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| author | Yann Ylavic <ylavic@apache.org> | 2022-10-19 15:28:03 +0000 |
|---|---|---|
| committer | Yann Ylavic <ylavic@apache.org> | 2022-10-19 15:28:03 +0000 |
| commit | cd279db3cfb82b185c82d1655ac1e629594d6e65 (patch) | |
| tree | 4bc7de2133a40c1515db4b804c1cac97a5e0d538 /include | |
| parent | 1a53fed88dc63e7f964bc7545d93e742f8938e0f (diff) | |
| download | apr-cd279db3cfb82b185c82d1655ac1e629594d6e65.tar.gz | |
apr_socket_sendv: WIN32: Follow up to r1902312: Avoid short writes.
We possibly (edge cases) can't send an entire iovec array in a single WSASend()
call because structs WSABUF and iovec are ABI incompatible.
To avoid breaking users that rely on full-write by apr_socket_sendv(), which
supposedly is guaranteed by WSASend(), repeat the call until the given iovec
array is exhausted.
There is no way to provide both full-write and atomicity guarantees for
apr_socket_sendv() on Windows, so we choose the former..
* include/apr_network_io.h:
Document apr_socket_sendv() full-write/atomicity (non-)guarantees above the
system ones.
* network_io/win32/sendrecv.c(apr_socket_sendv):
Change to a loop on WSASend() when needed, taking care of its API limits
w.r.t. the given struct iovec.
git-svn-id: https://svn.apache.org/repos/asf/apr/apr/trunk@1904699 13f79535-47bb-0310-9956-ffa450edef68
Diffstat (limited to 'include')
| -rw-r--r-- | include/apr_network_io.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/apr_network_io.h b/include/apr_network_io.h index b3536d802..e37b95297 100644 --- a/include/apr_network_io.h +++ b/include/apr_network_io.h @@ -574,6 +574,12 @@ APR_DECLARE(apr_status_t) apr_socket_send(apr_socket_t *sock, const char *buf, * socket option. * The number of bytes actually sent is stored in argument 4. * + * This function does not provide full-write and/or atomicity guarantees + * if the underlying system call does not either. Some systems (like Windows) + * guarantee both for a single system call but this call does not allow for + * as much data as an iovec vector can contain; in this case apr_socket_sendv() + * can issue multiple system calls thus favoring full-write over atomicity. + * * It is possible for both bytes to be sent and an error to be returned. * * APR_EINTR is never returned. |