Add kernel worker threads for handling various tasks (eg. interrupts)

1 files changed, 100 insertions, 0 deletions

diff --git a/src/kernel/core/worker.c b/src/kernel/core/worker.c
new file mode 100644
index 0000000..4be2f93
--- /dev/null
+++ b/src/kernel/core/worker.c
@@ -0,0 +1,100 @@
+#include <worker.h>
+#include <btree.h>
+#include <mutex.h>
+#include <malloc.h>
+
+static uint64_t time = 0;
+static uint64_t next_task_time = UINT64_MAX;
+
+static thread_t **workers = 0;
+static int nworkers = 0;
+
+static btree_t *tasks = 0;
+STATIC_MUTEX(tasks_mutex);
+
+static void worker_thread(void*);
+
+typedef struct {
+	uint64_t time;
+	entry_t fun;
+	void* data;
+} worker_task_t;
+
+int uint64_key_cmp_fun(const void* a, const void* b) {
+	uint64_t *x = (uint64_t*)a, *y = (uint64_t*)b;
+	return (*x == *y ? 0 : (*x > *y ? 1 : -1));
+}
+
+void start_workers(int n) {
+	ASSERT(n > 0);
+	workers = (thread_t**)malloc(n * sizeof(thread_t*));
+	ASSERT(workers != 0);
+
+	tasks = create_btree(uint64_key_cmp_fun, 0);
+	ASSERT(tasks != 0);
+
+	nworkers = n;
+	for (int i = 0; i < n; i++) {
+		workers[i] = new_thread(worker_thread, 0);
+	}
+}
+
+void worker_thread(void* x) {
+	uint64_t zero64 = 0;
+
+	while (true) {
+		mutex_lock(&tasks_mutex);
+		worker_task_t *t = btree_upper(tasks, &zero64);
+		next_task_time = (t == 0 ? UINT64_MAX : t->time);
+		if (t != 0 && t->time <= time) {
+			btree_remove_v(tasks, &t->time, t);
+		} else {
+			t = 0;
+		}
+		mutex_unlock(&tasks_mutex);
+		
+		if (t != 0) {
+			// do task :-)
+			t->fun(t->data);
+			free(t);
+		} else {
+			pause();
+		}
+	}
+}
+
+bool worker_push_in(int usecs, entry_t fun, void* data) {
+	worker_task_t *t = (worker_task_t*)malloc(sizeof(worker_task_t));
+	if (t == 0) return false;
+
+	t->time = time + usecs;
+	t->fun = fun;
+	t->data = data;
+
+	mutex_lock(&tasks_mutex);
+	btree_add(tasks, &t->time, t);
+	mutex_unlock(&tasks_mutex);
+	
+	if (t->time < next_task_time) next_task_time = t->time;
+
+	return true;
+}
+
+bool worker_push(entry_t fun, void* data) {
+	return worker_push_in(0, fun, data);
+}
+
+void worker_notify_time(int usecs) {
+	time += usecs;
+	if (next_task_time <= time) {
+		for (int i = 0; i < nworkers; i++) {
+			if (resume_thread(workers[i], false)) break;
+		}
+	}
+}
+
+uint64_t worker_get_time() {
+	return time;
+}
+
+/* vim: set ts=4 sw=4 tw=0 noet :*/