diff options
Diffstat (limited to 'core/bgdrtm/src/instance.c')
| -rw-r--r-- | core/bgdrtm/src/instance.c | 763 |
1 files changed, 763 insertions, 0 deletions
diff --git a/core/bgdrtm/src/instance.c b/core/bgdrtm/src/instance.c new file mode 100644 index 0000000..a91633c --- /dev/null +++ b/core/bgdrtm/src/instance.c @@ -0,0 +1,763 @@ +/* + * Copyright © 2006-2016 SplinterGU (Fenix/Bennugd) + * Copyright © 2002-2006 Fenix Team (Fenix) + * Copyright © 1999-2002 José Luis Cebrián Pagüe (Fenix) + * + * This file is part of Bennu - Game Development + * + * This software is provided 'as-is', without any express or implied + * warranty. In no event will the authors be held liable for any damages + * arising from the use of this software. + * + * Permission is granted to anyone to use this software for any purpose, + * including commercial applications, and to alter it and redistribute it + * freely, subject to the following restrictions: + * + * 1. The origin of this software must not be misrepresented; you must not + * claim that you wrote the original software. If you use this software + * in a product, an acknowledgment in the product documentation would be + * appreciated but is not required. + * + * 2. Altered source versions must be plainly marked as such, and must not be + * misrepresented as being the original software. + * + * 3. This notice may not be removed or altered from any source + * distribution. + * + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#ifdef TARGET_BEOS +#include <posix/assert.h> +#else +#include <assert.h> +#endif + +#include "offsets.h" +#include "bgdrtm.h" +#include "sysprocs_p.h" +#include "instance.h" +#include "xstrings.h" + +#undef STACK_SIZE +#define STACK_SIZE 4096 + +/* ---------------------------------------------------------------------- */ + +#define INSTANCE_MIN_PRIORITY -32768 +#define INSTANCE_MAX_PRIORITY 32767 +#define INSTANCE_NORMALIZE_PRIORITY 32768 + +/* ---------------------------------------------------------------------- */ +/* Módulo de gestión de instancias, con las funciones de incialización y */ +/* destrucción, duplicado, etc. */ +/* ---------------------------------------------------------------------- */ + +#define HASH(id) (unsigned int)((id)&0x0000ffff) +#define HASH_PRIORITY(id) (unsigned int)(((id) + INSTANCE_NORMALIZE_PRIORITY) & 0x0000ffff) +#define HASH_INSTANCE(id) (unsigned int)(((( uint32_t )(id)) >> 2 ) & 0x0000ffff) +#define HASH_SIZE 65536 + +INSTANCE ** hashed_by_id = NULL; +INSTANCE ** hashed_by_instance = NULL; +INSTANCE ** hashed_by_type = NULL; +INSTANCE ** hashed_by_priority = NULL; + +INSTANCE * first_instance = NULL ; + +/* Priority lists */ + +static INSTANCE * iterator_by_priority = NULL ; +static int iterator_pos = HASH_SIZE; + +static int instance_maxid = FIRST_INSTANCE_ID ; + +static int instance_min_actual_prio = INSTANCE_MAX_PRIORITY ; +static int instance_max_actual_prio = INSTANCE_MIN_PRIORITY ; + +/* ---------------------------------------------------------------------- */ +/* By id */ +/* ---------------------------------------------------------------------- */ + +void instance_add_to_list_by_id( INSTANCE * r, uint32_t id ) +{ + if ( !hashed_by_id ) hashed_by_id = calloc( HASH_SIZE, sizeof( INSTANCE * ) ); + hashed_by_id[HASH( id )] = r; +} + +/* ---------------------------------------------------------------------- */ + +void instance_remove_from_list_by_id( INSTANCE * r, uint32_t id ) +{ + hashed_by_id[HASH( id )] = NULL; +} + +/* ---------------------------------------------------------------------- */ +/* By instance */ +/* ---------------------------------------------------------------------- */ + +void instance_add_to_list_by_instance( INSTANCE * r ) +{ + unsigned int hash = HASH_INSTANCE( r ); + + if ( !hashed_by_instance ) hashed_by_instance = calloc( HASH_SIZE, sizeof( INSTANCE * ) ); + + r->prev_by_instance = NULL ; + r->next_by_instance = hashed_by_instance[hash]; + if ( r->next_by_instance ) r->next_by_instance->prev_by_instance = r ; + hashed_by_instance[hash] = r; +} + +/* ---------------------------------------------------------------------- */ + +void instance_remove_from_list_by_instance( INSTANCE * r ) +{ + unsigned int hash = HASH_INSTANCE( r ); + + if ( r->prev_by_instance ) r->prev_by_instance->next_by_instance = r->next_by_instance ; + if ( r->next_by_instance ) r->next_by_instance->prev_by_instance = r->prev_by_instance ; + + if ( hashed_by_instance[hash] == r ) hashed_by_instance[hash] = r->next_by_instance ; +} + +/* ---------------------------------------------------------------------- */ +/* By type */ +/* ---------------------------------------------------------------------- */ + +void instance_add_to_list_by_type( INSTANCE * r, uint32_t type ) +{ + unsigned int hash = HASH( type ); + + if ( !hashed_by_type ) hashed_by_type = calloc( HASH_SIZE, sizeof( INSTANCE * ) ); + + r->prev_by_type = NULL ; + r->next_by_type = hashed_by_type[hash]; + if ( r->next_by_type ) r->next_by_type->prev_by_type = r ; + hashed_by_type[hash] = r; +} + +/* ---------------------------------------------------------------------- */ + +void instance_remove_from_list_by_type( INSTANCE * r, uint32_t type ) +{ + unsigned int hash = HASH( type ); + + if ( r->prev_by_type ) r->prev_by_type->next_by_type = r->next_by_type ; + if ( r->next_by_type ) r->next_by_type->prev_by_type = r->prev_by_type ; + + if ( hashed_by_type[hash] == r ) hashed_by_type[hash] = r->next_by_type ; +} + +/* ---------------------------------------------------------------------- */ +/* By priority */ +/* ---------------------------------------------------------------------- */ + +void instance_add_to_list_by_priority( INSTANCE * r, int32_t priority ) +{ + unsigned int hash ; + + if ( priority < INSTANCE_MIN_PRIORITY ) priority = LOCINT32( r, PRIORITY ) = INSTANCE_MIN_PRIORITY; + if ( priority > INSTANCE_MAX_PRIORITY ) priority = LOCINT32( r, PRIORITY ) = INSTANCE_MAX_PRIORITY; + + hash = HASH_PRIORITY( priority ); + + if ( !hashed_by_priority ) hashed_by_priority = calloc( HASH_SIZE, sizeof( INSTANCE * ) ); + + r->prev_by_priority = NULL ; + r->next_by_priority = hashed_by_priority[hash]; + if ( r->next_by_priority ) r->next_by_priority->prev_by_priority = r ; + hashed_by_priority[hash] = r; + r->last_priority = priority ; + + if ( priority < instance_min_actual_prio ) instance_min_actual_prio = priority ; + if ( priority > instance_max_actual_prio ) instance_max_actual_prio = priority ; +} + +/* ---------------------------------------------------------------------- */ + +void instance_remove_from_list_by_priority( INSTANCE * r ) +{ + unsigned int hash = HASH_PRIORITY( r->last_priority ); + + /* Update iterator_by_priority if necessary */ + + if ( iterator_by_priority == r ) instance_next_by_priority() ; + + if ( r->prev_by_priority ) r->prev_by_priority->next_by_priority = r->next_by_priority ; + if ( r->next_by_priority ) r->next_by_priority->prev_by_priority = r->prev_by_priority ; + + if ( hashed_by_priority[hash] == r ) hashed_by_priority[hash] = r->next_by_priority ; + + if ( !hashed_by_priority[hash] ) + { + if ( r->last_priority == instance_min_actual_prio ) + { + while ( instance_min_actual_prio < instance_max_actual_prio && !hashed_by_priority[ instance_min_actual_prio + INSTANCE_NORMALIZE_PRIORITY ] ) + instance_min_actual_prio++; + } + + if ( r->last_priority == instance_max_actual_prio ) + { + while ( instance_max_actual_prio > instance_min_actual_prio && !hashed_by_priority[ instance_max_actual_prio + INSTANCE_NORMALIZE_PRIORITY ] ) + instance_max_actual_prio--; + } + } +} + +/* ---------------------------------------------------------------------- */ + +/* + * FUNCTION : instance_dirty + * + * Adds an instance