Mercurial > hg > nginx
view src/os/unix/ngx_writev_chain.c @ 5245:711fa02afae8
Valgrind: supressed complaints about uninitialized bytes.
Valgrind complains if we pass uninitialized memory to a syscall:
==36492== Syscall param sendmsg(msg.msg_iov[0]) points to uninitialised byte(s)
==36492== at 0x6B5E6A: sendmsg (in /usr/lib/system/libsystem_kernel.dylib)
==36492== by 0x10004288E: ngx_signal_worker_processes (ngx_process_cycle.c:527)
==36492== by 0x1000417A7: ngx_master_process_cycle (ngx_process_cycle.c:203)
==36492== by 0x100001F10: main (nginx.c:410)
==36492== Address 0x7fff5fbff71c is on thread 1's stack
Even initialization of all members of the structure passed isn't enough, as
there is padding which still remains uninitialized and results in Valgrind
complaint. Note there is no real problem here as data from uninitialized
memory isn't used.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Wed, 05 Jun 2013 19:44:22 +0400 |
parents | 089cc5154c1e |
children | f9c83484d9ce |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #if (IOV_MAX > 64) #define NGX_IOVS 64 #else #define NGX_IOVS IOV_MAX #endif ngx_chain_t * ngx_writev_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit) { u_char *prev; ssize_t n, size, sent; off_t send, prev_send; ngx_uint_t eintr, complete; ngx_err_t err; ngx_array_t vec; ngx_chain_t *cl; ngx_event_t *wev; struct iovec *iov, iovs[NGX_IOVS]; wev = c->write; if (!wev->ready) { return in; } #if (NGX_HAVE_KQUEUE) if ((ngx_event_flags & NGX_USE_KQUEUE_EVENT) && wev->pending_eof) { (void) ngx_connection_error(c, wev->kq_errno, "kevent() reported about an closed connection"); wev->error = 1; return NGX_CHAIN_ERROR; } #endif /* the maximum limit size is the maximum size_t value - the page size */ if (limit == 0 || limit > (off_t) (NGX_MAX_SIZE_T_VALUE - ngx_pagesize)) { limit = NGX_MAX_SIZE_T_VALUE - ngx_pagesize; } send = 0; vec.elts = iovs; vec.size = sizeof(struct iovec); vec.nalloc = NGX_IOVS; vec.pool = c->pool; for ( ;; ) { prev = NULL; iov = NULL; eintr = 0; complete = 0; prev_send = send; vec.nelts = 0; /* create the iovec and coalesce the neighbouring bufs */ for (cl = in; cl && send < limit; cl = cl->next) { if (ngx_buf_special(cl->buf)) { continue; } #if 1 if (!ngx_buf_in_memory(cl->buf)) { ngx_debug_point(); } #endif size = cl->buf->last - cl->buf->pos; if (send + size > limit) { size = (ssize_t) (limit - send); } if (prev == cl->buf->pos) { iov->iov_len += size; } else { if (vec.nelts >= IOV_MAX) { break; } iov = ngx_array_push(&vec); if (iov == NULL) { return NGX_CHAIN_ERROR; } iov->iov_base = (void *) cl->buf->pos; iov->iov_len = size; } prev = cl->buf->pos + size; send += size; } n = writev(c->fd, vec.elts, vec.nelts); if (n == -1) { err = ngx_errno; switch (err) { case NGX_EAGAIN: break; case NGX_EINTR: eintr = 1; break; default: wev->error = 1; (void) ngx_connection_error(c, err, "writev() failed"); return NGX_CHAIN_ERROR; } ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, "writev() not ready"); } sent = n > 0 ? n : 0; ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "writev: %z", 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 = cl->buf->last - cl->buf->pos; if (sent >= size) { sent -= size; cl->buf->pos = cl->buf->last; continue; } cl->buf->pos += sent; break; } if (eintr) { continue; } if (!complete) { wev->ready = 0; return cl; } if (send >= limit || cl == NULL) { return cl; } in = cl; } }