diff options
Diffstat (limited to 'lib/stdlib/doc/src/random.xml')
| -rw-r--r-- | lib/stdlib/doc/src/random.xml | 43 |
1 files changed, 26 insertions, 17 deletions
diff --git a/lib/stdlib/doc/src/random.xml b/lib/stdlib/doc/src/random.xml index e001058e19..fc4f796863 100644 --- a/lib/stdlib/doc/src/random.xml +++ b/lib/stdlib/doc/src/random.xml @@ -8,16 +8,17 @@ <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> - The contents of this file are subject to the Erlang Public License, - Version 1.1, (the "License"); you may not use this file except in - compliance with the License. You should have received a copy of the - Erlang Public License along with this software. If not, it can be - retrieved online at http://www.erlang.org/. - - Software distributed under the License is distributed on an "AS IS" - basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See - the License for the specific language governing rights and limitations - under the License. + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. </legalnotice> @@ -47,7 +48,10 @@ tuple of three integers.</p> <p>It should be noted that this random number generator is not cryptographically strong. If a strong cryptographic random number generator is needed for - example <c>crypto:rand_bytes/1</c> could be used instead.</p> + example <c>crypto:strong_rand_bytes/1</c> could be used instead.</p> + <note><p>The new and improved <seealso + marker="stdlib:rand">rand</seealso> module should be used + instead of this module.</p></note> </description> <datatypes> <datatype> @@ -70,12 +74,17 @@ <desc> <p>Seeds random number generation with integer values in the process dictionary, and returns the old state.</p> - <p>One way of obtaining a seed is to use the BIF <c>now/0</c>:</p> + <p>One easy way of obtaining a unique value to seed with is to:</p> <code type="none"> - ... - {A1,A2,A3} = now(), - random:seed(A1, A2, A3), - ...</code> +random:seed(erlang:phash2([node()]), + erlang:monotonic_time(), + erlang:unique_integer())</code> + <p>See <seealso marker="erts:erlang#phash2/1"> + erlang:phash2/1</seealso>, <seealso marker="erts:erlang#node/0"> + node/0</seealso>, <seealso marker="erts:erlang#monotonic_time/0"> + erlang:monotonic_time/0</seealso>, and + <seealso marker="erts:erlang#unique_integer/0"> + erlang:unique_integer/0</seealso>) for details.</p> </desc> </func> <func> @@ -139,7 +148,7 @@ <p>The implementation changed in R15. Upgrading to R15 will break applications that expect a specific output for a given seed. The output is still deterministic number series, but different compared to releases - older than R15. The seed <c>{0,0,0}</c> will for example no longer + older than R15. The seed <c>{0,0,0}</c> will, for example, no longer produce a flawed series of only zeros.</p> </section> </erlref> |