[pypy-commit] extradoc extradoc: Some extra slides

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: extradoc
Changeset: r5726:883f2ca7a592
Date: 2016-10-03 09:44 +0200
http://bitbucket.org/pypy/extradoc/changeset/883f2ca7a592/

Log:	Some extra slides

diff --git a/talk/pyconza2016/revdb/talk.rst b/talk/pyconza2016/revdb/talk.rst
--- a/talk/pyconza2016/revdb/talk.rst
+++ b/talk/pyconza2016/revdb/talk.rst
@@ -82,6 +82,8 @@
 * Performance issues: unlike gdb and pdb, they slow down normal
   execution (with some of them, massively)
 
+* (RevDB has the same issues)
+
 
 Why not well-known?
 ===================
@@ -93,6 +95,8 @@
 
 * Often proprietary software with restrictive licenses
 
+* (RevDB hopefully does not have the same issues)
+
 
 Sometimes you need the cannon
 =============================
@@ -108,3 +112,32 @@
 =====
 
 https://bitbucket.org/pypy/revdb/
+
+
+How does it work?  (slide 1/2)
+==============================
+
+* In PyPy, memory is naturally divided into "GC memory" and "raw memory"
+
+* Recording: write in the log the *result* of:
+
+    * each C library call
+
+    * each raw memory read
+
+* (Done by tweaking RPython, the language in which PyPy is itself written)
+
+
+How does it work?  (slide 2/2)
+==============================
+
+* Replaying: read from the log the *result* of the same operations
+
+* Everything else should be deterministic
+
+* Illusion of going backward:
+
+    * fork is the key
+
+    * to go back, throw away the current fork, restart from an
+      earlier fork, go forward again