Merge pull request #48 from SamCoVT/master

Proposed fix for #47 Save and restore termios settings with helper functions in utils.console

py65/monitor.py

@@ -53,28 +53,60 @@ class Monitor(cmd.Cmd):
         self._width = 78
         self.prompt = "."
         self._add_shortcuts()
-        cmd.Cmd.__init__(self, stdin=stdin, stdout=stdout)
 
-        if argv is None:
-            argv = sys.argv
-        load, rom, goto = self._parse_args(argv)
+        # Save the current system input mode so it can be restored after
+        # after processing commands and before exiting.
+        console.save_mode(sys.stdin)
 
-        self._reset(self.mpu_type, self.getc_addr, self.putc_addr)
+        # Attempt to get a copy of stdin that is unbuffered on systems
+        # that support it.  This allows for immediate response to
+        # typed input as well as pasted input.  If unable to get an
+        # unbuffered version of stdin, the original version is returned.
+        self.unbuffered_stdin = console.get_unbuffered_stdin(stdin)
 
-        if load is not None:
-            self.do_load("%r" % load)
+        cmd.Cmd.__init__(self, stdin=self.unbuffered_stdin, stdout=stdout)
 
-        if goto is not None:
-            self.do_goto(goto)
+        # Check for any exceptions thrown during __init__ while
+        # processing the arguments.
+        try:
+
+            if argv is None:
+                argv = sys.argv
+            load, rom, goto = self._parse_args(argv)
+
+            self._reset(self.mpu_type, self.getc_addr, self.putc_addr)
+
+            if load is not None:
+                self.do_load("%r" % load)
+
+            if goto is not None:
+                self.do_goto(goto)
+
+            if rom is not None:
+                # load a ROM and run from the reset vector
+                self.do_load("%r top" % rom)
+                physMask = self._mpu.memory.physMask
+                reset = self._mpu.RESET & physMask
+                dest = self._mpu.memory[reset] + \
+                    (self._mpu.memory[reset + 1] << self.byteWidth)
+                self.do_goto("$%x" % dest)
+        except:
+            # Restore input mode on any exception and then rethrow the
+            # exception.
+            console.restore_mode()
+            raise
+
+    def __del__(self):
+        try:
+            # Restore the input mode.
+            console.restore_mode()
+            # Close the unbuffered input file handle, if it exists.
+            if self.unbuffered_stdin != None:
+                if self.unbuffered_stdin != sys.stdin:
+                    self.unbuffered_stdin.close()
+        except:
+            pass
 
-        if rom is not None:
-            # load a ROM and run from the reset vector
-            self.do_load("%r top" % rom)
-            physMask = self._mpu.memory.physMask
-            reset = self._mpu.RESET & physMask
-            dest = self._mpu.memory[reset] + \
-                (self._mpu.memory[reset + 1] << self.byteWidth)
-            self.do_goto("$%x" % dest)
 
     def _parse_args(self, argv):
         try:
@@ -139,6 +171,9 @@ class Monitor(cmd.Cmd):
         if not line.startswith("quit"):
             self._output_mpu_status()
 
+        # Switch back to the previous input mode.
+        console.restore_mode()
+
         return result
 
     def _reset(self, mpu_type, getc_addr=0xF004, putc_addr=0xF001):
@@ -467,6 +502,10 @@ class Monitor(cmd.Cmd):
         mpu = self._mpu
         mem = self._mpu.memory
 
+        # Switch to immediate (noncanonical) no-echo input mode on POSIX
+        # operating systems.  This has no effect on Windows.
+        console.noncanonical_mode(self.stdin)
+        
         if not breakpoints:
             while True:
                 mpu.step()
@@ -483,6 +522,9 @@ class Monitor(cmd.Cmd):
                     self._output(msg % self._breakpoints.index(pc))
                     break
 
+        # Switch back to the previous input mode.
+        console.restore_mode()
+
     def help_radix(self):
         self._output("radix [H|D|O|B]")
         self._output("Set default radix to hex, decimal, octal, or binary.")
@@ -877,6 +919,7 @@ def main(args=None):
         c.cmdloop()
     except KeyboardInterrupt:
         c._output('')
+        console.restore_mode()
 
 if __name__ == "__main__":
     main()

py65/utils/console.py

@@ -3,6 +3,22 @@ import sys
 if sys.platform[:3] == "win":
     import msvcrt
 
+    def get_unbuffered_stdin(stdin):
+        """ get_unbuffered_stdin returns the given stdin on Windows. """
+        return stdin
+
+    def save_mode(stdin):
+        """ save_mode is a no-op on Windows. """
+        return
+
+    def noncanonical_mode(stdin):
+        """ noncanonical_mode is a no-op on Windows. """
+        return
+
+    def restore_mode(stdin):
+        """ restore_mode is a no-op on Windows. """
+        return
+
     def getch(stdin):
         """ Read one character from the Windows console, blocking until one
         is available.  Does not echo the character.  The stdin argument is
@@ -24,51 +40,156 @@ if sys.platform[:3] == "win":
         return ''
 
