path: root/engines/sci/engine/seg_manager.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * 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 General Public License for more details.

 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * $URL$
 * $Id$
 *
 */


#ifndef _SCI_SEG_MANAGER_H
#define _SCI_SEG_MANAGER_H

#include "sci/engine/int_hashmap.h"
#include "sci/include/sys_strings.h"
#include "sci/include/vm.h"

#define DEFAULT_SCRIPTS 32
#define DEFAULT_OBJECTS 8	    /* default # of objects per script */
#define DEFAULT_OBJECTS_INCREMENT 4 /* Number of additional objects to
** instantiate if we're running out of them  */

/* SCRIPT_ID must be 0 */
typedef enum {
SCRIPT_ID,
SEG_ID
} id_flag;

//void dbg_print( const char* msg, void *i );	/* for debug only */

/* verify the the given condition is true, output the message if condition is false, and exit
** Parameters:
**   cond - condition to be verified
**   msg  - the message to be printed if condition fails
** return:
**   none, terminate the program if fails
*/
#define VERIFY( cond, msg ) if (! ( cond ) ) {\
	sciprintf( "%s, line, %d, %s\n", __FILE__, __LINE__, msg ); \
	BREAKPOINT(); \
	}


#define MEM_OBJ_INVALID		0
#define MEM_OBJ_SCRIPT		1
#define MEM_OBJ_CLONES		2
#define MEM_OBJ_LOCALS		3
#define MEM_OBJ_STACK		4
#define MEM_OBJ_SYS_STRINGS	5
#define MEM_OBJ_LISTS		6
#define MEM_OBJ_NODES		7
#define MEM_OBJ_HUNK		8
#define MEM_OBJ_DYNMEM		9
#define MEM_OBJ_RESERVED	10
#define MEM_OBJ_MAX		MEM_OBJ_RESERVED /* For sanity checking */
typedef int mem_obj_enum;

struct _mem_obj;

#define GET_SEGMENT(mgr, index, rtype) ((index) > 0 && (mgr).heap_size > index)?		\
		(((mgr).heap[index] && (mgr).heap[index]->type == rtype)? (mgr).heap[index]	\
		: NULL) /* Type does not match */						\
	: NULL /* Invalid index */

#define GET_SEGMENT_ANY(mgr, index) ((index) > 0 && (mgr).heap_size > index)?			\
		(((mgr).heap[index])? (mgr).heap[index]						\
		: NULL) /* Type does not match */						\
	: NULL /* Invalid index */

#define GET_OBJECT_SEGMENT(mgr, index) ((index) > 0 && (mgr).heap_size > index)?		\
		(((mgr).heap[index]								\
                    && ((mgr).heap[index]->type == MEM_OBJ_SCRIPT				\
		        || (mgr).heap[index]->type == MEM_OBJ_CLONES))? (mgr).heap[index]	\
		: NULL) /* Type does not match */						\
	: NULL /* Invalid index */


typedef struct _seg_manager_t {
int_hash_map_t* id_seg_map; /* id - script id; seg - index of heap */
struct _mem_obj** heap;
int heap_size;		/* size of the heap */
int reserved_id;
int exports_wide;
int sci1_1;

int gc_mark_bits; /* For standard Mark&Sweep:
** 1 or 0, depending on what unreachable/freshly allocated
** memory is tagged as  */
size_t mem_allocated; /* Total amount of memory allocated */

seg_id_t clones_seg_id; /* ID of the (a) clones segment */
seg_id_t lists_seg_id; /* ID of the (a) list segment */
seg_id_t nodes_seg_id; /* ID of the (a) node segment */
seg_id_t hunks_seg_id; /* ID of the (a) hunk segment */
} seg_manager_t;



/*==============================================================*/
/* Toplevel functionality					*/
/*==============================================================*/
void
sm_init(seg_manager_t* self, int sci1_1);
/* Initialize the segment manager
*/

void
sm_destroy(seg_manager_t* self);
/* Deallocate all memory associated with the segment manager
*/

void
sm_gc(seg_manager_t *self, struct _state *s);
/* Perform garbage collection
** Parameters: (state_t *) s: The state to operate on
** Effects   : Unreachable objects in 's' are deallocated
*/



/*==============================================================*/
/* 1. Scripts							*/
/*==============================================================*/


void
sm_free_script(mem_obj_t* mem);

mem_obj_t*
sm_allocate_script(struct _seg_manager_t* self, struct _state *s, int script_nr, int* seg_id);
/* Allocate a script into the segment manager
** Parameters: (int) script_nr: number of the script to load
**	       (state_t *) s: The state containing resource manager handlers to load the
**			      script data
** Returns   : (int) 0 on failure, 1 on success
**	       (int) *seg_id: The segment ID of the newly allocated segment, on success

