Add libhurd-slab

* libhurd-slab: New directory
* Makefile (lib-subdirs): Add libhurd-slab.

1 files changed, 338 insertions, 0 deletions

diff --git a/libhurd-slab/slab.h b/libhurd-slab/slab.h
new file mode 100644
index 00000000..6eeb8e48
--- /dev/null
+++ b/libhurd-slab/slab.h
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+/* slab.h - The GNU Hurd slab allocator interface.
+   Copyright (C) 2003, 2005 Free Software Foundation, Inc.
+   Written by Marcus Brinkmann <marcus@gnu.org>
+
+   This file is part of the GNU Hurd.
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this program; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#ifndef _HURD_SLAB_H
+#define _HURD_SLAB_H	1
+
+#include <errno.h>
+#include <stdbool.h>
+#include <pthread.h>
+
+
+/* Allocate a buffer in *PTR of size SIZE which must be a power of 2
+   and self aligned (i.e. aligned on a SIZE byte boundary).  HOOK is
+   as provided to hurd_slab_create.  Return 0 on success, an error
+   code on failure.  */
+typedef error_t (*hurd_slab_allocate_buffer_t) (void *hook, size_t size,
+						void **ptr);
+
+/* Deallocate buffer BUFFER of size SIZE.  HOOK is as provided to
+   hurd_slab_create.  */
+typedef error_t (*hurd_slab_deallocate_buffer_t) (void *hook, void *buffer,
+						  size_t size);
+
+/* Initialize the slab object pointed to by OBJECT.  HOOK is as
+   provided to hurd_slab_create.  */
+typedef error_t (*hurd_slab_constructor_t) (void *hook, void *object);
+
+/* Destroy the slab object pointed to by OBJECT.  HOOK is as provided
+   to hurd_slab_create.  */
+typedef void (*hurd_slab_destructor_t) (void *hook, void *object);
+
+
+/* The type of a slab space.  
+
+   The structure is divided into two parts: the first is only used
+   while the slab space is constructed.  Its fields are either
+   initialized by a static initializer (HURD_SLAB_SPACE_INITIALIZER)
+   or by the hurd_slab_create function.  The initialization of the
+   space is delayed until the first allocation.  After that only the
+   second part is used.  */
+
+typedef struct hurd_slab_space *hurd_slab_space_t;
+struct hurd_slab_space
+{
+  /* First part.  Used when initializing slab space object.   */
+  
+  /* True if slab space has been initialized.  */
+  bool initialized;
+  
+  /* Protects this structure, along with all the slabs.  No need to
+     delay initialization of this field.  */
+  pthread_mutex_t lock;
+
+  /* The size and alignment of objects allocated using this slab
+     space.  These to fields are used to calculate the final object
+     size, which is put in SIZE (defined below).  */
+  size_t requested_size;
+  size_t requested_align;
+
+  /* The size of each slab. */
+  size_t slab_size;
+
+  /* The buffer allocator.  */
+  hurd_slab_allocate_buffer_t allocate_buffer;
+
+  /* The buffer deallocator.  */
+  hurd_slab_deallocate_buffer_t deallocate_buffer;
+
+  /* The constructor.  */
+  hurd_slab_constructor_t constructor;
+
+  /* The destructor.  */
+  hurd_slab_destructor_t destructor;
+
+  /* The user's private data.  */
+  void *hook;
+
+  /* Second part.  Runtime information for the slab space.  */
+
+  struct hurd_slab *slab_first;
+  struct hurd_slab *slab_last;
+
+  /* In the doubly-linked list of slabs, empty slabs come first, after
+     that the slabs that have some buffers allocated, and finally the
+     complete slabs (refcount == 0).  FIRST_FREE points to the first
+     non-empty slab.  */
+  struct hurd_slab *first_free;
+
+  /* For easy checking, this holds the value the reference counter
+     should have for an empty slab.  */
+  int full_refcount;
+
+  /* The size of one object.  Should include possible alignment as
+     well as the size of the bufctl structure.  */
+  size_t size;
+};
+
+
+/* Static initializer.  TYPE is used to get size and alignment of
+   objects the slab space will be used to allocate.  ALLOCATE_BUFFER
+   may be NULL in which case mmap is called.  DEALLOCATE_BUFFER may be
+   NULL in which case munmap is called.  CTOR and DTOR are the slab's
+   object constructor and destructor, respectivly and may be NULL if
+   not required.  HOOK is passed as user data to the constructor and
+   destructor.  */
+#define HURD_SLAB_SPACE_INITIALIZER(TYPE, ALLOC, DEALLOC, CTOR,	\
+				    DTOR, HOOK)			\
+  {								\
+    false,							\
+    PTHREAD_MUTEX_INITIALIZER, 					\
+    sizeof (TYPE),						\
+    __alignof__ (TYPE),						\
+    ALLOC,							\
+    DEALLOC,							\
+    CTOR,							\
+    DTOR,							\
+    HOOK							\
+    /* The rest of the structure will be filled with zeros,     \
+       which is good for us.  */				\
+  }
+
+
+/* Create a new slab space with the given object size, alignment,
+   constructor and destructor.  ALIGNMENT can be zero.
