Add per-direction wxSocket wait flags and byte counters.

Allow to specify whether the socket should block until all the data is read or
written or, on the contrary, avoid blocking only when reading or writing
instead of always using the same behaviour in both directions.

Also add separate counters for the bytes read/written instead of using the
same one for both.

These changes make it possible to use the same socket for reading/writing in
different threads.

Closes #14506.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72591 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -529,6 +529,8 @@ Major new features in this release
 
 All:
 
+- Add separate read/written bytes counters and per-direction NOWAIT and WAITALL
+  flags to wxSocket (Rob Bresalier).
 - Add wxDir::Close() method (Silverstorm82).
 - Fix compilation of wxHash{Map,Set} with g++ 4.7 (Nathan Ridge).
 - Fix posting large amounts of data in wxHTTP (Platonides).

include/wx/socket.h

@@ -77,7 +77,11 @@ enum
     wxSOCKET_BLOCK = 4,
     wxSOCKET_REUSEADDR = 8,
     wxSOCKET_BROADCAST = 16,
-    wxSOCKET_NOBIND = 32
+    wxSOCKET_NOBIND = 32,
+    wxSOCKET_NOWAIT_READ = 64,
+    wxSOCKET_WAITALL_READ = 128,
+    wxSOCKET_NOWAIT_WRITE = 256,
+    wxSOCKET_WAITALL_WRITE = 512
 };
 
 typedef int wxSocketFlags;
@@ -123,6 +127,8 @@ public:
     bool IsData() { return WaitForRead(0, 0); }
     bool IsDisconnected() const { return !IsConnected(); }
     wxUint32 LastCount() const { return m_lcount; }
+    wxUint32 LastReadCount() const { return m_lcount_read; }
+    wxUint32 LastWriteCount() const { return m_lcount_write; }
     wxSocketError LastError() const;
     void SaveState();
     void RestoreState();
@@ -171,6 +177,8 @@ public:
     bool GetOption(int level, int optname, void *optval, int *optlen);
     bool SetOption(int level, int optname, const void *optval, int optlen);
     wxUint32 GetLastIOSize() const { return m_lcount; }
+    wxUint32 GetLastIOReadSize() const { return m_lcount_read; }
+    wxUint32 GetLastIOWriteSize() const { return m_lcount_write; }
 
     // event handling
     void *GetClientData() const { return m_clientData; }
@@ -254,6 +262,8 @@ private:
     bool          m_writing;          // busy writing?
     bool          m_closed;           // was the other end closed?
     wxUint32      m_lcount;           // last IO transaction size
+    wxUint32      m_lcount_read;      // last IO transaction size of Read() direction.
+    wxUint32      m_lcount_write;     // last IO transaction size of Write() direction.
     unsigned long m_timeout;          // IO timeout value in seconds
                                       // (TODO: remove, wxSocketImpl has it too)
     wxList        m_states;           // stack of states (TODO: remove!)

interface/wx/socket.h

@@ -572,7 +572,32 @@ enum wxSocketEventFlags
     in the output buffer. This is the same as issuing exactly one nonblocking
     low-level call to @b recv() or @b send(). Note that @e nonblocking here
     refers to when the function returns, not to whether the GUI blocks during
-    this time.
+    this time.  Also note that this flag impacts both Read and Write
+    operations.  If it is desired to control Read independently of Write, for
+    example you want no wait on Read(), but you do want to wait on Write(), then
+    use wxSOCKET_NOWAIT_READ and wxSOCKET_NOWAIT_WRITE.
+
+    If @b wxSOCKET_NOWAIT_READ (this flag is new since wxWidgets 2.9.5) is
+    specified, Read operations will return immediately. Read operations will
+    retrieve only available data. This is the same as issuing exactly one
+    nonblocking low-level call to @b recv(). Note that @e nonblocking here
+    refers to when the function returns, not to whether the GUI blocks during
+    this time.  This flag should not be enabled if ReadMsg() is going to be
+    used (it will be ignored), if you do then thread-safety may be at risk.
+    Note that wxSOCKET_NOWAIT_READ impacts only Read operations and does not
+    impact Write operations, allowing Read and Write operations to be set
+    differently.
+
+    If @b wxSOCKET_NOWAIT_WRITE (this flag is new since wxWidgets 2.9.5) is
+    specified, Write operations will return immediately. Write operations will
+    write as much data as possible, depending on how much space is available in
+    the output buffer. This is the same as issuing exactly one nonblocking
+    low-level call to @b send(). Note that @e nonblocking here refers to when
+    the function returns, not to whether the GUI blocks during this time.  This
+    flag should not be enabled if WriteMsg() is going to be used (it will be
+    ignored), if you use it then thread safety may be at risk. Note that
+    wxSOCKET_NOWAIT_WRITE impacts only Write operations and does not impact
+    Write operations, allowing Read and Write operations to be set differently.
 
