andreastaliad/fork_vs_thread
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maybe hopefully fixed cpu fork logging

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andreastaliad
2026-05-22 21:41:32 +03:00
parent 83422abaf4
commit 10155bfaf1
2 changed files with 323 additions and 34 deletions
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fork_bomb/fork_bomb.c
+293 -11
View File
@@ -2,6 +2,11 @@
#include <fcntl.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <dirent.h>
#include <ctype.h>
#include <time.h>
#define DEFAULT_NUM_LEN 512
@@ -42,11 +47,236 @@ char *itoa(long num, char *strnum, size_t size){
return strnum;
}
int main()
{
int fd = open("fork_bomb.log", O_CREAT | O_WRONLY | O_TRUNC, 0600);
static int is_numeric_dir(const char *name) {
for (const char *p = name; *p; ++p) {
if (!isdigit((unsigned char)*p)) {
return 0;
}
}
return 1;
}
static long count_processes(void) {
DIR *dir = opendir("/proc");
if (!dir) {
return 0;
}
long count = 0;
char intstr[DEFAULT_NUM_LEN];
struct dirent *ent;
while ((ent = readdir(dir)) != NULL) {
if (ent->d_type == DT_DIR && is_numeric_dir(ent->d_name)) {
count++;
}
}
closedir(dir);
return count;
}
static long count_threads_total(void) {
DIR *dir = opendir("/proc");
if (!dir) {
return 0;
}
long total = 0;
struct dirent *ent;
while ((ent = readdir(dir)) != NULL) {
if (ent->d_type != DT_DIR || !is_numeric_dir(ent->d_name)) {
continue;
}
char path[256];
snprintf(path, sizeof(path), "/proc/%s/status", ent->d_name);
FILE *f = fopen(path, "r");
if (!f) {
continue;
}
char line[256];
while (fgets(line, sizeof(line), f)) {
if (strncmp(line, "Threads:", 8) == 0) {
long v = 0;
if (sscanf(line, "Threads: %ld", &v) == 1) {
total += v;
}
break;
}
}
fclose(f);
}
closedir(dir);
return total;
}
static void read_loadavg(double *l1, double *l5, double *l15) {
FILE *f = fopen("/proc/loadavg", "r");
if (!f) {
*l1 = *l5 = *l15 = 0.0;
return;
}
if (fscanf(f, "%lf %lf %lf", l1, l5, l15) != 3) {
*l1 = *l5 = *l15 = 0.0;
}
fclose(f);
}
static void read_meminfo(long *total_kb, long *avail_kb) {
FILE *f = fopen("/proc/meminfo", "r");
if (!f) {
*total_kb = 0;
*avail_kb = 0;
return;
}
char key[64];
long value = 0;
char unit[16];
while (fscanf(f, "%63s %ld %15s", key, &value, unit) == 3) {
if (strcmp(key, "MemTotal:") == 0) {
*total_kb = value;
} else if (strcmp(key, "MemAvailable:") == 0) {
*avail_kb = value;
}
if (*total_kb && *avail_kb) {
break;
}
}
fclose(f);
}
static void read_self_status(long *rss_kb, long *vsz_kb, long *stk_kb, long *heap_kb, long *threads) {
FILE *f = fopen("/proc/self/status", "r");
if (!f) {
*rss_kb = *vsz_kb = *stk_kb = *heap_kb = *threads = 0;
return;
}
char line[256];
while (fgets(line, sizeof(line), f)) {
if (sscanf(line, "VmRSS: %ld", rss_kb) == 1) {
continue;
}
if (sscanf(line, "VmSize: %ld", vsz_kb) == 1) {
continue;
}
if (sscanf(line, "VmStk: %ld", stk_kb) == 1) {