 else:
-    import select
-    import os
     import termios
-    import fcntl
+    import os
+    from select import select
+
+    oldattr = None
+    oldstdin = None
+
+    def get_unbuffered_stdin(stdin):
+        """ Attempt to get and return a copy of stdin that is 
+        unbuffered.  This allows for immediate response to typed input
+        as well as pasted input.  If unable to get an unbuffered
+        version of stdin, return the original version.
+        """
+        if stdin != None:
+            try:
+                # Reopen stdin with no buffer.
+                return os.fdopen(os.dup(stdin.fileno()), 'rb', 0)
+            except Exception as e:
+                print(e)
+                # Unable to reopen this file handle with no buffer.
+                # Just use the original file handle.
+                return stdin
+        else:
+            # If stdin is None, try using sys.stdin for input.
+            try:
+                # Reopen the system's stdin with no buffer.
+                return os.fdopen(os.dup(sys.stdin.fileno()), 'rb', 0)
+            except:
+                # If unable to get an unbuffered stdin, just return
+                # None, which is what we started with if we got here.
+                return None
+
+    def save_mode(stdin):
+        """ For operating systems that support it, save the original
+        input termios settings so they can be restored later.  This 
+        allows us to switch to noncanonical mode when software is
+        running in the simulator and back to the original mode when
+        accepting commands.
+        """
+        # For non-Windows systems, save the original input settings,
+        # which will typically be blocking reads with echo.
+        global oldattr
+        global oldstdin
+
+        # When the input is not a pty/tty, this will fail.
+        # In that case, it's ok to ignore the failure.
+        try:
+            # Save the current terminal setup.
+            oldstdin = stdin
+            fd = stdin.fileno()
+            oldattr = termios.tcgetattr(fd)
+        except:
+            # Quietly ignore termios errors, such as stdin not being
+            # a tty.
+            pass
+
+    def noncanonical_mode(stdin):
+        """For operating systems that support it, switch to noncanonical
+        mode.  In this mode, characters are given immediately to the
+        program and no processing of editing characters (like backspace)
+        is performed.  Echo is also turned off in this mode.  The
+        previous input behavior can be restored with restore_mode.
+        """
+        # For non-windows systems, switch to non-canonical
+        # and no-echo non-blocking-read mode.
+        try:
+            # Save the current terminal setup.
+            fd = stdin.fileno()
+            currentattr = termios.tcgetattr(fd)
+            # Switch to noncanonical (instant) mode with no echo.
+            newattr = currentattr[:]
+            newattr[3] &= ~termios.ICANON & ~termios.ECHO
+
+            # Switch to non-blocking reads with no timeout.
+            newattr[6][termios.VMIN] = 0
+            newattr[6][termios.VTIME] = 0
+            termios.tcsetattr(fd, termios.TCSANOW, newattr)
+        except:
+            # Quietly ignore termios errors, such as stdin not being
+            # a tty.
+            pass
+        
+    def restore_mode():
+        """For operating systems that support it, restore the previous 
+        input mode.
+        """
+
+        # Restore the previous input setup.
+        global oldattr
+        global oldstdin
+
+        try:
+            # Restore the original system stdin.
+            oldfd = oldstdin.fileno()
+            # If there is a previous setting, restore it.
+            if oldattr != None:
+                # Restore it on the original system stdin.
+                termios.tcsetattr(oldfd, termios.TCSANOW, oldattr)
+        except:
+            # Quietly ignore termios errors, such as stdin not being a tty.
+            pass
 
     def getch(stdin):
         """ Read one character from stdin, blocking until one is available.
         Does not echo the character.
         """
-        fd = stdin.fileno()
-        oldattr = termios.tcgetattr(fd)
-        newattr = oldattr[:]
-        newattr[3] &= ~termios.ICANON & ~termios.ECHO
-        try:
-            termios.tcsetattr(fd, termios.TCSANOW, newattr)
-            char = stdin.read(1)
-        finally:
-            termios.tcsetattr(fd, termios.TCSAFLUSH, oldattr)
+        # Try to get a character with a non-blocking read.
+        char = ''
+        noncanonical_mode(stdin)
+        # If we didn't get a character, ask again.
+        while char == '':
+            try:
+                # On OSX, calling read when no data is available causes the
+                # file handle to never return any future data, so we need to
+                # use select to make sure there is at least one char to read.
+                rd,wr,er = select([stdin], [], [], 0.01)
+                if rd != []:
+                    char = stdin.read(1)
+            except KeyboardInterrupt:
+                # Pass along a CTRL-C interrupt.
+                raise
+            except:
+                pass
         return char
 
     def getch_noblock(stdin):
         """ Read one character from stdin without blocking.  Does not echo the
         character.  If no character is available, an empty string is returned.
         """
+        char = ''
 
-        fd = stdin.fileno()
-
-        oldterm = termios.tcgetattr(fd)
-        newattr = oldterm[:]
-        newattr[3] = newattr[3] & ~termios.ICANON & ~termios.ECHO
-        termios.tcsetattr(fd, termios.TCSANOW, newattr)
-
-        oldflags = fcntl.fcntl(fd, fcntl.F_GETFL)
-        fcntl.fcntl(fd, fcntl.F_SETFL, oldflags | os.O_NONBLOCK)
+        # Using non-blocking read
+        noncanonical_mode(stdin)
 
         try:
-            char = ''
-            r, w, e = select.select([fd], [], [], 0.1)
-            if r:
+            # On OSX, calling read when no data is available causes the
+            # file handle to never return any future data, so we need to
+            # use select to make sure there is at least one char to read.
+            rd,wr,er = select([stdin], [], [], 0.01)
+            if rd != []:
                 char = stdin.read(1)
-                if char == "\n":
-                    char = "\r"
-        finally:
-            termios.tcsetattr(fd, termios.TCSAFLUSH, oldterm)
-            fcntl.fcntl(fd, fcntl.F_SETFL, oldflags)
+        except KeyboardInterrupt:
+            # Pass along a CTRL-C interrupt.
+            raise
+        except:
+            pass
+
+        # Convert linefeeds to carriage returns.
+        if char != '' and ord(char) == 10:
+            char = '\r'
         return char