Mercurial > hg > nginx-ranges
diff src/os/unix/ngx_file_aio_read.c @ 529:86dad910eeb6 NGINX_0_8_11
nginx 0.8.11
*) Change: directive "gzip_disable msie6" enables gzipping for
MSIE 6.0 SV1.
*) Feature: file AIO support on FreeBSD and Linux.
*) Feature: the "directio_alignment" directive.
author | Igor Sysoev <http://sysoev.ru> |
---|---|
date | Fri, 28 Aug 2009 00:00:00 +0400 |
parents | |
children | d41628eb4d0a |
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new file mode 100644 --- /dev/null +++ b/src/os/unix/ngx_file_aio_read.c @@ -0,0 +1,210 @@ + +/* + * Copyright (C) Igor Sysoev + */ + + +#include <ngx_config.h> +#include <ngx_core.h> +#include <ngx_event.h> + + +/* + * FreeBSD file AIO features and quirks: + * + * if an asked data are already in VM cache, then aio_error() returns 0, + * and the data are already copied in buffer; + * + * aio_read() preread in VM cache as minimum 32K; + * + * aio_read/aio_error() may return EINPROGRESS for just written data; + * + * kqueue EVFILT_AIO filter is level triggered only: an event repeats + * until aio_return() will be called; + * + * aio_cancel() can not cancel file AIO: it returns AIO_NOTCANCELED always. + */ + + +extern int ngx_kqueue; + + +static ssize_t ngx_file_aio_result(ngx_file_t *file, ngx_event_aio_t *aio, + ngx_event_t *ev); +static void ngx_file_aio_event_handler(ngx_event_t *ev); + + +ssize_t +ngx_file_aio_read(ngx_file_t *file, u_char *buf, size_t size, off_t offset, + ngx_pool_t *pool) +{ + int n; + ngx_event_t *ev; + ngx_event_aio_t *aio; + static ngx_uint_t enosys = 0; + + if (enosys) { + return ngx_read_file(file, buf, size, offset); + } + + aio = file->aio; + + if (aio == NULL) { + aio = ngx_pcalloc(pool, sizeof(ngx_event_aio_t)); + if (aio == NULL) { + return NGX_ERROR; + } + + aio->file = file; + aio->fd = file->fd; + aio->event.data = aio; + aio->event.ready = 1; + aio->event.log = file->log; + file->aio = aio; + } + + ev = &aio->event; + + if (!ev->ready) { + ngx_log_error(NGX_LOG_ALERT, file->log, 0, + "second aio post for \"%V\"", &file->name); + return NGX_AGAIN; + } + + ngx_log_debug4(NGX_LOG_DEBUG_CORE, file->log, 0, + "aio complete:%d @%O:%z %V", + ev->complete, offset, size, &file->name); + + if (ev->complete) { + ev->complete = 0; + ngx_set_errno(aio->err); + + if (aio->err == 0) { + return aio->nbytes; + } + + return NGX_ERROR; + } + + ngx_memzero(&aio->aiocb, sizeof(struct aiocb)); + + aio->aiocb.aio_fildes = file->fd; + aio->aiocb.aio_offset = offset; + aio->aiocb.aio_buf = buf; + aio->aiocb.aio_nbytes = size; +#if (NGX_HAVE_KQUEUE) + aio->aiocb.aio_sigevent.sigev_notify_kqueue = ngx_kqueue; + aio->aiocb.aio_sigevent.sigev_notify = SIGEV_KEVENT; + aio->aiocb.aio_sigevent.sigev_value.sigval_ptr = ev; +#endif + ev->handler = ngx_file_aio_event_handler; + + n = aio_read(&aio->aiocb); + + if (n == -1) { + n = ngx_errno; + + if (n == NGX_EAGAIN) { + return ngx_read_file(file, buf, size, offset); + } + + ngx_log_error(NGX_LOG_CRIT, file->log, n, + "aio_read(\"%V\") failed", &file->name); + + if (n == NGX_ENOSYS) { + enosys = 1; + return ngx_read_file(file, buf, size, offset); + } + + return NGX_ERROR; + } + + ngx_log_debug2(NGX_LOG_DEBUG_CORE, file->log, 0, + "aio_read: fd:%d %d", file->fd, n); + + ev->active = 1; + ev->ready = 0; + ev->complete = 0; + + return ngx_file_aio_result(aio->file, aio, ev); +} + + +static ssize_t +ngx_file_aio_result(ngx_file_t *file, ngx_event_aio_t *aio, ngx_event_t *ev) +{ + int n; + ngx_err_t err; + + n = aio_error(&aio->aiocb); + + ngx_log_debug2(NGX_LOG_DEBUG_CORE, file->log, 0, + "aio_error: fd:%d %d", file->fd, n); + + if (n == -1) { + err = ngx_errno; + aio->err = err; + + ngx_log_error(NGX_LOG_ALERT, file->log, err, + "aio_error(\"%V\") failed", &file->name); + return NGX_ERROR; + } + + if (n != 0) { + if (n == NGX_EINPROGRESS) { + if (ev->ready) { + ev->ready = 0; + ngx_log_error(NGX_LOG_ALERT, file->log, n, + "aio_read(\"%V\") still in progress", + &file->name); + } + + return NGX_AGAIN; + } + + aio->err = n; + ev->ready = 0; + + ngx_log_error(NGX_LOG_CRIT, file->log, n, + "aio_read(\"%V\") failed", &file->name); + return NGX_ERROR; + } + + n = aio_return(&aio->aiocb); + + if (n == -1) { + err = ngx_errno; + aio->err = err; + ev->ready = 0; + + ngx_log_error(NGX_LOG_ALERT, file->log, err, + "aio_return(\"%V\") failed", &file->name); + return NGX_ERROR; + } + + aio->err = 0; + aio->nbytes = n; + ev->ready = 1; + ev->active = 0; + + ngx_log_debug2(NGX_LOG_DEBUG_CORE, file->log, 0, + "aio_return: fd:%d %d", file->fd, n); + + return n; +} + + +static void +ngx_file_aio_event_handler(ngx_event_t *ev) +{ + ngx_event_aio_t *aio; + + aio = ev->data; + + ngx_log_debug2(NGX_LOG_DEBUG_CORE, ev->log, 0, + "aio event handler fd:%d %V", aio->fd, &aio->file->name); + + if (ngx_file_aio_result(aio->file, aio, ev) != NGX_AGAIN) { + aio->handler(ev); + } +}