mirror of
https://gitlab.com/sortix/sortix.git
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301 lines
7.1 KiB
C++
301 lines
7.1 KiB
C++
/*******************************************************************************
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Copyright(C) Jonas 'Sortie' Termansen 2011, 2012, 2013, 2014, 2015.
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This file is part of Sortix.
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Sortix is free software: you can redistribute it and/or modify it under the
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terms of the GNU General Public License as published by the Free Software
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Foundation, either version 3 of the License, or (at your option) any later
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version.
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Sortix is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
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details.
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You should have received a copy of the GNU General Public License along with
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Sortix. If not, see <http://www.gnu.org/licenses/>.
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dtable.cpp
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Table of file descriptors.
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*******************************************************************************/
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#include <assert.h>
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#include <errno.h>
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#include <limits.h>
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#include <string.h>
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#include <sortix/fcntl.h>
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#include <sortix/kernel/descriptor.h>
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#include <sortix/kernel/dtable.h>
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#include <sortix/kernel/kernel.h>
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#include <sortix/kernel/kthread.h>
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#include <sortix/kernel/process.h>
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#include <sortix/kernel/refcount.h>
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namespace Sortix {
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DescriptorTable::DescriptorTable()
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{
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dtablelock = KTHREAD_MUTEX_INITIALIZER;
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entries = NULL;
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numentries = 0;
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first_not_taken = 0;
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}
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DescriptorTable::~DescriptorTable()
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{
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Reset();
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}
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bool DescriptorTable::IsGoodEntry(int i)
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{
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bool ret = 0 <= i && i < numentries && entries[i].desc;
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return ret;
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}
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Ref<DescriptorTable> DescriptorTable::Fork()
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{
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ScopedLock lock(&dtablelock);
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Ref<DescriptorTable> ret(new DescriptorTable);
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if ( !ret ) { return Ref<DescriptorTable>(NULL); }
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ret->entries = new dtableent_t[numentries];
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if ( !ret->entries ) { return Ref<DescriptorTable>(NULL); }
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ret->first_not_taken = 0;
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for ( ret->numentries = 0; ret->numentries < numentries; ret->numentries++ )
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{
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int i = ret->numentries;
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if ( entries[i].desc && !(entries[i].flags & FD_CLOFORK) )
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{
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ret->entries[i] = entries[i];
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if ( i == ret->first_not_taken && i != INT_MAX )
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ret->first_not_taken++;
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}
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else
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/* Already set to NULL in dtableent_t::desc constructor. */{}
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}
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return ret;
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}
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Ref<Descriptor> DescriptorTable::Get(int index)
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{
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ScopedLock lock(&dtablelock);
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if ( !IsGoodEntry(index) ) { errno = EBADF; return Ref<Descriptor>(NULL); }
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return entries[index].desc;
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}
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bool DescriptorTable::Enlargen(int atleast)
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{
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if ( numentries == INT_MAX ) { errno = EOVERFLOW; return -1; }
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int newnumentries = INT_MAX - numentries < numentries ?
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INT_MAX :
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numentries ? 2 * numentries : 8;
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if ( newnumentries < atleast )
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newnumentries = atleast;
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dtableent_t* newentries = new dtableent_t[newnumentries];
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if ( !newentries )
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return false;
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for ( int i = 0; i < numentries; i++ )
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newentries[i].desc = entries[i].desc,
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newentries[i].flags = entries[i].flags;
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for ( int i = numentries; i < newnumentries; i++ )
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/* newentries[i].desc is set in dtableent_t::desc constructor */
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newentries[i].flags = 0;
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delete[] entries; entries = newentries;
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numentries = newnumentries;
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return true;
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}
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int DescriptorTable::AllocateInternal(Ref<Descriptor> desc, int flags,
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int min_index)
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{
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// dtablelock is held.