** The script must then be initialised; see section (1b.), below.
*/

int
sm_deallocate_script(struct _seg_manager_t* self, int script_nr);
/* Forcefully deallocate a previously allocated script
** Parameters: (int) script_nr: number of the script to deallocate
** Returns   : (int) 1 on success, 0 on failure
*/

int
sm_script_is_loaded(struct _seg_manager_t* self, int id, id_flag flag);
/* Determines whether a script has been loaded yet
** Parameters: (int) id: number of the script or ID of the script segment to check for
**             (id_flag) flag: Whether to address the script by script number (SCRIPT_ID) or
**				by its segment (SEG_ID). SEG_ID is faster than SCRIPT_ID,
**				but less convenient.
*/

guint16
sm_validate_export_func(struct _seg_manager_t* self, int pubfunct, int seg);
/* Validate whether the specified public function is exported by the script in the specified segment
** Parameters:	(int) pubfunct: Index of the function to validate
**		(int) seg: Segment ID of the script the check is to be performed for
** Returns   :  (guint16) 0 if the public function is invalid, its offset into the script's segment
**			  otherwise
**/

int
sm_seg_get(seg_manager_t* self, int script_nr);
/* Get the segment ID associated with a script number
** Parameters: (int) script_nr: Number of the script to look up
** Returns   : (int) The associated segment ID, or -1 if no matching segment exists
** This function is "pure" (i.e, it doesn't modify anything).
*/


/**************************/
/* script lock operations */
/**************************/

void
sm_increment_lockers(struct _seg_manager_t* self, int id, id_flag flag);
/* Increments the number of lockers of the script in question by one
** Parameters: (int) id: ID of the script or script segment to modify
**             (id_flag) flag: Whether to address the script by script number (SCRIPT_ID) or
**				by its segment (SEG_ID). SEG_ID is faster than SCRIPT_ID,
**				but less convenient.
*/

void
sm_decrement_lockers(struct _seg_manager_t* self, int id, id_flag flag);
/* Decrements the number of lockers of the script in question by one
** Parameters: (int) id: ID of the script or script segment to modify
**             (id_flag) flag: Whether to address the script by script number (SCRIPT_ID) or
**				by its segment (SEG_ID). SEG_ID is faster than SCRIPT_ID,
**				but less convenient.
*/

int
sm_get_lockers(struct _seg_manager_t* self, int id, id_flag flag);
/* Retrieves the number of locks held on this script
** Parameters: (int) id: ID of the script or script segment to read from
**             (id_flag) flag: Whether to address the script by script number (SCRIPT_ID) or
**				by its segment (SEG_ID). SEG_ID is faster than SCRIPT_ID,
**				but less convenient.
** Returns   : (int) The number of locks held on the previously identified script
*/

void
sm_set_lockers(struct _seg_manager_t* self, int lockers, int id, id_flag flag);
/* Sets the number of locks held on the specified script
** Parameters: (int) id: ID of the script or script segment to modify
**             (id_flag) flag: Whether to address the script by script number (SCRIPT_ID) or
**				by its segment (SEG_ID). SEG_ID is faster than SCRIPT_ID,
**				but less convenient.
*/

byte *
sm_get_synonyms(struct _seg_manager_t* self, int id, id_flag flag);
/* Retrieves a pointer to the synonyms associated with the specified script
** Parameters: (int) id: ID of the script or script segment to read from
**             (id_flag) flag: Whether to address the script by script number (SCRIPT_ID) or
**				by its segment (SEG_ID). SEG_ID is faster than SCRIPT_ID,
**				but less convenient.
** Returns   : (byte *) Pointer to the synonyms, in non-parsed format.
** A dynamic failure is issued if the specified ID does not reference a proper script.
*/

int
sm_get_synonyms_nr(struct _seg_manager_t* self, int id, id_flag flag);
/* Retrieves the number of synonyms associated with the specified script
** Parameters: (int) id: ID of the script or script segment to read from
**             (id_flag) flag: Whether to address the script by script number (SCRIPT_ID) or
**				by its segment (SEG_ID). SEG_ID is faster than SCRIPT_ID,
**				but less convenient.
** Returns   : (int) The number of synonyms associated with the specified script
** A dynamic failure is issued if the specified ID does not reference a proper script.
*/


