/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2004, Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at http://curl.haxx.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 * $Id: nwlib.c,v 1.4 2004/06/10 21:20:15 gknauf Exp $
 ***************************************************************************/

#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <library.h>
#include <netware.h>
#include <screen.h>
#include <nks/thread.h>
#include <nks/synch.h>

#include "memory.h"
#include "memdebug.h"

typedef struct
{
	int _errno;
	void    *twentybytes;
} libthreaddata_t;

typedef struct
{
	int x;
	int y;
	int z;
	void        *tenbytes;
	NXKey_t perthreadkey;     /* if -1, no key obtained... */
	NXMutex_t   *lock;
} libdata_t;

int gLibId      = -1;
void        *gLibHandle = (void *) NULL;
rtag_t gAllocTag   = (rtag_t) NULL;
NXMutex_t   *gLibLock   = (NXMutex_t *) NULL;

/* internal library function prototypes... */
int     DisposeLibraryData( void * );
void    DisposeThreadData( void * );
int     GetOrSetUpData( int id, libdata_t **data, libthreaddata_t **threaddata );


int _NonAppStart( void        *NLMHandle,
				  void        *errorScreen,
				  const char  *cmdLine,
				  const char  *loadDirPath,
				  size_t uninitializedDataLength,
				  void        *NLMFileHandle,
				  int ( *readRoutineP )( int conn,
										 void *fileHandle, size_t offset,
										 size_t nbytes,
										 size_t *bytesRead,
										 void *buffer ),
				  size_t customDataOffset,
				  size_t customDataSize,
				  int messageCount,
				  const char  **messages ) {
	NX_LOCK_INFO_ALLOC( liblock, "Per-Application Data Lock", 0 );

#ifndef __GNUC__
#pragma unused(cmdLine)
#pragma unused(loadDirPath)
#pragma unused(uninitializedDataLength)
#pragma unused(NLMFileHandle)
#pragma unused(readRoutineP)
#pragma unused(customDataOffset)
#pragma unused(customDataSize)
#pragma unused(messageCount)
#pragma unused(messages)
#endif

/*
** Here we process our command line, post errors (to the error screen),
** perform initializations and anything else we need to do before being able
** to accept calls into us. If we succeed, we return non-zero and the NetWare
** Loader will leave us up, otherwise we fail to load and get dumped.
*/
	gAllocTag = AllocateResourceTag( NLMHandle,
									 "<library-name> memory allocations",
									 AllocSignature );

	if ( !gAllocTag ) {
		OutputToScreen( errorScreen, "Unable to allocate resource tag for "
									 "library memory allocations.\n" );
		return -1;
	}

	gLibId = register_library( DisposeLibraryData );

	if ( gLibId < -1 ) {
		OutputToScreen( errorScreen, "Unable to register library with kernel.\n" );
		return -1;
	}

	gLibHandle = NLMHandle;

	gLibLock = NXMutexAlloc( 0, 0, &liblock );

	if ( !gLibLock ) {
		OutputToScreen( errorScreen, "Unable to allocate library data lock.\n" );
		return -1;
	}

	return 0;
}

/*
** Here we clean up any resources we allocated. Resource tags is a big part
** of what we created, but NetWare doesn't ask us to free those.
*/
void _NonAppStop( void ) {
	(void) unregister_library( gLibId );
	NXMutexFree( gLibLock );
}

/*
** This function cannot be the first in the file for if the file is linked
** first, then the check-unload function's offset will be nlmname.nlm+0
** which is how to tell that there isn't one. When the check function is
** first in the linked objects, it is ambiguous. For this reason, we will
** put it inside this file after the stop function.
**
** Here we check to see if it's alright to ourselves to be unloaded. If not,
** we return a non-zero value. Right now, there isn't any reason not to allow
** it.
*/
int  _NonAppCheckUnload( void ) {
	return 0;
}

int GetOrSetUpData( int id, libdata_t **appData,
					libthreaddata_t **threadData ) {
	int err;
	libdata_t           *app_data;
	libthreaddata_t *thread_data;
	NXKey_t key;
	NX_LOCK_INFO_ALLOC( liblock, "Application Data Lock", 0 );

	err         = 0;
	thread_data = (libthreaddata_t *) NULL;