to the dirty instances list. This is a list of all + * instances which priority changed since the last execution. + * + * PARAMS : + * i Pointer to the instance + * + * RETURN VALUE : + * None + */ + +void instance_dirty( INSTANCE * i ) +{ + instance_remove_from_list_by_priority( i ); + instance_add_to_list_by_priority( i, LOCINT32( i, PRIORITY ) ); +} + +/* ---------------------------------------------------------------------- */ + +/* + * FUNCTION : instance_get + * + * Returns a instance, given its ID. + * + * PARAMS : + * id Integer ID of the instance + * + * RETURN VALUE : + * Pointer to the found instance or NULL if not found + */ + +INSTANCE * instance_get( int id ) +{ + if ( !hashed_by_id || !id ) return NULL; + return ( hashed_by_id[HASH( id )] ); +} + +/* ---------------------------------------------------------------------- */ + +/* + * FUNCTION : instance_getid + * + * Allocate and return a free instance identifier code. + * + * PARAMS : + * None + * + * RETURN VALUE : + * A new, unused instance identifier + * -1 if error + */ + +int instance_getid() +{ + int id = instance_maxid++ ; + + if ( !hashed_by_id ) hashed_by_id = calloc( HASH_SIZE, sizeof( INSTANCE * ) ); + + if ( id <= LAST_INSTANCE_ID && !hashed_by_id[ HASH( id ) ] ) return id; + + if ( instance_maxid > LAST_INSTANCE_ID ) + { + for ( instance_maxid = FIRST_INSTANCE_ID; instance_maxid <= LAST_INSTANCE_ID; instance_maxid++ ) + { + if ( !hashed_by_id[HASH( instance_maxid )] ) return instance_maxid++; + } + } + else + { + for ( ; instance_maxid <= LAST_INSTANCE_ID; instance_maxid++ ) + { + if ( !hashed_by_id[HASH( instance_maxid )] ) return instance_maxid++; + } + for ( instance_maxid = FIRST_INSTANCE_ID; instance_maxid < id; instance_maxid++ ) + { + if ( !hashed_by_id[HASH( instance_maxid )] ) return instance_maxid++; + } + } + return -1; +} + +/* ---------------------------------------------------------------------- */ + +/* + * FUNCTION : instance_duplicate + * + * Create a copy of an instance, using the same local/private data + * - Updates the instance list, adding the new instance + * - Marks all local and private strings + * - Updates all parents local family variables + * + * The new instance uses the same code pointer as the father + * (it begins execution at the same line, instead of the first one) + * + * PARAMS : + * father Pointer to the original instance + * + * RETURN VALUE : + * Pointer to the new instance + */ + +INSTANCE * instance_duplicate( INSTANCE * father ) +{ + INSTANCE * r, * brother ; + int n, pid ; + uint32_t type ; + + if ( ( pid = instance_getid() ) == -1 ) return NULL; + + r = ( INSTANCE * ) calloc( 1, sizeof( INSTANCE ) ) ; + assert( r ) ; + + r->pridata = ( int * ) malloc( father->private_size + 4 ) ; + r->pubdata = ( int * ) malloc( father->public_size + 4 ) ; + r->locdata = ( int * ) malloc( local_size + 4 ) ; + r->code = father->code ; + r->codeptr = father->codeptr ; + r->exitcode = father->exitcode ; + r->errorcode = father->errorcode ; + r->proc = father->proc ; + r->call_level = father->call_level ; + + r->switchval = 0; + r->switchval_string = 0; + r->cased = 0; + + r->breakpoint = 0 ; + + r->private_size = father->private_size ; + r->public_size = father->public_size ; + r->first_run = 1 ; + + if ( father->private_size > 0 ) memcpy( r->pridata, father->pridata, r->private_size ) ; + if ( father->public_size > 0 ) memcpy( r->pubdata, father->pubdata, r->public_size ) ; + if ( local_size > 0 ) memcpy( r->locdata, father->locdata, local_size ) ; + + /* Inicializa datos de jerarquia */ + + /* Crea el proceso clónico como si lo hubiera llamado el padre */ + + type = LOCDWORD( father, PROCESS_TYPE ) ; + LOCDWORD( r, PROCESS_ID ) = pid ; + LOCDWORD( r, SON ) = 0 ; + LOCDWORD( r, SMALLBRO ) = 0 ; + + LOCDWORD( r, FATHER ) = LOCDWORD( father, PROCESS_ID ) ; + brother = instance_get( LOCDWORD( father, SON ) ) ; + if ( brother ) + { + LOCDWORD( r, BIGBRO ) = LOCDWORD( brother, PROCESS_ID ) ; + LOCDWORD( brother, SMALLBRO ) = pid ; + } + else + { + LOCDWORD( r, BIGBRO ) = 0 ; + } + LOCDWORD( father, SON ) = pid ; + + /* Actualiza las cuentas de uso de las cadenas */ + + for ( n = 0; n < r->proc->string_count; n++ ) string_use( PRIDWORD( r, r->proc->strings[n] ) ) ; /* Strings privadas */ + for ( n = 0; n < r->proc->pubstring_count; n++ ) string_use( PUBDWORD( r, r->proc->pubstrings[n] ) ) ; /* Strings publicas */ + for ( n = 0; n < local_strings; n++ ) string_use( LOCDWORD( r, localstr[n] ) ) ; /* Strings locales */ + + r->prev = NULL ; + r->next = first_instance ; + if ( first_instance ) first_instance->prev = r; + first_instance = r ; + + instance_add_to_list_by_id( r, pid ); + instance_add_to_list_by_instance( r ); + instance_add_to_list_by_type( r, type ); + instance_add_to_list_by_priority( r, LOCINT32( r, PRIORITY ) ); + + /* The called_by pointer should be set only when the caller + * is waiting for this process to return */ + + r->called_by = NULL; + + r->stack = malloc( father->stack[0] ); + memmove(r->stack, father->stack, (int)father->stack_ptr - (int)father->stack); + r->stack_ptr = &r->stack[1]; + + /* Initialize list pointers */ + + LOCDWORD( r, STATUS ) = STATUS_RUNNING; + + if ( instance_create_hook_count ) + for ( n = 0; n < instance_create_hook_count; n++ ) + instance_create_hook_list[n]( r ); + + return r ; +} + +/* ---------------------------------------------------------------------- */ + +/* + * FUNCTION : instance_new + * + * Create a new instance, using the default local/private data + * - Updates the instance list, adding the new instance + * - Marks all local and private strings + * - Updates all parents local family variables + * + * PARAMS : + * proc Pointer to the procedure definition + * father Pointer to the father instance (may be NULL) + * + * RETURN VALUE : + * Pointer to the new instance + */ + +INSTANCE * instance_new( PROCDEF * proc, INSTANCE * father ) +{ + INSTANCE * r, * brother; + int n, pid; + + if ( ( pid = instance_getid() ) == -1 ) return NULL; + + r = ( INSTANCE * ) calloc( 1, sizeof( INSTANCE ) ) ; + assert( r ) ; + + r->pridata = ( int * ) malloc( proc->private_size + 4 ) ; + r->pubdata = ( int * ) malloc( proc->public_size + 4 ) ; + r->locdata = ( int * ) malloc( local_size + 4 ) ; + r->code = proc->code ; + r->codeptr = proc->code ; + r->exitcode = proc->exitcode ; + r->errorcode = proc->errorcode ; + r->proc = proc ; + r->call_level = 0 ; + + r->switchval = 0; + r->switchval_string = 0; + r->cased = 0; + + r->breakpoint = 0 ; + + r->private_size = proc->private_size ; + r->public_size = proc->public_size ; + r->first_run = 1 ; + + if ( proc->private_size > 0 ) memcpy( r->pridata, proc->pridata, proc->private_size ) ; + if ( proc->public_size > 0 ) memcpy( r->pubdata, proc->pubdata, proc->public_size ) ; + if ( local_size > 0 ) memcpy( r->locdata, localdata, local_size ) ; + + /* Inicializa datos de jerarquia */ + + LOCDWORD( r, PROCESS_TYPE ) = proc->type ; + LOCDWORD( r, PROCESS_ID ) = pid ; + LOCDWORD( r, SON ) = 0 ; + LOCDWORD( r, SMALLBRO ) = 0 ; + + if ( father ) + { + LOCDWORD( r, FATHER ) = LOCDWORD( father, PROCESS_ID ) ; + brother = instance_get( LOCDWORD( father, SON ) ) ; + if ( brother ) + { + LOCDWORD( r, BIGBRO ) = LOCDWORD( brother, PROCESS_ID ) ; + LOCDWORD( brother, SMALLBRO ) = pid ; + } + else + { + LOCDWORD( r, BIGBRO ) = 0 ; + } + LOCDWORD( father, SON ) = pid ; + } + else + { + LOCDWORD( r, FATHER ) = 0 ; + LOCDWORD( r, BIGBRO ) = 0 ; + } + + /* Cuenta los usos de las variables tipo cadena */ + + for ( n = 0; n < proc->string_count; n++ ) string_use( PRIDWORD( r, proc->strings[n] ) ) ; /* Strings privadas */ + for ( n = 0; n < proc->pubstring_count; n++ ) string_use( PUBDWORD( r, proc->pubstrings[n] ) ) ; /* Strings