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iio: iio_generic_buffer: Cleanup when receiving signals
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This will clean (disable buffer/trigger/channels) when doing
something like a CTRL-C. Otherwise restarting generic_buffer requires a
manual echo 0 > buffer/enable

This also cleanup up all the code freeing string buffers at
the end of main. We initialize all pointers to NULL so that cleanup can
all be done under a single error label.

Signed-off-by: Crestez Dan Leonard <[email protected]>
Signed-off-by: Jonathan Cameron <[email protected]>
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@jic23
Crestez Dan Leonard authored and jic23 committed May 29, 2016
1 parent 90e9a95 commit 4f20d59
Showing 1 changed file with 108 additions and 64 deletions.
172 changes: 108 additions & 64 deletions tools/iio/iio_generic_buffer.c
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Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,8 @@
#include <endian.h>
#include <getopt.h>
#include <inttypes.h>
#include <stdbool.h>
#include <signal.h>
#include "iio_utils.h"

/**
Expand Down Expand Up @@ -254,32 +256,90 @@ void print_usage(void)
" -w <n> Set delay between reads in us (event-less mode)\n");
}

enum autochan autochannels = AUTOCHANNELS_DISABLED;
char *dev_dir_name = NULL;
char *buf_dir_name = NULL;
bool current_trigger_set = false;

void cleanup(void)
{
int ret;

/* Disable trigger */
if (dev_dir_name && current_trigger_set) {
/* Disconnect the trigger - just write a dummy name. */
ret = write_sysfs_string("trigger/current_trigger",
dev_dir_name, "NULL");
if (ret < 0)
fprintf(stderr, "Failed to disable trigger: %s\n",
strerror(-ret));
current_trigger_set = false;
}

/* Disable buffer */
if (buf_dir_name) {
ret = write_sysfs_int("enable", buf_dir_name, 0);
if (ret < 0)
fprintf(stderr, "Failed to disable buffer: %s\n",
strerror(-ret));
}

/* Disable channels if auto-enabled */
if (dev_dir_name && autochannels == AUTOCHANNELS_ACTIVE) {
ret = enable_disable_all_channels(dev_dir_name, 0);
if (ret)
fprintf(stderr, "Failed to disable all channels\n");
autochannels = AUTOCHANNELS_DISABLED;
}
}

void sig_handler(int signum)
{
fprintf(stderr, "Caught signal %d\n", signum);
cleanup();
exit(-signum);
}

void register_cleanup(void)
{
struct sigaction sa = { .sa_handler = sig_handler };
const int signums[] = { SIGINT, SIGTERM, SIGABRT };
int ret, i;

for (i = 0; i < ARRAY_SIZE(signums); ++i) {
ret = sigaction(signums[i], &sa, NULL);
if (ret) {
perror("Failed to register signal handler");
exit(-1);
}
}
}

int main(int argc, char **argv)
{
unsigned long num_loops = 2;
unsigned long timedelay = 1000000;
unsigned long buf_len = 128;

int ret, c, i, j, toread;
int fp;
int fp = -1;

int num_channels;
int num_channels = 0;
char *trigger_name = NULL, *device_name = NULL;
char *dev_dir_name, *buf_dir_name;

int datardytrigger = 1;
char *data;
char *data = NULL;
ssize_t read_size;
int dev_num, trig_num;
char *buffer_access;
char *buffer_access = NULL;
int scan_size;
int noevents = 0;
int notrigger = 0;
enum autochan autochannels = AUTOCHANNELS_DISABLED;
char *dummy;

struct iio_channel_info *channels;

register_cleanup();

while ((c = getopt(argc, argv, "ac:egl:n:t:w:")) != -1) {
switch (c) {
case 'a':
Expand All @@ -288,8 +348,10 @@ int main(int argc, char **argv)
case 'c':
errno = 0;
num_loops = strtoul(optarg, &dummy, 10);
if (errno)
return -errno;
if (errno) {
ret = -errno;
goto error;
}

break;
case 'e':
Expand All @@ -301,26 +363,30 @@ int main(int argc, char **argv)
case 'l':
errno = 0;
buf_len = strtoul(optarg, &dummy, 10);
if (errno)
return -errno;
if (errno) {
ret = -errno;
goto error;
}

break;
case 'n':
device_name = optarg;
break;
case 't':
trigger_name = optarg;
datardytrigger = 0;
trigger_name = strdup(optarg);
break;
case 'w':
errno = 0;
timedelay = strtoul(optarg, &dummy, 10);
if (errno)
return -errno;
if (errno) {
ret = -errno;
goto error;
}
break;
case '?':
print_usage();
return -1;
ret = -1;
goto error;
}
}

Expand All @@ -334,14 +400,17 @@ int main(int argc, char **argv)
dev_num = find_type_by_name(device_name, "iio:device");
if (dev_num < 0) {
fprintf(stderr, "Failed to find the %s\n", device_name);
return dev_num;
ret = dev_num;
goto error;
}

printf("iio device number being used is %d\n", dev_num);

ret = asprintf(&dev_dir_name, "%siio:device%d", iio_dir, dev_num);
if (ret < 0)
return -ENOMEM;
if (ret < 0) {
ret = -ENOMEM;
goto error;
}

if (!notrigger) {
if (!trigger_name) {
Expand All @@ -354,7 +423,7 @@ int main(int argc, char **argv)
"%s-dev%d", device_name, dev_num);
if (ret < 0) {
ret = -ENOMEM;
goto error_free_dev_dir_name;
goto error;
}
}

