improved tcb handling in preparation for processes

1 files changed, 82 insertions, 16 deletions

diff --git a/common/tcb.c b/common/tcb.c
index 212e20f..32c31e1 100644
--- a/common/tcb.c
+++ b/common/tcb.c
@@ -2,6 +2,7 @@
 #include <arch/cpu.h>
 #include <apos/mem.h>
 #include <apos/pmem.h>
+#include <apos/vmem.h>
 #include <apos/nodes.h>
 #include <apos/types.h>
 #include <apos/assert.h>
@@ -12,7 +13,6 @@
 static id_t start_tid;
 static size_t num_tids;
 
-static struct node_root root;
 static struct tcb **tcbs;
 
 /* if we ever support systems with massive amounts of cpus, this should probably
@@ -31,8 +31,7 @@ void init_tcbs()
 
 void destroy_tcbs()
 {
-	destroy_nodes(&root);
-	free_page(MM_O2, (pm_t)tcbs);
+	free_page(MM_O1, (pm_t)tcbs);
 }
 
 static id_t __alloc_tid(struct tcb *t)
@@ -50,10 +49,9 @@ static id_t __alloc_tid(struct tcb *t)
 	return ERR_NF;
 }
 
-struct tcb *new_thread()
+struct tcb *create_thread(struct tcb *p)
 {
-	if (unlikely(!tcbs))
-		return 0;
+	hard_assert(tcbs, 0);
 
 	vm_t bottom = alloc_page(MM_O0, 0);
 	/* move tcb to top of kernel stack, keeping alignment in check
@@ -67,20 +65,80 @@ struct tcb *new_thread()
 	tcbs[tid] = t;
 	t->tid = tid;
 
+	if (p) {
+		t->pid = p->pid;
+		t->proc = p;
+	} else {
+		t->pid = t->tid;
+	}
+
 	return t;
 }
 
-void destroy_thread(struct tcb *t)
+static stat_t __clone_proc(struct tcb *p, struct tcb *n)
+{
+	/* TODO: clone memory regions, and mark them MR_COW, as well as copy
+	 * bm_branch tree but with VM_W off, also at some point write COW
+	 * handler */
+	return OK;
+}
+
+struct tcb *create_proc(struct tcb *p)
 {
-	if (unlikely(!tcbs))
-		return;
+	hard_assert(tcbs, 0);
 
-	/* remove thread id from list */
-	tcbs[t->tid] = 0;
+	/* create a new thread outside the current process */
+	struct tcb *n = create_thread(0);
+	n->b_r = create_vmem();
 
-	/* free associated kernel stack */
+	if (likely(p))
+		__clone_proc(p, n); /* we have a parent thread */
+	else
+		init_uvmem(n, UVMEM_START, UVMEM_END);
+
+	return n;
+}
+
+static stat_t __destroy_thread_data(struct tcb *t)
+{
+	/* free vm_branch */
+	destroy_vmem(t->b_r);
+
+	/* free associated kernel stack and the structure itself */
 	vm_t bottom = align_down((vm_t)t, __o_size(MM_O0));
 	free_page(MM_O0, (pm_t)bottom);
+
+	return OK;
+}
+
+stat_t destroy_thread(struct tcb *t)
+{
+	hard_assert(tcbs, ERR_NOINIT);
+	hard_assert(!is_proc(t), ERR_INVAL);
+
+	/* remove thread id from list */
+	tcbs[t->tid] = 0;
+
+	/* remove thread from process list */
+	if (t->next)
+		t->next->prev = t->prev;
+
+	if (t->prev)
+		t->prev->next = t->next;
+
+	return __destroy_thread_data(t);
+}
+
+stat_t destroy_proc(struct tcb *p)
+{
+	hard_assert(tcbs, ERR_NOINIT);
+	hard_assert(is_proc(p), ERR_INVAL);
+
+	for (struct tcb *iter = p; (iter = iter->next);)
+		destroy_thread(iter);
+
+	catastrophic_assert(destroy_uvmem(p));
+	return __destroy_thread_data(p);
 }
 
 struct tcb *cur_tcb()
@@ -88,6 +146,15 @@ struct tcb *cur_tcb()
 	return cpu_tcb[cpu_id()];
 }
 
+struct tcb *cur_proc()
+{
+	struct tcb *t = cur_tcb();
+	if (likely(is_proc(t)))
+		return t;
+	else
+		return t->proc;
+}
+
 void use_tcb(struct tcb *t)
 {
 	cpu_tcb[cpu_id()] = t;
@@ -95,18 +162,17 @@ void use_tcb(struct tcb *t)
 
 struct tcb *get_tcb(id_t tid)
 {
-	if (unlikely(!tcbs))
-		return 0;
+	hard_assert(tcbs, 0);
 
 	return tcbs[tid];
 }
 
 stat_t clone_tcb_maps(struct tcb *r)
 {
-	hard_assert(r && !r->parent, ERR_INVAL);
+	hard_assert(r && is_proc(r), ERR_INVAL);
 	struct tcb *t = r;
 	while ((t = t->next)) {
-		stat_t ret = clone_vmbranch(r->b_r, t->b_r);
+		stat_t ret = clone_uvmem(r->b_r, t->b_r);
 		if (ret)
 			return ret;
 	}