publicas */ + for ( n = 0; n < local_strings; n++ ) string_use( LOCDWORD( r, localstr[n] ) ) ; /* Strings locales */ + + r->prev = NULL ; + r->next = first_instance ; + if ( first_instance ) first_instance->prev = r; + first_instance = r ; + + instance_add_to_list_by_id( r, pid ); + instance_add_to_list_by_instance( r ); + instance_add_to_list_by_type( r, proc->type ); + instance_add_to_list_by_priority( r, 0 ); + + /* The called_by pointer should be set only when the caller + * is waiting for this process to return */ + + r->called_by = NULL; + + r->stack = malloc( STACK_SIZE ); + r->stack_ptr = &r->stack[1]; + r->stack[0] = STACK_SIZE; + + /* Initialize list pointers */ + + LOCDWORD( r, STATUS ) = STATUS_RUNNING; + + if ( instance_create_hook_count ) + for ( n = 0; n < instance_create_hook_count; n++ ) + instance_create_hook_list[n]( r ); + + return r ; +} + +/* ---------------------------------------------------------------------- */ + +INSTANCE * instance_getfather( INSTANCE * i ) +{ + return instance_get( LOCDWORD( i, FATHER ) ) ; +} + +/* ---------------------------------------------------------------------- */ + +INSTANCE * instance_getson( INSTANCE * i ) +{ + return instance_get( LOCDWORD( i, SON ) ) ; +} + +/* ---------------------------------------------------------------------- */ + +INSTANCE * instance_getbigbro( INSTANCE * i ) +{ + return instance_get( LOCDWORD( i, BIGBRO ) ) ; +} + +/* ---------------------------------------------------------------------- */ + +INSTANCE * instance_getsmallbro( INSTANCE * i ) +{ + return instance_get( LOCDWORD( i, SMALLBRO ) ) ; +} + +/* ---------------------------------------------------------------------- */ + +/* + * FUNCTION : instance_destroy_all + * + * Destroy all instances. Simply calls instance_destroy + * for any and every instance in existence. + * + * PARAMS : + * except Don't destroy this instance (used for LET_ME_ALONE) + * + * RETURN VALUE : + * None + */ + +void instance_destroy_all( INSTANCE * except ) +{ + INSTANCE * i, * next ; + + i = first_instance ; + while ( i ) + { + next = i->next ; + if ( i != except ) instance_destroy( i ) ; + i = next ; + } +} + +/* ---------------------------------------------------------------------- */ + +/* + * FUNCTION : instance_destroy + * + * Destroy an instance, effectively + * - Updates any instance list, removing the given instance + * - Discards all local and private strings + * - Updates all parents local family variables + * - Frees any memory involved + * + * PARAMS : + * r Pointer to the instance + * + * RETURN VALUE : + * None + */ + +void instance_destroy( INSTANCE * r ) +{ + INSTANCE * father, * bigbro, * smallbro; + int n ; + + LOCDWORD( r, STATUS ) = STATUS_RUNNING; + + if ( instance_destroy_hook_count ) + for ( n = 0; n < instance_destroy_hook_count; n++ ) + instance_destroy_hook_list[n]( r ); + + /* Actualiza la cuenta de referencia de las variables tipo string */ + + for ( n = 0 ; n < r->proc->string_count ; n++ ) string_discard( PRIDWORD( r, r->proc->strings[n] ) ) ; /* Strings privadas */ + for ( n = 0 ; n < r->proc->pubstring_count ; n++ ) string_discard( PUBDWORD( r, r->proc->pubstrings[n] ) ) ; /* Strings publicas */ + for ( n = 0 ; n < local_strings ; n++ ) string_discard( LOCDWORD( r, localstr[n] ) ) ; /* Strings locales */ + + /* Actualiza árbol de jerarquias */ + + bigbro = instance_get( LOCDWORD( r, BIGBRO ) ) ; /* Tengo hermano mayor? */ + if ( bigbro ) LOCDWORD( bigbro, SMALLBRO ) = LOCDWORD( r, SMALLBRO ) ; /* El hermano menor de mi hermano mayor es mi hermano menor */ + + smallbro = instance_get( LOCDWORD( r, SMALLBRO ) ) ; /* Tengo hermano menor? */ + if ( smallbro ) LOCDWORD( smallbro, BIGBRO ) = LOCDWORD( r, BIGBRO ) ; /* El hermano mayor de mi hermano menor es mi hermano mayor */ + + father = instance_get( LOCDWORD( r, FATHER ) ) ; /* Tengo padre? */ + if ( father && instance_get( LOCDWORD( father, SON ) ) == r ) LOCDWORD( father, SON ) = LOCDWORD( r, BIGBRO ); /* Si tengo padre y soy el hijo menor, mi hermano mayor pasa a ser el menor hijo de mi padre */ + + /* Quita la instancia de la lista */ + + if ( r->prev ) r->prev->next = r->next ; + if ( r->next ) r->next->prev = r->prev ; + + if ( first_instance == r ) first_instance = r->next ; + + /* Remove the instance from all hash lists */ + + instance_remove_from_list_by_id( r, LOCDWORD( r, PROCESS_ID ) ); + instance_remove_from_list_by_instance( r ); + instance_remove_from_list_by_type( r, LOCDWORD( r, PROCESS_TYPE ) ); + instance_remove_from_list_by_priority( r ); + + if ( r->stack ) free( r->stack ) ; + + if ( r->locdata ) free( r->locdata ) ; + if ( r->pubdata ) free( r->pubdata ) ; + if ( r->pridata ) free( r->pridata ) ; + free( r ) ; +} + +/* ---------------------------------------------------------------------- */ + +/* + * FUNCTION : instance_exists + * + * Given an instance pointer, returns TRUE if it is still valid. + * + * PARAMS : + * i Pointer to the instance + * + * RETURN VALUE : + * 1 if the instance pointer is in the global instance list, 0 otherwise + */ + +int instance_exists( INSTANCE * r ) +{ + INSTANCE * i ; + + if ( !hashed_by_instance || !r ) return 0; + + i = hashed_by_instance[HASH_INSTANCE( r )]; + while ( i ) + { + if ( r == i ) return 1 ; + i = i->next_by_instance ; + } + + return 0 ; +} + +/* ---------------------------------------------------------------------- */ + +/* + * FUNCTION : instance_next_by_priority + * + * Gets the next instance pointer until no more instances are + * returned. Instances are returned sorted by priority. + * + * PARAMS : + * None + * + * RETURN VALUE : + * Pointer to the next priority on the list or NULL + * if there is no more instances. The next call in this + * case will return a pointer to the first instance + * (the one with the lower priority) + */ + +INSTANCE * instance_next_by_priority() +{ + INSTANCE * r = iterator_by_priority ; + + if ( iterator_by_priority ) iterator_by_priority = iterator_by_priority->next_by_priority; + + if ( !iterator_by_priority ) + { + if ( !hashed_by_priority ) return NULL; + + if ( iterator_pos < ( instance_min_actual_prio + INSTANCE_NORMALIZE_PRIORITY ) || + iterator_pos > ( instance_max_actual_prio + INSTANCE_NORMALIZE_PRIORITY ) + ) + iterator_pos = instance_max_actual_prio + INSTANCE_NORMALIZE_PRIORITY + 1; + + while ( --iterator_pos >= ( instance_min_actual_prio + INSTANCE_NORMALIZE_PRIORITY ) && !( iterator_by_priority = hashed_by_priority[iterator_pos] ) ); + } + + return ( r ) ; +} + +/* ---------------------------------------------------------------------- */ + +/* + * FUNCTION : instance_get_by_type + * + * Returns a instance, given its type. + * + * PARAMS : + * type Integer type of the first instance + * context Pointer to an INSTANCE * use as context (internal use) + * + * RETURN VALUE : + * Pointer to the found instance or NULL if not found + */ + +/* +context = NULL = start scan +context = pointer = continue scan +context = -1 = end scan +*/ + +INSTANCE * instance_get_by_type( uint32_t type, INSTANCE ** context ) +{ + INSTANCE * i; + + if ( !context || !hashed_by_type || !type /* || type >= FIRST_INSTANCE_ID */ ) return NULL; + + if ( !*context ) /* start scan */ + i = hashed_by_type[HASH( type )]; + else if ( ( i = *context ) == ( INSTANCE * ) -1 ) /* End scan */ + return ( *context = NULL ); + + if ( i ) /* Valid instance, continue scan */ + { + if ( i->next_by_type ) + *context = i->next_by_type ; + else + *context = ( INSTANCE * ) -1 ; /* Next call will be "end scan" */ + + return i; + } + + /* Here only if hashed_by_type[HASH( type )] is NULL */ + return ( *context = NULL ) ; /* return is null, then end scan */ +} + +/* ---------------------------------------------------------------------- */ |