Reworked the file locking option as a command instead of as a

compile-time option.  The behavior can now be controlled from
within the program with "locking disable" or "locking enable".

commands/CmdLQ.c

@@ -54,6 +54,9 @@ void CmdPaintEraseButton();
 
 extern Label *DefaultLabel;
 
+/* See the "locking" command */
+extern bool FileLocking;
+
 /*
  * ----------------------------------------------------------------------------
  *
@@ -527,7 +530,7 @@ CmdLoad(w, cmd)
 
 /*
  * Function callback which continues the search through all cells for
- * expansion/unexpansion.
+ * expansion/unexpansion, used by CmdLoad() above.
  */
 
 int
@@ -538,6 +541,70 @@ keepGoing(use, clientdata)
     return 0;	/* keep the search going */
 }
 
+/*
+ * ----------------------------------------------------------------------------
+ *
+ * CmdLocking --
+ *
+ * Implement the "locking" command.
+ *
+ * Usage:
+ *	locking [enable|disable]
+ *
+ * This command controls the behavior of file locking.  If enabled, then
+ * every layout read from a .mag file will generate a file descriptor in
+ * the operating system, and the file will be held open for the duration
+ * of use.  This is a fairly simple way of preventing two different
+ * processes of magic from attempting to write to the same .mag file.
+ * Generally speaking, the file locking should remain on at all times,
+ * and read/write behavior of any specific cell can be controlled with
+ * the "cellname writeable" command option.  However, in some cases,
+ * layouts with many components may exceed the operating system's
+ * allotted number of open file descriptors, in which case the only real
+ * option is to disable file locking altogether using "locking disable".
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Sets global boolean variable FileLocking.
+ *
+ * ----------------------------------------------------------------------------
+ */
+
+void
+CmdLocking(w, cmd)
+    MagWindow *w;
+    TxCommand *cmd;
+{
+    int option;
+
+    static char *cmdLockingYesNo[] = { "disable", "no", "false", "off", "0",
+	    "enable", "yes", "true", "on", "1", 0 };
+
+    if (cmd->tx_argc <= 1)
+    {
+#ifdef MAGIC_WRAPPER
+	/* Interpreter return value is the state of locking */
+	Tcl_SetResult(magicinterp, (FileLocking) ? "enabled" : "disabled",
+		TCL_VOLATILE);
+#else
+	/* Print the status of file locking to the console */
+	TxPrintf("%s\n", (FileLocking) ? "enabled" : "disabled");
+#endif
+    }
+    else
+    {
+	option = Lookup(cmd->tx_argv[1], cmdLockingYesNo);
+	if (option < 0)
+	{
+	    TxError("Unknown locking option \"%s\"\n", cmd->tx_argv[1]);
+	    return;
+	}
+	FileLocking = (option <= 4) ? FALSE : TRUE;
+    }
+}
+
 /*
  * ----------------------------------------------------------------------------
  *

dbwind/DBWcommands.c

@@ -46,7 +46,7 @@ extern void CmdDelete(), CmdDown(), CmdDrc(), CmdDrop(), CmdDump();
 extern void CmdEdit(), CmdElement(), CmdErase(), CmdExpand(), CmdExtract();
 extern void CmdFeedback(), CmdFill(), CmdFindBox(), CmdFindLabel(), CmdFlush();
 extern void CmdGetcell(), CmdGrid(), CmdIdentify();
-extern void CmdLabel(), CmdLoad();
+extern void CmdLabel(), CmdLoad(), CmdLocking();
 extern void CmdMove(), CmdNetlist(), CmdOrient(), CmdPaint(), CmdPath();
 extern void CmdPlow(), CmdPolygon(), CmdPort(), CmdProperty();
 extern void CmdRandom(), CmdSave(), CmdScaleGrid(), CmdSee();
@@ -369,6 +369,9 @@ DBWInitCommands()
     WindAddCommand(DBWclientID,
 	"load [cellname]	load a cell into a window",
 	CmdLoad, FALSE);
+    WindAddCommand(DBWclientID,
+	"locking [enable|disable]	enable or disable file locking",
+	CmdLocking, FALSE);
     WindAddCommand(DBWclientID,
 	"move [dir [amount]]	OR\n"
 	"move to x y		move box and selection, either by amount\n\

scripts/configure

@@ -6598,7 +6598,7 @@ if test $usingTcl ; then
 # Find the version of "wish" that corresponds to TCL_EXEC_PREFIX
 # We really ought to run "ldd" to confirm that the linked libraries match.
 
