From 379064981ecccc8c099623cdb93894d02a6bcdc1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Tue, 23 Aug 2011 05:41:28 +0200
Subject: Allow refc binaries in literal pools

To simplify the implementation of literal pools (constant pools)
for the R12 release, a shortcut was taken regarding binaries --
all binaries would be stored as heap binaries regardless of size.

To allow a module containing literals to be unloaded, literal
terms are copied when sent to another process. That means that
huge literal binaries will also be copied if they are sent to
another process, which could be surprising.

Another problem is that the arity field in the header for the heap
object may not be wide enough to handle big binaries.

Therefore, bite the bullet and allow refc binaries to be stored
in literal pools. In short, the following need to be changed:

* Each loaded module needs a MSO list, linking all refc binaries
  in the literal pool.

* When check_process_code/2 copies literals to a process heap,
  it must link each referenced binary into the MSO list for the
  process and increment the reference counter for the binary.

* purge_module/1 must decrement the reference counter for each
  refc binary in the literal pool.
---
 erts/emulator/test/code_SUITE_data/literals.erl | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

(limited to 'erts/emulator/test/code_SUITE_data/literals.erl')

diff --git a/erts/emulator/test/code_SUITE_data/literals.erl b/erts/emulator/test/code_SUITE_data/literals.erl
index 9f99b1a780..d9cb8938db 100644
--- a/erts/emulator/test/code_SUITE_data/literals.erl
+++ b/erts/emulator/test/code_SUITE_data/literals.erl
@@ -18,7 +18,7 @@
 %%
 
 -module(literals).
--export([a/0,b/0,huge_bignum/0]).
+-export([a/0,b/0,huge_bignum/0,binary/0,unused_binaries/0,bits/0]).
 
 a() ->
     {a,42.0,[7,38877938333399637266518333334747]}.
@@ -81,3 +81,22 @@ b() ->
 
 huge_bignum() ->
     36#9987333333392789234879423987243987423432879423879234897423879423874328794323248423872348742323487423987423879243872347824374238792437842374283926276478623462342363243SDKJFSDLEFHDSHJFE48H3838973879JFSDKJLFASLKJVBJKLEJKLDYEIOEHFEOU39873487SFHJSLDFASUIDFHSDHFEYR0R987YDFHDHFDLKHFSIDFHSIDFSIFDHSIFHWIHR07373767667987769707660766789076874238792437842374283926276478623462342363243SDKJFSDLEFHDSHJFE48H3838973879JFSDKJLFASLKJVBJKLEJKLDYEIOEHFEOU39873487SFHJSLDFASUIDFHSDHFEYR0R987YDFHDHFDLKHFSIDFHSIDFSIFDHSIFHWIHR0737376766798779987333333392789234879423987243987423432879423879234897423879423874328794323248423872348742323487423987423879243872347824374238792437842374283926276478623462342363243SDKJFSDLEFHDSHJFE48H3838973879JFSDKJLFASLKJVBJKLEJKLDYEIOEHFEOU39873487SFHJSLDFASUIDFHSDHFEYR0R987YDFHDHFDLKHFSIDFHSIDFSIFDHSIFHWIHR07373767667987769707660766789076874238792437842374283926276478623462342363243SDKJFSDLEFHDSHJFE48H3838973879JFSDKJLFASLKJVBJKLEJKLDYEIOEHFEOU39873487SFHJSLDFASUIDFHSDHFEYR0R987YDFHDHFDLKHFSIDFHSIDFSIFDHSIFHWIHR07373767667987779JFSDKJLFASLKJVBJKLEJKLDYEIOEHFEOU39873487SFHJSLDFASUIDFHSDHFEYR0R987YDFHDHFDLKHFSIDFHSIDFSIFDHSIFHWIHR07373767667987769707660766789076874238792437842374283926276478623462342363243SDKJFSDLEFHDSHJFE48H3838973879JFSDKJLFASLKJVBJKLEJKLDYEIOEHFEOU39873487SFHJSLDFASUIDFHSDHFEYR0R987YDFHDHFDLKHFSIDFHSIDFSIFDHSIFHWIHR0737376766798779987333333392789234879423987243987423432879423879234897423879423874328794323248423872348742323487423987423879243872347824374238792437842374283926276478623462342363243SDKJFSDLEFHDSHJFE48H3838973879JFSDKJLFASLKJVBJKLEJKLDYEIOEHFEOU39873487SFHJSLDFASUIDFHSDHFEYR0R987YDFHDHFDLKHFSIDFHSIDFSIFDHSIFHWIHR07373767667987769707660766789076874238792437842374283926276478623462342363243SDKJFSDLEFHDSHJFE48H3838973879JFSDKJLFASLKJVBJKLEJKLDYEIOEHFEOU39873487SFHJSLDFASUIDFHSDHFEYR0R987YDFHDHFDLKHFSIDFHSIDFSIFDHSIFHWIHR073737676679877.
+
+-define(TIMES_FOUR(X), X,X,X,X).
+-define(BYTES_256, 0:256,1:256,2:256,3:256, 4:256,5:256,6:256,7:256).
+-define(KB_1, ?TIMES_FOUR(?BYTES_256)).
+-define(KB_4, ?TIMES_FOUR(?KB_1)).
+-define(KB_16, ?TIMES_FOUR(?KB_4)).
+-define(KB_64, ?TIMES_FOUR(?KB_16)).
+-define(KB_128, ?TIMES_FOUR(?KB_64)).
+-define(MB_1, ?TIMES_FOUR(?KB_128)).
+
+binary() ->
+    %% Too big to be a heap binary.
+    <<?MB_1>>.
+
+unused_binaries() ->
+    {<<?KB_128>>,<<?BYTES_256>>}.
+
+bits() ->
+    {bits,<<42:13,?MB_1>>}.
-- 
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