Library: Net
Package: Sockets
Header: Poco/Net/Socket.h
Description
Socket is the common base class for StreamSocket, ServerSocket, DatagramSocket and other socket classes.
It provides operations common to all socket types.
Inheritance
Known Derived Classes: DatagramSocket, DialogSocket, ICMPSocket, MulticastSocket, RawSocket, ServerSocket, StreamSocket, WebSocket
Member Summary
Member Functions: address, available, close, destroyBufVec, error, fromFileDescriptor, getBlocking, getError, getKeepAlive, getLinger, getNoDelay, getOOBInline, getOption, getReceiveBufferSize, getReceiveTimeout, getReuseAddress, getReusePort, getSendBufferSize, getSendTimeout, impl, init, isDatagram, isNull, isRaw, isStream, lastError, lastErrorDesc, makeBufVec, makeBuffer, operator !=, operator <, operator <=, operator =, operator ==, operator >, operator >=, peerAddress, poll, secure, select, setBlocking, setKeepAlive, setLinger, setNoDelay, setOOBInline, setOption, setReceiveBufferSize, setReceiveTimeout, setReuseAddress, setReusePort, setSendBufferSize, setSendTimeout, sockfd, supportsIPv4, supportsIPv6, type
Types Aliases
BufVec
using BufVec = SocketBufVec;
SocketList
using SocketList = std::vector < Socket >;
Type
using Type = SocketImpl::Type;
Enumerations
SelectMode
SELECT_READ = 1
SELECT_WRITE = 2
SELECT_ERROR = 4
Constructors
Socket
Socket();
Creates an uninitialized socket.
Socket
Socket(
const Socket & socket
);
Copy constructor.
Attaches the SocketImpl from the other socket and increments the reference count of the SocketImpl.
Socket 
Socket(
SocketImpl * pImpl
);
Creates the Socket and attaches the given SocketImpl. The socket takes ownership of the SocketImpl.
Destructor
~Socket 
virtual ~Socket();
Destroys the Socket and releases the SocketImpl.
Member Functions
address 
SocketAddress address() const;
Returns the IP address and port number of the socket.
available
int available() const;
Returns the number of bytes available that can be read without causing the socket to block.
close
void close();
Closes the socket.
destroyBufVec 
static void destroyBufVec(
SocketBufVec & buf
);
Releases the memory pointed to by vector members and shrinks the vector to size 0. The vector must be created by makeBufVec(size_t, size_t).
error
static void error();
Throws an appropriate exception for the last error.
fromFileDescriptor
static Socket fromFileDescriptor(
int fd
);
getBlocking
bool getBlocking() const;
Returns the blocking mode of the socket. This method will only work if the blocking modes of the socket are changed via the setBlocking method!
getError
int getError() const;
Returns the socket error.
getKeepAlive
bool getKeepAlive() const;
Returns the value of the SO_KEEPALIVE socket option.
getLinger
void getLinger(
bool & on,
int & seconds
) const;
Returns the value of the SO_LINGER socket option.
getNoDelay
bool getNoDelay() const;
Returns the value of the TCP_NODELAY socket option.
getOOBInline
bool getOOBInline() const;
Returns the value of the SO_OOBINLINE socket option.
getOption
void getOption(
int level,
int option,
int & value
) const;
Returns the value of the socket option specified by level and option.
getOption
void getOption(
int level,
int option,
unsigned & value
) const;
Returns the value of the socket option specified by level and option.
getOption
void getOption(
int level,
int option,
unsigned char & value
) const;
Returns the value of the socket option specified by level and option.
getOption
void getOption(
int level,
int option,
Poco::Timespan & value
) const;
Returns the value of the socket option specified by level and option.
getOption
void getOption(
int level,
int option,
IPAddress & value
) const;
Returns the value of the socket option specified by level and option.
getReceiveBufferSize
int getReceiveBufferSize() const;
Returns the size of the receive buffer.
The returned value may be different than the value previously set with setReceiveBufferSize(), as the system is free to adjust the value.
getReceiveTimeout
Poco::Timespan getReceiveTimeout() const;
Returns the receive timeout for the socket.
The returned timeout may be different than the timeout previously set with getReceiveTimeout(), as the system is free to adjust the value.
getReuseAddress
bool getReuseAddress() const;
Returns the value of the SO_REUSEADDR socket option.
getReusePort
bool getReusePort() const;
Returns the value of the SO_REUSEPORT socket option.
Returns false if the socket implementation does not support SO_REUSEPORT.
getSendBufferSize
int getSendBufferSize() const;
Returns the size of the send buffer.
The returned value may be different than the value previously set with setSendBufferSize(), as the system is free to adjust the value.
getSendTimeout
Poco::Timespan getSendTimeout() const;
Returns the send timeout for the socket.
The returned timeout may be different than the timeout previously set with setSendTimeout(), as the system is free to adjust the value.
impl
SocketImpl * impl() const;
Returns the SocketImpl for this socket.
init
void init(
int af
);
Creates the underlying system socket for the given address family.
Normally, this method should not be called directly, as socket creation will be handled automatically. There are a few situations where calling this method after creation of the Socket object makes sense. One example is setting a socket option before calling bind() on a ServerSocket.
isDatagram
bool isDatagram() const;
Returns true if socket is a datagram socket, false otherwise.
isNull
bool isNull() const;
Returns true if pointer to implementation is null.
isRaw
bool isRaw() const;
Returns true if socket is a raw socket, false otherwise.
isStream
bool isStream() const;
Returns true if socket is a stream socket, false otherwise.
lastError
static int lastError();
Returns the last error code.
lastErrorDesc
static std::string lastErrorDesc();
Returns the last error description.
makeBufVec
static SocketBufVec makeBufVec(
std::size_t size,
std::size_t bufLen
);
Creates and returns a vector of requested size, with allocated buffers and lengths set accordingly. This utility function works well when all buffers are of same size.
makeBufVec
static SocketBufVec makeBufVec(
const std::vector < char * > & vec
);
Creates and returns a vector of requested size, with buffers pointing to the supplied data (so, vec must remain available at the time of use) and lengths set accordingly. Notes:
- data length is determined using strlen, so this function is not meant to be used with binary data.
