Mercurial > hg > nginx-quic
view src/stream/ngx_stream_write_filter_module.c @ 6949:ff0c8e11edbc
Simplified and improved sendfile() code on Linux.
The ngx_linux_sendfile() function is now used for both normal sendfile()
and sendfile in threads. The ngx_linux_sendfile_thread() function was
modified to use the same interface as ngx_linux_sendfile(), and is simply
called from ngx_linux_sendfile() when threads are enabled.
Special return code NGX_DONE is used to indicate that a thread task was
posted and no further actions are needed.
If number of bytes sent is less that what we were sending, we now always
retry sending. This is needed for sendfile() in threads as the number
of bytes we are sending might have been changed since the thread task
was posted. And this is also needed for Linux 4.3+, as sendfile() might
be interrupted at any time and provides no indication if it was interrupted
or not (ticket #1174).
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Tue, 28 Mar 2017 18:15:39 +0300 |
parents | 56fc55e32f23 |
children | a7ff19afbb14 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_stream.h> typedef struct { ngx_chain_t *from_upstream; ngx_chain_t *from_downstream; } ngx_stream_write_filter_ctx_t; static ngx_int_t ngx_stream_write_filter(ngx_stream_session_t *s, ngx_chain_t *in, ngx_uint_t from_upstream); static ngx_int_t ngx_stream_write_filter_init(ngx_conf_t *cf); static ngx_stream_module_t ngx_stream_write_filter_module_ctx = { NULL, /* preconfiguration */ ngx_stream_write_filter_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL /* merge server configuration */ }; ngx_module_t ngx_stream_write_filter_module = { NGX_MODULE_V1, &ngx_stream_write_filter_module_ctx, /* module context */ NULL, /* module directives */ NGX_STREAM_MODULE, /* module type */ NULL, /* init master */ NULL, /* init module */ NULL, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; static ngx_int_t ngx_stream_write_filter(ngx_stream_session_t *s, ngx_chain_t *in, ngx_uint_t from_upstream) { off_t size; ngx_uint_t last, flush, sync; ngx_chain_t *cl, *ln, **ll, **out, *chain; ngx_connection_t *c; ngx_stream_write_filter_ctx_t *ctx; ctx = ngx_stream_get_module_ctx(s, ngx_stream_write_filter_module); if (ctx == NULL) { ctx = ngx_pcalloc(s->connection->pool, sizeof(ngx_stream_write_filter_ctx_t)); if (ctx == NULL) { return NGX_ERROR; } ngx_stream_set_ctx(s, ctx, ngx_stream_write_filter_module); } if (from_upstream) { c = s->connection; out = &ctx->from_upstream; } else { c = s->upstream->peer.connection; out = &ctx->from_downstream; } if (c->error) { return NGX_ERROR; } size = 0; flush = 0; sync = 0; last = 0; ll = out; /* find the size, the flush point and the last link of the saved chain */ for (cl = *out; cl; cl = cl->next) { ll = &cl->next; ngx_log_debug7(NGX_LOG_DEBUG_EVENT, c->log, 0, "write old buf t:%d f:%d %p, pos %p, size: %z " "file: %O, size: %O", cl->buf->temporary, cl->buf->in_file, cl->buf->start, cl->buf->pos, cl->buf->last - cl->buf->pos, cl->buf->file_pos, cl->buf->file_last - cl->buf->file_pos); #if 1 if (ngx_buf_size(cl->buf) == 0 && !ngx_buf_special(cl->buf)) { ngx_log_error(NGX_LOG_ALERT, c->log, 0, "zero size buf in writer " "t:%d r:%d f:%d %p %p-%p %p %O-%O", cl->buf->temporary, cl->buf->recycled, cl->buf->in_file, cl->buf->start, cl->buf->pos, cl->buf->last, cl->buf->file, cl->buf->file_pos, cl->buf->file_last); ngx_debug_point(); return NGX_ERROR; } #endif size += ngx_buf_size(cl->buf); if (cl->buf->flush || cl->buf->recycled) { flush = 1; } if (cl->buf->sync) { sync = 1; } if (cl->buf->last_buf) { last = 1; } } /* add the new chain to the existent one */ for (ln = in; ln; ln = ln->next) { cl = ngx_alloc_chain_link(c->pool); if (cl == NULL) { return NGX_ERROR; } cl->buf = ln->buf; *ll = cl; ll = &cl->next; ngx_log_debug7(NGX_LOG_DEBUG_EVENT, c->log, 0, "write new buf t:%d f:%d %p, pos %p, size: %z " "file: %O, size: %O", cl->buf->temporary, cl->buf->in_file, cl->buf->start, cl->buf->pos, cl->buf->last - cl->buf->pos, cl->buf->file_pos, cl->buf->file_last - cl->buf->file_pos); #if 1 if (ngx_buf_size(cl->buf) == 0 && !ngx_buf_special(cl->buf)) { ngx_log_error(NGX_LOG_ALERT, c->log, 0, "zero size buf in writer " "t:%d r:%d f:%d %p %p-%p %p %O-%O", cl->buf->temporary, cl->buf->recycled, cl->buf->in_file, cl->buf->start, cl->buf->pos, cl->buf->last, cl->buf->file, cl->buf->file_pos, cl->buf->file_last); ngx_debug_point(); return NGX_ERROR; } #endif size += ngx_buf_size(cl->buf); if (cl->buf->flush || cl->buf->recycled) { flush = 1; } if (cl->buf->sync) { sync = 1; } if (cl->buf->last_buf) { last = 1; } } *ll = NULL; ngx_log_debug3(NGX_LOG_DEBUG_STREAM, c->log, 0, "stream write filter: l:%ui f:%ui s:%O", last, flush, size); if (size == 0 && !(c->buffered & NGX_LOWLEVEL_BUFFERED) && !(last && c->need_last_buf)) { if (last || flush || sync) { for (cl = *out; cl; /* void */) { ln = cl; cl = cl->next; ngx_free_chain(c->pool, ln); } *out = NULL; c->buffered &= ~NGX_STREAM_WRITE_BUFFERED; return NGX_OK; } ngx_log_error(NGX_LOG_ALERT, c->log, 0, "the stream output chain is empty"); ngx_debug_point(); return NGX_ERROR; } chain = c->send_chain(c, *out, 0); ngx_log_debug1(NGX_LOG_DEBUG_STREAM, c->log, 0, "stream write filter %p", chain); if (chain == NGX_CHAIN_ERROR) { c->error = 1; return NGX_ERROR; } for (cl = *out; cl && cl != chain; /* void */) { ln = cl; cl = cl->next; ngx_free_chain(c->pool, ln); } *out = chain; if (chain) { if (c->shared) { ngx_log_error(NGX_LOG_ALERT, c->log, 0, "shared connection is busy"); return NGX_ERROR; } c->buffered |= NGX_STREAM_WRITE_BUFFERED; return NGX_AGAIN; } c->buffered &= ~NGX_STREAM_WRITE_BUFFERED; if (c->buffered & NGX_LOWLEVEL_BUFFERED) { return NGX_AGAIN; } return NGX_OK; } static ngx_int_t ngx_stream_write_filter_init(ngx_conf_t *cf) { ngx_stream_top_filter = ngx_stream_write_filter; return NGX_OK; }