/*==============================================================*/
/* 1b. Script Initialisation					*/
/*==============================================================*/

/*******************************************/
/* The set of functions below are intended */
/* to be used during script instantiation, */
/* i.e. loading and linking.		   */
/*******************************************/

void
sm_script_initialise_locals_zero(struct _seg_manager_t *self, seg_id_t seg, int nr);
/* Initializes a script's local variable block
** Parameters: (seg_id_t) seg: Segment containing the script to initialize
**             (int) nr: Number of local variables to allocate
** All variables are initialized to zero.
*/

void
sm_script_initialise_locals(struct _seg_manager_t *self, reg_t location);
/* Initializes a script's local variable block according to a prototype
** Parameters: (reg_t) location: Location to initialize from
*/

object_t *
sm_script_obj_init(seg_manager_t *self, struct _state *s, reg_t obj_pos);
/* Initializes an object within the segment manager
** Parameters: (reg_t) obj_pos: Location (segment, offset) of the object
** Returns   : (object_t *) A newly created object_t describing the object
** obj_pos must point to the beginning of the script/class block (as opposed
** to what the VM considers to be the object location)
** The corresponding object_t is stored within the relevant script.
*/

void
sm_script_add_code_block(struct _seg_manager_t* self, reg_t location);
/* Informs the segment manager that a code block must be relocated
** Parameters: (reg_t) location: Start of block to relocate
*/

void
sm_set_export_width(struct _seg_manager_t* self, int flag);
/* Tells the segment manager whether exports are wide (32-bit) or not.
** Parameters: (int) flag: 1 if exports are wide, 0 otherwise */

void
sm_script_relocate(struct _seg_manager_t* self, reg_t block);
/* Processes a relocation block witin a script
** Parameters: (reg_t) obj_pos: Location (segment, offset) of the block
** Returns   : (object_t *) Location of the relocation block
** This function is idempotent, but it must only be called after all
** objects have been instantiated, or a run-time error will occur.
*/

void
sm_script_free_unused_objects(struct _seg_manager_t *self, seg_id_t segid);
/* Deallocates all unused but allocated entries for objects
** Parameters: (seg_id_t) segid: segment of the script to prune in this way
** These entries are created during script instantiation; deallocating them
** frees up some additional memory.
*/

void
sm_set_export_table_offset(struct _seg_manager_t* self, int offset, int id, id_flag flag);
/* Sets the script-relative offset of the exports table
** Parameters: (int) offset: The script-relative exports table offset
**	       (int) id: ID of the script or script segment to write to
**             (id_flag) flag: Whether to address the script by script number (SCRIPT_ID) or
**				by its segment (SEG_ID). SEG_ID is faster than SCRIPT_ID,
**				but less convenient.
** A dynamic failure is issued if the specified ID does not reference a proper script.
*/

void
sm_set_synonyms_offset(struct _seg_manager_t* self, int offset, int id, id_flag flag);
/* Sets the script-relative offset of the synonyms associated with the specified script
** Parameters: (int) offset: The script-relative offset of the synonyms block
**	       (int) id: ID of the script or script segment to write to
**             (id_flag) flag: Whether to address the script by script number (SCRIPT_ID) or
**				by its segment (SEG_ID). SEG_ID is faster than SCRIPT_ID,
**				but less convenient.
** A dynamic failure is issued if the specified ID does not reference a proper script.
*/

void
sm_set_synonyms_nr(struct _seg_manager_t* self, int nr, int id, id_flag flag);
/* Sets the number of synonyms associated with the specified script
** Parameters: (int) nr: The number of synonyms, as to be stored within the script
**	       (int) id: ID of the script or script segment to write to
**             (id_flag) flag: Whether to address the script by script number (SCRIPT_ID) or
**				by its segment (SEG_ID). SEG_ID is faster than SCRIPT_ID,
**				but less convenient.
** A dynamic failure is issued if the specified ID does not reference a proper script.
*/

void
sm_mark_script_deleted(seg_manager_t* self, int script_nr);
/* Marks the script identified by its script number as deleted
** Parameters: (int) script_nr: Script number to mark as deleted
** This will not actually delete the script.  If references remain present on the
** heap or the stack, the script will stay in memory in a quasi-deleted state until
** either unreachable (resulting in its eventual deletion) or reloaded (resulting
** in its data being updated).
*/

void
sm_unmark_script_deleted(seg_manager_t* self, int script_nr);
/* Marks the script identified by its script number as not deleted
** Parameters: (int) script_nr: Script number to mark as not deleted
*/

int
sm_script_is_marked_as_deleted(seg_manager_t* self, seg_id_t seg);
/* Determines whether the script referenced by the indicated segment is marked as being deleted.
** Parameters: (seg_id_t) Segment ID of the script to investigate
** Returns   : (int) 1 iff seg points to a script and the segment is deleted, 0 otherwise
** Will return 0 when applied to an invalid or non-script seg.
*/