- if the returned buffer is used for read operations (ie. operations that write to the bufer), pointing to string literals will result in undefined behavior, in best case an I/O error and subsequent exception
makeBufVec
static SocketBufVec makeBufVec(
const std::vector < std::string > & vec
);
Creates and returns a vector of requested size, with buffers pointing to the supplied data (so, vec must remain available at the time of use) and lengths set accordingly. Note:: this function is not suitable for creation of buffers used for writing (ie. reading from socket into buffers).
makeBuffer
static SocketBuf makeBuffer(
void * buffer,
std::size_t length
);
Creates and returns buffer. Suitable for creating the appropriate buffer for the platform.
operator !=
bool operator != (
const Socket & socket
) const;
Returns false if both sockets share the same SocketImpl, true otherwise.
operator <
bool operator < (
const Socket & socket
) const;
Compares the SocketImpl pointers.
operator <=
bool operator <= (
const Socket & socket
) const;
Compares the SocketImpl pointers.
operator =
Socket & operator = (
const Socket & socket
);
Assignment operator.
Releases the socket's SocketImpl and attaches the SocketImpl from the other socket and increments the reference count of the SocketImpl.
operator ==
bool operator == (
const Socket & socket
) const;
Returns true if both sockets share the same SocketImpl, false otherwise.
operator >
bool operator > (
const Socket & socket
) const;
Compares the SocketImpl pointers.
operator >=
bool operator >= (
const Socket & socket
) const;
Compares the SocketImpl pointers.
peerAddress
SocketAddress peerAddress() const;
Returns the IP address and port number of the peer socket.
poll
bool poll(
const Poco::Timespan & timeout,
int mode
) const;
Determines the status of the socket, using a call to poll() or select().
The mode argument is constructed by combining the values of the SelectMode enumeration.
Returns true if the next operation corresponding to mode will not block, false otherwise.
secure
bool secure() const;
Returns true iff the socket's connection is secure (using SSL or TLS).
select
static int select(
SocketList & readList,
SocketList & writeList,
SocketList & exceptList,
const Poco::Timespan & timeout
);
Determines the status of one or more sockets, using a call to select().
ReadList contains the list of sockets which should be checked for readability.
WriteList contains the list of sockets which should be checked for writeability.
ExceptList contains a list of sockets which should be checked for a pending error.
Returns the number of sockets ready.
After return,
- readList contains those sockets ready for reading,
- writeList contains those sockets ready for writing,
- exceptList contains those sockets with a pending error.
If the total number of sockets passed in readList, writeList and exceptList is zero, select() will return immediately and the return value will be 0.
If one of the sockets passed to select() is closed while select() runs, select will return immediately. However, the closed socket will not be included in any list. In this case, the return value may be greater than the sum of all sockets in all list.
This function is deprecated and may be removed in the future releases, please use PollSet class instead.
setBlocking
void setBlocking(
bool flag
);
Sets the socket in blocking mode if flag is true, disables blocking mode if flag is false.
setKeepAlive
void setKeepAlive(
bool flag
);
Sets the value of the SO_KEEPALIVE socket option.
setLinger
void setLinger(
bool on,
int seconds
);
Sets the value of the SO_LINGER socket option.
setNoDelay
void setNoDelay(
bool flag
);
Sets the value of the TCP_NODELAY socket option.
setOOBInline
void setOOBInline(
bool flag
);
Sets the value of the SO_OOBINLINE socket option.
setOption
void setOption(
int level,
int option,
int value
);
Sets the socket option specified by level and option to the given integer value.
setOption
void setOption(
int level,
int option,
unsigned value
);
Sets the socket option specified by level and option to the given integer value.
setOption
void setOption(
int level,
int option,
unsigned char value
);
Sets the socket option specified by level and option to the given integer value.
setOption
void setOption(
int level,
int option,
const Poco::Timespan & value
);
Sets the socket option specified by level and option to the given time value.
setOption
void setOption(
int level,
int option,
const IPAddress & value
);
Sets the socket option specified by level and option to the given time value.
setReceiveBufferSize
void setReceiveBufferSize(
int size
);
Sets the size of the receive buffer.
setReceiveTimeout
void setReceiveTimeout(
const Poco::Timespan & timeout
);
Sets the receive timeout for the socket.
On systems that do not support SO_RCVTIMEO, a workaround using poll() is provided.
setReuseAddress
void setReuseAddress(
bool flag
);
Sets the value of the SO_REUSEADDR socket option.
setReusePort
void setReusePort(
bool flag
);
Sets the value of the SO_REUSEPORT socket option. Does nothing if the socket implementation does not support SO_REUSEPORT.
setSendBufferSize
void setSendBufferSize(
int size
);
Sets the size of the send buffer.
setSendTimeout
void setSendTimeout(
const Poco::Timespan & timeout
);
Sets the send timeout for the socket.
supportsIPv4
static bool supportsIPv4();
Returns true if the system supports IPv4.
supportsIPv6
static bool supportsIPv6();
Returns true if the system supports IPv6.
type
Type type() const;
Returns the socket type.
sockfd
int sockfd() const;
Returns the socket descriptor for this socket.