/*

www.sourceforge.net/projects/dfhack

Copyright (c) 2009 Petr Mrázek (peterix)

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.

*/

/**

* This is the source for the DF <-> dfhack shm bridge

*/

#include <stdio.h>

#include <dlfcn.h>

#include <stdint.h>

#include <stdlib.h>

#include <string.h>

#include <sys/shm.h>

#include <sys/types.h>

#include <sys/ipc.h>

#include <unistd.h>

#include <vector>

#include <string>

#include "shms.h"

#include "mod-core.h"

#include <sched.h>

#include <pthread.h>

#include <time.h>

#define DFhackCExport extern "C" __attribute__ ((visibility("default")))

// various crud

int counter = 0;

int errorstate = 0;

char *shm = 0;

int shmid = 0;

bool inited = 0;

synchro * mutexes = 0;

/*******************************************************************************

* SHM part starts here *

*******************************************************************************/

// FIXME: add error checking?

bool isValidSHM()

{

shmid_ds descriptor;

shmctl(shmid, IPC_STAT, &descriptor);

//fprintf(stderr,"ID %d, attached: %d\n",shmid, descriptor.shm_nattch);

return (descriptor.shm_nattch == 2);

}

uint32_t OS_getPID()

{

return getpid();

}

uint32_t OS_getAffinity()

{

cpu_set_t mask;

sched_getaffinity(0,sizeof(cpu_set_t),&mask);

// FIXME: truncation

uint32_t affinity = *(uint32_t *) &mask;

return affinity;

}

void SHM_Init ( void )

{

// check that we do this only once per process

if(inited)

{

fprintf(stderr, "SDL_Init was called twice or more!\n");

return;

}

inited = true;

// name for the segment

key_t key = 123466;

// find previous segment, check if it's used by some processes.

// if it isn't, kill it with fire

if ((shmid = shmget(key, SHM_SIZE, 0600)) != -1)

{

shmid_ds descriptor;

shmctl(shmid, IPC_STAT, &descriptor);

if(descriptor.shm_nattch == 0)

{

shmctl(shmid,IPC_RMID,NULL);

fprintf(stderr,"dfhack: killed dangling resources from crashed DF.\n");

}

}

// create the segment, make sure only ww are really creating it

if ((shmid = shmget(key, SHM_SIZE, IPC_CREAT | IPC_EXCL | 0600)) < 0)

{

perror("shmget");

errorstate = 1;

return;

}

// attach the segment

if ((shm = (char *) shmat(shmid, 0, 0)) == (char *) -1)

{

perror("shmat");

errorstate = 1;

return;

}

// init communication basics

mutexes = (synchro *) (shm + SHM_SYNC);

if(pthread_mutexattr_init(&mutexes->mattr)) perror("1");

if(pthread_mutexattr_setpshared(&mutexes->mattr,true)) perror("2");

if(pthread_mutex_init (&mutexes->mutex, &mutexes->mattr)) perror("3");

if(pthread_condattr_init(&mutexes->clattr)) perror("4");

if(pthread_condattr_setpshared(&mutexes->clattr,true)) perror("5");

if(pthread_cond_init (&mutexes->cond_set_by_cl, &mutexes->clattr)) perror("6");

if(pthread_condattr_init(&mutexes->svattr)) perror("7");

if(pthread_condattr_setpshared(&mutexes->svattr,true)) perror("8");

if(pthread_cond_init (&mutexes->cond_set_by_sv, &mutexes->svattr)) perror("9");

((shm_cmd *)shm)->pingpong = CORE_RUNNING; // we start out with nothing attached

InitModules();

}

inline bool lock_set_wait (uint32_t command)

{

pthread_mutex_lock(&mutexes->mutex);

}

void SHM_Destroy ( void )

{

if(inited && !errorstate)

{

KillModules();

shmid_ds descriptor;

shmctl(shmid, IPC_STAT, &descriptor);

shmdt(shm);

while(descriptor.shm_nattch != 0)

