From 262feb1ad0838bb585955b6ada5acbe106dbc9bf Mon Sep 17 00:00:00 2001 From: ajs Date: Wed, 16 Feb 2005 20:35:47 +0000 Subject: 2005-02-16 Andrew J. Schorr * stream.h: Declare new function stream_read_try suitable for use with non-blocking file descriptors. Indicate that stream_read and stream_read_unblock are deprecated. * stream.c: (stream_read_try) New function for use with non-blocking I/O. (stream_recvmsg) Should return -1 if the stream is too small to contain the data. --- lib/stream.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) (limited to 'lib/stream.c') diff --git a/lib/stream.c b/lib/stream.c index e15d0426..7e75f0da 100644 --- a/lib/stream.c +++ b/lib/stream.c @@ -603,6 +603,31 @@ stream_read_unblock (struct stream *s, int fd, size_t size) return nbytes; } +ssize_t +stream_read_try(struct stream *s, int fd, size_t size) +{ + ssize_t nbytes; + + STREAM_VERIFY_SANE(s); + + if (STREAM_WRITEABLE(s) < size) + { + STREAM_BOUND_WARN (s, "put"); + /* Fatal (not transient) error, since retrying will not help + (stream is too small to contain the desired data). */ + return -1; + } + + if ((nbytes = read(fd, s->data + s->endp, size)) >= 0) + { + s->endp += nbytes; + return nbytes; + } + /* Error: was it transient (return -2) or fatal (return -1)? */ + return ((errno == EAGAIN) || (errno == EWOULDBLOCK) || (errno == EINTR)) ? + -2 : -1; +} + /* Read up to smaller of size or SIZE_REMAIN() bytes to the stream, starting * from endp. * First iovec will be used to receive the data. @@ -621,7 +646,9 @@ stream_recvmsg (struct stream *s, int fd, struct msghdr *msgh, int flags, if (STREAM_WRITEABLE (s) < size) { STREAM_BOUND_WARN (s, "put"); - return 0; + /* This is a logic error in the calling code: the stream is too small + to hold the desired data! */ + return -1; } iov = &(msgh->msg_iov[0]); -- cgit v1.2.1