AIO-switch-updater/include/service_guard.h

#pragma once
#include <switch/kernel/mutex.h>
#include <switch/result.h>
#include <switch/services/sm.h>
#include <switch/sf/service.h>
#include <switch/types.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;                                    \
    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), ())