? 64bit_keyt.patch
Index: winsup/cygwin/cygwin.din
===================================================================
RCS file: /cvs/src/src/winsup/cygwin/cygwin.din,v
retrieving revision 1.87
diff -u -r1.87 cygwin.din
--- winsup/cygwin/cygwin.din	9 May 2003 22:11:25 -0000	1.87
+++ winsup/cygwin/cygwin.din	14 May 2003 06:21:37 -0000
@@ -508,6 +508,8 @@
 _ftello64 = ftello64
 ftime
 _ftime = ftime
+ftok
+_ftok = ftok
 ftruncate
 _ftruncate = ftruncate
 _ftruncate64 = ftruncate64
Index: winsup/cygwin/ipc.cc
===================================================================
RCS file: /cvs/src/src/winsup/cygwin/ipc.cc,v
retrieving revision 1.8
diff -u -r1.8 ipc.cc
--- winsup/cygwin/ipc.cc	12 May 2003 11:06:26 -0000	1.8
+++ winsup/cygwin/ipc.cc	14 May 2003 06:21:38 -0000
@@ -17,23 +17,116 @@
 extern "C"
 {
 
+/* 
+ * we don't do 'fat' 64-32 bit here, because ftok has not as
+ * yet been an official part of cygwin -- so there's no need
+ * to allow for 'old' binaries.  However, we provide the old
+ * implementation here as well, ifdef'ed out.
+ */
+#ifdef __CYGWIN_USE_BIG_TYPES__
+
 /* Notes: we return a valid key even if id's low order 8 bits are 0. */
 key_t
 ftok (const char *path, int id)
 {
   struct __stat64 statbuf;
+  key_t tmp;
   if (stat64 (path, &statbuf))
     {
       /* stat set the appropriate errno for us */
       return (key_t) -1;
     }
 
-  /* dev_t is short for cygwin
-   * ino_t is long for cygwin
+  /*
+   * When __CYGWIN_USE_BIG_TYPES__,
+   * dev_t is 32bits for cygwin
+   * ino_t is 64bits for cygwin
    * and we need 8 bits for the id.
-   * thus key_t is long long.
+   * thus key_t needs 104 bits total -- but we only have 64 (long long)
+   * We will have to alias; leaving open the possibility that the same
+   * key will be returned for multiple files.  This possibility exists
+   * also on Linux; the question is, how to minimize this possibility.
+   *
+   * How to solve?  Well, based on C. Vinshen's research, the nFileIndex*
+   * words vary as follows, on a partition with > 110,000 files
+   * nFileIndexHigh:    564 values between 0x00010000 -- 0xffff0000
+   * nFileIndexLow : 103812 values between 0x00000000 -- 0x0003ffff
+   * R. Collins suggests that these may represent a tree path, 
+   * and that it would require ~2.9M files to force the tree depth
+   * to increase and reveal more bit usage.
+   *
+   * Implementation details: dev_t is 32bits, but is formed by
+   *    device(32bits) << 16 | unit(32bits)
+   * But device is ACTUALLY == status & FH_DEVMASK, where FH_DEVMASK
+   * is 0x00000fff --> 12 bits
+   *
+   * As it happens, the maximum number of devices is actually 
+   * FH_NDEV, not FH_DEVMASK, where FH_NDEV is currently 0x0000001d.
+   * However, FH_NDEV grows as new device types are added.  So
+   * currently the device number needs 5 bits, but later?  Let's
+   * take a cue from Linux, and use the lower 8 bits (instead of the
+   * lower 12 or 16) for the device (major?) number.
+   *
+   * Similarly, while 'units' is an int (32bits), it is unclear
+   * how many of these are significant. For most devices, it seems that
+   * 'units' is equivalent to 'minor'.  For FH_TAPE, it's obvious that
+   * only 8 bits are important.  However, for FH_SOCKET...it might be
+   * as high as 16 significant bits.
+   *
+   * Let's assume that we only need 8 bits from device (major) and
+   * only 8 bits from unit (minor). (On linux, only 8 bits of minor
+   * are used, and none from major).
+   * ---> so, we only need 0x00ff00ff (16 bits) of dev_t
+   *
+   * ---> we MUST have all 8 bits of id.
+   *
+   * ---> So, we only have 64 - 8 - 16 = 40 bits for ino_t.  But, we
+   * need 0xffff0000 for nFileIndexHigh and 0x0003ffff for nFileIndexLow
+   * minimum, or 16 + 18 = 34 bits.  Lucky us - we have 6 more bits
+   * to distribute.
+   *
+   * For lack of a better idea, we'll allocate 2 of the extra bits to
+   * nFileIndexHigh and 4 to nFileIndexLow.
+   */
+  // get 8 bits from dev_t (major), put into 0xff00000000000000L
+  tmp  = (((key_t) statbuf.st_dev) & 0x0000000000ff0000L) << 40;
+  // get 8 bits from dev_t (minor), put into 0x00ff000000000000L
+  tmp |= (((key_t) statbuf.st_dev) & 0x00000000000000ffL) << 48;
+  // get upper 16+2 bits from nFileInfoHigh, put into 0x0000ffffc0000000L 
+  // shift down first, then mask, to avoid sign extension on rightshift 
+  tmp |= (((key_t) statbuf.st_ino) >> 16) & 0x0000ffffc0000000L;
+  // get lower 18+4 bits from nFileInfoLow, put into  0x000000003fffff00L 
+  tmp |= (((key_t) statbuf.st_ino) & 0x00000000003fffffL) << 8;
+  // use all 8 bits of id, and put into 0x00000000000000ffL
+  tmp |= (id & 0x00ff);
+  return tmp;
+}
+
+#else /* __CYGWIN_USE_BIG_TYPES__ */
+
+key_t
+ftok (const char *path, int id)
+{
+  struct __stat32 statbuf;
+  if (stat (path, &statbuf))
+    {
+      /* stat set the appropriate errno for us */
+      return (key_t) -1;
+    }
+
+  /*
+   * When !__CYGWIN_USE_BIG_TYPES__,
+   * dev_t is short for cygwin
+   * ino_t is long for cygwin
+   * and we need 8 bits for the id.  (16 + 32 + 8 == 56)
+   * This must all fit into 32 bits.  For backwards compatibility
+   * with old cygipc, we use its hash.
    */
-  return ((long long) statbuf.st_dev << (5*8)) | (statbuf.st_ino << (8) ) | (id & 0x00ff);
+   return ((statbuf.st_ino & 0x0000ffff) |
+          ((st.st_dev & 0x000000ff) << 16) |
+          ((id & 0x000000ff) << 24));
 }
+
+#endif /* __CYGWIN_USE_BIG_TYPES__ */
 
