nxdumptool/source/service_guard.h

/*
 * service_guard.h
 *
 * Copyright (c) 2018-2020, Switchbrew and libnx contributors.
 * Copyright (c) 2020, DarkMatterCore <pabloacurielz@gmail.com>.
 *
 * This file is part of nxdumptool (https://github.com/DarkMatterCore/nxdumptool).
 *
 * nxdumptool is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * nxdumptool is distributed in the hope 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/>.
 */

#pragma once

#ifndef __SERVICE_GUARD_H__
#define __SERVICE_GUARD_H__

#include <switch.h>

typedef struct ServiceGuard {
    Mutex mutex;
    u32 refCount;
} ServiceGuard;

NX_INLINE bool serviceGuardBeginInit(ServiceGuard* g)
{
    mutexLock(&g->mutex);
    return (g->refCount++) == 0;
}

NX_INLINE Result serviceGuardEndInit(ServiceGuard* g, Result rc, void (*cleanupFunc)(void))
{
    if (R_FAILED(rc)) {
        cleanupFunc();
        --g->refCount;
    }
    mutexUnlock(&g->mutex);
    return rc;
}

NX_INLINE void serviceGuardExit(ServiceGuard* g, void (*cleanupFunc)(void))
{
    mutexLock(&g->mutex);
    if (g->refCount && (--g->refCount) == 0)
        cleanupFunc();
    mutexUnlock(&g->mutex);
}

#define NX_GENERATE_SERVICE_GUARD_PARAMS(name, _paramdecl, _parampass) \
\
static ServiceGuard g_##name##Guard = {0}; \
NX_INLINE Result _##name##Initialize _paramdecl; \
static void _##name##Cleanup(void); \
\
Result name##Initialize _paramdecl \
{ \
    Result rc = 0; \
    if (serviceGuardBeginInit(&g_##name##Guard)) \
        rc = _##name##Initialize _parampass; \
    return serviceGuardEndInit(&g_##name##Guard, rc, _##name##Cleanup); \
} \
\
void name##Exit(void) \
{ \
    serviceGuardExit(&g_##name##Guard, _##name##Cleanup); \
}

#define NX_GENERATE_SERVICE_GUARD(name) NX_GENERATE_SERVICE_GUARD_PARAMS(name, (void), ())

#endif /* __SERVICE_GUARD_H__ */