Add a helper function for adjusting mode flags

[libs/core.git] / source / io / base.h

diff --git a/source/io/base.h b/source/io/base.h
index 3d862169177f1711c6a9d3820e4fb3f97a6b94ca..8d29caffd9813096747b1c2822f6e1b185b1d854 100644 (file)
--- a/source/io/base.h
+++ b/source/io/base.h
@@ -2,6 +2,7 @@
 #define MSP_IO_BASE_H_
 
 #include <sigc++/sigc++.h>
+#include <msp/core/mutex.h>
 #include "handle.h"
 #include "mode.h"
 #include "poll.h"
@@ -11,13 +12,22 @@ namespace IO {
 
 /**
 Common interface for all I/O objects.
-
-A derived class must call set_events(P_NONE) before it is destroyed to avoid
-leaving stale pointers in an EventDispatcher.
 */
 class Base
 {
 public:
+       /** RAII synchronization primitive.  Prevents concurrent access to the
+       target object during the lifetime of the Synchronize object. */
+       class Synchronize
+       {
+       private:
+               Base &io;
+
+       public:
+               Synchronize(Base &);
+               ~Synchronize();
+       };
+
        /** Emitted when there is no more data to be read. */
        sigc::signal<void> signal_end_of_file;
 
@@ -32,6 +42,7 @@ public:
 protected:
        Mode mode;
        bool eof_flag;
+       Mutex *mutex;
 
        Base();
 private:
@@ -87,7 +98,9 @@ protected:
        void set_eof();
 
 public:
-       /** Returns the end-of-file flag. */
+       /** Returns the end-of-file flag.  Note that some types of objects won't
+       indicate end-of-file until you try to read at least one byte past the actual
+       end, while others indicate it when you've read the last byte. */
        bool eof() const { return eof_flag; }
 
        /** Returns the system-level handle for the object.  Used by Console to