     If @b wxSOCKET_WAITALL is specified, IO calls won't return until ALL
     the data has been read or written (or until an error occurs), blocking if
@@ -580,7 +605,32 @@ enum wxSocketEventFlags
     same as having a loop which makes as many blocking low-level calls to
     @b recv() or @b send() as needed so as to transfer all the data. Note
     that @e blocking here refers to when the function returns, not
-    to whether the GUI blocks during this time.
+    to whether the GUI blocks during this time.  Note that wxSOCKET_WAITALL
+    impacts both Read and Write operations.  If you desire to wait
+    for all on just Read operations, but not on Write operations, (or vice versa),
+    use wxSOCKET_WAITALL_READ or wxSOCKET_WAITALL_WRITE.
+
+    If @b wxSOCKET_WAITALL_READ (this flag is new since wxWidgets 2.9.5) is
+    specified, Read operations won't return until ALL the data has been read
+    (or until an error occurs), blocking if necessary, and issuing several low
+    level calls if necessary. This is the same as having a loop which makes as
+    many blocking low-level calls to @b recv() as needed so as to transfer all
+    the data. Note that @e blocking here refers to when the function returns,
+    not to whether the GUI blocks during this time.  Note that
+    wxSOCKET_WAITALL_READ only has an impact on Read operations, and has no
+    impact on Write operations, allowing Read and Write operations to have
+    different settings.
+
+    If @b wxSOCKET_WAITALL_WRITE (this flag is new since wxWidgets 2.9.5) is
+    specified, Write() and WriteMsg() calls won't return until ALL the data has
+    been written (or until an error occurs), blocking if necessary, and issuing
+    several low level calls if necessary. This is the same as having a loop
+    which makes as many blocking low-level calls to @b send() as needed so as
+    to transfer all the data. Note that @e blocking here refers to when the
+    function returns, not to whether the GUI blocks during this time.  Note
+    that wxSOCKET_WAITALL_WRITE only has an impact on Write operations, and has
+    no impact on Read operations, allowing Read and Write operations to have
+    different settings.
 
     The @b wxSOCKET_BLOCK flag controls whether the GUI blocks during
     IO operations. If this flag is specified, the socket will not yield
@@ -627,9 +677,13 @@ enum
     wxSOCKET_BLOCK = 4,     ///< Block the GUI (do not yield) while reading/writing data.
     wxSOCKET_REUSEADDR = 8, ///< Allows the use of an in-use port.
     wxSOCKET_BROADCAST = 16, ///< Switches the socket to broadcast mode
-    wxSOCKET_NOBIND = 32    ///< Stops the socket from being bound to a specific
+    wxSOCKET_NOBIND = 32,   ///< Stops the socket from being bound to a specific
                             ///< adapter (normally used in conjunction with
                             ///< @b wxSOCKET_BROADCAST)
+    wxSOCKET_NOWAIT_READ = 64,    ///< Read as much data as possible and return immediately
+    wxSOCKET_WAITALL_READ = 128,  ///< Wait for all required data to be read unless an error occurs.
+    wxSOCKET_NOWAIT_WRITE = 256,   ///< Write as much data as possible and return immediately
+    wxSOCKET_WAITALL_WRITE = 512   ///< Wait for all required data to be written unless an error occurs.
 };
 
 
@@ -804,9 +858,42 @@ public:
         Use this function to get the number of bytes actually transferred
         after using one of the following IO calls: Discard(), Peek(), Read(),
         ReadMsg(), Unread(), Write(), WriteMsg().
+
+        @deprecated
+        This function is kept mostly for backwards compatibility.  Use
+        LastReadCount() or LastWriteCount() instead.  LastCount() is still
+        needed for use with less commonly used functions: Discard(),
+        Peek(), and Unread().
     */
     wxUint32 LastCount() const;
 
+    /**
+        Returns the number of bytes read by the last Read() or ReadMsg()
+        call (receive direction only).
+
+        This function is thread-safe, in case Read() is executed in a
+        different thread than Write().  Use LastReadCount() instead of
+        LastCount() for this reason.
+
+        Unlike LastCount(), the functions Discard(), Peek(), and Unread()
+        are currently not supported by LastReadCount().
+
+        @since 2.9.5
+    */
+    wxUint32 LastReadCount() const;
+
+    /**
+        Returns the number of bytes written by the last Write() or WriteMsg()
+        call (transmit direction only).
+
+        This function is thread-safe, in case Write() is executed in a
+        different thread than Read().  Use LastWriteCount() instead of
+        LastCount() for this reason.
+
+        @since 2.9.5
+    */
+    wxUint32 LastWriteCount() const;
+
     /**
         Returns the last wxSocket error. See @ref wxSocketError .
 
