1 files changed, 128 insertions, 0 deletions
diff --git a/src/kernel/handleset.c b/src/kernel/handleset.c
new file mode 100644
index 0000000..b52eaa0
--- /dev/null
+++ b/src/kernel/handleset.c
@@ -0,0 +1,128 @@
+#include <camellia/errno.h>
+#include <camellia/flags.h>
+#include <kernel/handleset.h>
+#include <kernel/malloc.h>
+#include <kernel/panic.h>
+
+HandleSet *
+hs_init(void)
+{
+	HandleSet *hs = kzalloc(sizeof *hs, "handles");
+	hs->refcount = 1;
+	return hs;
+}
+
+HandleSet *
+hs_copy(HandleSet *from)
+{
+	HandleSet *hs = hs_init();
+	assert(from);
+	for (hid_t i = 0; i < HANDLE_MAX; i++) {
+		hs->h[i] = from->h[i];
+		if (hs->h[i]) {
+			hs->h[i]->refcount++;
+		}
+	}
+	return hs;
+}
+
+void
+hs_unref(HandleSet *hs)
+{
+	assert(hs);
+	assert(hs->refcount != 0);
+	hs->refcount--;
+	if (hs->refcount == 0) {
+		for (hid_t i = 0; i < HANDLE_MAX; i++) {
+			hs_close(hs, i);
+		}
+		kfree(hs);
+	}
+}
+
+hid_t
+hs_findfree(HandleSet *hs, hid_t start)
+{
+	if (start < 0) start = 0;
+	for (hid_t i = start; i < HANDLE_MAX; i++) {
+		if (hs->h[i] == NULL) {
+			return i;
+		}
+	}
+	return -1;
+}
+
+Handle *
+hs_get(HandleSet *hs, hid_t id)
+{
+	if (id == HANDLE_NULLFS) {
+		// TODO get rid of this stupid hack
+		static Handle h = (Handle){
+			.type = HANDLE_FS_FRONT,
+			.backend = NULL,
+			.refcount = 2, /* never free */
+		};
+		return &h;
+	} else if (0 <= id && id < HANDLE_MAX) {
+		return hs->h[id];
+	} else {
+		return NULL;
+	}
+}
+
+hid_t
+hs_hinit(HandleSet *hs, enum handle_type type, Handle **hp)
+{
+	hid_t hid = hs_findfree(hs, 1);
+	if (hid < 0) return -1;
+	hs->h[hid] = handle_init(type);
+	if (hp) *hp = hs->h[hid];
+	return hid;
+}
+
+hid_t
+hs_dup(HandleSet *hs, hid_t from, hid_t to, int flags)
+{
+	Handle *fromh, **toh;
+
+	if (to < 0 || (flags & DUP_SEARCH)) {
+		to = hs_findfree(hs, to);
+		if (to < 0) return -EMFILE;
+	} else if (to >= HANDLE_MAX) {
+		return -EBADF;
+	}
+
+	if (to == from) return to;
+	toh = &hs->h[to];
+	fromh = hs_get(hs, from);
+
+	if (*toh) handle_close(*toh);
+	*toh = fromh;
+	if (fromh) fromh->refcount++;
+
+	return to;
+}
+
+Handle *
+hs_take(HandleSet *hs, hid_t hid)
+{
+	if (hid < 0 || hid >= HANDLE_MAX) {
+		return hs_get(hs, hid); // TODO can't this cause HANDLE_NULLFS to be freed?
+	}
+	Handle *h = hs->h[hid];
+	hs->h[hid] = NULL;
+	return h;
+}
+
+hid_t
+hs_put(HandleSet *hs, Handle *h)
+{
+	assert(h);
+	hid_t hid = hs_findfree(hs, 1);
+	if (hid < 0) {
+		handle_close(h);
+		return hid;
+	}
+	hs->h[hid] = h;
+	return hid;
+}