release/src/router/nginx/src/os/unix/ngx_linux_aio_read.c

   1
   2 /*
   3  * Copyright (C) Igor Sysoev
   4  * Copyright (C) Nginx, Inc.
   5  */
   6
   7
   8 #include <ngx_config.h>
   9 #include <ngx_core.h>
  10 #include <ngx_event.h>
  11
  12
  13 extern int            ngx_eventfd;
  14 extern aio_context_t  ngx_aio_ctx;
  15
  16
  17 static void ngx_file_aio_event_handler(ngx_event_t *ev);
  18
  19
  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 }
  25
  26
  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;
  35
  36     if (!ngx_file_aio) {
  37         return ngx_read_file(file, buf, size, offset);
  38     }
  39
  40     aio = file->aio;
  41
  42     if (aio == NULL) {
  43         aio = ngx_pcalloc(pool, sizeof(ngx_event_aio_t));
  44         if (aio == NULL) {
  45             return NGX_ERROR;
  46         }
  47
  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     }
  55
  56     ev = &aio->event;
  57
  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     }
  63
  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);
  67
  68     if (ev->complete) {
  69         ev->active = 0;
  70         ev->complete = 0;
  71
  72         if (aio->res >= 0) {
  73             ngx_set_errno(0);
  74             return aio->res;
  75         }
  76
  77         ngx_set_errno(-aio->res);
  78
  79         ngx_log_error(NGX_LOG_CRIT, file->log, ngx_errno,
  80                       "aio read \"%s\" failed", file->name.data);
  81
  82         return NGX_ERROR;
  83     }
  84
  85     ngx_memzero(&aio->aiocb, sizeof(struct iocb));
  86
  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;
  95
  96     ev->handler = ngx_file_aio_event_handler;
  97
  98     piocb[0] = &aio->aiocb;
  99
 100     if (io_submit(ngx_aio_ctx, 1, piocb) == 1) {
 101         ev->active = 1;
 102         ev->ready = 0;
 103         ev->complete = 0;
 104
 105         return NGX_AGAIN;
 106     }
 107
 108     err = ngx_errno;
 109
 110     if (err == NGX_EAGAIN) {
 111         return ngx_read_file(file, buf, size, offset);
 112     }
 113
 114     ngx_log_error(NGX_LOG_CRIT, file->log, err,
 115                   "io_submit(\"%V\") failed", &file->name);
 116
 117     if (err == NGX_ENOSYS) {
 118         ngx_file_aio = 0;
 119         return ngx_read_file(file, buf, size, offset);
 120     }
 121
 122     return NGX_ERROR;
 123 }
 124
 125
 126 static void
 127 ngx_file_aio_event_handler(ngx_event_t *ev)
 128 {
 129     ngx_event_aio_t  *aio;
 130
 131     aio = ev->data;
 132
 133     ngx_log_debug2(NGX_LOG_DEBUG_CORE, ev->log, 0,
 134                    "aio event handler fd:%d %V", aio->fd, &aio->file->name);
 135
 136     aio->handler(ev);
 137 }