/*==============================================================*/
/* 2. Clones							*/
/*==============================================================*/

clone_t*
sm_alloc_clone(struct _seg_manager_t *self, reg_t *addr);
/* Allocate a fresh clone
** Returns : (clone_t*): Reference to the memory allocated for the clone
**           (reg_t) *addr: The offset of the freshly allocated clone
*/

void
sm_free_clone(struct _seg_manager_t *self, reg_t addr);
/* Deallocates a clone
** Parameters: (reg_t) addr: Offset of the clone scheduled for termination
*/



/*==============================================================*/
/* Objects (static, from Scripts, and dynmic, from Clones)	*/
/*==============================================================*/

/* Not all of these functions are fully operational for clones ATM */

gint16
sm_get_heap(struct _seg_manager_t* self, reg_t reg);
/* Retrieves a 16 bit value from within a script's heap representation
** Parameters: (reg_t) reg: The address to read from
** Returns   : (gint16) The value read from the specified location
*/

void
sm_put_heap(struct _seg_manager_t* self, reg_t reg, gint16 value);
/* Writes a 16 bit value into a script's heap representation
** Parameters: (reg_t) reg: The address to write to
**	       (gint16) value: The value to write
*/

void
sm_mcpy_in_out(seg_manager_t* self, int dst, const void* src, size_t n, int id, int flag);
/* Copies a byte string into a script's heap representation
** Parameters: (int) dst: The script-relative offset of the destination area
**	       (const void *) src: Pointer to the data source location
**	       (size_t) n: Number of bytes to copy
**	       (int) id: ID of the script or script segment to write to
**             (id_flag) flag: Whether to address the script by script number (SCRIPT_ID) or
**				by its segment (SEG_ID). SEG_ID is faster than SCRIPT_ID,
**				but less convenient.
** A dynamic failure is issued if the specified ID does not reference a proper script.
*/


/*==============================================================*/
/* 4. Stack							*/
/*==============================================================*/

dstack_t *
sm_allocate_stack(struct _seg_manager_t *self, int size, seg_id_t *segid);
/* Allocates a data stack
** Parameters: (int) size: Number of stack entries to reserve
** Returns   : (dstack_t *): The physical stack
**             (seg_id_t) segid: Segment ID of the stack
*/



/*==============================================================*/
/* 5. System Strings						*/
/*==============================================================*/

sys_strings_t *
sm_allocate_sys_strings(struct _seg_manager_t *self, seg_id_t *segid);
/* Allocates a system string table
** Returns   : (dstack_t *): The physical stack
**             (seg_id_t) segid: Segment ID of the stack
** See also sys_string_acquire();
*/



/*==============================================================*/
/* 6, 7. Lists and Nodes					*/
/*==============================================================*/

list_t*
sm_alloc_list(struct _seg_manager_t *self, reg_t *addr);
/* Allocate a fresh list
** Returns : (listY_t*): Reference to the memory allocated for the list
**           (reg_t) *addr: The offset of the freshly allocated list
*/

void
sm_free_list(struct _seg_manager_t *self, reg_t addr);
/* Deallocates a list
** Parameters: (reg_t) addr: Offset of the list scheduled for termination
*/


node_t*
sm_alloc_node(struct _seg_manager_t *self, reg_t *addr);
/* Allocate a fresh node
** Returns : (node_t*): Reference to the memory allocated for the node
**           (reg_t) *addr: The offset of the freshly allocated node
*/

void
sm_free_node(struct _seg_manager_t *self, reg_t addr);
/* Deallocates a list node
** Parameters: (reg_t) addr: Offset of the node scheduled for termination
*/



/*==============================================================*/
/* 8. Hunk Memory						*/
/*==============================================================*/

hunk_t*
sm_alloc_hunk_entry(struct _seg_manager_t *self, const char *hunk_type, int size, reg_t *addr);
/* Allocate a fresh chunk of the hunk
** Parameters: (int) size: Number of bytes to allocate for the hunk entry
**             (const char *) hunk_type: A descriptive string for the hunk entry,
**				for debugging purposes
** Returns   : (hunk_t*): Reference to the memory allocated for the hunk piece
**             (reg_t) *addr: The offset of the freshly allocated hunk entry
*/

void
sm_free_hunk_entry(struct _seg_manager_t *self, reg_t addr);
/* Deallocates a hunk eentry
** Parameters: (reg_t) addr: Offset of the hunk entry to delete
*/



