One Level Up Top Level

src/os/unix/ngx_linux_aio_read.c - nginx-1.7.10

Functions defined

Source code


  2. /*
  3. * Copyright (C) Igor Sysoev
  4. * Copyright (C) Nginx, Inc.
  5. */


  8. #include <ngx_config.h>
  9. #include <ngx_core.h>
  10. #include <ngx_event.h>


  13. extern int            ngx_eventfd;
  14. extern aio_context_t  ngx_aio_ctx;


  17. static void ngx_file_aio_event_handler(ngx_event_t *ev);


  20. static int
  21. ‌io_submit(aio_context_t ctx, long n, struct iocb **paiocb)
  22. {
  23.     return syscall(SYS_io_submit, ctx, n, paiocb);
  24. }


  27. ssize_t
  28. ‌ngx_file_aio_read(ngx_file_t *file, u_char *buf, size_t size, off_t offset,
  29.     ngx_pool_t *pool)
  30. {
  31.     ngx_err_t         err;
  32.     struct iocb      *piocb[1];
  33.     ngx_event_t      *ev;
  34.     ngx_event_aio_t  *aio;

  36.     if (!ngx_file_aio) {
  37.         return ngx_read_file(file, buf, size, offset);
  38.     }

  40.     aio = file->aio;

  42.     if (aio == NULL) {
  43.         aio = ngx_pcalloc(pool, sizeof(ngx_event_aio_t));
  44.         if (aio == NULL) {
  45.             return NGX_ERROR;
  46.         }

  48.         aio->file = file;
  49.         aio->fd = file->fd;
  50.         aio->event.data = aio;
  51.         aio->event.ready = 1;
  52.         aio->event.log = file->log;
  53.         file->aio = aio;
  54.     }

  56.     ev = &aio->event;

  58.     if (!ev->ready) {
  59.         ngx_log_error(NGX_LOG_ALERT, file->log, 0,
  60.                       "second aio post for \"%V\"", &file->name);
  61.         return NGX_AGAIN;
  62.     }

  64.     ngx_log_debug4(NGX_LOG_DEBUG_CORE, file->log, 0,
  65.                    "aio complete:%d @%O:%z %V",
  66.                    ev->complete, offset, size, &file->name);

  68.     if (ev->complete) {
  69.         ev->active = 0;
  70.         ev->complete = 0;

  72.         if (aio->res >= 0) {
  73.             ngx_set_errno(0);
  74.             return aio->res;
  75.         }

  77.         ngx_set_errno(-aio->res);

  79.         ngx_log_error(NGX_LOG_CRIT, file->log, ngx_errno,
  80.                       "aio read \"%s\" failed", file->name.data);

  82.         return NGX_ERROR;
  83.     }

  85.     ngx_memzero(&aio->aiocb, sizeof(struct iocb));

  87.     aio->aiocb.aio_data = (uint64_t) (uintptr_t) ev;
  88.     aio->aiocb.aio_lio_opcode = IOCB_CMD_PREAD;
  89.     aio->aiocb.aio_fildes = file->fd;
  90.     aio->aiocb.aio_buf = (uint64_t) (uintptr_t) buf;
  91.     aio->aiocb.aio_nbytes = size;
  92.     aio->aiocb.aio_offset = offset;
  93.     aio->aiocb.aio_flags = IOCB_FLAG_RESFD;
  94.     aio->aiocb.aio_resfd = ngx_eventfd;

  96.     ev->handler = ngx_file_aio_event_handler;

  98.     piocb[0] = &aio->aiocb;

  100.     if (io_submit(ngx_aio_ctx, 1, piocb) == 1) {
  101.         ev->active = 1;
  102.         ev->ready = 0;
  103.         ev->complete = 0;

  105.         return NGX_AGAIN;
  106.     }

  108.     err = ngx_errno;

  110.     if (err == NGX_EAGAIN) {
  111.         return ngx_read_file(file, buf, size, offset);
  112.     }

  114.     ngx_log_error(NGX_LOG_CRIT, file->log, err,
  115.                   "io_submit(\"%V\") failed", &file->name);

  117.     if (err == NGX_ENOSYS) {
  118.         ngx_file_aio = 0;
  119.         return ngx_read_file(file, buf, size, offset);
  120.     }

  122.     return NGX_ERROR;
  123. }


  126. static void
  127. ‌ngx_file_aio_event_handler(ngx_event_t *ev)
  128. {
  129.     ngx_event_aio_t  *aio;

  131.     aio = ev->data;

  133.     ngx_log_debug2(NGX_LOG_DEBUG_CORE, ev->log, 0,
  134.                    "aio event handler fd:%d %V", aio->fd, &aio->file->name);

  136.     aio->handler(ev);
  137. }

One Level Up Top Level