Merge remote-tracking branch 'origin/stable-2.0'

Conflicts:
	libguile/debug.h
	module/ice-9/psyntax-pp.scm
	module/ice-9/psyntax.scm
	module/language/tree-il/peval.scm
	module/language/tree-il/primitives.scm

1 files changed, 11 insertions, 39 deletions

diff --git a/libguile/symbols.c b/libguile/symbols.c
index 9dd204478..9cb300ab0 100644
--- a/libguile/symbols.c
+++ b/libguile/symbols.c
@@ -33,7 +33,6 @@
 #include "libguile/variable.h"
 #include "libguile/alist.h"
 #include "libguile/fluids.h"
-#include "libguile/threads.h"
 #include "libguile/strings.h"
 #include "libguile/vectors.h"
 #include "libguile/weak-set.h"
@@ -379,9 +378,7 @@ SCM_DEFINE (scm_string_ci_to_symbol, "string-ci->symbol", 1, 0, 0,
 /* The default prefix for `gensym'd symbols.  */
 static SCM default_gensym_prefix;
 
-#define GENSYM_LENGTH      22  /* bytes */
-#define GENSYM_RADIX_BITS  6
-#define GENSYM_RADIX       (1 << (GENSYM_RADIX_BITS))
+#define MAX_PREFIX_LENGTH 30
 
 SCM_DEFINE (scm_gensym, "gensym", 0, 1, 0,
             (SCM prefix),
@@ -392,47 +389,22 @@ SCM_DEFINE (scm_gensym, "gensym", 0, 1, 0,
 	    "resetting the counter.")
 #define FUNC_NAME s_scm_gensym
 {
-  static const char base64[GENSYM_RADIX] =
-    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789$@";
-  static const char base4[4] = "_.-~";
-
-  unsigned char *digit_buf = SCM_I_CURRENT_THREAD->gensym_counter;
-  char char_buf[GENSYM_LENGTH];
+  static int gensym_counter = 0;
+  
   SCM suffix, name;
-  int i;
+  int n, n_digits;
+  char buf[SCM_INTBUFLEN];
 
   if (SCM_UNBNDP (prefix))
     prefix = default_gensym_prefix;
 
-  if (SCM_UNLIKELY (digit_buf == NULL))
-    {
-      /* This is the first time gensym has been called in this thread.
-         Allocate and randomize our new thread-local gensym counter */
-      digit_buf = (unsigned char *)
-        scm_gc_malloc_pointerless (GENSYM_LENGTH, "gensym-counter");
-      scm_i_random_bytes_from_platform (digit_buf, GENSYM_LENGTH);
-      for (i = (GENSYM_LENGTH - 1); i >= 0; --i)
-        digit_buf[i] &= (GENSYM_RADIX - 1);
-      SCM_I_CURRENT_THREAD->gensym_counter = digit_buf;
-    }
-
-  /* Increment our thread-local gensym_counter. */
-  for (i = (GENSYM_LENGTH - 1); i >= 0; --i)
-    {
-      if (SCM_LIKELY (++(digit_buf[i]) < GENSYM_RADIX))
-        break;
-      else
-        digit_buf[i] = 0;
-    }
-
-  /* Encode digit_buf as base64, except for the first character where we
-     use the sparse glyphs "_.-~" (base 4) to provide some visual
-     separation between the prefix and the dense base64 block. */
-  for (i = (GENSYM_LENGTH - 1); i > 0; --i)
-    char_buf[i] = base64[digit_buf[i]];
-  char_buf[0] = base4[digit_buf[0] & 3];
+  /* mutex in case another thread looks and incs at the exact same moment */
+  scm_i_scm_pthread_mutex_lock (&scm_i_misc_mutex);
+  n = gensym_counter++;
+  scm_i_pthread_mutex_unlock (&scm_i_misc_mutex);
 
-  suffix = scm_from_latin1_stringn (char_buf, GENSYM_LENGTH);
+  n_digits = scm_iint2str (n, 10, buf);
+  suffix = scm_from_latin1_stringn (buf, n_digits);
   name = scm_string_append (scm_list_2 (prefix, suffix));
   return scm_string_to_symbol (name);
 }