/*==============================================================*/
/* 9. Dynamic Memory						*/
/*==============================================================*/

unsigned char *
sm_alloc_dynmem(struct _seg_manager_t *self, int size, const char *description, reg_t *addr);
/* Allocate some dynamic memory
** Parameters: (int) size: Number of bytes to allocate
**             (const char_ *) description: A descriptive string,
**				for debugging purposes
** Returns   : (unsigned char*): Raw pointer into the allocated dynamic memory
**             (reg_t) *addr: The offset of the freshly allocated X
*/

int
sm_free_dynmem(struct _seg_manager_t *self, reg_t addr);
/* Deallocates a piece of dynamic memory
** Parameters: (reg_t) addr: Offset of the dynmem chunk to free
*/

const char *
sm_get_description(struct _seg_manager_t *self, reg_t addr);
/* Gets the description of a dynmem segment
** Parameters: (reg_t) addr: Segment to describe
** Returns   : (const char *): Pointer to the descriptive string set in
** sm_alloc_dynmem
*/

/*==============================================================*/
/* 10. Reserved segments					*/
/*==============================================================*/

seg_id_t
sm_allocate_reserved_segment(struct _seg_manager_t *self, char *name);
/* Reserves a special-purpose segment
** Parameters: (char *) name: A string name identifying the segment (the string is cloned and retained)
** Returns   : A fresh segment ID for the segment in question
** Reserved segments are never used by the segment manager.  They can be used to tag special-purpose addresses.
** Segment 0 is implicitly reserved for numbers.
*/

/*==============================================================*/
/* Generic Operations on Segments and Addresses			*/
/*==============================================================*/

byte *
sm_dereference(struct _seg_manager_t *self, reg_t reg, int *size);
/* Dereferences a raw memory pointer
** Parameters: (reg_t) reg: The reference to dereference
** Returns   : (byte *) The data block referenced
**             (int) size: (optionally) the theoretical maximum size of it
*/


/*==============================================================*/
/* 11. Segment interface, primarily for GC			*/
/*==============================================================*/

typedef struct _seg_interface {
	seg_manager_t *segmgr;
	mem_obj_t *mobj;
	seg_id_t seg_id;
	mem_obj_enum type_id;	/* Segment type */
	const char *type;	/* String description of the segment type */

	reg_t
	(*find_canonic_address)(struct _seg_interface *self, reg_t sub_addr);
	/* Finds the canonic address associated with sub_reg
	** Parameters: (reg_t) sub_addr: The base address whose canonic address is to be found
	** For each valid address a, there exists a canonic address c(a) such that c(a) = c(c(a)).
	** This address "governs" a in the sense that deallocating c(a) will deallocate a.
	*/

	void
	(*free_at_address)(struct _seg_interface *self, reg_t sub_addr);
	/* Deallocates all memory associated with the specified address
	** Parameters: (reg_t) sub_addr: The address (within the given segment) to deallocate
	*/

	void
	(*list_all_deallocatable)(struct _seg_interface *self, void *param, void (*note)(void *param, reg_t addr));
	/* Iterates over and reports all addresses within the current segment
	** Parameters: note : (voidptr * addr) -> (): Invoked for each address on which free_at_address()
	**                                makes sense
	**             (void *) param: Parameter passed to 'note'
	*/

	void
	(*list_all_outgoing_references)(struct _seg_interface *self, struct _state *s, reg_t object, void *param, void (*note)(void *param, reg_t addr));
	/* Iterates over all references reachable from the specified object
	** Parameters: (reg_t) object: The object (within the current segment) to analyse
	**             (void *) param: Parameter passed to 'note'
	**             note : (voidptr * addr) -> (): Invoked for each outgoing reference within the object
	** Note: This function may also choose to report numbers (segment 0) as adresses
	*/

	void
	(*deallocate_self)(struct _seg_interface *self);
	/* Deallocates the segment interface
	 */

} seg_interface_t;

seg_interface_t *
get_seg_interface(seg_manager_t *self, seg_id_t segid);
/* Retrieves the segment interface to the specified segment
** Parameters: (seg_id_t) segid: ID of the segment to look up
** Returns   : (seg_interface_t *): An interface to the specified segment ID, or NULL on error
** The returned interface 'si' must be freed after use by calling 'si->dealloc_self(si)';
*/



#endif