Fix bugs introduced by rewrite (in particular, time-based initialization
got broken). Also added new method .jumpahead(N). This finally gives us
a semi-decent answer to how Python's RNGs can be used safely and efficiently
in multithreaded programs (although it requires the user to use the new
machinery!).
diff --git a/Misc/NEWS b/Misc/NEWS
index 058d55c..def0dd3 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -8,7 +8,12 @@
- random.py is now self-contained, and offers all the functionality of
the now-deprecated whrandom.py. See the docs for details. random.py
also supports new functions getstate() and setstate(), for saving
- and restoring the internal state of all the generators.
+ and restoring the internal state of the generator; and jumpahead(n),
+ for quickly forcing the internal state to be the same as if n calls to
+ random() had been made. The latter is particularly useful for multi-
+ threaded programs, creating one instance of the random.Random() class for
+ each thread, then using .jumpahead() to force each instance to use a
+ non-overlapping segment of the full period.
What's New in Python 2.1 alpha 1?
@@ -107,12 +112,12 @@
a complicated (but still thread-safe) method using fgets() is used by
default.
- You can force use of the fgets() method by #define'ing
- USE_FGETS_IN_GETLINE at build time (it may be faster than
+ You can force use of the fgets() method by #define'ing
+ USE_FGETS_IN_GETLINE at build time (it may be faster than
getc_unlocked()).
- You can force fgets() not to be used by #define'ing
- DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
+ You can force fgets() not to be used by #define'ing
+ DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
test_bufio.py fails -- and let us know if it does!).
- In addition, the fileinput module, while still slower than the other