Mercurial > hg > nginx
view src/os/unix/ngx_recv.c @ 7670:ccb5ff87ab3e
Cache: introduced min_free cache clearing.
Clearing cache based on free space left on a file system is
expected to allow better disk utilization in some cases, notably
when disk space might be also used for something other than nginx
cache (including nginx own temporary files) and while loading
cache (when cache size might be inaccurate for a while, effectively
disabling max_size cache clearing).
Based on a patch by Adam Bambuch.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 22 Jun 2020 18:03:00 +0300 |
parents | efd71d49bde0 |
children | 5119c8150478 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> ssize_t ngx_unix_recv(ngx_connection_t *c, u_char *buf, size_t size) { ssize_t n; ngx_err_t err; ngx_event_t *rev; rev = c->read; #if (NGX_HAVE_KQUEUE) if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) { ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0, "recv: eof:%d, avail:%d, err:%d", rev->pending_eof, rev->available, rev->kq_errno); if (rev->available == 0) { if (rev->pending_eof) { rev->ready = 0; rev->eof = 1; if (rev->kq_errno) { rev->error = 1; ngx_set_socket_errno(rev->kq_errno); return ngx_connection_error(c, rev->kq_errno, "kevent() reported about an closed connection"); } return 0; } else { rev->ready = 0; return NGX_AGAIN; } } } #endif #if (NGX_HAVE_EPOLLRDHUP) if (ngx_event_flags & NGX_USE_EPOLL_EVENT) { ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "recv: eof:%d, avail:%d", rev->pending_eof, rev->available); if (rev->available == 0 && !rev->pending_eof) { rev->ready = 0; return NGX_AGAIN; } } #endif do { n = recv(c->fd, buf, size, 0); ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0, "recv: fd:%d %z of %uz", c->fd, n, size); if (n == 0) { rev->ready = 0; rev->eof = 1; #if (NGX_HAVE_KQUEUE) /* * on FreeBSD recv() may return 0 on closed socket * even if kqueue reported about available data */ if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) { rev->available = 0; } #endif return 0; } if (n > 0) { #if (NGX_HAVE_KQUEUE) if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) { rev->available -= n; /* * rev->available may be negative here because some additional * bytes may be received between kevent() and recv() */ if (rev->available <= 0) { if (!rev->pending_eof) { rev->ready = 0; } rev->available = 0; } return n; } #endif #if (NGX_HAVE_FIONREAD) if (rev->available >= 0) { rev->available -= n; /* * negative rev->available means some additional bytes * were received between kernel notification and recv(), * and therefore ev->ready can be safely reset even for * edge-triggered event methods */ if (rev->available < 0) { rev->available = 0; rev->ready = 0; } ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "recv: avail:%d", rev->available); } else if ((size_t) n == size) { if (ngx_socket_nread(c->fd, &rev->available) == -1) { n = ngx_connection_error(c, ngx_socket_errno, ngx_socket_nread_n " failed"); break; } ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "recv: avail:%d", rev->available); } #endif #if (NGX_HAVE_EPOLLRDHUP) if ((ngx_event_flags & NGX_USE_EPOLL_EVENT) && ngx_use_epoll_rdhup) { if ((size_t) n < size) { if (!rev->pending_eof) { rev->ready = 0; } rev->available = 0; } return n; } #endif if ((size_t) n < size && !(ngx_event_flags & NGX_USE_GREEDY_EVENT)) { rev->ready = 0; } return n; } err = ngx_socket_errno; if (err == NGX_EAGAIN || err == NGX_EINTR) { ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, "recv() not ready"); n = NGX_AGAIN; } else { n = ngx_connection_error(c, err, "recv() failed"); break; } } while (err == NGX_EINTR); rev->ready = 0; if (n == NGX_ERROR) { rev->error = 1; } return n; }