Adding upstream version 9.1.upstream/9.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 143 insertions, 0 deletions

diff --git a/lib/qobj.h b/lib/qobj.h
new file mode 100644
index 0000000..a3883fd
--- /dev/null
+++ b/lib/qobj.h
@@ -0,0 +1,143 @@
+// SPDX-License-Identifier: ISC
+/*
+ * Copyright (c) 2015-16  David Lamparter, for NetDEF, Inc.
+ */
+
+#ifndef _QOBJ_H
+#define _QOBJ_H
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <stddef.h>
+
+#include "typesafe.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* reserve a specific amount of bytes for a struct, which can grow up to
+ * that size (or be dummy'd out if not needed)
+ *
+ * note the padding's array size will be an error if it gets negative or zero;
+ * this is intentional to prevent the struct from growing beyond the allocated
+ * space.
+ */
+#ifndef __cplusplus
+#define RESERVED_SPACE_STRUCT(name, fieldname, size)                           \
+	struct {                                                               \
+		struct name fieldname;                                         \
+		char padding##fieldname[size - sizeof(struct name)];           \
+	};
+#else
+#define RESERVED_SPACE_STRUCT(name, fieldname, size)                           \
+	struct name fieldname;                                                 \
+	char padding##fieldname[size - sizeof(struct name)];
+#endif
+
+/* don't need struct definitions for these here.  code actually using
+ * these needs to define the struct *before* including this header.
+ * HAVE_QOBJ_xxx should be defined to +1 in that case, like this:
+ *
+ * #if defined(HAVE_QOBJ_NODETYPE_CLI) && HAVE_QOBJ_NODETYPE_CLI < 0
+ * #error include files are in wrong order
+ * #else
+ * #define HAVE_QOBJ_NODETYPE_CLI 1
+ * struct qobj_nodetype_cli { ... }
+ * #endif
+ */
+#ifndef HAVE_QOBJ_NODETYPE_CLI
+#define HAVE_QOBJ_NODETYPE_CLI -1
+struct qobj_nodetype_cli {
+	int dummy;
+};
+#endif
+
+#ifndef HAVE_QOBJ_NODETYPE_CAPNP
+#define HAVE_QOBJ_NODETYPE_CAPNP -1
+struct qobj_nodetype_capnp {
+	int dummy;
+};
+#endif
+
+#include "typesafe.h"
+
+/* each different kind of object will have a global variable of this type,
+ * which can be used by various other pieces to store type-related bits.
+ * type equality can be tested as pointer equality. (cf. QOBJ_GET_TYPESAFE)
+ */
+struct qobj_nodetype {
+	ptrdiff_t node_member_offset;
+	RESERVED_SPACE_STRUCT(qobj_nodetype_cli, cli, 256)
+	RESERVED_SPACE_STRUCT(qobj_nodetype_capnp, capnp, 256)
+};
+
+PREDECL_HASH(qobj_nodes);
+
+/* anchor to be embedded somewhere in the object's struct */
+struct qobj_node {
+	uint64_t nid;
+	struct qobj_nodes_item nodehash;
+	const struct qobj_nodetype *type;
+};
+
+#define QOBJ_FIELDS struct qobj_node qobj_node
+
+/* call these at the end of any _create function (QOBJ_REG)
+ * and beginning of any _destroy function (QOBJ_UNREG) */
+#define QOBJ_REG(n, structname) qobj_reg(&n->qobj_node, &qobj_t_##structname)
+#define QOBJ_UNREG(n) qobj_unreg(&n->qobj_node)
+
+/* internals - should not be directly used without a good reason
+ *
+ * note: qobj_get is essentially never safe to use in MT context because
+ * the object could be deleted by another thread -- and worse, it could be
+ * of the "wrong" type and deleted.
+ *
+ * with qobj_get_typed, the type check is done under lock, which means that
+ * it can be used as long as another lock prevents the deletion of objects
+ * of the expected type.
+ *
+ * in the long this may need another touch, e.g. built-in per-object locking.
+ */
+void qobj_reg(struct qobj_node *node, const struct qobj_nodetype *type);
+void qobj_unreg(struct qobj_node *node);
+struct qobj_node *qobj_get(uint64_t id);
+void *qobj_get_typed(uint64_t id, const struct qobj_nodetype *type);
+
+/* type declarations */
+#define DECLARE_QOBJ_TYPE(structname)                                          \
+	extern const struct qobj_nodetype qobj_t_##structname                  \
+	/* end */
+#define DEFINE_QOBJ_TYPE(structname)                                           \
+	const struct qobj_nodetype qobj_t_##structname = {                     \
+		.node_member_offset =                                          \
+			(ptrdiff_t)offsetof(struct structname, qobj_node)}     \
+	/* end */
+#define DEFINE_QOBJ_TYPE_INIT(structname, ...)                                 \
+	const struct qobj_nodetype qobj_t_##structname = {                     \
+		.node_member_offset =                                          \
+			(ptrdiff_t)offsetof(struct structname, qobj_node),     \
+		__VA_ARGS__}                                                   \
+	/* end */
+
+/* ID dereference with typecheck.
+ * will return NULL if id not found or wrong type. */
+#define QOBJ_GET_TYPESAFE(id, structname)                                      \
+	((struct structname *)qobj_get_typed((id), &qobj_t_##structname))
+
+#define QOBJ_ID(ptr) ((ptr)->qobj_node.nid)
+#define QOBJ_ID_0SAFE(ptr)                                                     \
+	({                                                                     \
+		typeof(ptr) _ptr = (ptr);                                      \
+		_ptr ? _ptr->qobj_node.nid : 0ULL;                             \
+	})
+
+void qobj_init(void);
+void qobj_finish(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _QOBJ_H */