+   ALLOCATE_BUFFER may be NULL in which case mmap is called.
+   DEALLOCATE_BUFFER may be NULL in which case munmap is called.  CTOR
+   and DTOR are the slabs object constructor and destructor,
+   respectivly and may be NULL if not required.  HOOK is passed as the
+   first argument to the constructor and destructor.  */
+error_t hurd_slab_create (size_t size, size_t alignment,
+			  hurd_slab_allocate_buffer_t allocate_buffer,
+			  hurd_slab_deallocate_buffer_t deallocate_buffer,
+			  hurd_slab_constructor_t constructor,
+			  hurd_slab_destructor_t destructor,
+			  void *hook,
+			  hurd_slab_space_t *space);
+
+/* Destroy all objects and the slab space SPACE.  If there were no
+   outstanding allocations free the slab space.  Returns EBUSY if
+   there are still allocated objects in the slab space.  The dual of
+   hurd_slab_create.  */
+error_t hurd_slab_free (hurd_slab_space_t space);
+
+/* Like hurd_slab_create, but does not allocate storage for the slab.  */
+error_t hurd_slab_init (hurd_slab_space_t space, size_t size, size_t alignment,
+			hurd_slab_allocate_buffer_t allocate_buffer,
+			hurd_slab_deallocate_buffer_t deallocate_buffer,
+			hurd_slab_constructor_t constructor,
+			hurd_slab_destructor_t destructor,
+			void *hook);
+
+/* Destroy all objects and the slab space SPACE.  Returns EBUSY if
+   there are still allocated objects in the slab.  The dual of
+   hurd_slab_init.  */
+error_t hurd_slab_destroy (hurd_slab_space_t space);
+
+/* Allocate a new object from the slab space SPACE.  */
+error_t hurd_slab_alloc (hurd_slab_space_t space, void **buffer);
+
+/* Deallocate the object BUFFER from the slab space SPACE.  */
+void hurd_slab_dealloc (hurd_slab_space_t space, void *buffer);
+
+/* Create a more strongly typed slab interface a la a C++ template.
+
+   NAME is the name of the new slab class.  NAME is used to synthesize
+   names for the class types and methods using the following rule: the
+   hurd_ namespace will prefix all method names followed by NAME
+   followed by an underscore and finally the method name.  The
+   following are thus exposed:
+
+    Types:
+     struct hurd_NAME_slab_space
+     hurd_NAME_slab_space_t
+
+     error_t (*hurd_NAME_slab_constructor_t) (void *hook, element_type *buffer)
+     void (*hurd_NAME_slab_destructor_t) (void *hook, element_type *buffer)
+
+    Functions:
+     error_t hurd_NAME_slab_create (hurd_slab_allocate_buffer_t
+                                     allocate_buffer,
+                                    hurd_slab_deallocate_buffer_t
+                                     deallocate_buffer,
+                                    hurd_NAME_slab_constructor_t constructor,
+                                    hurd_NAME_slab_destructor_t destructor,
+                                    void *hook,
+                                    hurd_NAME_slab_space_t *space);
+     error_t hurd_NAME_slab_free (hurd_NAME_slab_space_t space);
+
+     error_t hurd_NAME_slab_init (hurd_NAME_slab_space_t space,
+                                  hurd_slab_allocate_buffer_t allocate_buffer,
+                                  hurd_slab_deallocate_buffer_t
+                                   deallocate_buffer,
+                                  hurd_NAME_slab_constructor_t constructor,
+                                  hurd_NAME_slab_destructor_t destructor,
+                                  void *hook);
+     error_t hurd_NAME_slab_destroy (hurd_NAME_slab_space_t space);
+
+     error_t hurd_NAME_slab_alloc (hurd_NAME_slab_space_t space,
+                                   element_type **buffer);
+     void hurd_NAME_slab_dealloc (hurd_NAME_slab_space_t space,
+                                  element_type *buffer);
+
+  ELEMENT_TYPE is the type of elements to store in the slab.  If you
+  want the slab to contain struct foo, pass `struct foo' as the
+  ELEMENT_TYPE (not `struct foo *'!!!).
