More work on IPC

1 files changed, 113 insertions, 0 deletions

diff --git a/src/kernel/ipc/object.c b/src/kernel/ipc/object.c
new file mode 100644
index 0000000..70c31b2
--- /dev/null
+++ b/src/kernel/ipc/object.c
@@ -0,0 +1,113 @@
+#include "object.h"
+#include <lib/mutex.h>
+#include <mem/mem.h>
+
+struct object* obj_new(struct process* owner) {
+	struct object* ret = kmalloc(sizeof(struct object));
+	ret->owner = owner;
+	ret->descriptors = 0;
+	ret->busyMutex = MUTEX_UNLOCKED;
+	ret->request = 0;
+	return ret;
+}
+
+void obj_delete(struct object* obj) {
+	if (obj->descriptors > 0) return;
+	if (obj->busyMutex != MUTEX_UNLOCKED) return;
+	if (obj->request != 0) return;
+	kfree(obj);
+}
+
+int obj_createP(struct process* p) {
+	return objdesc_add(p, obj_new(p));
+}
+
+void obj_closeP(struct process* p, int id) {
+	struct object* obj = objdesc_read(p, id);
+	if (obj == 0) return;
+	objdesc_rm(p, id);
+	if (obj->owner == p) {
+		if (obj->descriptors > 0) {
+			obj->owner = 0; // set object to be invalid
+			//if a request was being handled, give it a null response
+		} else {
+			obj_delete(obj);
+		}
+	} else {
+		if (obj->descriptors == 0 && obj->owner == 0) {
+			obj_delete(obj);
+		}
+		//future : send message becuz object was closed
+	}
+}
+
+void obj_closeall(struct process* p) {
+	while (p->objects != 0) obj_closeP(p, p->objects->id);
+}
+
+// DESCRIPTORS
+
+int objdesc_add(struct process* proc, struct object* obj) {
+	struct obj_descriptor *ret = kmalloc(sizeof(struct obj_descriptor));
+	ret->obj = obj;
+	ret->id = proc->next_objdesc;
+	ret->next = proc->objects;
+	proc->objects = ret;
+	obj->descriptors++;
+	proc->next_objdesc++;
+	return ret->id;
+}
+
+int objdesc_get(struct process* proc, struct object* obj) {
+	struct obj_descriptor *it = proc->objects;
+	while (it != 0) {
+		if (it->obj == obj) return it->id;
+		it = it->next;
+	}
+	return -1;
+}
+
+struct object* objdesc_read(struct process* proc, int id) {
+	struct obj_descriptor *it = proc->objects;
+	while (it != 0) {
+		if (it->id == id) return it->obj;
+		it = it->next;
+	}
+	return 0;
+}
+
+void objdesc_rm(struct process* proc, int id) {
+	struct obj_descriptor *e = proc->objects;
+	if (e != 0 && e->id == id) {
+		proc->objects = e->next;
+		e->obj->descriptors--;
+		kfree(e);
+		return;
+	}
+	while (e->next != 0) {
+		if (e->next->id == id) {
+			e->next = e->next->next;
+			e->next->obj->descriptors--;
+			kfree(e->next);
+			return;
+		}
+		e = e->next;
+	}
+}
+
+// SYSCALLS
+
+int object_create() {
+	return obj_createP(current_thread->process);
+}
+
+int object_owned(int id) {
+	struct object *obj = objdesc_read(current_thread->process, id);
+	if (obj == 0) return -1;
+	if (obj->owner == current_thread->process) return 1;
+	return 0;
+}
+
+void object_close(int id) {
+	obj_closeP(current_thread->process, id);
+}