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/*
Fakeroot Next Generation - run command with fake root privileges
This program is copyrighted. Copyright information is available at the
AUTHORS file at the root of the source tree for the fakeroot-ng project
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "config.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <stdio.h>
#include <assert.h>
#include "arch/platform.h"
#include "parent.h"
#include "shared_mem.h"
size_t shared_mem::shared_mem_size(0);
void shared_mem::init_size( size_t size )
{
assert( shared_mem_size==0 );
shared_mem_size=size;
}
shared_mem::shared_mem() : data(NULL), mem_next(0), mem_prev(0), us(0)
{
}
shared_mem::shared_mem( void *ptr ) : data(new struct shared_mem::data), mem_next(0), mem_prev(0), us(0)
{
if( data!=NULL ) {
data->reference_count=1;
data->wait_next=0;
data->wait_prev=0;
data->local_pointer=((char *)ptr)+ptlib_prepare_memory_len();
}
}
// Copy constructor and operator=
shared_mem::shared_mem( const shared_mem &rhs ) : data(rhs.data), mem_next(0), mem_prev(0), us(0)
{
if( data!=NULL )
data->reference_count++;
}
shared_mem &shared_mem::operator =( const shared_mem &rhs )
{
release();
data=rhs.data;
if( data!=NULL ) {
data->reference_count++;
// Link us to the other
assert(us!=rhs.us || us==0);
if( us!=0 && rhs.us!=0 ) {
mem_next=rhs.us;
mem_prev=rhs.mem_prev;
pid_state *other_state;
if( mem_prev!=0 ) {
other_state=lookup_state( mem_prev );
assert(other_state!=NULL);
other_state->shared_mem_local.mem_next=us;
}
if( mem_next!=0 ) {
other_state=lookup_state( mem_next );
assert( other_state!=NULL && &(other_state->shared_mem_local)==&rhs );
other_state->shared_mem_local.mem_prev=us;
}
}
}
return *this;
}
shared_mem::~shared_mem()
{
release();
}
void shared_mem::release()
{
if( data && (--data->reference_count)==0 ) {
munmap( ((char *)data->local_pointer)-ptlib_prepare_memory_len(), shared_mem_size );
delete data;
}
pid_state *other_state;
// Unlink us from the shared memory resource
if( mem_next!=0 ) {
other_state=lookup_state(mem_next);
assert( other_state!=NULL && other_state->shared_mem_local.mem_prev==us );
other_state->shared_mem_local.mem_prev=mem_prev;
}
if( mem_prev!=0 ) {
other_state=lookup_state(mem_prev);
assert( other_state!=NULL && other_state->shared_mem_local.mem_next==us );
other_state->shared_mem_local.mem_next=mem_next;
}
data=NULL;
mem_next=mem_prev=0;
}
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