@@ -936,7 +1023,7 @@ public:
     /**
         Read up to the given number of bytes from the socket.
 
-        Use LastCount() to verify the number of bytes actually read.
+        Use LastReadCount() to verify the number of bytes actually read.
         Use Error() to determine if the operation succeeded.
 
         @param buffer
@@ -950,7 +1037,7 @@ public:
             The exact behaviour of Read() depends on the combination of flags being used.
             For a detailed explanation, see SetFlags()
 
-        @see Error(), LastError(), LastCount(),
+        @see Error(), LastError(), LastReadCount(),
              SetFlags()
     */
     wxSocketBase& Read(void* buffer, wxUint32 nbytes);
@@ -962,7 +1049,7 @@ public:
         bytes will be discarded. This function always waits for the buffer to
         be entirely filled, unless an error occurs.
 
-        Use LastCount() to verify the number of bytes actually read.
+        Use LastReadCount() to verify the number of bytes actually read.
 
         Use Error() to determine if the operation succeeded.
 
@@ -978,8 +1065,15 @@ public:
             and it will always ignore the @b wxSOCKET_NOWAIT flag.
             The exact behaviour of ReadMsg() depends on the @b wxSOCKET_BLOCK flag.
             For a detailed explanation, see SetFlags().
+            For thread safety, in case ReadMsg() and WriteMsg() are called in
+            different threads, it is a good idea to call
+            SetFlags(wxSOCKET_WAITALL|wx_SOCKET_BLOCK) before the first calls
+            to ReadMsg() and WriteMsg() in different threads, as each of these
+            functions will call SetFlags() which performs read/modify/write.  By
+            setting these flags before the multi-threading, it will ensure that
+            they don't get reset by thread race conditions.
 
-        @see Error(), LastError(), LastCount(), SetFlags(), WriteMsg()
+        @see Error(), LastError(), LastReadCount(), SetFlags(), WriteMsg()
     */
     wxSocketBase& ReadMsg(void* buffer, wxUint32 nbytes);
 
@@ -1163,7 +1257,7 @@ public:
     /**
         Write up to the given number of bytes to the socket.
 
-        Use LastCount() to verify the number of bytes actually written.
+        Use LastWriteCount() to verify the number of bytes actually written.
 
         Use Error() to determine if the operation succeeded.
 
@@ -1179,7 +1273,7 @@ public:
         The exact behaviour of Write() depends on the combination of flags being used.
         For a detailed explanation, see SetFlags().
 
-        @see Error(), LastError(), LastCount(), SetFlags()
+        @see Error(), LastError(), LastWriteCount(), SetFlags()
     */
     wxSocketBase& Write(const void* buffer, wxUint32 nbytes);
 
@@ -1192,7 +1286,7 @@ public:
         This function always waits for the entire buffer to be sent, unless an
         error occurs.
 
-        Use LastCount() to verify the number of bytes actually written.
+        Use LastWriteCount() to verify the number of bytes actually written.
 
         Use Error() to determine if the operation succeeded.
 
@@ -1209,8 +1303,15 @@ public:
         it will always ignore the @b wxSOCKET_NOWAIT flag. The exact behaviour of
         WriteMsg() depends on the @b wxSOCKET_BLOCK flag. For a detailed explanation,
         see SetFlags().
+        For thread safety, in case ReadMsg() and WriteMsg() are called in
+        different threads, it is a good idea to call
+        @code SetFlags(wxSOCKET_WAITALL|wx_SOCKET_BLOCK) @endcode before the
+        first calls to ReadMsg() and WriteMsg() in different threads, as each
+        of these functions calls SetFlags() which performs read/modify/write.
+        By setting these flags before the multi-threading, it will ensure that
+        they don't get reset by thread race conditions.
 
-        @see  Error(), LastError(), LastCount(), SetFlags(), ReadMsg()
+        @see  Error(), LastError(), LastWriteCount(), SetFlags(), ReadMsg()
 
     */
     wxSocketBase& WriteMsg(const void* buffer, wxUint32 nbytes);
@@ -1321,7 +1422,7 @@ public:
     /**
         Write a buffer of @a nbytes bytes to the socket.
 
