Mercurial > hg > nginx
view src/os/unix/ngx_linux_sendfile_chain.c @ 3440:88741ec7731a stable-0.7
merge r3294, r3305:
Fix a bug introduced in r2032: After a child process has read a terminate
message from a channel, the process tries to read the channel again.
The kernel (at least FreeBSD) may preempt the process and sends a SIGIO
signal to a master process. The master process sends a new terminate message,
the kernel switches again to the the child process, and the child process
reads the messages instead of an EAGAIN error. And this may repeat over
and over. Being that the child process can not exit the cycle and test
the termination flag set by the message handler.
The fix disallow the master process to send a new terminate message on
SIGIO signal reception. It may send the message only on SIGALARM signal.
author | Igor Sysoev <igor@sysoev.ru> |
---|---|
date | Mon, 01 Feb 2010 15:49:36 +0000 |
parents | f69d1aab6a0f |
children | 6f6d7ea70805 |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> /* * On Linux up to 2.4.21 sendfile() (syscall #187) works with 32-bit * offsets only, and the including <sys/sendfile.h> breaks the compiling, * if off_t is 64 bit wide. So we use own sendfile() definition, where offset * parameter is int32_t, and use sendfile() for the file parts below 2G only, * see src/os/unix/ngx_linux_config.h * * Linux 2.4.21 has the new sendfile64() syscall #239. * * On Linux up to 2.6.16 sendfile() does not allow to pass the count parameter * more than 2G-1 bytes even on 64-bit platforms: it returns EINVAL, * so we limit it to 2G-1 bytes. */ #define NGX_SENDFILE_LIMIT 2147483647L #if (IOV_MAX > 64) #define NGX_HEADERS 64 #else #define NGX_HEADERS IOV_MAX #endif ngx_chain_t * ngx_linux_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit) { int rc, tcp_nodelay; off_t size, send, prev_send, aligned, sent, fprev; u_char *prev; size_t file_size; ngx_err_t err; ngx_buf_t *file; ngx_uint_t eintr, complete; ngx_array_t header; ngx_event_t *wev; ngx_chain_t *cl; struct iovec *iov, headers[NGX_HEADERS]; #if (NGX_HAVE_SENDFILE64) off_t offset; #else int32_t offset; #endif wev = c->write; if (!wev->ready) { return in; } /* the maximum limit size is 2G-1 - the page size */ if (limit == 0 || limit > (off_t) (NGX_SENDFILE_LIMIT - ngx_pagesize)) { limit = NGX_SENDFILE_LIMIT - ngx_pagesize; } send = 0; header.elts = headers; header.size = sizeof(struct iovec); header.nalloc = NGX_HEADERS; header.pool = c->pool; for ( ;; ) { file = NULL; file_size = 0; eintr = 0; complete = 0; prev_send = send; header.nelts = 0; prev = NULL; iov = NULL; /* create the iovec and coalesce the neighbouring bufs */ for (cl = in; cl && header.nelts < IOV_MAX && send < limit; cl = cl->next) { if (ngx_buf_special(cl->buf)) { continue; } #if 1 if (!ngx_buf_in_memory(cl->buf) && !cl->buf->in_file) { ngx_log_error(NGX_LOG_ALERT, c->log, 0, "zero size buf in sendfile " "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_CHAIN_ERROR; } #endif if (!ngx_buf_in_memory_only(cl->buf)) { break; } size = cl->buf->last - cl->buf->pos; if (send + size > limit) { size = limit - send; } if (prev == cl->buf->pos) { iov->iov_len += (size_t) size; } else { iov = ngx_array_push(&header); if (iov == NULL) { return NGX_CHAIN_ERROR; } iov->iov_base = (void *) cl->buf->pos; iov->iov_len = (size_t) size; } prev = cl->buf->pos + (size_t) size; send += size; } /* set TCP_CORK if there is a header before a file */ if (c->tcp_nopush == NGX_TCP_NOPUSH_UNSET && header.nelts != 0 && cl && cl->buf->in_file) { /* the TCP_CORK and TCP_NODELAY