109 lines
3.2 KiB
C++
109 lines
3.2 KiB
C++
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/*******************************************************************************
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Copyright(C) Jonas 'Sortie' Termansen 2013.
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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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segment.cpp
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Structure representing a segment in a process.
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*******************************************************************************/
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#include <sys/types.h>
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#include <stddef.h>
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#include <stdint.h>
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#include <stdlib.h>
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#include <sortix/kernel/decl.h>
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#include <sortix/kernel/memorymanagement.h>
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#include <sortix/kernel/process.h>
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#include <sortix/kernel/segment.h>
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namespace Sortix {
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bool AreSegmentsOverlapping(const struct segment* a, const struct segment* b)
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{
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return a->addr < b->addr + b->size && b->addr < a->addr + a->size;
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}
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bool IsUserspaceSegment(const struct segment* segment)
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{
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uintptr_t userspace_addr;
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size_t userspace_size;
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Memory::GetUserVirtualArea(&userspace_addr, &userspace_size);
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if ( segment->addr < userspace_addr )
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return false;
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uintptr_t userspace_end = userspace_addr + userspace_size;
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if ( userspace_end - segment->addr < segment->size )
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return false;
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return true;
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}
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struct segment* FindOverlappingSegment(Process* process, const struct segment* new_segment)
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{
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// process->segment_lock is held at this point.
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// TODO: Speed up using binary search.
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for ( size_t i = 0; i < process->segments_used; i++ )
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{
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struct segment* segment = &process->segments[i];
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if ( AreSegmentsOverlapping(segment, new_segment) )
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return segment;
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}
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return NULL;
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}
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bool IsSegmentOverlapping(Process* process, const struct segment* new_segment)
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{
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// process->segment_lock is held at this point.
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return FindOverlappingSegment(process, new_segment) != NULL;
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}
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bool AddSegment(Process* process, const struct segment* new_segment)
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{
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// process->segment_lock is held at this point.
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// assert(!IsSegmentOverlapping(new_segment));
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// Check if we need to expand the segment list.
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if ( process->segments_used == process->segments_length )
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{
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size_t new_length = process->segments_length ?
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process->segments_length * 2 : 8;
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size_t new_size = new_length * sizeof(struct segment);
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struct segment* new_segments =
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(struct segment*) realloc(process->segments, new_size);
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if ( !new_segments )
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return false;
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process->segments = new_segments;
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process->segments_length = new_length;
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}
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// Add the new segment to the segment list.
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process->segments[process->segments_used++] = *new_segment;
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// Sort the segment list after address.
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qsort(process->segments, process->segments_used, sizeof(struct segment),
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segmentcmp);
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return true;
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}
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} // namespace Sortix
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