From: Andre Noll <maan@systemlinux.org>
Date: Sun, 25 Apr 2010 17:34:35 +0000 (+0200)
Subject: dccp_recv/udp_recv: Use the new nonblock API.
X-Git-Tag: v0.4.3~25^2~15
X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=commitdiff_plain;h=de7b5b177b8ad295820bd14c00b049fd8a5ec21f

dccp_recv/udp_recv: Use the new nonblock API.

This simplifies the code quite a bit. In particular it allows to
kill the extra check for EAGAIN that was necessary to deal with
unreliable return value of FD_ISSET().
---

diff --git a/dccp_recv.c b/dccp_recv.c
index f71a7253..2ab9fcab 100644
--- a/dccp_recv.c
+++ b/dccp_recv.c
@@ -153,34 +153,27 @@ static void dccp_recv_post_select(struct sched *s, struct task *t)
 	struct btr_node *btrn = rn->btrn;
 	struct iovec iov[2];
 	int ret, iovcnt;
+	size_t num_bytes;
 
 	ret = btr_node_status(btrn, 0, BTR_NT_ROOT);
-	if (ret < 0)
-		goto err;
-	if (ret == 0)
-		return;
-	if (!FD_ISSET(pdd->fd, &s->rfds))
-		return; /* nothing to do */
+	if (ret <= 0)
+		goto out;
 	iovcnt = btr_pool_get_buffers(pdd->btrp, iov);
 	ret = -E_DCCP_OVERRUN;
 	if (iovcnt == 0)
-		goto err;
-	ret = para_readv(pdd->fd, iov, iovcnt);
-	/* EAGAIN is possible even if FD_ISSET */
-	if (ret < 0 && is_errno(-ret, EAGAIN))
-		return;
-	if (ret == 0)
-		ret = -E_RECV_EOF;
-	if (ret < 0)
-		goto err;
-	if (ret <= iov[0].iov_len) /* only the first buffer was filled */
-		btr_add_output_pool(pdd->btrp, ret, btrn);
+		goto out;
+	ret = readv_nonblock(pdd->fd, iov, iovcnt, &s->rfds, &num_bytes);
+	if (num_bytes == 0)
+		goto out;
+	if (num_bytes <= iov[0].iov_len) /* only the first buffer was filled */
+		btr_add_output_pool(pdd->btrp, num_bytes, btrn);
 	else { /* both buffers contain data */
 		btr_add_output_pool(pdd->btrp, iov[0].iov_len, btrn);
-		btr_add_output_pool(pdd->btrp, ret - iov[0].iov_len, btrn);
+		btr_add_output_pool(pdd->btrp, num_bytes - iov[0].iov_len, btrn);
 	}
-	return;
-err:
+out:
+	if (ret >= 0)
+		return;
 	btr_remove_node(rn->btrn);
 	t->error = ret;
 }
diff --git a/fd.c b/fd.c
index d56a3110..2e59bc95 100644
--- a/fd.c
+++ b/fd.c
@@ -177,27 +177,6 @@ int read_nonblock(int fd, void *buf, size_t sz, fd_set *rfds, size_t *num_bytes)
 	return readv_nonblock(fd, &iov, 1, rfds, num_bytes);
 }
 
-/**
- * Simple wrapper for readv().
- *
- * \param fd The file descriptor to read from.
- * \param iov Scatter/gather array used in readv().
- * \param iovcnt Number of elements in \a iov.
- *
- * \return A negative error code on errors, the return value of the underlying
- * call to readv() otherwise.
- *
- * \sa readv(2).
- */
-int para_readv(int fd, struct iovec *iov, int iovcnt)
-{
-	int ret = readv(fd, iov, iovcnt);
-
-	if (ret < 0)
-		return -ERRNO_TO_PARA_ERROR(errno);
-	return ret;
-}
-
 /**
  * Check whether a file exists.
  *
diff --git a/fd.h b/fd.h
index b9558820..787784d3 100644
--- a/fd.h
+++ b/fd.h
@@ -7,7 +7,6 @@
 /** \file fd.h exported symbols from fd.c */
 
 int write_all(int fd, const char *buf, size_t *len);
-int para_readv(int fd, struct iovec *iov, int iovcnt);
 int file_exists(const char *);
 int para_select(int n, fd_set *readfds, fd_set *writefds,
 		struct timeval *timeout_tv);
diff --git a/udp_recv.c b/udp_recv.c
index 00ad3e27..5520c6fb 100644
--- a/udp_recv.c
+++ b/udp_recv.c
@@ -67,43 +67,36 @@ static void udp_recv_post_select(__a_unused struct sched *s, struct task *t)
 	struct receiver_node *rn = container_of(t, struct receiver_node, task);
 	struct private_udp_recv_data *purd = rn->private_data;
 	struct btr_node *btrn = rn->btrn;
-	size_t packet_size;
+	size_t num_bytes;
 	struct iovec iov[2];
-	int ret, iovcnt;
+	int ret, readv_ret, iovcnt;
 
 	t->error = 0;
 	ret = btr_node_status(btrn, 0, BTR_NT_ROOT);
-	if (ret < 0)
-		goto err;
-	if (ret == 0)
-		return;
-	if (!FD_ISSET(purd->fd, &s->rfds))
-		return;
+	if (ret <= 0)
+		goto out;
 	iovcnt = btr_pool_get_buffers(purd->btrp, iov);
 	ret = -E_UDP_OVERRUN;
 	if (iovcnt == 0)
-		goto err;
-	ret = para_readv(purd->fd, iov, iovcnt);
-	/* EAGAIN is possible even if FD_ISSET */
-	if (ret < 0 && is_errno(-ret, EAGAIN))
-		return;
-	if (ret == 0)
-		ret = -E_RECV_EOF;
+		goto out;
+	ret = readv_nonblock(purd->fd, iov, iovcnt, &s->rfds, &num_bytes);
+	if (num_bytes == 0)
+		goto out;
+	readv_ret = ret;
+	ret = udp_check_eof(num_bytes, iov);
 	if (ret < 0)
-		goto err;
-	packet_size = ret;
-	ret = udp_check_eof(packet_size, iov);
-	if (ret < 0)
-		goto err;
-	if (iov[0].iov_len >= packet_size)
-		btr_add_output_pool(purd->btrp, packet_size, btrn);
+		goto out;
+	if (iov[0].iov_len >= num_bytes)
+		btr_add_output_pool(purd->btrp, num_bytes, btrn);
 	else { /* both buffers contain data */
 		btr_add_output_pool(purd->btrp, iov[0].iov_len, btrn);
-		btr_add_output_pool(purd->btrp, packet_size - iov[0].iov_len,
+		btr_add_output_pool(purd->btrp, num_bytes - iov[0].iov_len,
 			btrn);
 	}
-	return;
-err:
+	ret = readv_ret;
+out:
+	if (ret >= 0)
+		return;
 	btr_remove_node(btrn);
 	t->error = ret;
 	close(purd->fd);