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| author | Björn Gustavsson <[email protected]> | 2015-12-04 14:34:20 +0100 |
|---|---|---|
| committer | Björn Gustavsson <[email protected]> | 2015-12-07 11:40:24 +0100 |
| commit | 807f0c8904be14c9088ebc41ade885ffac142b34 (patch) | |
| tree | 3a5a7383c05247d3d6d92e9b6012b394a93a88a7 /lib | |
| parent | f86828fead59ba0a28658d3f5e7d8dc80f1c73fb (diff) | |
| download | otp-807f0c8904be14c9088ebc41ade885ffac142b34.tar.gz otp-807f0c8904be14c9088ebc41ade885ffac142b34.tar.bz2 otp-807f0c8904be14c9088ebc41ade885ffac142b34.zip | |
Correct rand:export_seed/0 when there is no prior seed
According to the documentation, rand:export_seed/0 should return
'undefined' if the seed has not been intialized. However, it will
create and return a seed. That means that the following code
will not work as expected:
case rand:export_seed() of
undefined -> rand:seen({1,2,3});
_ -> ok
end,
rand:uniform(Range)
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/stdlib/src/rand.erl | 2 | ||||
| -rw-r--r-- | lib/stdlib/test/rand_SUITE.erl | 3 |
2 files changed, 4 insertions, 1 deletions
diff --git a/lib/stdlib/src/rand.erl b/lib/stdlib/src/rand.erl index 8e8d0bc801..dc060e82d9 100644 --- a/lib/stdlib/src/rand.erl +++ b/lib/stdlib/src/rand.erl @@ -63,7 +63,7 @@ %% Return algorithm and seed so that RNG state can be recreated with seed/1 -spec export_seed() -> undefined | export_state(). export_seed() -> - case seed_get() of + case get(?SEED_DICT) of {#{type:=Alg}, Seed} -> {Alg, Seed}; _ -> undefined end. diff --git a/lib/stdlib/test/rand_SUITE.erl b/lib/stdlib/test/rand_SUITE.erl index 111bf620de..03b5ce1a25 100644 --- a/lib/stdlib/test/rand_SUITE.erl +++ b/lib/stdlib/test/rand_SUITE.erl @@ -126,6 +126,9 @@ seed_1(Alg) -> false = (S1 =:= rand:seed_s(Alg)), %% Negative integers works _ = rand:seed_s(Alg, {-1,-1,-1}), + %% Check that export_seed/1 returns 'undefined' if there is no seed + erase(rand_seed), + undefined = rand:export_seed(), %% Other term do not work {'EXIT', _} = (catch rand:seed_s(foobar, os:timestamp())), |