dso.cpp

贡献一份commoncpp2,有兴趣的可以研究一下

// Copyright (C) 1999-2005 Open Source Telecom Corporation.
//
// 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 02111-1307, USA.
// 
// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however    
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.    
//
// This exception applies only to the code released under the name GNU
// Common C++.  If you copy code from other releases into a copy of GNU
// Common C++, as the General Public License permits, the exception does
// not apply to the code that you add in this way.  To avoid misleading
// anyone as to the status of such modified files, you must delete
// this exception notice from them.
//
// If you write modifications of your own for GNU Common C++, it is your choice
// whether to permit this exception to apply to your modifications.
// If you do not wish that, delete this exception notice.
//

#include <cc++/config.h>
#include <cc++/export.h>
#include <cc++/exception.h>
#include <cc++/slog.h>
#include <cc++/file.h>
#include "private.h"

#ifdef	CCXX_NAMESPACES
namespace ost {
#endif

#ifdef	HAVE_MODULES
DSO	*DSO::first = NULL;
DSO	*DSO::last = NULL;
Mutex	DSO::mutex;

#if defined(HAVE_DLFCN_H)

extern "C" {
#include <dlfcn.h>
}

#ifndef	RTLD_GLOBAL
#define	RTLD_GLOBAL	0
#endif

#endif // HAVE_DLFN_H

void DSO::dynunload(void)
{
	while(DSO::last)
		delete DSO::last;
}


DSO::~DSO()
{
#if defined(HAVE_MACH_DYLD)
	NSSymbol sym;
	void (*fini)(void);
#endif
	MutexLock lock(mutex);
#if defined(WIN32)
	if(hImage)
		FreeLibrary(hImage);
#elif defined(HAVE_MACH_DYLD)
	if(oModule == NULL)
		return;

	sym = NSLookupSymbolInModule(oModule, "__fini");
	if(sym != NULL)
	{
		fini = (void (*)(void))NSAddressOfSymbol(sym);
		fini();
	}

	NSUnLinkModule(oModule, NSUNLINKMODULE_OPTION_NONE);		
#elif defined(HAVE_SHL_LOAD)
	if(image)
		shl_unload(image);
#else
	if(image)
		dlclose(image);
#endif

	if(first == this && last == this)
		first = last = NULL;

	if(!next && !prev)
		return;

	if(prev)
		prev->next = next;

	if(next)
		next->prev = prev;
	
	if(first == this)
		first = next;
	if(last == this)
		last = prev;
}

void DSO::loader(const char *filename, bool flag)
{
#if defined(HAVE_MACH_DYLD)
	NSObjectFileImage oImage;
	NSSymbol sym = NULL;
	void (*init)(void);
#endif

	id = strrchr(filename, '/');
	if(id)
		++id;
	else
		id = filename;

	next = prev = NULL;

#if defined(WIN32)
	hImage = LoadLibrary(filename);
	err = "none";
#elif defined(HAVE_MACH_DYLD)
	err = "none";
	oModule = NULL;

	fprintf(stderr, "**** HERE %s\n", filename);

	switch(NSCreateObjectFileImageFromFile(filename, &oImage)) 
	{
	case NSObjectFileImageSuccess:
		break;
	default:
		err = "unknown error";
		return;
	}
	if(flag)
		oModule = NSLinkModule(oImage, filename, NSLINKMODULE_OPTION_BINDNOW | NSLINKMODULE_OPTION_RETURN_ON_ERROR);
	else
		oModule = NSLinkModule(oImage, filename, NSLINKMODULE_OPTION_RETURN_ON_ERROR); 
	NSDestroyObjectFileImage(oImage);
	if(oModule != NULL)
		sym = NSLookupSymbolInModule(oModule, "__init");
	if(sym)
	{
		init = (void (*)(void))NSAddressOfSymbol(sym);
		init();
	}

