int acquire() {
/* fork ourselves if not asked otherwise */
char* no_fork = getenv("no_fork");
if (! no_fork || strcmp("1", no_fork)) {
if (fork()) return;
// we are the child, complete the daemonization
/* Close standard IO */
fclose(stdin);
fclose(stdout);
fclose(stderr);
/* create new session and process group */
setsid();
}
/* write the pid */
FILE* pid_file = fopen(pid_filename, "w");
fprintf(pid_file, "%d\n", getpid());
fclose(pid_file);
/* loop each second */
while (1) {
/* wait until next second */
time_t epoch = wait_until_next_second();
/* Reading /proc/stat */
FILE* f = fopen(PROC_STAT, "r");
// Read and ignore the 1rst line
char buffer[1024];
fgets(buffer, 1024, f);
/* open the spoolfile */
FILE* cache_file = fopen(cache_filename, "a");
/* lock */
flock(fileno(cache_file), LOCK_EX);
while (! feof(f)) {
if (fgets(buffer, 1024, f) == 0) {
// EOF
break;
}
// Not on CPU lines anymore
if (strncmp(buffer, "cpu", 3)) break;
char cpu_id[64];
long usr, nice, sys, idle, iowait, irq, softirq;
sscanf(buffer, "%s %ld %ld %ld %ld %ld %ld %ld", cpu_id, &usr, &nice, &sys, &idle, &iowait, &irq, &softirq);
long used = usr + nice + sys + iowait + irq + softirq;
fprintf(cache_file, "%s.value %ld:%ld\n", cpu_id, epoch, used);
}
fclose(cache_file);
fclose(f);
}
}
int acquire() {
/* fork ourselves if not asked otherwise */
char* no_fork = getenv("no_fork");
if (! no_fork || strcmp("1", no_fork)) {
if (fork()) return;
// we are the child, complete the daemonization
/* Close standard IO */
fclose(stdin);
fclose(stdout);
fclose(stderr);
/* create new session and process group */
setsid();
}
/* write the pid */
FILE* pid_file = fopen(pid_filename, "w");
fprintf(pid_file, "%d\n", getpid());
fclose(pid_file);
/* Reading /proc/stat */
int f = open(PROC_STAT, O_RDONLY);
/* open the spoolfile */
int cache_file = open(cache_filename, O_CREAT | O_APPEND | O_WRONLY);
/* loop each second */
while (1) {
/* wait until next second */
time_t epoch = wait_until_next_second();
const int buffer_size = 64 * 1024;
char buffer[buffer_size];
if (lseek(f, 0, SEEK_SET) < 0) {
return fail("cannot seek " PROC_STAT);
}
// whole /proc/stat can be read in 1 syscall
if (read(f, buffer, buffer_size) <= 0) {
return fail("cannot read " PROC_STAT);
}
// ignore the 1rst line
char* line;
const char* newl = "\n";
line = strtok(buffer, newl);
/* lock */
flock(cache_file, LOCK_EX);
for (line = strtok(NULL, newl); line; line = strtok(NULL, newl)) {
// Not on CPU lines anymore
if (strncmp(line, "cpu", 3)) break;
char cpu_id[64];
long usr, nice, sys, idle, iowait, irq, softirq;
sscanf(line, "%s %ld %ld %ld %ld %ld %ld %ld", cpu_id, &usr, &nice, &sys, &idle, &iowait, &irq, &softirq);
long used = usr + nice + sys + iowait + irq + softirq;
char out_buffer[1024];
sprintf(out_buffer, "%s.value %ld:%ld\n", cpu_id, epoch, used);
write(cache_file, out_buffer, strlen(out_buffer));
}
/* unlock */
flock(cache_file, LOCK_UN);
}
close(cache_file);
close(f);
return 0;
}
int acquire() {
/* fork ourselves if not asked otherwise */
char* no_fork = getenv("no_fork");
if (! no_fork || strcmp("1", no_fork)) {
pid_t child_pid = fork();
if (child_pid) {
printf("# acquire() launched as PID %d\n", child_pid);
return 0;
}
// we are the child, complete the daemonization
/* Close standard IO */
fclose(stdin);
fclose(stdout);
fclose(stderr);
/* create new session and process group */
setsid();
}
/* write the pid */
FILE* pid_file = fopen(pid_filename, "w");
fprintf(pid_file, "%d\n", getpid());
fclose(pid_file);
/* Reading /proc/stat */
int f = open(PROC_STAT, O_RDONLY);
if ( f == -1 ) {
return fail("cannot open " PROC_STAT);
}
/* open the spoolfile */
int cache_file = open(cache_filename, O_CREAT | O_APPEND | O_WRONLY, S_IRUSR | S_IWUSR);
if ( cache_file == -1 ) {
return fail("# cannot open cache_file");
}
/* loop each second */
while (1) {
/* wait until next second */
time_t epoch = wait_until_next_second();
const int buffer_size = 64 * 1024;
char buffer[buffer_size];
if (lseek(f, 0, SEEK_SET) < 0) {
return fail("cannot seek " PROC_STAT);
}
// whole PROC file can be read in 1 syscall
if (read(f, buffer, buffer_size) <= 0) {
return fail("cannot read " PROC_STAT);
}
// ignore the 1rst line
char* line; char *saveptr;
const char* newl = "\n";
/* lock */
flock(cache_file, LOCK_EX);
int nif = -2;
for (line = strtok_r(buffer, newl, &saveptr); line; line = strtok_r(NULL, newl, &saveptr)) {
// Skip the header lines
if (nif ++ < 0) { continue; }
char if_id[64];
uint_fast64_t r_bytes, r_packets, r_errs, r_drop, r_fifo, r_frame, r_compressed, r_multicast;
uint_fast64_t t_bytes, t_packets, t_errs, t_drop, t_fifo, t_frame, t_compressed, t_multicast;
sscanf(line, "%s"
" "
"%llu %llu %llu %llu %llu %llu %llu %llu"
" "
"%llu %llu %llu %llu %llu %llu %llu %llu"
, if_id
, &r_bytes, &r_packets, &r_errs, &r_drop, &r_fifo, &r_frame, &r_compressed, &r_multicast
, &t_bytes, &t_packets, &t_errs, &t_drop, &t_fifo, &t_frame, &t_compressed, &t_multicast
);
// Remove trailing ':' of if_id
if_id[strlen(if_id) - 1] = '\0';
char out_buffer[1024];
sprintf(out_buffer,
"multigraph if_%s_1sec" "\n"
"up.value %ld:%llu" "\n"
"down.value %ld:%llu" "\n"
, if_id
, epoch, r_bytes
, epoch, t_bytes
);
write(cache_file, out_buffer, strlen(out_buffer));
}
/* unlock */
flock(cache_file, LOCK_UN);
}
close(cache_file);
close(f);
return 0;
}
