add oversampler

oversampling/WDL/shm_connection.h

@@ -0,0 +1,87 @@
+#ifndef _WDL_SHM_CONNECTION_H_
+#define _WDL_SHM_CONNECTION_H_
+
+#ifdef _WIN32
+#include <windows.h>
+#else
+#include "swell/swell.h"
+#include "swell/swell-internal.h"
+#endif
+
+#include <time.h>
+
+#include "wdlstring.h"
+#include "wdltypes.h"
+#include "queue.h"
+
+class WDL_SHM_Connection
+{
+public:
+  WDL_SHM_Connection(bool whichChan, // a true con connects to a false con -- note on SHM false should be created FIRST.
+                     const char *uniquestring, // identify 
+                     int shmsize=262144, // bytes, whoever opens first decides
+                     int timeout_sec=0,
+                     int extra_flags=0 // on posix, set 1 for the master to create a .lock file as well
+                     );
+
+  ~WDL_SHM_Connection();
+
+  int Run(); // call as often as possible, returns <0 error, >0 if did something
+
+  bool WantSendKeepAlive(); // called when it needs a keepalive to be sent (may be never, or whatever interval it decides)
+  
+ // wait for this if you want to see when data comes in
+  HANDLE GetWaitEvent() 
+  { 
+    #ifdef _WIN32
+    return m_events[m_whichChan]; 
+    #else
+    return m_waitevt;
+    #endif
+  }
+  
+  // receiving and sending data
+  WDL_Queue recv_queue;
+  WDL_Queue send_queue;
+
+
+private:
+
+
+  int m_timeout_sec;
+  time_t m_last_recvt;
+  int m_timeout_cnt;
+
+  WDL_String m_tempfn;
+
+  int m_whichChan; // which channel we read from
+
+#ifdef _WIN32
+
+  HANDLE m_file, m_filemap; 
+  HANDLE m_events[2]; // [m_whichChan] set when the other side did something useful
+  HANDLE m_lockmutex;
+
+  unsigned char *m_mem; 
+#else
+  time_t m_next_keepalive;
+  
+  int m_sockbufsize;
+
+  int m_rdbufsize;
+  char *m_rdbuf; // m_rdbufsize
+
+  int m_listen_socket;
+  int m_socket;
+
+  HANDLE m_waitevt;
+  void *m_sockaddr;
+
+  void acquireListener();
+  WDL_String m_lockfn;
+  int m_lockhandle;
+#endif
+
+};
+
+#endif