#elif defined(HAVE_SHL_LOAD)
	err = "none";
	if(flag)
		image = shl_load(filename, BIND_IMMEDIATE, 0L);
	else
		image = shl_load(filename, BIND_DEFERRED, 0L); 
#else
	if(flag)
		image = dlopen(filename, RTLD_NOW | RTLD_GLOBAL);
	else
		image = dlopen(filename, RTLD_LAZY | RTLD_GLOBAL);

#endif

#if defined(WIN32)
	if(!hImage)
	{
		err = "load failed";
#elif defined(HAVE_MACH_DYLD)
	if(oModule == NULL)
	{
		err = "load failed";
#elif defined(HAVE_SHL_LOAD)
	if(!image)
	{
		err = "load failed";
#else
	if(!image)
	{
		err = dlerror();
#endif

// since generally failure to map or load a plugin is fatel in most
// cases, we should generally log the error to syslog as well as notify
// the upper level system of the failure through exception.

		slog.error() << "dso: " << id << ": " << err << std::endl;

#ifdef	CCXX_EXCEPTIONS
		if(Thread::getException() == Thread::throwObject)
			throw(this);
#ifdef	COMMON_STD_EXCEPTION
		else if(Thread::getException() == Thread::throwException)
			throw(DSOException(String(id) + err));
#endif
#endif
		return;
	}

	if(!last)
	{
		last = first = this;
		return;
	}

	mutex.enterMutex();
	last->next = this;
	prev = last;
	last = this;
	mutex.leaveMutex();
}	

DSO *DSO::getObject(const char *id)
{
	const char *chk = strrchr(id, '/');
	DSO *dso;

	if(chk)
		++chk;
	else
		chk = id;

	mutex.enterMutex();
	dso = first;
	while(dso)
	{
		if(!stricmp(dso->id, chk))
			break;
		dso = dso->next;
	}
	mutex.leaveMutex();
	return dso;
}
	
bool DSO::isValid(void)
{
#if	defined(WIN32)
	if(!hImage)
#elif	defined(HAVE_MACH_DYLD)
	if(oModule == NULL)
#else
	if(!image)
#endif
		return false;

	return true;
}

void *DSO::operator[](const char *sym)
{
#if   defined(HAVE_SHL_LOAD)
	int value;
	shl_t handle = (shl_t)image;

	if(shl_findsym(&handle, sym, 0, &value) == 0)
		return (void *)value;
	else
		return NULL;
#elif defined(HAVE_MACH_DYLD)
	NSSymbol oSymbol = NSLookupSymbolInModule(oModule, sym);
	if(oSymbol)
		return NSAddressOfSymbol(oSymbol);
	else
		return NULL;
#elif defined(WIN32)
	void *addr = (void *)GetProcAddress(hImage, sym);
	if(!addr)
		err = "symbol missing";

	return addr;
#else
	return dlsym(image, (char *)sym);
#endif
}

#endif


#ifdef	HAVE_MACH_DYLD
static void MyLinkError(NSLinkEditErrors c, int errorNumber, const char *filename, const char *errstr)
{
	slog.error() << "dyld: " << filename << ": " << errstr << std::endl;
}

static void MyUndefined(const char *symname)
{
	slog.error() << "dyld: undefined: " << symname << std::endl;
}

static NSModule MyMultiple(NSSymbol s, NSModule oMod, NSModule nMod)
{
	slog.error() << "dyld: multiply defined symbols" << std::endl;
}

void DSO::setDebug(void)
{
	static NSLinkEditErrorHandlers handlers = {
		&MyUndefined, 
		&MyMultiple, 
		&MyLinkError};

	NSInstallLinkEditErrorHandlers(&handlers);
}

#else

void DSO::setDebug(void)
{
}

#endif

#ifdef	CCXX_NAMESPACES
}
#endif


/** EMACS **
 * Local variables:
 * mode: c++
 * c-basic-offset: 8
 * End:
 */