Merge GDB 7.5.1

gdb/serial.h

Index: gdb/serial.h
diff --git a/gdb/serial.h b/gdb/serial.h
index 02a3b2d4737ce701b1785506a8bc87df1f118062..b16406222957bcfc4ced7707e032e9e8011c74cd 100644
--- a/gdb/serial.h
+++ b/gdb/serial.h
@@ -37,13 +37,18 @@ typedef void *serial_ttystate;
 struct serial;
 
 /* Try to open NAME.  Returns a new `struct serial *' on success, NULL
-   on failure.  Note that some open calls can block and, if possible, 
-   should be  written to be non-blocking, with calls to ui_look_hook 
-   so they can be cancelled.  An async interface for open could be
-   added to GDB if necessary.  */
+   on failure.  The new serial object has a reference count of 1.
+   Note that some open calls can block and, if possible, should be
+   written to be non-blocking, with calls to ui_look_hook so they can
+   be cancelled.  An async interface for open could be added to GDB if
+   necessary.  */
 
 extern struct serial *serial_open (const char *name);
 
+/* Returns true if SCB is open.  */
+
+extern int serial_is_open (struct serial *scb);
+
 /* Find an already opened serial stream using a file handle.  */
 
 extern struct serial *serial_for_fd (int fd);
@@ -52,10 +57,18 @@ extern struct serial *serial_for_fd (int fd);
 
 extern struct serial *serial_fdopen (const int fd);
 
-/* Push out all buffers, close the device and destroy SCB.  */
+/* Push out all buffers, close the device and unref SCB.  */
 
 extern void serial_close (struct serial *scb);
 
+/* Increment reference count of SCB.  */
+
+extern void serial_ref (struct serial *scb);
+
+/* Decrement reference count of SCB.  */
+
+extern void serial_unref (struct serial *scb);
+
 /* Create a pipe, and put the read end in files[0], and the write end
    in filde[1].  Returns 0 for success, negative value for error (in
    which case errno contains the error).  */
@@ -213,6 +226,10 @@ extern int serial_debug_p (struct serial *scb);
 
 struct serial
   {
+    /* serial objects are ref counted (but not the underlying
+       connection, just the object's lifetime in memory).  */
+    int refcnt;
+
     int fd;			/* File descriptor */
     /* File descriptor for a separate error stream that should be
        immediately forwarded to gdb_stderr.  This may be -1.
@@ -233,7 +250,6 @@ struct serial
 				   more seconds.  */
     char *name;			/* The name of the device or host */
     struct serial *next;	/* Pointer to the next `struct serial *' */
-    int refcnt;			/* Number of pointers to this block */
     int debug_p;		/* Trace this serial devices operation.  */
     int async_state;		/* Async internal state.  */
     void *async_context;	/* Async event thread's context */