Refactored sendfile() AIO preload.

This reduces layering violation and simplifies the logic of AIO preread, since
it's now triggered by the send chain function itself without falling back to
the copy filter.  The context of AIO operation is now stored per file buffer,
which makes it possible to properly handle cases when multiple buffers come
from different locations, each with its own configuration.

3 files changed, 35 insertions, 2 deletions

diff --git a/src/core/ngx_buf.h b/src/core/ngx_buf.h
index 13536a69a..219894ffc 100644
--- a/src/core/ngx_buf.h
+++ b/src/core/ngx_buf.h
@@ -94,6 +94,9 @@ struct ngx_output_chain_ctx_s {
     unsigned                     aio:1;
 
     ngx_output_chain_aio_pt      aio_handler;
+#if (NGX_HAVE_FILE_AIO)
+    ssize_t                    (*aio_preload)(ngx_buf_t *file);
+#endif
 #endif
 
     off_t                        alignment;
diff --git a/src/core/ngx_connection.h b/src/core/ngx_connection.h
index ed14e6023..143cab7b3 100644
--- a/src/core/ngx_connection.h
+++ b/src/core/ngx_connection.h
@@ -181,9 +181,7 @@ struct ngx_connection_s {
 #endif
 
 #if (NGX_HAVE_AIO_SENDFILE)
-    unsigned            aio_sendfile:1;
     unsigned            busy_count:2;
-    ngx_buf_t          *busy_sendfile;
 #endif
 
 #if (NGX_THREADS)
diff --git a/src/core/ngx_output_chain.c b/src/core/ngx_output_chain.c
index 9d7a8460f..ca390e254 100644
--- a/src/core/ngx_output_chain.c
+++ b/src/core/ngx_output_chain.c
@@ -29,6 +29,10 @@
 
 static ngx_inline ngx_int_t
     ngx_output_chain_as_is(ngx_output_chain_ctx_t *ctx, ngx_buf_t *buf);
+#if (NGX_HAVE_AIO_SENDFILE)
+static ngx_int_t ngx_output_chain_aio_setup(ngx_output_chain_ctx_t *ctx,
+    ngx_file_t *file);
+#endif
 static ngx_int_t ngx_output_chain_add_copy(ngx_pool_t *pool,
     ngx_chain_t **chain, ngx_chain_t *in);
 static ngx_int_t ngx_output_chain_align_file_buf(ngx_output_chain_ctx_t *ctx,
@@ -252,6 +256,12 @@ ngx_output_chain_as_is(ngx_output_chain_ctx_t *ctx, ngx_buf_t *buf)
         buf->in_file = 0;
     }
 
+#if (NGX_HAVE_AIO_SENDFILE)
+    if (ctx->aio_preload && buf->in_file) {
+        (void) ngx_output_chain_aio_setup(ctx, buf->file);
+    }
+#endif
+
     if (ctx->need_in_memory && !ngx_buf_in_memory(buf)) {
         return 0;
     }
@@ -264,6 +274,28 @@ ngx_output_chain_as_is(ngx_output_chain_ctx_t *ctx, ngx_buf_t *buf)
 }
 
 
+#if (NGX_HAVE_AIO_SENDFILE)
+
+static ngx_int_t
+ngx_output_chain_aio_setup(ngx_output_chain_ctx_t *ctx, ngx_file_t *file)
+{
+    ngx_event_aio_t  *aio;
+
+    if (file->aio == NULL && ngx_file_aio_init(file, ctx->pool) != NGX_OK) {
+        return NGX_ERROR;
+    }
+
+    aio = file->aio;
+
+    aio->data = ctx->filter_ctx;
+    aio->preload_handler = ctx->aio_preload;
+
+    return NGX_OK;
+}
+
+#endif
+
+
 static ngx_int_t
 ngx_output_chain_add_copy(ngx_pool_t *pool, ngx_chain_t **chain,
     ngx_chain_t *in)