From e065c44808a10c2c1e6db17c1827a021de628d52 Mon Sep 17 00:00:00 2001
From: Daniel M <daniel.q.mueller@stud.h-da.de>
Date: Wed, 12 May 2021 00:54:02 +0200
Subject: [PATCH] Add read functions with timeout
- Added timeout read for TcpStream and UdpSocket
---
inc/tcpstream.hpp | 40 +++++++++++++++++++++++++
inc/udpsocket.hpp | 36 ++++++++++++++++++++--
src/tcpstream.cpp | 76 +++++++++++++++++++++++++++++++++++++++++++++++
src/udpsocket.cpp | 38 ++++++++++++++++++++++--
4 files changed, 186 insertions(+), 4 deletions(-)
diff --git a/inc/tcpstream.hpp b/inc/tcpstream.hpp
index 63ff1fc..fb3c5f4 100644
--- a/inc/tcpstream.hpp
+++ b/inc/tcpstream.hpp
@@ -167,6 +167,46 @@ public:
*/
ssize_t readAll(void *data, size_t len);
+ /**
+ * @brief Same as TcpStream::read but with a millisecond timeout. If the
+ * timeout is reached without receiving data, 0 is returned.
+ *
+ * If receiving fails, an exception is thrown.
+ *
+ * @param data Pointer to at least len bytes where the data received over
+ * the tcp connection will be stored.
+ * @param len The maxiumum number of bytes that will be received over the
+ * tcp connection.
+ * @param timeoutMs The number of milliseconds before a timeout occurs.
+ *
+ * @return The number of bytes that were actually received over the
+ * connection. This can be less than len. If a timeout occurs 0 is
+ * returned.
+ */
+ ssize_t readTimeout(void *data, size_t len, int timeoutMs);
+
+ /**
+ * @brief Same as TcpStream::readAll but with a millisecond timeout. If
+ * the timeout is reached without receiving any data, 0 is returned. If
+ * the timout occurs after receiving some data, the number of bytes
+ * received before the timeout is returned as NEGATIVE. The timeout
+ * starts from the begining if partial data is received.
+ *
+ * If receiving failed an exception is thrown.
+ *
+ * @param data Pointer to at least len bytes where the data received over
+ * the tcp connection will be stored.
+ * @param len The number of bytes that will be received over the tcp
+ * connection.
+ * @param timeoutMs The number of milliseconds before a timeout occurs.
+ *
+ * @return The number of bytes that were actually received over the
+ * connection. This can be less than len if the connection is closed.
+ * If a timout occurs after some data was already read, the number of
+ * bytes is returned as negative.
+ */
+ ssize_t readAllTimeout(void *data, size_t len, int timeoutMs);
+
/**
* @brief Get the socket address of the connection target.
*
diff --git a/inc/udpsocket.hpp b/inc/udpsocket.hpp
index 7ed5df1..83d03a5 100644
--- a/inc/udpsocket.hpp
+++ b/inc/udpsocket.hpp
@@ -138,7 +138,7 @@ public:
* @param remote A reference to a SockAddr that is used to store the origin
* of the UDP packet.
*
- * @return The numbe of bytes that were actually copied.
+ * @return The number of bytes that were actually copied.
*/
ssize_t receive(void *data, size_t len, SockAddr &remote);
@@ -150,10 +150,42 @@ public:
* will be copied.
* @param len The maximum number of bytes that can be copied into data.
*
- * @return The numbe of bytes that were actually copied.
+ * @return The number of bytes that were actually copied.
*/
ssize_t receive(void *data, size_t len);
+ /**
+ * @brief Receive a UDP packet and copy a maximum number of len bytes from
+ * the packet payload into data. Store the senders origin socket address
+ * into remote. If the timeout occurs, 0 is returned.
+ *
+ * @param data Pointer to at least len bytes of data in which the payload
+ * will be copied.
+ * @param len The maximum number of bytes that can be copied into data.
+ * @param remote A reference to a SockAddr that is used to store the origin
+ * of the UDP packet.
+ * @param timeoutMs The number of milliseconds before a timeout occurs.
+ *
+ * @return The number of bytes that were actually copied, or 0 if a timeout
+ * occured.
+ */
+ ssize_t receiveTimeout(void *data, size_t len, SockAddr &remote, int timeoutMs);
+
+ /**
+ * @brief Receive a UDP packet and copy a maximum number of len bytes from
+ * the packet payload into data. The packets origin is not stored. If the
+ * timeout occurs, 0 is returned.
+ *
+ * @param data Pointer to at least len bytes of data in which the payload
+ * will be copied.
+ * @param len The maximum number of bytes that can be copied into data.
+ * @param timeoutMs The number of milliseconds before a timeout occurs.
+ *
+ * @return The number of bytes that were actually copied, or 0 if a timeout
+ * occured.
