aio_subsys.h File Reference

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Functions
Size	AioShmemSize (void)
void	AioShmemInit (void)
void	pgaio_init_backend (void)
void	pgaio_error_cleanup (void)
void	AtEOXact_Aio (bool is_commit)
bool	pgaio_workers_enabled (void)

Function Documentation

AioShmemInit()

void AioShmemInit ( void  )

extern

Definition at line 149 of file aio_init.c.

{
    bool        found;
    uint32      io_handle_off = 0;
    uint32      iovec_off = 0;
    uint32      per_backend_iovecs = io_max_concurrency * io_max_combine_limit;
 
    pgaio_ctl = (PgAioCtl *)
        ShmemInitStruct("AioCtl", AioCtlShmemSize(), &found);
 
    if (found)
        goto out;
 
    memset(pgaio_ctl, 0, AioCtlShmemSize());
 
    pgaio_ctl->io_handle_count = AioProcs() * io_max_concurrency;
    pgaio_ctl->iovec_count = AioProcs() * per_backend_iovecs;
 
    pgaio_ctl->backend_state = (PgAioBackend *)
        ShmemInitStruct("AioBackend", AioBackendShmemSize(), &found);
 
    pgaio_ctl->io_handles = (PgAioHandle *)
        ShmemInitStruct("AioHandle", AioHandleShmemSize(), &found);
 
    pgaio_ctl->iovecs = (struct iovec *)
        ShmemInitStruct("AioHandleIOV", AioHandleIOVShmemSize(), &found);
    pgaio_ctl->handle_data = (uint64 *)
        ShmemInitStruct("AioHandleData", AioHandleDataShmemSize(), &found);
 
    for (int procno = 0; procno < AioProcs(); procno++)
    {
        PgAioBackend *bs = &pgaio_ctl->backend_state[procno];
 
        bs->io_handle_off = io_handle_off;
        io_handle_off += io_max_concurrency;
 
        dclist_init(&bs->idle_ios);
        memset(bs->staged_ios, 0, sizeof(PgAioHandle *) * PGAIO_SUBMIT_BATCH_SIZE);
        dclist_init(&bs->in_flight_ios);
 
        /* initialize per-backend IOs */
        for (int i = 0; i < io_max_concurrency; i++)
        {
            PgAioHandle *ioh = &pgaio_ctl->io_handles[bs->io_handle_off + i];
 
            ioh->generation = 1;
            ioh->owner_procno = procno;
            ioh->iovec_off = iovec_off;
            ioh->handle_data_len = 0;
            ioh->report_return = NULL;
            ioh->resowner = NULL;
            ioh->num_callbacks = 0;
            ioh->distilled_result.status = PGAIO_RS_UNKNOWN;
            ioh->flags = 0;
 
            ConditionVariableInit(&ioh->cv);
 
            dclist_push_tail(&bs->idle_ios, &ioh->node);
            iovec_off += io_max_combine_limit;
        }
    }
 
out:
    /* Initialize IO method specific resources. */
    if (pgaio_method_ops->shmem_init)
        pgaio_method_ops->shmem_init(!found);
}

References AioBackendShmemSize(), AioCtlShmemSize(), AioHandleDataShmemSize(), AioHandleIOVShmemSize(), AioHandleShmemSize(), AioProcs(), PgAioCtl::backend_state, ConditionVariableInit(), dclist_init(), dclist_push_tail(), fb(), PgAioHandle::generation, PgAioCtl::handle_data, i, PgAioCtl::io_handle_count, PgAioBackend::io_handle_off, PgAioCtl::io_handles, io_max_combine_limit, io_max_concurrency, PgAioCtl::iovec_count, PgAioCtl::iovecs, pgaio_ctl, pgaio_method_ops, PGAIO_RS_UNKNOWN, PGAIO_SUBMIT_BATCH_SIZE, IoMethodOps::shmem_init, and ShmemInitStruct().

Referenced by CreateOrAttachShmemStructs().

AioShmemSize()

Size AioShmemSize ( void  )

extern

Definition at line 113 of file aio_init.c.

