From 32d3e55a6e50907ec96dd4a042d08acfbc7e9cf6 Mon Sep 17 00:00:00 2001 From: Sam Hocevar Date: Fri, 5 Jan 2001 13:57:12 +0000 Subject: [PATCH] . Added files needed for the forthcoming module management. Notes: Plugins are now called modules, because we will be able to compile them either as a dynamic plugin, or within the program. And, more important, I can commit this without having to break the vlc :) I tried to be as clear as possible in my comments, please tell me if a few prototypes still have an unclear beahaviour. Current features: . none, files haven't even been added to the Makefile yet. Future features: . dynamic loading (done) . built-in modules (still to do) . automatic unloading of plugins (done) . dynamic configuration (still to do) . automatic choosing of the most appropriate plugin for a given task (still to do but well prepared) --- include/modules.h | 145 ++++++++++++ include/modules_config.h | 57 +++++ include/modules_inner.h | 98 ++++++++ src/misc/modules.c | 468 +++++++++++++++++++++++++++++++++++++++ 4 files changed, 768 insertions(+) create mode 100644 include/modules.h create mode 100644 include/modules_config.h create mode 100644 include/modules_inner.h create mode 100644 src/misc/modules.c diff --git a/include/modules.h b/include/modules.h new file mode 100644 index 0000000000..f7d12a814d --- /dev/null +++ b/include/modules.h @@ -0,0 +1,145 @@ +/***************************************************************************** + * modules.h : Module management functions. + ***************************************************************************** + * Copyright (C) 2001 VideoLAN + * + * Authors: Samuel Hocevar + * + * 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., 59 Temple Place - Suite 330, Boston, MA 02111, USA. + *****************************************************************************/ + +/* Number of tries before we unload an unused module */ +#define MODULE_HIDE_DELAY 10 + +/* The module handle type. */ +#ifdef SYS_BEOS +typedef int module_handle_t; +#else +typedef void * module_handle_t; +#endif + +/***************************************************************************** + * Configuration structure + *****************************************************************************/ +typedef struct module_config_s +{ + int i_type; /* Configuration widget type */ + char * psz_text; /* Text commenting or describing the widget */ + char * psz_name; /* Variable name */ + void * p_getlist; /* Function to call to get a choice list */ + void * p_change; /* Function to call when commiting a change */ +} module_config_t; + +/***************************************************************************** + * Bank and module description structures + *****************************************************************************/ + +/* The main module structure */ +typedef struct module_s +{ + boolean_t b_builtin; /* Set to true if the module is built in */ + + module_handle_t handle; /* Unique handle to refer to the module */ + char * psz_filename; /* Module filename */ + + char * psz_name; /* Module _unique_ name */ + char * psz_longname; /* Module descriptive name */ + char * psz_version; /* Module version */ + + int i_usage; /* Reference counter */ + int i_unused_delay; /* Delay until module is unloaded */ + + struct module_s * next; /* Next module */ + struct module_s * prev; /* Previous module */ + + u32 i_capabilities; /* Capability list */ + + module_config_t * p_config; /* Module configuration structure table */ + +} module_t; + +/* The module bank structure */ +typedef struct module_bank_s +{ + module_t * first; /* First module of the bank */ + + vlc_mutex_t lock; /* Global lock -- you can't imagine how awful it + is to design thread-safe linked lists. */ +} module_bank_t; + +/***************************************************************************** + * Stuff for handling dynamic modules + *****************************************************************************/ + +/* Function to load a dynamic module, returns 0 if successful. */ +static __inline__ int +module_load( char * psz_filename, module_handle_t * handle ) +{ +#ifdef SYS_BEOS + *handle = load_add_on( psz_filename ); + return( *handle >= 0 ); +#else + *handle = dlopen( psz_filename, RTLD_NOW | RTLD_GLOBAL ); + return( *handle != NULL ); +#endif +} + +/* Unload a dynamic module. */ +static __inline__ void +module_unload( module_handle_t handle ) +{ +#ifdef SYS_BEOS + unload_add_on( handle ); +#else + dlclose( handle ); +#endif + return; +} + +/* Get a given symbol from a module. */ +static __inline__ void * +module_getsymbol( module_handle_t handle, char * psz_function ) +{ +#ifdef SYS_BEOS + void * p_symbol; + get_image_symbol( handle, psz_function, B_SYMBOL_TYPE_TEXT, &p_symbol ); + return( p_symbol ); +#else + return( dlsym( handle, psz_function ) ); +#endif +} + +/* Wrapper to dlerror() for systems that don't have it. */ +static __inline__ char * +module_error( void ) +{ +#ifdef SYS_BEOS + return( "failed" ); +#else + return( dlerror() ); +#endif +} + +/***************************************************************************** + * Exported functions. + *****************************************************************************/ +module_bank_t * module_InitBank ( void ); +int module_DestroyBank ( module_bank_t * p_bank ); +int module_ResetBank ( module_bank_t * p_bank ); +void module_ManageBank ( module_bank_t * p_bank ); + +int module_Need ( module_t * p_module ); +int module_Unneed ( module_t * p_module ); + diff --git a/include/modules_config.h b/include/modules_config.h new file mode 100644 index 0000000000..7a3a527804 --- /dev/null +++ b/include/modules_config.h @@ -0,0 +1,57 @@ +/***************************************************************************** + * modules_config.h : Module configuration tools. + ***************************************************************************** + * Copyright (C) 2001 VideoLAN + * + * Authors: Samuel Hocevar + * + * 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., 59 Temple Place - Suite 330, Boston, MA 02111, USA. + *****************************************************************************/ + +/***************************************************************************** + * Module capabilities. + *****************************************************************************/ +#define MODULE_CAPABILITY_NULL 0 /* The Module can't do anything */ +#define MODULE_CAPABILITY_INTF 1<<0 /* Interface */ +#define MODULE_CAPABILITY_INPUT 1<<1 /* Input */ +#define MODULE_CAPABILITY_DECAPS 1<<2 /* Decaps */ +#define MODULE_CAPABILITY_ADEC 1<<3 /* Audio decoder */ +#define MODULE_CAPABILITY_VDEC 1<<4 /* Video decoder */ +#define MODULE_CAPABILITY_AOUT 1<<5 /* Audio output */ +#define MODULE_CAPABILITY_VOUT 1<<6 /* Video output */ +#define MODULE_CAPABILITY_YUV 1<<7 /* YUV colorspace conversion */ +#define MODULE_CAPABILITY_AFX 1<<8 /* Audio effects */ +#define MODULE_CAPABILITY_VFX 1<<9 /* Video effects */ + +/***************************************************************************** + * Macros used to build the configuration structure. + *****************************************************************************/ + +/* Mandatory first and last parts of the structure */ +#define MODULE_CONFIG_ITEM_START 0x01 /* The main window */ +#define MODULE_CONFIG_ITEM_END 0x00 /* End of the window */ + +/* Configuration widgets */ +#define MODULE_CONFIG_ITEM_PANE 0x02 /* A notebook pane */ +#define MODULE_CONFIG_ITEM_FRAME 0x03 /* A frame */ +#define MODULE_CONFIG_ITEM_COMMENT 0x04 /* A comment text */ +#define MODULE_CONFIG_ITEM_STRING 0x05 /* A string */ +#define MODULE_CONFIG_ITEM_FILE 0x06 /* A file selector */ +#define MODULE_CONFIG_ITEM_CHECK 0x07 /* A checkbox */ +#define MODULE_CONFIG_ITEM_CHOOSE 0x08 /* A choose box */ +#define MODULE_CONFIG_ITEM_RADIO 0x09 /* A radio box */ +#define MODULE_CONFIG_ITEM_SCALE 0x0a /* A horizontal ruler */ +#define MODULE_CONFIG_ITEM_SPIN 0x0b /* A numerical selector */ + diff --git a/include/modules_inner.h b/include/modules_inner.h new file mode 100644 index 0000000000..a966569bcc --- /dev/null +++ b/include/modules_inner.h @@ -0,0 +1,98 @@ +/***************************************************************************** + * modules_inner.h : Macros used from within a module. + ***************************************************************************** + * Copyright (C) 2001 VideoLAN + * + * Authors: Samuel Hocevar + * + * 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., 59 Temple Place - Suite 330, Boston, MA 02111, USA. + *****************************************************************************/ + +/***************************************************************************** + * Check that we are within a module. + *****************************************************************************/ +#ifndef MODULE_NAME +# error "You must define MODULE_NAME before using modules_inner.h !" +#endif + +/***************************************************************************** + * Add a few defines. You do not want to read this section. Really. + *****************************************************************************/ + +/* Explanation: + * + * if user has #defined MODULE_NAME foo, then we will need: + * #define MODULE_STRING "foo" + * #define MODULE_VAR(blah) "VLC_MODULE_foo_blah" + * + * and, if BUILTIN is set, we will also need: + * #define InitModule foo_InitModule + * #define ActivateModule foo_ActivateModule + * #define DeactivateModule foo_DeactivateModule + * + * this can't easily be done with the C preprocessor, thus a few ugly hacks. + */ + +/* I can't believe I need to do this to change « foo » to « "foo" » */ +#define UGLY_KLUDGE(z) NASTY_CROCK(z) +#define NASTY_CROCK(z) #z +/* And I need to do _this_ to change « foo bar » to « foo_bar » ! */ +#define AWFUL_BRITTLE(y,z) CRUDE_HACK(y,z) +#define CRUDE_HACK(y,z) y##_##z + +/* Also, I need to do this to change « blah » to « "VLC_MODULE_foo_blah" » */ +#define MODULE_STRING UGLY_KLUDGE(MODULE_NAME) +#define MODULE_VAR(z) "VLC_MODULE_" UGLY_KLUDGE(MODULE_NAME) "_" #z + +/* If the module is built-in, then we need to define foo_InitModule instead + * of InitModule. Same for Activate- and DeactivateModule. */ +#ifdef BUILTIN +# define InitModule AWFUL_BRITTLE(MODULE_NAME,InitModule) +# define ActivateModule AWFUL_BRITTLE(MODULE_NAME,ActivateModule) +# define DeactivateModule AWFUL_BRITTLE(MODULE_NAME,DeactivateModule) +#endif + +/***************************************************************************** + * Macros used to build the configuration structure. + *****************************************************************************/ +#define MODULE_CONFIG_START( text ) \ +static module_config_t p_config[] = { \ + { MODULE_CONFIG_ITEM_START, text, NULL, NULL, NULL }, + +#define MODULE_CONFIG_END \ + { MODULE_CONFIG_ITEM_END, NULL, NULL, NULL, NULL } \ +}; + +#define ADD_FRAME( text ) \ + { MODULE_CONFIG_ITEM_FRAME, text, NULL, NULL, NULL }, +#define ADD_PANE( text ) \ + { MODULE_CONFIG_ITEM_PANE, text, NULL, NULL, NULL }, +#define ADD_COMMENT( text ) \ + { MODULE_CONFIG_ITEM_COMMENT, text, NULL, NULL, NULL }, +#define ADD_STRING( text, name, p_update ) \ + { MODULE_CONFIG_ITEM_STRING, text, name, NULL, p_update }, +#define ADD_FILE( text, name, p_update ) \ + { MODULE_CONFIG_ITEM_FILE, text, name, NULL, p_update }, +#define ADD_CHECK( text, name, p_update ) \ + { MODULE_CONFIG_ITEM_CHECK, text, name, NULL, p_update }, +#define ADD_CHOOSE( text, name, p_getlist, p_update ) \ + { MODULE_CONFIG_ITEM_CHOOSE, text, name, p_getlist, p_update }, +#define ADD_RADIO( text, name, p_getlist, p_update ) \ + { MODULE_CONFIG_ITEM_RADIO, text, name, p_getlist, p_update }, +#define ADD_SCALE( text, name, p_getlist, p_update ) \ + { MODULE_CONFIG_ITEM_SCALE, text, name, p_getlist, p_update }, +#define ADD_SPIN( text, name, p_getlist, p_update ) \ + { MODULE_CONFIG_ITEM_SPIN, text, name, p_getlist, p_update }, + diff --git a/src/misc/modules.c b/src/misc/modules.c new file mode 100644 index 0000000000..0f533f5190 --- /dev/null +++ b/src/misc/modules.c @@ -0,0 +1,468 @@ +/***************************************************************************** + * modules.c : Built-in and dynamic modules management functions + ***************************************************************************** + * Copyright (C) 2001 VideoLAN + * + * Authors: Samuel Hocevar + * + * 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., 59 Temple Place - Suite 330, Boston, MA 02111, USA. + *****************************************************************************/ +#include "defs.h" + +#include "config.h" + +#include /* free(), strtol() */ +#include /* sprintf() */ +#include /* strerror() */ +#include /* ENOMEM */ +#include /* open */ +#include +#include +#include /* close */ + +#if defined(HAVE_DLFCN_H) /* Linux, BSD, Hurd */ +#include /* dlopen(), dlsym(), dlclose() */ + +#elif defined(HAVE_IMAGE_H) /* BeOS */ +#include + +#else +/* FIXME: this isn't supposed to be an error */ +#error no dynamic plugins available on your system ! +#endif + +#ifdef SYS_BEOS +#include "beos_specific.h" +#endif + +#include "common.h" +#include "threads.h" + +#include "intf_msg.h" +#include "modules.h" + +/* Local prototypes */ +static int AllocateDynModule( module_bank_t * p_bank, char * psz_filename ); +static int HideModule( module_t * p_module ); +static int FreeModule( module_bank_t * p_bank, module_t * p_module ); +static int CallSymbol( module_t * p_module, char * psz_name ); + +/***************************************************************************** + * module_InitBank: create the module bank. + ***************************************************************************** + * This function creates a module bank structure and fills it with the + * built-in modules, as well as all the dynamic modules it can find. + *****************************************************************************/ +module_bank_t * module_InitBank( void ) +{ + module_bank_t * p_bank; + + intf_ErrMsg( "FIXME: module_InitBank unimplemented" ); + p_bank = malloc( sizeof( module_bank_t ) ); + + return( p_bank ); +} + +/***************************************************************************** + * module_DestroyBank: destroy the module bank. + ***************************************************************************** + * This function unloads all unused dynamic modules and removes the module + * bank in case of success. + *****************************************************************************/ +int module_DestroyBank( module_bank_t * p_bank ) +{ + intf_ErrMsg( "FIXME: module_DestroyBank unimplemented" ); + return( -1 ); +} + +/***************************************************************************** + * module_ResetBank: reset the module bank. + ***************************************************************************** + * This function resets the plugin bank by unloading all unused dynamic + * modules. + *****************************************************************************/ +int module_ResetBank( module_bank_t * p_bank ) +{ + intf_ErrMsg( "FIXME: module_ResetBank unimplemented" ); + return( -1 ); +} + +/***************************************************************************** + * module_ManageBank: manage the module bank. + ***************************************************************************** + * This function parses the module bank and hides modules that have been + * unused for a while. + *****************************************************************************/ +void module_ManageBank( module_bank_t * p_bank ) +{ + module_t * p_module; + + /* We take the global lock */ + vlc_mutex_lock( &p_bank->lock ); + + /* Parse the module list to see if any modules need to be unloaded */ + for( p_module = p_bank->first ; + p_module != NULL ; + p_module = p_module->next ) + { + /* If the module is unused and if it is a dynamic module... */ + if( p_module->i_usage == 0 && !p_module->b_builtin ) + { + if( p_module->i_unused_delay < MODULE_HIDE_DELAY ) + { + p_module->i_unused_delay++; + } + else + { + intf_Msg( "hiding unused module %s", p_module->psz_name ); + HideModule( p_module ); + } + } + } + + /* We release the global lock */ + vlc_mutex_lock( &p_bank->lock ); + + return; +} + +/***************************************************************************** + * module_Need: increase the usage count of a module and load it if needed. + ***************************************************************************** + * This function has to be called before a thread starts using a module. If + * the module is already loaded, we just increase its usage count. If it isn't + * loaded, we have to dynamically open it and initialize it. + * If you successfully call module_Need() at any moment, be careful to call + * module_Unneed() when you don't need it anymore. + *****************************************************************************/ +int module_Need( module_t * p_module ) +{ + if( p_module->i_usage >= 0 ) + { + /* This module is already loaded and activated, we can return */ + p_module->i_usage++; + return( 0 ); + } + + if( p_module->b_builtin ) + { + /* A built-in module should always have a refcount >= 0 ! */ + intf_ErrMsg( "module error: built-in module %s has refcount %i", + p_module->psz_name, p_module->i_usage ); + return( -1 ); + } + + if( p_module->i_usage != -1 ) + { + /* This shouldn't happen. Ever. We have serious problems here. */ + intf_ErrMsg( "module error: dynamic module %s has refcount %i", + p_module->psz_name, p_module->i_usage ); + return( -1 ); + } + + /* i_usage == -1, which means that the module isn't in memory */ + if( ! module_load( p_module->psz_filename, &p_module->handle ) ) + { + /* The dynamic module couldn't be opened */ + intf_ErrMsg( "module error: cannot open %s (%s)", + p_module->psz_filename, module_error() ); + return( -1 ); + } + + if( CallSymbol( p_module, "ActivateModule" ) != 0 ) + { + /* We couldn't call ActivateModule() -- looks nasty, but + * we can't do much about it. Just try to unload module. */ + module_unload( p_module->handle ); + p_module->i_usage = -1; + return( -1 ); + } + + /* Everything worked fine ! The module is ready to be used */ + p_module->i_usage = 1; + + return( 0 ); +} + +/***************************************************************************** + * module_Unneed: decrease the usage count of a module. + ***************************************************************************** + * This function has to be called before a thread starts using a module. If + * the module is already loaded, we just increase its usage count. If it isn't + * loaded, we have to dynamically open it and initialize it. + * If you successfully call module_Need() at any moment, be careful to call + * module_Unneed() when you don't need it anymore. + *****************************************************************************/ +int module_Unneed( module_t * p_module ) +{ + if( p_module->i_usage <= 0 ) + { + /* This shouldn't happen. Ever. We have serious problems here. */ + intf_ErrMsg( "module error: trying to call module_Unneed() on %s" + " which isn't even in use", p_module->psz_name ); + return( -1 ); + } + + /* This module is still in use, we can return */ + p_module->i_usage--; + p_module->i_unused_delay = 0; + + return( 0 ); +} + +/***************************************************************************** + * Following functions are local. + *****************************************************************************/ + +/***************************************************************************** + * AllocateDynModule: load a module into memory and initialize it. + ***************************************************************************** + * This function loads a dynamically loadable module and allocates a structure + * for its information data. The module can then be handled by module_Need, + * module_Unneed and HideModule. It can be removed by FreeModule. + *****************************************************************************/ +static int AllocateDynModule( module_bank_t * p_bank, char * psz_filename ) +{ + module_t * p_module; + module_handle_t handle; + + /* Try to dynamically load the module. */ + if( ! module_load( psz_filename, &handle ) ) + { + /* The dynamic module couldn't be opened */ + intf_ErrMsg( "module error: cannot open %s (%s)", + psz_filename, module_error() ); + return( -1 ); + } + + /* Now that we have successfully loaded the module, we can + * allocate a structure for it */ + p_module = malloc( sizeof( module_t ) ); + if( p_module == NULL ) + { + intf_ErrMsg( "module error: can't allocate p_module" ); + module_unload( handle ); + return( -1 ); + } + + /* We need to fill these since they may be needed by CallSymbol() */ + p_module->psz_filename = psz_filename; + p_module->handle = handle; + + if( CallSymbol( p_module, "InitModule" ) != 0 ) + { + /* We couldn't call InitModule() */ + free( p_module ); + module_unload( handle ); + return( -1 ); + } + + if( CallSymbol( p_module, "ActivateModule" ) != 0 ) + { + /* We couldn't call ActivateModule() */ + free( p_module ); + module_unload( handle ); + return( -1 ); + } + + /* We strdup() these entries so that they are still valid when the + * module is unloaded. */ + p_module->psz_filename = strdup( p_module->psz_filename ); + p_module->psz_name = strdup( p_module->psz_name ); + p_module->psz_longname = strdup( p_module->psz_longname ); + p_module->psz_version = strdup( p_module->psz_version ); + if( p_module->psz_filename == NULL + || p_module->psz_name == NULL + || p_module->psz_longname == NULL + || p_module->psz_version == NULL ) + { + intf_ErrMsg( "module error: can't duplicate strings" ); + free( p_module->psz_filename ); + free( p_module->psz_name ); + free( p_module->psz_longname ); + free( p_module->psz_version ); + free( p_module ); + module_unload( handle ); + return( -1 ); + } + + /* Everything worked fine ! The module is ready to be added to the list. */ + p_module->i_usage = 0; + p_module->i_unused_delay = 0; + + p_module->b_builtin = 0; + + /* Link module across linked list */ + if( p_bank->first != NULL ) + { + p_bank->first->prev = p_module; + } + p_module->next = p_bank->first; + p_bank->first = p_module; + + return( 0 ); +} + +/***************************************************************************** + * HideModule: remove a module from memory but keep its structure. + ***************************************************************************** + * This function can only be called if i_usage == 0. It will make a call + * to the module's inner DeactivateModule() symbol, and then unload it + * from memory. A call to module_Need() will automagically load it again. + *****************************************************************************/ +static int HideModule( module_t * p_module ) +{ + if( p_module->b_builtin ) + { + /* A built-in module should never be hidden. */ + intf_ErrMsg( "module error: trying to hide built-in module %s", + p_module->psz_name ); + return( -1 ); + } + + if( p_module->i_usage >= 1 ) + { + intf_ErrMsg( "module error: trying to hide module %s which is still" + " in use", p_module->psz_name ); + return( -1 ); + } + + if( p_module->i_usage <= -1 ) + { + intf_ErrMsg( "module error: trying to hide module %s which is already" + " hidden", p_module->psz_name ); + return( -1 ); + } + + if( CallSymbol( p_module, "DeactivateModule" ) != 0 ) + { + /* We couldn't call DeactivateModule() -- looks nasty, but + * we can't do much about it. Just try to unload module anyway. */ + module_unload( p_module->handle ); + p_module->i_usage = -1; + return( -1 ); + } + + /* Everything worked fine, we can safely unload the module. */ + module_unload( p_module->handle ); + p_module->i_usage = -1; + + return( 0 ); +} + +/***************************************************************************** + * FreeModule: delete a module and its structure. + ***************************************************************************** + * This function can only be called if i_usage <= 0. + *****************************************************************************/ +static int FreeModule( module_bank_t * p_bank, module_t * p_module ) +{ + /* If the module is not in use but is still in memory, we first have + * to hide it and remove it from memory before we can free the + * data structure. */ + if( p_module->b_builtin ) + { + if( p_module->i_usage != 0 ) + { + intf_ErrMsg( "module error: trying to free builtin module %s with" + " usage %i", p_module->psz_name, p_module->i_usage ); + return( -1 ); + } + } + else + { + if( p_module->i_usage >= 1 ) + { + intf_ErrMsg( "module error: trying to free module %s which is" + " still in use", p_module->psz_name ); + return( -1 ); + } + + /* Two possibilities here: i_usage == -1 and the module is already + * unloaded, we can continue, or i_usage == 0, and we have to hide + * the module before going on. */ + if( p_module->i_usage == 0 ) + { + if( HideModule( p_module ) != 0 ) + { + return( -1 ); + } + } + } + + /* Unlink the module from the linked list. */ + if( p_module == p_bank->first ) + { + p_bank->first = p_module->next; + } + + if( p_module->prev != NULL ) + { + p_module->prev->next = p_module->next; + } + + if( p_module->next != NULL ) + { + p_module->next->prev = p_module->prev; + } + + /* We free the structures that we strdup()ed in Allocate*Module(). */ + free( p_module->psz_filename ); + free( p_module->psz_name ); + free( p_module->psz_longname ); + free( p_module->psz_version ); + + free( p_module ); + + return( 0 ); +} + +/***************************************************************************** + * CallSymbol: calls a module symbol. + ***************************************************************************** + * This function calls a symbol given its name and a module structure. The + * symbol MUST refer to a function returning int and taking a module_t* as + * an argument. + *****************************************************************************/ +static int CallSymbol( module_t * p_module, char * psz_name ) +{ + typedef int ( symbol_t ) ( module_t * p_module ); + symbol_t * p_symbol; + + /* Try to resolve the symbol */ + p_symbol = module_getsymbol( p_module->handle, psz_name ); + + if( !p_symbol ) + { + /* We couldn't load the symbol */ + intf_ErrMsg( "module error: cannot find %s in module %s (%s)", + psz_name, p_module->psz_filename, module_error() ); + return( -1 ); + } + + /* We can now try to call the symbol */ + if( p_symbol( p_module ) != 0 ) + { + /* With a well-written module we shouldn't have to print an + * additional error message here, but just make sure. */ + intf_ErrMsg( "module error: failed calling %s in module %s", + psz_name, p_module->psz_filename ); + return( -1 ); + } + + /* Everything worked fine, we can return */ + return( 0 ); +} +