/*
** Attempt to get our data for the application calling us. This is where we
** store whatever application-specific information we need to carry in support
** of calling applications.
*/
	app_data = (libdata_t *) get_app_data( id );

	if ( !app_data ) {
/*
** This application hasn't called us before; set up application AND per-thread
** data. Of course, just in case a thread from this same application is calling
** us simultaneously, we better lock our application data-creation mutex. We
** also need to recheck for data after we acquire the lock because WE might be
** that other thread that was too late to create the data and the first thread
** in will have created it.
*/
		NXLock( gLibLock );

		if ( !( app_data = (libdata_t *) get_app_data( id ) ) ) {
			app_data = (libdata_t *) malloc( sizeof( libdata_t ) );

			if ( app_data ) {
				memset( app_data, 0, sizeof( libdata_t ) );

				app_data->tenbytes = malloc( 10 );
				app_data->lock     = NXMutexAlloc( 0, 0, &liblock );

				if ( !app_data->tenbytes || !app_data->lock ) {
					if ( app_data->lock ) {
						NXMutexFree( app_data->lock );
					}

					free( app_data );
					app_data = (libdata_t *) NULL;
					err      = ENOMEM;
				}

				if ( app_data ) {
/*
** Here we burn in the application data that we were trying to get by calling
** get_app_data(). Next time we call the first function, we'll get this data
** we're just now setting. We also go on here to establish the per-thread data
** for the calling thread, something we'll have to do on each application
** thread the first time it calls us.
*/
					err = set_app_data( gLibId, app_data );

					if ( err ) {
						free( app_data );
						app_data = (libdata_t *) NULL;
						err      = ENOMEM;
					} else {
						/* create key for thread-specific data... */
						err = NXKeyCreate( DisposeThreadData, (void *) NULL, &key );

						if ( err ) { /* (no more keys left?) */
							key = -1;
						}

						app_data->perthreadkey = key;
					}
				}
			}
		}

		NXUnlock( gLibLock );
	}

	if ( app_data ) {
		key = app_data->perthreadkey;

		if ( key != -1 /* couldn't create a key? no thread data */
			 && !( err = NXKeyGetValue( key, (void **) &thread_data ) )
			 && !thread_data ) {
/*
** Allocate the per-thread data for the calling thread. Regardless of whether
** there was already application data or not, this may be the first call by a
** a new thread. The fact that we allocation 20 bytes on a pointer is not very
** important, this just helps to demonstrate that we can have arbitrarily
** complex per-thread data.
*/
			thread_data = (libthreaddata_t *) malloc( sizeof( libthreaddata_t ) );

			if ( thread_data ) {
				thread_data->_errno      = 0;
				thread_data->twentybytes = malloc( 20 );

				if ( !thread_data->twentybytes ) {
					free( thread_data );
					thread_data = (libthreaddata_t *) NULL;
					err         = ENOMEM;
				}

				if ( ( err = NXKeySetValue( key, thread_data ) ) ) {
					free( thread_data->twentybytes );
					free( thread_data );
					thread_data = (libthreaddata_t *) NULL;
				}
			}
		}
	}

	if ( appData ) {
		*appData = app_data;
	}

	if ( threadData ) {
		*threadData = thread_data;
	}

	return err;
}

int DisposeLibraryData( void    *data ) {
	if ( data ) {
		void    *tenbytes = ( (libdata_t *) data )->tenbytes;

		if ( tenbytes ) {
			free( tenbytes );
		}

		free( data );
	}

	return 0;
}

void DisposeThreadData( void    *data ) {
	if ( data ) {
		void    *twentybytes = ( (libthreaddata_t *) data )->twentybytes;

		if ( twentybytes ) {
			free( twentybytes );
		}

		free( data );
	}
}