 }
Index: winsup/cygwin/include/cygwin/types.h
===================================================================
RCS file: /cvs/src/src/winsup/cygwin/include/cygwin/types.h,v
retrieving revision 1.20
diff -u -r1.20 types.h
--- winsup/cygwin/include/cygwin/types.h	11 May 2003 12:50:18 -0000	1.20
+++ winsup/cygwin/include/cygwin/types.h	14 May 2003 06:21:38 -0000
@@ -101,7 +101,13 @@
 
 #ifndef __key_t_defined
 #define __key_t_defined
-typedef long key_t;
+typedef long __key32_t;
+typedef long long __key64_t;
+#ifdef __CYGWIN_USE_BIG_TYPES__
+typedef __key64_t key_t;
+#else
+typedef __key32_t key_t;
+#endif
 #endif /* __key_t_defined */
 
 #ifndef __BIT_TYPES_DEFINED
Index: winsup/cygwin/include/cygwin/version.h
===================================================================
RCS file: /cvs/src/src/winsup/cygwin/include/cygwin/version.h,v
retrieving revision 1.117
diff -u -r1.117 version.h
--- winsup/cygwin/include/cygwin/version.h	9 May 2003 22:11:25 -0000	1.117
+++ winsup/cygwin/include/cygwin/version.h	14 May 2003 06:21:40 -0000
@@ -205,12 +205,13 @@
            underscore.  No problems with backward compatibility since no
            official release has been made so far.  This change removes
            exported symbols like fopen64, which might confuse configure.
+       86: Export ftok
      */
 
      /* Note that we forgot to bump the api for ualarm, strtoll, strtoull */
 
 #define CYGWIN_VERSION_API_MAJOR 0
-#define CYGWIN_VERSION_API_MINOR 85
+#define CYGWIN_VERSION_API_MINOR 86
 
      /* There is also a compatibity version number associated with the
 	shared memory regions.  It is incremented when incompatible