Cancel threads task with signal

.gitignore

@@ -57,5 +57,6 @@ dkms.conf
 
 # User specific
 /kernel-sign
+.vscode/
 
 # End of https://www.toptal.com/developers/gitignore/api/c

chp4_threads/cancel_threads_signal/.gitignore

@@ -0,0 +1 @@
+cancel_threads

chp4_threads/cancel_threads_signal/Makefile

@@ -0,0 +1,18 @@
+CC=gcc
+CFLAGS=-o cancel_threads -Wall -lpthread -lc -D_GNU_SOURCE
+SRCS=main.c
+
+.DEFAULT_GOAL := build
+
+build:
+	$(CC) $(CFLAGS) -fsanitize=address -static-libasan $(SRCS)
+	
+release:
+	$(CC) $(CFLAGS) $(SRCS)
+
+debug:
+	$(CC) $(CFLAGS) -fsanitize=address -static-libasan -ggdb $(SRCS)
+	gdb -q cancel_threads
+
+clean:
+	rm -f cancel_threads

chp4_threads/cancel_threads_signal/main.c

@@ -0,0 +1,66 @@
+#include <pthread.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#define THREAD_COUNT 10
+
+void *expensive_task(void *);
+void send_finish_signal(void *);
+void handler(int);
+
+pthread_t main_thread;
+pthread_t threads[THREAD_COUNT];
+
+int main(void) {
+  main_thread = pthread_self();
+
+  // Register handler for SIGCHLD signal
+  signal(SIGCHLD, handler);
+
+  pthread_attr_t attr;
+  if (pthread_attr_init(&attr) != 0) {
+    perror("Error");
+    return EXIT_FAILURE;
+  }
+
+  int n[THREAD_COUNT];
+  for (int i = 0; i < THREAD_COUNT; i++) {
+    n[i] = i;
+    printf("Create thread number %d\n", i);
+    pthread_create(&threads[i], &attr, expensive_task, (void *)&n[i]);
+  }
+
+  for (int i = 0; i < THREAD_COUNT; i++) {
+    printf("Waiting thread number %d...\n", i);
+    pthread_join(threads[i], NULL);
+    printf("Thread %d joined\n", i);
+  }
+
+  return EXIT_SUCCESS;
+}
+
+void handler(int sig) {
+  printf("Caught signal %d\n", sig);
+  for (int i = 0; i < THREAD_COUNT; i++) {
+    pthread_cancel(threads[i]);
+  }
+}
+
+void send_finish_signal(void *args) {
+  int *id = (int *)args;
+  printf("Thread %d send SIGCHLD signal\n", *id);
+  pthread_kill(main_thread, SIGCHLD);
+  printf("Thread %d cleanup handle is done\n", *id);
+}
+
+void *expensive_task(void *args) {
+  pthread_cleanup_push(send_finish_signal, args);
+  const int tid = *((int *)args);
+  printf("Thread %d are running...\n", tid);
+  sleep(rand() % 31);
+  printf("Thread %d terminated!!!\n", tid);
+  pthread_cleanup_pop(1);
+  pthread_exit(0);
+}