Mercurial > hg > nginx
view src/os/unix/ngx_recv.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 | c11d96cbad75 |
children | ac33852faaac |
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/* * Copyright (C) Igor Sysoev */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #if (NGX_HAVE_KQUEUE) 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_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; } } } do { n = recv(c->fd, buf, size, 0); ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0, "recv: fd:%d %d of %d", c->fd, n, size); if (n >= 0) { 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; } if (rev->available < 0) { rev->available = 0; } } if (n == 0) { /* * on FreeBSD recv() may return 0 on closed socket * even if kqueue reported about available data */ rev->eof = 1; rev->available = 0; } return n; } if ((size_t) n < size) { rev->ready = 0; } if (n == 0) { rev->eof = 1; } 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; } #else /* ! NGX_HAVE_KQUEUE */ 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; do { n = recv(c->fd, buf, size, 0); ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0, "recv: fd:%d %d of %d", c->fd, n, size); if (n == 0) { rev->ready = 0; rev->eof = 1; return n; } else if (n > 0) { 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; } #endif /* NGX_HAVE_KQUEUE */