continue;
}
if (sscanf(line, "VmData: %ld", heap_kb) == 1) {
continue;
}
if (sscanf(line, "Threads: %ld", threads) == 1) {
continue;
}
}
fclose(f);
}
static long read_self_ticks(void) {
FILE *f = fopen("/proc/self/stat", "r");
if (!f) {
return 0;
}
long utime = 0;
long stime = 0;
char buf[512];
if (fgets(buf, sizeof(buf), f)) {
char *p = strrchr(buf, ')');
if (p) {
long vals[64];
int n = 0;
p++;
while (*p && n < 64) {
while (*p == ' ') {
p++;
}
if (!*p) {
break;
}
vals[n++] = strtol(p, &p, 10);
}
if (n > 13) {
utime = vals[11];
stime = vals[12];
}
}
}
fclose(f);
return utime + stime;
}
static void read_cpu_total(long *total, long *idle) {
FILE *f = fopen("/proc/stat", "r");
if (!f) {
*total = 0;
*idle = 0;
return;
}
char cpu[8];
long user = 0, nice = 0, system = 0, idle_v = 0, iowait = 0, irq = 0, softirq = 0, steal = 0;
if (fscanf(f, "%7s %ld %ld %ld %ld %ld %ld %ld %ld", cpu, &user, &nice, &system, &idle_v, &iowait, &irq, &softirq, &steal) == 9) {
*total = user + nice + system + idle_v + iowait + irq + softirq + steal;
*idle = idle_v + iowait;
} else {
*total = 0;
*idle = 0;
}
fclose(f);
}
static void format_timestamp(char *out, size_t size) {
time_t now = time(NULL);
struct tm tm_now;
localtime_r(&now, &tm_now);
strftime(out, size, "%Y-%m-%dT%H:%M:%S%z", &tm_now);
}
static double read_uptime(void) {
FILE *f = fopen("/proc/uptime", "r");
if (!f) {
return 0.0;
}
double up = 0.0;
if (fscanf(f, "%lf", &up) != 1) {
up = 0.0;
}
fclose(f);
return up;
}
int main(void)
{
const char *csv_path = getenv("FORK_BOMB_CSV");
if (!csv_path || !*csv_path) {
csv_path = "fork_bomb.csv";
}
long proc_step = 50;
const char *step_env = getenv("PROC_SAMPLE_STEP");
if (step_env && *step_env) {
long v = strtol(step_env, NULL, 10);
if (v > 0) {
proc_step = v;
}
}
FILE *csv = fopen(csv_path, "w");
if (!csv) {
perror("fopen csv");
return 1;
}
fprintf(csv, "timestamp,elapsed_s,load1,load5,load15,mem_total_kb,mem_available_kb,mem_used_kb,proc_count,thread_count_total,pid,cpu_pct,sys_cpu_pct,rss_kb,vsz_kb,stack_kb,heap_kb,proc_threads\n");
long count = 0;
long prev_proc_count = 0;
long proc_accum = 0;
double start_uptime = read_uptime();
long prev_cpu_total = 0;
long prev_cpu_idle = 0;
read_cpu_total(&prev_cpu_total, &prev_cpu_idle);
long prev_ticks = read_self_ticks();
double prev_uptime = read_uptime();
long clk_tck = sysconf(_SC_CLK_TCK);
if (clk_tck <= 0) {
clk_tck = 100;
}
while (1) {
pid_t pid = fork();
@@ -57,20 +287,72 @@ int main()
}
if (pid == 0) {
// child: do nothing, just exist
pause();
return 0;
}
// parent: log count
count++;
lseek(fd, 0, SEEK_SET);
memset(intstr, 0, sizeof(intstr));
itoa(count, intstr, DEFAULT_NUM_LEN);
write(fd, intstr, strlen(intstr));
long proc_count = count_processes();
if (prev_proc_count > 0) {
long delta = proc_count - prev_proc_count;
if (delta > 0) {
proc_accum += delta;
}
}
prev_proc_count = proc_count;