+ */
+ ssize_t receiveTimeout(void *data, size_t len, int timeoutMs);
+
/**
* @brief Check if the socket is closed or open. Open in this case means
* bound and ready to send / receive.
diff --git a/src/tcpstream.cpp b/src/tcpstream.cpp
index 630c928..c08d403 100644
--- a/src/tcpstream.cpp
+++ b/src/tcpstream.cpp
@@ -5,6 +5,7 @@
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
+#include <poll.h>
TcpStream::TcpStream(SockAddr _remote)
: remote{_remote}, sockfd{0}
@@ -154,6 +155,81 @@ ssize_t TcpStream::readAll(void *data, size_t len)
return bytesReadTotal;
}
+ssize_t TcpStream::readTimeout(void *data, size_t len, int timeoutMs)
+{
+ if (timeoutMs <= 0) return read(data, len);
+
+ if (sockfd == 0)
+ throw std::runtime_error("Can't read from closed socket");
+
+ pollfd pfd = {0};
+ pfd.fd = sockfd;
+ pfd.events = POLLIN;
+
+ // block until data is available or the timeout is reached
+ int res = poll(&pfd, 1, timeoutMs);
+
+ // a timout occured
+ if (res == 0) return 0;
+
+ // a poll error occured
+ if (res < 0)
+ {
+ close();
+ throw std::runtime_error("Error while reading from socket");
+ }
+
+ ssize_t bytes_read = ::read(sockfd, data, len);
+ if (bytes_read < 0)
+ {
+ close();
+ throw std::runtime_error("Error while reading from socket");
+ }
+ return bytes_read;
+}
+
+ssize_t TcpStream::readAllTimeout(void *data, size_t len, int timeoutMs)
+{
+ if (timeoutMs <= 0) return readAll(data, len);
+
+ if (sockfd == 0)
+ throw std::runtime_error("Can't read from closed socket");
+
+ pollfd pfd = {0};
+ pfd.fd = sockfd;
+ pfd.events = POLLIN;
+
+
+ size_t bytesReadTotal = 0;
+ while (true)
+ {
+ // block until data is available or the timeout is reached
+ int res = poll(&pfd, 1, timeoutMs);
+
+ // a timout occured
+ if (res == 0) return -1 * bytesReadTotal;
+
+ // a poll error occured
+ if (res < 0)
+ {
+ close();
+ throw std::runtime_error("Error while reading from socket");
+ }
+
+ ssize_t bytesRead = ::read(sockfd, (uint8_t*)data + bytesReadTotal, len-bytesReadTotal);
+
+ if (bytesRead == 0) break;
+ if (bytesRead < 0)
+ {
+ close();
+ throw std::runtime_error("Error while reading from socket");
+ }
+
+ bytesReadTotal += bytesRead;
+ }
+ return bytesReadTotal;
+}
+
const SockAddr & TcpStream::getRemoteAddr() const
{
return remote;
diff --git a/src/udpsocket.cpp b/src/udpsocket.cpp
index 895fabc..91744c2 100644
--- a/src/udpsocket.cpp
+++ b/src/udpsocket.cpp
@@ -4,6 +4,7 @@
#include <unistd.h>
#include <sys/socket.h>
+#include <poll.h>
UdpSocket::UdpSocket(SockAddr _local)
@@ -93,9 +94,10 @@ ssize_t UdpSocket::sendTo(const std::string &remoteAddrPort, const void *data, s
ssize_t UdpSocket::receive(void *data, size_t len, SockAddr &remote)
{
SockAddr::RawSockAddr remote_raw_saddr = {0};
+ socklen_t remote_raw_socklen = raw_socklen;
// TODO: Lookup flags
- ssize_t bytes_read = ::recvfrom(sockfd, data, len, 0, &remote_raw_saddr.generic, &raw_socklen);
+ ssize_t bytes_read = ::recvfrom(sockfd, data, len, 0, &remote_raw_saddr.generic, &remote_raw_socklen);
if (bytes_read < 0)
{
@@ -108,20 +110,52 @@ ssize_t UdpSocket::receive(void *data, size_t len, SockAddr &remote)
}
ssize_t UdpSocket::receive(void *data, size_t len)
+{
+ SockAddr saddr;
+ return receive(data, len, saddr);
+}
+
+ssize_t UdpSocket::receiveTimeout(void *data, size_t len, SockAddr &remote, int timeoutMs)
{
SockAddr::RawSockAddr remote_raw_saddr = {0};
+ socklen_t remote_raw_socklen = raw_socklen;
+
+ pollfd pfd = {0};
+ pfd.fd = sockfd;
+ pfd.events = POLLIN;
+
+ // block until data is available or the timeout is reached
+ int res = poll(&pfd, 1, timeoutMs);
+
+ // a timout occured
+ if (res == 0) return 0;
+
+ // a poll error occured
+ if (res < 0)
+ {
+ close();
+ throw std::runtime_error("Error while reading from socket");
+ }
// TODO: Lookup flags
- ssize_t bytes_read = ::recvfrom(sockfd, data, len, 0, &remote_raw_saddr.generic, &raw_socklen);
+ ssize_t bytes_read = ::recvfrom(sockfd, data, len, 0, &remote_raw_saddr.generic, &remote_raw_socklen);
if (bytes_read < 0)
{
throw std::runtime_error("Error while reading from socket");
}
+ remote = SockAddr(&remote_raw_saddr.generic, local.address.type);
+
return bytes_read;
}
+ssize_t UdpSocket::receiveTimeout(void *data, size_t len, int timeoutMs)
+{
+ SockAddr saddr;
+ return receiveTimeout(data, len, saddr, timeoutMs);
+}
+
void UdpSocket::close()
{
if (sockfd != 0)
--
GitLab