{
    Size        sz = 0;
 
    /*
     * We prefer to report this value's source as PGC_S_DYNAMIC_DEFAULT.
     * However, if the DBA explicitly set io_max_concurrency = -1 in the
     * config file, then PGC_S_DYNAMIC_DEFAULT will fail to override that and
     * we must force the matter with PGC_S_OVERRIDE.
     */
    if (io_max_concurrency == -1)
    {
        char        buf[32];
 
        snprintf(buf, sizeof(buf), "%d", AioChooseMaxConcurrency());
        SetConfigOption("io_max_concurrency", buf, PGC_POSTMASTER,
                        PGC_S_DYNAMIC_DEFAULT);
        if (io_max_concurrency == -1)   /* failed to apply it? */
            SetConfigOption("io_max_concurrency", buf, PGC_POSTMASTER,
                            PGC_S_OVERRIDE);
    }
 
    sz = add_size(sz, AioCtlShmemSize());
    sz = add_size(sz, AioBackendShmemSize());
    sz = add_size(sz, AioHandleShmemSize());
    sz = add_size(sz, AioHandleIOVShmemSize());
    sz = add_size(sz, AioHandleDataShmemSize());
 
    /* Reserve space for method specific resources. */
    if (pgaio_method_ops->shmem_size)
        sz = add_size(sz, pgaio_method_ops->shmem_size());
 
    return sz;
}

References add_size(), AioBackendShmemSize(), AioChooseMaxConcurrency(), AioCtlShmemSize(), AioHandleDataShmemSize(), AioHandleIOVShmemSize(), AioHandleShmemSize(), buf, fb(), io_max_concurrency, pgaio_method_ops, PGC_POSTMASTER, PGC_S_DYNAMIC_DEFAULT, PGC_S_OVERRIDE, SetConfigOption(), IoMethodOps::shmem_size, and snprintf.

Referenced by CalculateShmemSize().

AtEOXact_Aio()

void AtEOXact_Aio ( bool  is_commit )

extern

Definition at line 1193 of file aio.c.

{
    /*
     * We should never be in batch mode at transactional boundaries. In case
     * an error was thrown while in batch mode, pgaio_error_cleanup() should
     * have exited batchmode.
     *
     * In case we are in batchmode somehow, make sure to submit all staged
     * IOs, other backends may need them to complete to continue.
     */
    if (pgaio_my_backend->in_batchmode)
    {
        pgaio_error_cleanup();
        elog(WARNING, "open AIO batch at end of (sub-)transaction");
    }
 
    /*
     * As we aren't in batchmode, there shouldn't be any unsubmitted IOs.
     */
    Assert(pgaio_my_backend->num_staged_ios == 0);
}

References Assert, elog, PgAioBackend::in_batchmode, PgAioBackend::num_staged_ios, pgaio_error_cleanup(), pgaio_my_backend, and WARNING.

Referenced by AbortSubTransaction(), AbortTransaction(), CommitTransaction(), pgaio_shutdown(), and PrepareTransaction().

pgaio_error_cleanup()

void pgaio_error_cleanup ( void  )

extern

Definition at line 1165 of file aio.c.

{
    /*
     * It is possible that code errored out after pgaio_enter_batchmode() but
     * before pgaio_exit_batchmode() was called. In that case we need to
     * submit the IO now.
     */
    if (pgaio_my_backend->in_batchmode)
    {
        pgaio_my_backend->in_batchmode = false;
 
        pgaio_submit_staged();
    }
 
    /*
     * As we aren't in batchmode, there shouldn't be any unsubmitted IOs.
     */
    Assert(pgaio_my_backend->num_staged_ios == 0);
}

References Assert, PgAioBackend::in_batchmode, PgAioBackend::num_staged_ios, pgaio_my_backend, and pgaio_submit_staged().

Referenced by AbortSubTransaction(), AbortTransaction(), AtEOXact_Aio(), AutoVacLauncherMain(), BackgroundWriterMain(), CheckpointerMain(), pgarch_archiveXlog(), WalSndErrorCleanup(), WalSummarizerMain(), and WalWriterMain().

pgaio_init_backend()

void pgaio_init_backend ( void  )

extern

Definition at line 218 of file aio_init.c.

{
    /* shouldn't be initialized twice */
    Assert(!pgaio_my_backend);
 
    if (MyBackendType == B_IO_WORKER)
        return;
 
    if (MyProc == NULL || MyProcNumber >= AioProcs())
        elog(ERROR, "aio requires a normal PGPROC");
 
    pgaio_my_backend = &pgaio_ctl->backend_state[MyProcNumber];
 
    if (pgaio_method_ops->init_backend)
        pgaio_method_ops->init_backend();
 
    before_shmem_exit(pgaio_shutdown, 0);
}

References AioProcs(), Assert, B_IO_WORKER, PgAioCtl::backend_state, before_shmem_exit(), elog, ERROR, fb(), IoMethodOps::init_backend, MyBackendType, MyProc, MyProcNumber, pgaio_ctl, pgaio_method_ops, pgaio_my_backend, and pgaio_shutdown().

Referenced by BaseInit().

pgaio_workers_enabled()

bool pgaio_workers_enabled ( void  )

extern

Definition at line 590 of file method_worker.c.

{
    return io_method == IOMETHOD_WORKER;
}

References io_method, and IOMETHOD_WORKER.

Referenced by maybe_adjust_io_workers().