if (proc_accum >= proc_step) {
proc_accum = 0;
double now_uptime = read_uptime();
double elapsed_s = now_uptime - start_uptime;
double load1 = 0.0, load5 = 0.0, load15 = 0.0;
read_loadavg(&load1, &load5, &load15);
long mem_total = 0, mem_avail = 0;
read_meminfo(&mem_total, &mem_avail);
long mem_used = mem_total - mem_avail;
long thread_total = count_threads_total();
long rss = 0, vsz = 0, stk = 0, heap = 0, proc_threads = 0;
read_self_status(&rss, &vsz, &stk, &heap, &proc_threads);
long cur_ticks = read_self_ticks();
double dt = now_uptime - prev_uptime;
double cpu_pct = 0.0;
if (dt > 0.0) {
cpu_pct = (100.0 * (double)(cur_ticks - prev_ticks)) / (dt * (double)clk_tck);
}
prev_uptime = now_uptime;
prev_ticks = cur_ticks;
long cpu_total = 0;
long cpu_idle = 0;
read_cpu_total(&cpu_total, &cpu_idle);
long dt_total = cpu_total - prev_cpu_total;
long dt_idle = cpu_idle - prev_cpu_idle;
double sys_cpu_pct = 0.0;
if (dt_total > 0) {
sys_cpu_pct = 100.0 * (double)(dt_total - dt_idle) / (double)dt_total;
}
prev_cpu_total = cpu_total;
prev_cpu_idle = cpu_idle;
char ts[64];
format_timestamp(ts, sizeof(ts));
fprintf(csv, "%s,%.3f,%.2f,%.2f,%.2f,%ld,%ld,%ld,%ld,%ld,%ld,%.2f,%.2f,%ld,%ld,%ld,%ld,%ld\n",
ts, elapsed_s, load1, load5, load15,
mem_total, mem_avail, mem_used, proc_count, thread_total,
(long)getpid(), cpu_pct, sys_cpu_pct, rss, vsz, stk, heap, proc_threads);
fflush(csv);
}
}
close(fd);
fclose(csv);
return 0;
}
run_all_experiments.sh
+12 -5
View File
@@ -165,6 +165,7 @@ ALLOW_DANGEROUS=${ALLOW_DANGEROUS:-0}
FORK_BOMB_SECONDS=${FORK_BOMB_SECONDS:-5}
CREATION_TIME_ITERS=${CREATION_TIME_ITERS:-"100 1000 10000"}
CREATION_TIME_SECONDS=${CREATION_TIME_SECONDS:-60}
PROC_SAMPLE_STEP=${PROC_SAMPLE_STEP:-50}
CREATION_TIME_STDOUT="$OUT_DIR/creation_time_stdout.log"
CREATION_TIME_STDERR="$OUT_DIR/creation_time_stderr.log"
@@ -176,11 +177,17 @@ run_with_sampling \
"$CREATION_TIME_SECONDS"
if [ "$ALLOW_DANGEROUS" -eq 1 ]; then
run_with_sampling \
"fork_bomb" \
"cd '$ROOT_DIR/fork_bomb' && ./fork_bomb" \
"$OUT_DIR/fork_bomb.csv" \
"$FORK_BOMB_SECONDS"
log "Starting fork_bomb (C-side logging)"
if command -v timeout >/dev/null 2>&1; then
timeout "$FORK_BOMB_SECONDS" sh -c "cd '$ROOT_DIR/fork_bomb' && FORK_BOMB_CSV='$OUT_DIR/fork_bomb.csv' PROC_SAMPLE_STEP='$PROC_SAMPLE_STEP' ./fork_bomb" || true
else
(cd "$ROOT_DIR/fork_bomb" && FORK_BOMB_CSV="$OUT_DIR/fork_bomb.csv" PROC_SAMPLE_STEP="$PROC_SAMPLE_STEP" ./fork_bomb) &
FB_PID=$!
sleep "$FORK_BOMB_SECONDS" || true
kill -TERM "-$FB_PID" 2>/dev/null || true
sleep 2
kill -KILL "-$FB_PID" 2>/dev/null || true
fi
else
log "Skipping fork_bomb (set ALLOW_DANGEROUS=1 to run)"
echo "timestamp,elapsed_s,load1,load5,load15,mem_total_kb,mem_available_kb,mem_used_kb,proc_count,thread_count_total,pid,cpu_pct,sys_cpu_pct,rss_kb,vsz_kb,stack_kb,heap_kb,proc_threads" > "$OUT_DIR/fork_bomb.csv"