-        Use wxSocketBase::LastCount() to verify the number of bytes actually wrote.
+        Use wxSocketBase::LastWriteCount() to verify the number of bytes actually wrote.
         Use wxSocketBase::Error() to determine if the operation succeeded.
 
         @param address

src/common/socket.cpp

@@ -817,6 +817,8 @@ void wxSocketBase::Init()
     m_writing      =
     m_closed       = false;
     m_lcount       = 0;
+    m_lcount_read  = 0;
+    m_lcount_write = 0;
     m_timeout      = 600;
     m_beingDeleted = false;
 
@@ -947,7 +949,8 @@ wxSocketBase& wxSocketBase::Read(void* buffer, wxUint32 nbytes)
 {
     wxSocketReadGuard read(this);
 
-    m_lcount = DoRead(buffer, nbytes);
+    m_lcount_read = DoRead(buffer, nbytes);
+    m_lcount = m_lcount_read;
 
     return *this;
 }
@@ -983,7 +986,7 @@ wxUint32 wxSocketBase::DoRead(void* buffer_, wxUint32 nbytes)
             if ( m_impl->GetLastError() == wxSOCKET_WOULDBLOCK )
             {
                 // if we don't want to wait, just return immediately
-                if ( m_flags & wxSOCKET_NOWAIT )
+                if ( m_flags & (wxSOCKET_NOWAIT|wxSOCKET_NOWAIT_READ ))
                 {
                     // this shouldn't be counted as an error in this case
                     SetError(wxSOCKET_NOERROR);
@@ -1019,7 +1022,7 @@ wxUint32 wxSocketBase::DoRead(void* buffer_, wxUint32 nbytes)
             // we're not going to read anything else and so if we haven't read
             // anything (or not everything in wxSOCKET_WAITALL case) already,
             // signal an error
-            if ( (m_flags & wxSOCKET_WAITALL) || !total )
+            if ( (m_flags & (wxSOCKET_WAITALL|wxSOCKET_WAITALL_READ)) || !total )
                 SetError(wxSOCKET_IOERR);
             break;
         }
@@ -1028,7 +1031,7 @@ wxUint32 wxSocketBase::DoRead(void* buffer_, wxUint32 nbytes)
 
         // if we are happy to read something and not the entire nbytes bytes,
         // then we're done
-        if ( !(m_flags & wxSOCKET_WAITALL) )
+        if ( !(m_flags & (wxSOCKET_WAITALL|wxSOCKET_WAITALL_READ)) )
             break;
 
         nbytes -= ret;
@@ -1048,7 +1051,7 @@ wxSocketBase& wxSocketBase::ReadMsg(void* buffer, wxUint32 nbytes)
 
     wxSocketReadGuard read(this);
 
-    wxSocketWaitModeChanger changeFlags(this, wxSOCKET_WAITALL);
+    wxSocketWaitModeChanger changeFlags(this, (wxSOCKET_WAITALL|wxSOCKET_WAITALL_READ));
 
     bool ok = false;
     if ( DoRead(&msg, sizeof(msg)) == sizeof(msg) )
@@ -1075,7 +1078,8 @@ wxSocketBase& wxSocketBase::ReadMsg(void* buffer, wxUint32 nbytes)
                 len2 = 0;
 
             // Don't attempt to read if the msg was zero bytes long.
-            m_lcount = len ? DoRead(buffer, len) : 0;
+            m_lcount_read = len ? DoRead(buffer, len) : 0;
+            m_lcount = m_lcount_read;
 
             if ( len2 )
             {
@@ -1131,7 +1135,8 @@ wxSocketBase& wxSocketBase::Write(const void *buffer, wxUint32 nbytes)
 {
     wxSocketWriteGuard write(this);
 
-    m_lcount = DoWrite(buffer, nbytes);
+    m_lcount_write = DoWrite(buffer, nbytes);
+    m_lcount = m_lcount_write;
 
     return *this;
 }
@@ -1151,7 +1156,7 @@ wxUint32 wxSocketBase::DoWrite(const void *buffer_, wxUint32 nbytes)
     {
         if ( m_impl->m_stream && !m_connected )
         {
-            if ( (m_flags & wxSOCKET_WAITALL) || !total )
+            if ( (m_flags & (wxSOCKET_WAITALL|wxSOCKET_WAITALL_WRITE)) || !total )
                 SetError(wxSOCKET_IOERR);
             break;
         }
@@ -1161,7 +1166,7 @@ wxUint32 wxSocketBase::DoWrite(const void *buffer_, wxUint32 nbytes)
         {
             if ( m_impl->GetLastError() == wxSOCKET_WOULDBLOCK )
             {
-                if ( m_flags & wxSOCKET_NOWAIT )
+                if ( m_flags & (wxSOCKET_NOWAIT|wxSOCKET_NOWAIT_WRITE) )
                     break;
 
                 if ( !DoWaitWithTimeout(wxSOCKET_OUTPUT_FLAG) )
@@ -1181,7 +1186,7 @@ wxUint32 wxSocketBase::DoWrite(const void *buffer_, wxUint32 nbytes)
 
         total += ret;
 