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if ( flags & ~__FD_ALLOWED_FLAGS )
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return errno = EINVAL, -1;
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if ( min_index < 0 )
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return errno = EINVAL, -1;
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if ( min_index < first_not_taken )
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min_index = first_not_taken;
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for ( int i = min_index; i < numentries; i++ )
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{
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if ( !entries[i].desc )
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{
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entries[i].desc = desc;
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entries[i].flags = flags;
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return i;
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}
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if ( i == first_not_taken && i != INT_MAX )
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first_not_taken++;
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}
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int oldnumentries = numentries;
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if ( !Enlargen(min_index) )
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return -1;
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int i = oldnumentries++;
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entries[i].desc = desc;
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entries[i].flags = flags;
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return i;
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}
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int DescriptorTable::Allocate(Ref<Descriptor> desc, int flags, int min_index)
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{
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ScopedLock lock(&dtablelock);
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return AllocateInternal(desc, flags, min_index);
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}
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int DescriptorTable::Allocate(int src_index, int flags, int min_index)
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{
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ScopedLock lock(&dtablelock);
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if ( !IsGoodEntry(src_index) )
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return errno = EBADF, -1;
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return AllocateInternal(entries[src_index].desc, flags, min_index);
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}
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int DescriptorTable::Copy(int from, int to, int flags)
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{
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if ( flags & ~__FD_ALLOWED_FLAGS )
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return errno = EINVAL, -1;
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ScopedLock lock(&dtablelock);
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if ( from < 0 || to < 0 )
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return errno = EINVAL, -1;
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if ( !(from < numentries) )
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return errno = EBADF, -1;
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if ( !entries[from].desc )
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return errno = EBADF, -1;
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if ( from == to )
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return errno = EINVAL, -1;
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while ( !(to < numentries) )
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if ( !Enlargen(to+1) )
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return -1;
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if ( entries[to].desc != entries[from].desc )
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{
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if ( entries[to].desc )
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/* TODO: Should this be synced or otherwise properly closed? */{}
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entries[to].desc = entries[from].desc;
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if ( to == first_not_taken && to != INT_MAX )
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first_not_taken++;
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}
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entries[to].flags = flags;
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return to;
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}
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Ref<Descriptor> DescriptorTable::FreeKeepInternal(int index)
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{
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if ( !IsGoodEntry(index) ) { errno = EBADF; return Ref<Descriptor>(NULL); }
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Ref<Descriptor> ret = entries[index].desc;
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entries[index].desc.Reset();
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if ( index < first_not_taken )
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first_not_taken = index;
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return ret;
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}
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Ref<Descriptor> DescriptorTable::FreeKeep(int index)
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{
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ScopedLock lock(&dtablelock);
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return FreeKeepInternal(index);
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}
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void DescriptorTable::Free(int index)
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{
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FreeKeep(index);
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}
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void DescriptorTable::OnExecute()
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{
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ScopedLock lock(&dtablelock);
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for ( int i = 0; i < numentries; i++ )
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{
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if ( !entries[i].desc )
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continue;
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if ( !(entries[i].flags & FD_CLOEXEC) )
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continue;
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entries[i].desc.Reset();
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if ( i < first_not_taken )
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first_not_taken = i;
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}
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}
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void DescriptorTable::Reset()
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{
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ScopedLock lock(&dtablelock);
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numentries = 0;
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delete[] entries;
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entries = NULL;
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first_not_taken = 0;
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}
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bool DescriptorTable::SetFlags(int index, int flags)
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{
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if ( flags & ~__FD_ALLOWED_FLAGS )
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return errno = EINVAL, -1;
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ScopedLock lock(&dtablelock);
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if ( !IsGoodEntry(index) ) { errno = EBADF; return false; }
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entries[index].flags = flags;
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return true;
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}
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int DescriptorTable::GetFlags(int index)
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{
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ScopedLock lock(&dtablelock);
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if ( !IsGoodEntry(index) ) { errno = EBADF; return -1; }
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return entries[index].flags;
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}
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int DescriptorTable::Previous(int index)
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{
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ScopedLock lock(&dtablelock);
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if ( index < 0 )
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index = numentries;
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do index--;
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while ( 0 <= index && !IsGoodEntry(index) );
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if ( index < 0 )
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return errno = EBADF, -1;
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return index;
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}
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int DescriptorTable::Next(int index)
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{
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ScopedLock lock(&dtablelock);
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if ( index < 0 )
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index = -1;
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if ( numentries <= index )
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return errno = EBADF, -1;
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do index++;
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while ( index < numentries && !IsGoodEntry(index) );
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if ( numentries <= index )
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return errno = EBADF, -1;
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return index;
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}
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int DescriptorTable::CloseFrom(int index)
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{
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if ( index < 0 )
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return errno = EBADF, -1;
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ScopedLock lock(&dtablelock);
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bool any = false;
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while ( index < numentries )
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{
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if ( !IsGoodEntry(index) )
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continue;
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FreeKeepInternal(index);
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any = true;
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}
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return any ? 0 : (errno = EBADF, -1);
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}
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} // namespace Sortix
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