+     
+*/
+#define SLAB_CLASS(name, element_type)                                       \
+struct hurd_##name##_slab_space						     \
+{									     \
+  struct hurd_slab_space space;						     \
+};									     \
+typedef struct hurd_##name##_slab_space *hurd_##name##_slab_space_t;	     \
+									     \
+typedef error_t (*hurd_##name##_slab_constructor_t) (void *hook,	     \
+						     element_type *buffer);  \
+									     \
+typedef void (*hurd_##name##_slab_destructor_t) (void *hook,		     \
+						 element_type *buffer);	     \
+									     \
+static inline error_t							     \
+hurd_##name##_slab_create (hurd_slab_allocate_buffer_t allocate_buffer,	     \
+			   hurd_slab_deallocate_buffer_t deallocate_buffer,  \
+			   hurd_##name##_slab_constructor_t constructor,     \
+			   hurd_##name##_slab_destructor_t destructor,	     \
+			   void *hook,					     \
+			   hurd_##name##_slab_space_t *space)		     \
+{									     \
+  union									     \
+  {									     \
+    hurd_##name##_slab_constructor_t t;					     \
+    hurd_slab_constructor_t u;						     \
+  } con;								     \
+  union									     \
+  {									     \
+    hurd_##name##_slab_destructor_t t;					     \
+    hurd_slab_destructor_t u;						     \
+  } des;								     \
+  union									     \
+  {									     \
+    hurd_##name##_slab_space_t *t;					     \
+    hurd_slab_space_t *u;						     \
+  } foo;								     \
+  con.t = constructor;							     \
+  des.t = destructor;							     \
+  foo.t = space;							     \
+									     \
+  return hurd_slab_create(sizeof (element_type), __alignof__ (element_type), \
+			  allocate_buffer, deallocate_buffer,		     \
+			  con.u, des.u, hook, foo.u);			     \
+}									     \
+									     \
+static inline error_t							     \
+hurd_##name##_slab_free (hurd_##name##_slab_space_t space)		     \
+{									     \
+  return hurd_slab_free (&space->space);				     \
+}									     \
+									     \
+static inline error_t							     \
+hurd_##name##_slab_init (hurd_##name##_slab_space_t space,		     \
+			 hurd_slab_allocate_buffer_t allocate_buffer,	     \
+			 hurd_slab_deallocate_buffer_t deallocate_buffer,    \
+			 hurd_##name##_slab_constructor_t constructor,	     \
+			 hurd_##name##_slab_destructor_t destructor,	     \
+			 void *hook)					     \
+{									     \
+  union									     \
+  {									     \
+    hurd_##name##_slab_constructor_t t;					     \
+    hurd_slab_constructor_t u;						     \
+  } con;								     \
+  union									     \
+  {									     \
+    hurd_##name##_slab_destructor_t t;					     \
+    hurd_slab_destructor_t u;						     \
+  } des;								     \
+  con.t = constructor;							     \
+  des.t = destructor;							     \
+									     \
+  return hurd_slab_init (&space->space,					     \
+			 sizeof (element_type), __alignof__ (element_type),  \
+			 allocate_buffer, deallocate_buffer,		     \
+			 con.u, des.u, hook);				     \
+}									     \
+									     \
+static inline error_t							     \
+hurd_##name##_slab_destroy (hurd_##name##_slab_space_t space)		     \
+{									     \
+  return hurd_slab_destroy (&space->space);				     \
+}									     \
+									     \
+static inline error_t							     \
+hurd_##name##_slab_alloc (hurd_##name##_slab_space_t space,		     \
+			  element_type **buffer)			     \
+{									     \
+  union									     \
+  {									     \
+    element_type **e;							     \
+    void **v;								     \
+  } foo;								     \
+  foo.e = buffer;							     \
+									     \
+  return hurd_slab_alloc (&space->space, foo.v);			     \
+}									     \
+									     \
+static inline void							     \
+hurd_##name##_slab_dealloc (hurd_##name##_slab_space_t space,		     \
+			    element_type *buffer)			     \
+{									     \
+  union									     \
+  {									     \
+    element_type *e;							     \
+    void *v;								     \
+  } foo;								     \
+  foo.e = buffer;							     \
+									     \
+  hurd_slab_dealloc (&space->space, foo.v);				     \
+}
+
+#endif	/* _HURD_SLAB_H */