-        if ( !(m_flags & wxSOCKET_WAITALL) )
+        if ( !(m_flags & (wxSOCKET_WAITALL|wxSOCKET_WAITALL_WRITE)) )
             break;
 
         nbytes -= ret;
@@ -1201,7 +1206,7 @@ wxSocketBase& wxSocketBase::WriteMsg(const void *buffer, wxUint32 nbytes)
 
     wxSocketWriteGuard write(this);
 
-    wxSocketWaitModeChanger changeFlags(this, wxSOCKET_WAITALL);
+    wxSocketWaitModeChanger changeFlags(this, (wxSOCKET_WAITALL|wxSOCKET_WAITALL_WRITE));
 
     msg.sig[0] = (unsigned char) 0xad;
     msg.sig[1] = (unsigned char) 0xde;
@@ -1216,8 +1221,9 @@ wxSocketBase& wxSocketBase::WriteMsg(const void *buffer, wxUint32 nbytes)
     bool ok = false;
     if ( DoWrite(&msg, sizeof(msg)) == sizeof(msg) )
     {
-        m_lcount = DoWrite(buffer, nbytes);
+        m_lcount_write = DoWrite(buffer, nbytes);
-        if ( m_lcount == nbytes )
+        m_lcount = m_lcount_write;
+        if ( m_lcount_write == nbytes )
         {
             msg.sig[0] = (unsigned char) 0xed;
             msg.sig[1] = (unsigned char) 0xfe;

tests/net/socket.cpp

@@ -186,6 +186,7 @@ void SocketTestCase::ReadNormal()
 
     CPPUNIT_ASSERT_EQUAL( wxSOCKET_NOERROR, sock->LastError() );
     CPPUNIT_ASSERT_EQUAL( WXSIZEOF(bufSmall), (size_t)sock->LastCount() );
+    CPPUNIT_ASSERT_EQUAL( WXSIZEOF(bufSmall), (size_t)sock->LastReadCount() );
 
 
     char bufBig[102400];
@@ -193,6 +194,7 @@ void SocketTestCase::ReadNormal()
 
     CPPUNIT_ASSERT_EQUAL( wxSOCKET_NOERROR, sock->LastError() );
     CPPUNIT_ASSERT( WXSIZEOF(bufBig) >= sock->LastCount() );
+    CPPUNIT_ASSERT( WXSIZEOF(bufBig) >= sock->LastReadCount() );
 }
 
 void SocketTestCase::ReadBlock()
@@ -206,6 +208,7 @@ void SocketTestCase::ReadBlock()
 
     CPPUNIT_ASSERT_EQUAL( wxSOCKET_NOERROR, sock->LastError() );
     CPPUNIT_ASSERT_EQUAL( WXSIZEOF(bufSmall), (size_t)sock->LastCount() );
+    CPPUNIT_ASSERT_EQUAL( WXSIZEOF(bufSmall), (size_t)sock->LastReadCount() );
 
 
     char bufBig[102400];
@@ -213,6 +216,7 @@ void SocketTestCase::ReadBlock()
 
     CPPUNIT_ASSERT_EQUAL( wxSOCKET_NOERROR, sock->LastError() );
     CPPUNIT_ASSERT( WXSIZEOF(bufBig) >= sock->LastCount() );
+    CPPUNIT_ASSERT( WXSIZEOF(bufBig) >= sock->LastReadCount() );
 }
 
 void SocketTestCase::ReadNowait()
@@ -242,6 +246,7 @@ void SocketTestCase::ReadWaitall()
 
     CPPUNIT_ASSERT_EQUAL( wxSOCKET_NOERROR, sock->LastError() );
     CPPUNIT_ASSERT_EQUAL( WXSIZEOF(buf), (size_t)sock->LastCount() );
+    CPPUNIT_ASSERT_EQUAL( WXSIZEOF(buf), (size_t)sock->LastReadCount() );
 }
 
 void SocketTestCase::UrlTest()