nano(&toc, &tic) < delay.tv_nsec) {
// printf("%lld\n", timespec_diff_nano(&toc, &tic));
clock_gettime(CLOCK_REALTIME, &toc);
}
clock_gettime(CLOCK_REALTIME, &tic);
} }
} }
int main(int argc, char *argv[]) { int main(int argc, char *argv[]) {
//----- Arguments handling -----
handle_arguments(argc, argv);
int sampling_frequency = strtol(argv[1], NULL, 10) ;
//----- Create a shared memory ----- //----- Create a shared memory -----
const char *memory_name = "/dsp"; const char *memory_name = "/dsp";
@ -62,10 +83,9 @@ int main(int argc, char *argv[]) {
fprintf(stderr, "shm_open: "); fprintf(stderr, "shm_open: ");
exit(EXIT_FAILURE); exit(EXIT_FAILURE);
} }
printf("Shared memory file descriptor: %d\n", fd); // printf("Shared memory file descriptor: %d\n", fd);
//----- Truncate memory to the buffer's size //----- Truncate memory to the buffer's size
if (ftruncate(fd, sizeof(struct CircBuffer)) < 0) { if (ftruncate(fd, sizeof(struct CircBuffer)) < 0) {
fprintf(stderr, "ftruncate: \n"); fprintf(stderr, "ftruncate: \n");
exit(EXIT_FAILURE); exit(EXIT_FAILURE);
@ -81,7 +101,8 @@ int main(int argc, char *argv[]) {
buffer->info.size = sizeof(buffer->data)/sizeof(double); buffer->info.size = sizeof(buffer->data)/sizeof(double);
buffer->info.free_idx = 0; buffer->info.free_idx = 0;
producer(fd); //----- Sample the producer -----
producer(fd, sampling_frequency);
return 0; return 0;
} }