Expand All @@ -367,7 +436,7 @@ int main(int argc, char **argv)
"%s-trigger", device_name);
if (ret < 0) {
ret = -ENOMEM;
goto error_free_dev_dir_name;
goto error;
}
}

Expand All @@ -376,7 +445,7 @@ int main(int argc, char **argv)
fprintf(stderr, "Failed to find the trigger %s\n",
trigger_name);
ret = trig_num;
goto error_free_triggername;
goto error;
}

printf("iio trigger number being used is %d\n", trig_num);
Expand All @@ -392,7 +461,7 @@ int main(int argc, char **argv)
if (ret) {
fprintf(stderr, "Problem reading scan element information\n"
"diag %s\n", dev_dir_name);
goto error_free_triggername;
goto error;
}
if (num_channels && autochannels == AUTOCHANNELS_ENABLED) {
fprintf(stderr, "Auto-channels selected but some channels "
Expand All @@ -407,7 +476,7 @@ int main(int argc, char **argv)
ret = enable_disable_all_channels(dev_dir_name, 1);
if (ret) {
fprintf(stderr, "Failed to enable all channels\n");
goto error_free_triggername;
goto error;
}

/* This flags that we need to disable the channels again */
Expand All @@ -419,12 +488,12 @@ int main(int argc, char **argv)
fprintf(stderr, "Problem reading scan element "
"information\n"
"diag %s\n", dev_dir_name);
goto error_disable_channels;
goto error;
}
if (!num_channels) {
fprintf(stderr, "Still no channels after "
"auto-enabling, giving up\n");
goto error_disable_channels;
goto error;
}
}

Expand All @@ -436,7 +505,7 @@ int main(int argc, char **argv)
"/*_en or pass -a to autoenable channels and "
"try again.\n", dev_dir_name);
ret = -ENOENT;
goto error_free_triggername;
goto error;
}

/*
Expand All @@ -448,7 +517,7 @@ int main(int argc, char **argv)
"%siio:device%d/buffer", iio_dir, dev_num);
if (ret < 0) {
ret = -ENOMEM;
goto error_free_channels;
goto error;
}

if (!notrigger) {
Expand All @@ -463,42 +532,42 @@ int main(int argc, char **argv)
if (ret < 0) {
fprintf(stderr,
"Failed to write current_trigger file\n");
goto error_free_buf_dir_name;
goto error;
}
}

/* Setup ring buffer parameters */
ret = write_sysfs_int("length", buf_dir_name, buf_len);
if (ret < 0)
goto error_free_buf_dir_name;
goto error;

/* Enable the buffer */
ret = write_sysfs_int("enable", buf_dir_name, 1);
if (ret < 0) {
fprintf(stderr,
"Failed to enable buffer: %s\n", strerror(-ret));
goto error_free_buf_dir_name;
goto error;
}

scan_size = size_from_channelarray(channels, num_channels);
data = malloc(scan_size * buf_len);
if (!data) {
ret = -ENOMEM;
goto error_free_buf_dir_name;
goto error;
}

ret = asprintf(&buffer_access, "/dev/iio:device%d", dev_num);
if (ret < 0) {
ret = -ENOMEM;
goto error_free_data;
goto error;
}

/* Attempt to open non blocking the access dev */
fp = open(buffer_access, O_RDONLY | O_NONBLOCK);
if (fp == -1) { /* TODO: If it isn't there make the node */
ret = -errno;
fprintf(stderr, "Failed to open %s\n", buffer_access);
goto error_free_buffer_access;
goto error;
}

for (j = 0; j < num_loops; j++) {
Expand All @@ -511,7 +580,7 @@ int main(int argc, char **argv)
ret = poll(&pfd, 1, -1);
if (ret < 0) {
ret = -errno;
goto error_close_buffer_access;
goto error;
} else if (ret == 0) {
continue;
}
Expand All @@ -536,45 +605,20 @@ int main(int argc, char **argv)
num_channels);
}

/* Stop the buffer */
ret = write_sysfs_int("enable", buf_dir_name, 0);
if (ret < 0)
goto error_close_buffer_access;

if (!notrigger)
/* Disconnect the trigger - just write a dummy name. */
ret = write_sysfs_string("trigger/current_trigger",
dev_dir_name, "NULL");
if (ret < 0)
fprintf(stderr, "Failed to write to %s\n",
dev_dir_name);
error:
cleanup();

error_close_buffer_access:
if (close(fp) == -1)
if (fp >= 0 && close(fp) == -1)
perror("Failed to close buffer");

error_free_buffer_access:
free(buffer_access);
error_free_data:
free(data);
error_free_buf_dir_name:
free(buf_dir_name);
error_free_channels:
for (i = num_channels - 1; i >= 0; i--) {
free(channels[i].name);
free(channels[i].generic_name);
}
free(channels);
error_free_triggername:
if (datardytrigger)
free(trigger_name);
error_disable_channels:
if (autochannels == AUTOCHANNELS_ACTIVE) {
ret = enable_disable_all_channels(dev_dir_name, 0);
if (ret)
fprintf(stderr, "Failed to disable all channels\n");
}
error_free_dev_dir_name:
free(trigger_name);
free(dev_dir_name);

return ret;
Expand Down

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