Lesson 10

10-ConcurrencyAndSynchronization/Makefile

@@ -0,0 +1,15 @@
+#!/usr/bin/make
+obj-m+=thread_test.o
+all: kernel_path_check.o
+	make -C ${BUILD_KERNEL} M=$(PWD) modules
+clean:
+	make -C ${BUILD_KERNEL} M=$(PWD) clean
+
+kernel_path_check.o:
+	if [ -z "${BUILD_KERNEL}" ]; \
+	then \
+		echo 'BUILD_KERNEL is not set. abort'>&2; \
+		exit 1; \
+	else \
+		echo 'BUILD_KERNEL is set. continue'; \
+	fi

10-ConcurrencyAndSynchronization/thread_test.c

@@ -0,0 +1,48 @@
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+
+#define THREAD_NUMBER 5
+static int delay_sec = 5;
+static int thread_num = THREAD_NUMBER;
+
+static struct task_struct *(thread_st[THREAD_NUMBER]);
+module_param(delay_sec, int, 0);
+
+
+static int thread_func(void *data)
+{
+	int total_sleep = 0;
+
+	while (!kthread_should_stop()) {
+		pr_info("thread: child process [%d] is running for %d seconds\n",
+		current->pid, total_sleep);
+		ssleep(1);
+		total_sleep += 1;
+	}
+	pr_info("thread: child process [%d] is completed. total sleep = %d\n",
+	current->pid, total_sleep);
+	return 0;
+}
+
+int test_thread(void)
+{
+	int i = 0;
+
+	pr_info("thread: main process [%d] is running\n", current->pid);
+	for (i = 0; i < thread_num; i++)
+		thread_st[i] = kthread_run(thread_func, NULL, "test_thread");
+	ssleep(delay_sec);
+	for (i = 0; i < thread_num; i++)
+		kthread_stop(thread_st[i]);
+	pr_info("thread: main process [%d] is completed\n", current->pid);
+	return -1;
+}
+
+module_init(test_thread);
+
+MODULE_AUTHOR("Oleksandr.Siruk <alexsirook@gmail.com>");
+MODULE_DESCRIPTION("Simple Kernel module example");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("0.1");