-  if text "x${magic_with_wish_binary}" = "x" ; then
+  if test "x${magic_with_wish_binary}" = "x" ; then
     { $as_echo "$as_me:${as_lineno-$LINENO}: checking for wish executable" >&5
 $as_echo_n "checking for wish executable... " >&6; }
     for dir in \
@@ -6844,15 +6844,8 @@ else
 fi
 
 
-if test "x$enable_locking" = "xyes" ; then
+if test "x$enable_locking" = "xno" ; then
-  case $target in
+  echo "File locking no longer set during configuration;  ignoring option."
-     *cygwin*)
-	;;
-     *)
-	$as_echo "#define FILE_LOCKS 1" >>confdefs.h
-
-        ;;
-  esac
 fi
 
 # Check whether --enable-calma was given.

scripts/configure.in

@@ -705,7 +705,7 @@ if test $usingTcl ; then
 # Find the version of "wish" that corresponds to TCL_EXEC_PREFIX
 # We really ought to run "ldd" to confirm that the linked libraries match.
 
-  if text "x${magic_with_wish_binary}" = "x" ; then
+  if test "x${magic_with_wish_binary}" = "x" ; then
     AC_MSG_CHECKING([for wish executable])
     for dir in \
     ${TK_EXEC_PREFIX}/bin \
@@ -935,14 +935,8 @@ AC_ARG_ENABLE(locking,
 [],
 [enable_locking=yes])
 
-if test "x$enable_locking" = "xyes" ; then
+if test "x$enable_locking" = "xno" ; then
-  case $target in
+  echo "File locking no longer set during configuration;  ignoring option."
-     *cygwin*)
-	;;
-     *)
-	AC_DEFINE(FILE_LOCKS)
-        ;;
-  esac
 fi
 
 AC_ARG_ENABLE(calma,

utils/flock.c

@@ -11,8 +11,6 @@
  *-------------------------------------------------------------------------
  */
 
-#ifdef FILE_LOCKS
-
 #include <unistd.h>
 #include <fcntl.h>
 
@@ -166,5 +164,3 @@ FILE *flock_open(filename, mode, is_locked)
 done:
     return f;
 }
-
-#endif  /* FILE_LOCKS */

utils/path.c

@@ -46,6 +46,8 @@ static char rcsid[] __attribute__ ((unused)) = "$Header: /usr/cvsroot/magic-8.0/
 static HashTable expansionTable;
 static bool noTable = TRUE;
 
+bool FileLocking = TRUE;
+
 /* Limit on how long a single file name may be: */
 
 #define MAXSIZE MAXPATHLEN
@@ -454,11 +456,10 @@ PaLockOpen(file, mode, ext, path, library, pRealName, is_locked)
 	p2 = file;
 	if (PaExpand(&p2, &p1, MAXSIZE) < 0) return NULL;
 
-#ifndef FILE_LOCKS
+	if (FileLocking)
-	return fopen(realName, mode);
+	    return flock_open(realName, mode, is_locked);
-#else
+	else
-	return flock_open(realName, mode, is_locked);
+	    return fopen(realName, mode);
-#endif
     }
 
     /* If we were already given a full rooted file name,
@@ -473,11 +474,11 @@ PaLockOpen(file, mode, ext, path, library, pRealName, is_locked)
     {
 	(void) strncpy(realName, file, MAXSIZE-1);
 	realName[MAXSIZE-1] = '\0';
-#ifndef FILE_LOCKS
+
-	return fopen(realName, mode);
+	if (FileLocking)
-#else
+	    return flock_open(realName, mode, is_locked);
-	return flock_open(realName, mode, is_locked);
+	else
-#endif
+	    return fopen(realName, mode);
     }
 
     /* Now try going through the path, one entry at a time. */
@@ -485,11 +486,12 @@ PaLockOpen(file, mode, ext, path, library, pRealName, is_locked)
     while (nextName(&path, file, realName, MAXSIZE) != NULL)
     {
 	if (*realName == 0) continue;
-#ifndef FILE_LOCKS
+
-	f = fopen(realName, mode);
+	if (FileLocking)
-#else
+	    f = flock_open(realName, mode, is_locked);
-	f = flock_open(realName, mode, is_locked);
+	else
-#endif
+	    f = fopen(realName, mode);
+
 	if (f != NULL) return f;
 
 	// If any error other than "file not found" occurred,
@@ -504,11 +506,11 @@ PaLockOpen(file, mode, ext, path, library, pRealName, is_locked)
     if (library == NULL) return NULL;
     while (nextName(&library, file, realName, MAXSIZE) != NULL)
     {
-#ifndef FILE_LOCKS
+	if (FileLocking)
-	f = fopen(realName, mode);
+	    f = flock_open(realName, mode, is_locked);
-#else
+	else
-	f = flock_open(realName, mode, is_locked);
+	    f = fopen(realName, mode);
-#endif
+
 	if (f != NULL) return f;
 
 	// If any error other than "file not found" occurred,

utils/utils.h

@@ -54,9 +54,7 @@ extern bool StrIsNumeric(char *);
 
 extern int SetNoisyBool(bool *, char *, FILE *);
 
-#ifdef FILE_LOCKS
 extern FILE *flock_open();
-#endif
 
 /* The following macro takes an integer and returns another integer that
  * is the same as the first except that all the '1' bits are turned off,