ClickHouse/src/IO/AIO.h

#pragma once

#include <boost/noncopyable.hpp>

#if defined(OS_LINUX)

/// https://stackoverflow.com/questions/20759750/resolving-redefinition-of-timespec-in-time-h
#    define timespec linux_timespec
#    define timeval linux_timeval
#    define itimerspec linux_itimerspec
#    define sigset_t linux_sigset_t

#    include <linux/aio_abi.h>

#    undef timespec
#    undef timeval
#    undef itimerspec
#    undef sigset_t


/** Small wrappers for asynchronous I/O.
  */

int io_setup(unsigned nr, aio_context_t * ctxp);

int io_destroy(aio_context_t ctx);

/// last argument is an array of pointers technically speaking
int io_submit(aio_context_t ctx, long nr, struct iocb * iocbpp[]);

int io_getevents(aio_context_t ctx, long min_nr, long max_nr, io_event * events, struct timespec * timeout);


struct AIOContext : private boost::noncopyable
{
    aio_context_t ctx = 0;

    AIOContext() {}
    AIOContext(unsigned int nr_events);
    ~AIOContext();
    AIOContext(AIOContext && rhs) noexcept;
    AIOContext & operator=(AIOContext && rhs) noexcept;
};

#elif defined(OS_FREEBSD)

#    include <aio.h>
#    include <sys/event.h>
#    include <sys/time.h>
#    include <sys/types.h>

typedef struct kevent io_event;
typedef int aio_context_t;

struct iocb
{
    struct aiocb aio;
    long aio_data;
};

int io_setup(void);

int io_destroy(void);

/// last argument is an array of pointers technically speaking
int io_submit(int ctx, long nr, struct iocb * iocbpp[]);

int io_getevents(int ctx, long min_nr, long max_nr, struct kevent * events, struct timespec * timeout);


struct AIOContext : private boost::noncopyable
{
    int ctx;

    AIOContext(unsigned int nr_events = 128);
    ~AIOContext();
};

#endif