101 lines
2.3 KiB
C

/*
* This file is part of open_agb_firm
* Copyright (C) 2021 derrek, profi200
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*/
#include <stdlib.h>
#include "types.h"
#include "internal/list.h"
#include "internal/kernel_private.h"
#include "internal/util.h"
#include "internal/slabheap.h"
#include "internal/config.h"
typedef struct
{
s32 count;
ListNode waitQueue;
} KSema;
static SlabHeap g_semaSlab = {0};
void _semaphoreSlabInit(void)
{
slabInit(&g_semaSlab, sizeof(KSema), MAX_SEMAPHORES);
}
// TODO: Test semaphore with multiple cores.
KHandle createSemaphore(int32_t count)
{
KSema *const ksema = (KSema*)slabAlloc(&g_semaSlab);
ksema->count = count;
listInit(&ksema->waitQueue);
return (KHandle)ksema;
}
void deleteSemaphore(KHandle const ksema)
{
KSema *const sema = (KSema*)ksema;
kernelLock();
waitQueueWakeN(&sema->waitQueue, (u32)-1, KRES_HANDLE_DELETED, true);
slabFree(&g_semaSlab, sema);
}
KRes pollSemaphore(KHandle const ksema)
{
KSema *const sema = (KSema*)ksema;
KRes res;
// TODO: Plain spinlocks instead?
kernelLock();
if(UNLIKELY(sema->count <= 0)) res = KRES_WOULD_BLOCK;
else {sema->count--; res = KRES_OK;}
kernelUnlock();
return res;
}
KRes waitForSemaphore(KHandle const ksema)
{
KSema *const sema = (KSema*)ksema;
KRes res;
kernelLock();
if(UNLIKELY(--sema->count < 0)) res = waitQueueBlock(&sema->waitQueue);
else {kernelUnlock(); res = KRES_OK;}
return res;
}
void signalSemaphore(KHandle const ksema, uint32_t signalCount, bool reschedule)
{
KSema *const sema = (KSema*)ksema;
kernelLock();
//if(UNLIKELY(++sema->count <= 0))
if(UNLIKELY((sema->count += signalCount) <= 0))
waitQueueWakeN(&sema->waitQueue, signalCount, KRES_OK, reschedule);
else kernelUnlock();
}