127 lines
3.2 KiB
C++
127 lines
3.2 KiB
C++
/*
|
|
* Copyright (c) 2014 Jonas 'Sortie' Termansen.
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*
|
|
* ptable.cpp
|
|
* Process table.
|
|
*/
|
|
|
|
#include <sys/types.h>
|
|
|
|
#include <assert.h>
|
|
#include <errno.h>
|
|
#include <string.h>
|
|
|
|
#include <sortix/kernel/kthread.h>
|
|
#include <sortix/kernel/process.h>
|
|
#include <sortix/kernel/ptable.h>
|
|
#include <sortix/kernel/refcount.h>
|
|
|
|
// TODO: Process memory ownership needs to be reference counted.
|
|
// TODO: This implementation is rather run-time inefficient.
|
|
// TODO: The Free method potentially leaks memory as the ptable is never shrunk.
|
|
// TODO: The next_pid counter could potentially overflow.
|
|
|
|
namespace Sortix {
|
|
|
|
ProcessTable::ProcessTable()
|
|
{
|
|
ptablelock = KTHREAD_MUTEX_INITIALIZER;
|
|
next_pid = 0;
|
|
entries = NULL;
|
|
entries_used = 0;
|
|
entries_length = 0;
|
|
}
|
|
|
|
ProcessTable::~ProcessTable()
|
|
{
|
|
delete[] entries;
|
|
}
|
|
|
|
Process* ProcessTable::Get(pid_t pid)
|
|
{
|
|
ScopedLock lock(&ptablelock);
|
|
for ( size_t i = 0; i < entries_used; i++ )
|
|
if ( entries[i].pid == pid )
|
|
return entries[i].process;
|
|
return errno = ESRCH, (Process*) NULL;
|
|
}
|
|
|
|
pid_t ProcessTable::Allocate(Process* process)
|
|
{
|
|
ScopedLock lock(&ptablelock);
|
|
if ( entries_used == entries_length )
|
|
{
|
|
size_t new_length = entries_length ? 2 * entries_length : 64;
|
|
struct ptable_entry* new_entries = new struct ptable_entry[new_length];
|
|
if ( !new_entries )
|
|
return -1;
|
|
if ( entries )
|
|
{
|
|
size_t old_size = sizeof(struct ptable_entry) * entries_length;
|
|
memcpy(new_entries, entries, old_size);
|
|
delete[] entries;
|
|
}
|
|
entries = new_entries;
|
|
entries_length = new_length;
|
|
}
|
|
|
|
struct ptable_entry* entry = &entries[entries_used++];
|
|
entry->process = process;
|
|
return entry->pid = next_pid++;
|
|
}
|
|
|
|
void ProcessTable::Free(pid_t pid)
|
|
{
|
|
ScopedLock lock(&ptablelock);
|
|
for ( size_t i = 0; i < entries_used; i++ )
|
|
{
|
|
if ( entries[i].pid != pid )
|
|
continue;
|
|
entries[i] = entries[--entries_used];
|
|
return;
|
|
}
|
|
assert(false);
|
|
}
|
|
|
|
pid_t ProcessTable::Prev(pid_t pid)
|
|
{
|
|
ScopedLock lock(&ptablelock);
|
|
pid_t result = -1;
|
|
for ( size_t i = 0; i < entries_used; i++ )
|
|
{
|
|
if ( pid <= entries[i].process->pid )
|
|
continue;
|
|
if ( result == -1 || result < entries[i].process->pid )
|
|
result = entries[i].process->pid;
|
|
}
|
|
return result;
|
|
}
|
|
|
|
pid_t ProcessTable::Next(pid_t pid)
|
|
{
|
|
ScopedLock lock(&ptablelock);
|
|
pid_t result = -1;
|
|
for ( size_t i = 0; i < entries_used; i++ )
|
|
{
|
|
if ( entries[i].process->pid <= pid )
|
|
continue;
|
|
if ( result == -1 || entries[i].process->pid < result )
|
|
result = entries[i].process->pid;
|
|
}
|
|
return result;
|
|
}
|
|
|
|
} // namespace Sortix
|