are mutually exclusive */ if (c->tcp_nodelay == NGX_TCP_NODELAY_SET) { tcp_nodelay = 0; if (setsockopt(c->fd, IPPROTO_TCP, TCP_NODELAY, (const void *) &tcp_nodelay, sizeof(int)) == -1) { err = ngx_errno; /* * there is a tiny chance to be interrupted, however, * we continue a processing with the TCP_NODELAY * and without the TCP_CORK */ if (err != NGX_EINTR) { wev->error = 1; ngx_connection_error(c, err, "setsockopt(TCP_NODELAY) failed"); return NGX_CHAIN_ERROR; } } else { c->tcp_nodelay = NGX_TCP_NODELAY_UNSET; ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0, "no tcp_nodelay"); } } if (c->tcp_nodelay == NGX_TCP_NODELAY_UNSET) { if (ngx_tcp_nopush(c->fd) == NGX_ERROR) { err = ngx_errno; /* * there is a tiny chance to be interrupted, however, * we continue a processing without the TCP_CORK */ if (err != NGX_EINTR) { wev->error = 1; ngx_connection_error(c, err, ngx_tcp_nopush_n " failed"); return NGX_CHAIN_ERROR; } } else { c->tcp_nopush = NGX_TCP_NOPUSH_SET; ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0, "tcp_nopush"); } } } /* get the file buf */ if (header.nelts == 0 && cl && cl->buf->in_file && send < limit) { file = cl->buf; /* coalesce the neighbouring file bufs */ do { size = cl->buf->file_last - cl->buf->file_pos; if (send + size > limit) { size = limit - send; aligned = (cl->buf->file_pos + size + ngx_pagesize - 1) & ~((off_t) ngx_pagesize - 1); if (aligned <= cl->buf->file_last) { size = aligned - cl->buf->file_pos; } } file_size += (size_t) size; send += size; fprev = cl->buf->file_pos + size; cl = cl->next; } while (cl && cl->buf->in_file && send < limit && file->file->fd == cl->buf->file->fd && fprev == cl->buf->file_pos); } if (file) { #if 1 if (file_size == 0) { ngx_debug_point(); return NGX_CHAIN_ERROR; } #endif #if (NGX_HAVE_SENDFILE64) offset = file->file_pos; #else offset = (int32_t) file->file_pos; #endif ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "sendfile: @%O %uz", file->file_pos, file_size); rc = sendfile(c->fd, file->file->fd, &offset, file_size); if (rc == -1) { err = ngx_errno; if (err == NGX_EAGAIN || err == NGX_EINTR) { if (err == NGX_EINTR) { eintr = 1; } ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, "sendfile() is not ready"); } else { wev->error = 1; ngx_connection_error(c, err, "sendfile() failed"); return NGX_CHAIN_ERROR; } } sent = rc > 0 ? rc : 0; ngx_log_debug4(NGX_LOG_DEBUG_EVENT, c->log, 0, "sendfile: %d, @%O %O:%uz", rc, file->file_pos, sent, file_size); } else { rc = writev(c->fd, header.elts, header.nelts); if (rc == -1) { err = ngx_errno; if (err == NGX_EAGAIN || err == NGX_EINTR) { if (err == NGX_EINTR) { eintr = 1; } ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, "writev() not ready"); } else { wev->error = 1; ngx_connection_error(c, err, "writev() failed"); return NGX_CHAIN_ERROR; } } sent = rc > 0 ? rc : 0; ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "writev: %O", sent); } if (send - prev_send == sent) { complete = 1; } c->sent += sent; for (cl = in; cl; cl = cl->next) { if (ngx_buf_special(cl->buf)) { continue; } if (sent == 0) { break; } size = ngx_buf_size(cl->buf); if (sent >= size) { sent -= size; if (ngx_buf_in_memory(cl->buf)) { cl->buf->pos = cl->buf->last; } if (cl->buf->in_file) { cl->buf->file_pos = cl->buf->file_last; } continue; } if (ngx_buf_in_memory(cl->buf)) { cl->buf->pos += (size_t) sent; } if (cl->buf->in_file) { cl->buf->file_pos += sent; } break; } if (eintr) { continue; } if (!complete) { wev->ready = 0; return cl; } if (send >= limit || cl == NULL) { return cl; } in = cl; } }