{

shmctl(shmid, IPC_STAT, &descriptor);

}

shmctl(shmid,IPC_RMID,NULL);

fprintf(stderr,"dfhack: destroyed shared segment.\n");

inited = false;

}

}

/*******************************************************************************

* SDL part starts here *

*******************************************************************************/

// ptr to the real functions

static void (*_SDL_GL_SwapBuffers)(void) = 0;

static void (*_SDL_Quit)(void) = 0;

static int (*_SDL_Init)(uint32_t flags) = 0;

static int (*_SDL_Flip)(void * some_ptr) = 0;

// hook - called every tick in OpenGL mode of DF

DFhackCExport void SDL_GL_SwapBuffers(void)

{

if(_SDL_GL_SwapBuffers)

{

if(!errorstate && ((shm_cmd *)shm)->pingpong != CORE_RUNNING)

{

SHM_Act();

}

counter ++;

_SDL_GL_SwapBuffers();

}

}

// hook - called every tick in the 2D mode of DF

DFhackCExport int SDL_Flip(void * some_ptr)

{

if(_SDL_Flip)

{

if(!errorstate && ((shm_cmd *)shm)->pingpong != CORE_RUNNING)

{

SHM_Act();

}

counter ++;

return _SDL_Flip(some_ptr);

}

return 0;

}

// hook - called at program exit

DFhackCExport void SDL_Quit(void)

{

if(!errorstate)

{

SHM_Destroy();

}

if(_SDL_Quit)

{

_SDL_Quit();

}

}

// hook - called at program start, initialize some stuffs we'll use later

DFhackCExport int SDL_Init(uint32_t flags)

{

// find real functions

_SDL_GL_SwapBuffers = (void (*)( void )) dlsym(RTLD_NEXT, "SDL_GL_SwapBuffers");

_SDL_Init = (int (*)( uint32_t )) dlsym(RTLD_NEXT, "SDL_Init");

_SDL_Flip = (int (*)( void * )) dlsym(RTLD_NEXT, "SDL_Flip");

_SDL_Quit = (void (*)( void )) dlsym(RTLD_NEXT, "SDL_Quit");

// check if we got them

if(_SDL_GL_SwapBuffers && _SDL_Init && _SDL_Quit)

{

fprintf(stderr,"dfhack: hooking successful\n");

}

else

{

// bail, this would be a disaster otherwise

fprintf(stderr,"dfhack: something went horribly wrong\n");

exit(1);

}

SHM_Init();

return _SDL_Init(flags);

}

/*******************************************************************************

* NCURSES part starts here *

*******************************************************************************/

static int (*_refresh)(void) = 0;

//extern NCURSES_EXPORT(int) refresh (void);

DFhackCExport int refresh (void)

{

if(_refresh)

{

if(!errorstate && ((shm_cmd *)shm)->pingpong != CORE_RUNNING)

{

SHM_Act();

}

counter ++;

return _refresh();

}

return 0;

}

static int (*_endwin)(void) = 0;

//extern NCURSES_EXPORT(int) endwin (void);

DFhackCExport int endwin (void)

{

if(!errorstate)

{

SHM_Destroy();

}

if(_endwin)

{

return _endwin();

}

}

typedef void WINDOW;

//extern NCURSES_EXPORT(WINDOW *) initscr (void);

static WINDOW * (*_initscr)(void) = 0;

DFhackCExport WINDOW * initscr (void)

{

// find real functions

_refresh = (int (*)( void )) dlsym(RTLD_NEXT, "refresh");

_endwin = (int (*)( void )) dlsym(RTLD_NEXT, "endwin");

_initscr = (WINDOW * (*)( void )) dlsym(RTLD_NEXT, "initscr");

// check if we got them

if(_refresh && _endwin && _initscr)

{

fprintf(stderr,"dfhack: hooking successful\n");

}

else

{

// bail, this would be a disaster otherwise

fprintf(stderr,"dfhack: something went horribly wrong\n");

exit(1);

}

SHM_Init();

return _initscr();

}