diff options
Diffstat (limited to 'system/doc')
| -rw-r--r-- | system/doc/design_principles/statem.xml | 10 | ||||
| -rw-r--r-- | system/doc/getting_started/conc_prog.xml | 4 | ||||
| -rw-r--r-- | system/doc/programming_examples/bit_syntax.xml | 21 | ||||
| -rw-r--r-- | system/doc/reference_manual/distributed.xml | 13 |
4 files changed, 30 insertions, 18 deletions
diff --git a/system/doc/design_principles/statem.xml b/system/doc/design_principles/statem.xml index 0667af7868..7febe31df3 100644 --- a/system/doc/design_principles/statem.xml +++ b/system/doc/design_principles/statem.xml @@ -1582,10 +1582,12 @@ format_status(Opt, [_PDict,State,Data]) -> for example, a complex state term like a tuple. </p> <p> - One reason to use this is when you have - a state item that affects the event handling, - in particular in combination with postponing events. - We complicate the previous example + One reason to use this is when you have a state item + that when changed should cancel the + <seealso marker="#State Time-Outs">state time-out</seealso>, + or one that affects the event handling + in combination with postponing events. + We will complicate the previous example by introducing a configurable lock button (this is the state item in question), which in the <c>open</c> state immediately locks the door, diff --git a/system/doc/getting_started/conc_prog.xml b/system/doc/getting_started/conc_prog.xml index f3136898ad..4b19095d95 100644 --- a/system/doc/getting_started/conc_prog.xml +++ b/system/doc/getting_started/conc_prog.xml @@ -355,8 +355,8 @@ pong ! {ping, self()},</code> <p>Let us rewrite the ping pong program with "ping" and "pong" on different computers. First a few things are needed to set up to get this to work. The distributed Erlang - implementation provides a basic security mechanism to prevent - unauthorized access to an Erlang system on another computer. + implementation provides a very basic authentication mechanism to prevent + unintentional access to an Erlang system on another computer. Erlang systems which talk to each other must have the same <em>magic cookie</em>. The easiest way to achieve this is by having a file called <c>.erlang.cookie</c> in your home diff --git a/system/doc/programming_examples/bit_syntax.xml b/system/doc/programming_examples/bit_syntax.xml index 0af295b7b7..98ad2808cf 100644 --- a/system/doc/programming_examples/bit_syntax.xml +++ b/system/doc/programming_examples/bit_syntax.xml @@ -32,6 +32,8 @@ <section> <title>Introduction</title> + <p>The complete specification for the bit syntax appears in the + <seealso marker="doc/reference_manual:expressions#bit_syntax">Reference Manual</seealso>.</p> <p>In Erlang, a Bin is used for constructing binaries and matching binary patterns. A Bin is written with the following syntax:</p> <code type="none"><![CDATA[ @@ -45,7 +47,7 @@ Bin = <<E1, E2, ... En>>]]></code> <<E1, E2, ... En>> = Bin ]]></code> <p>Here, <c>Bin</c> is bound and the elements are bound or unbound, as in any match.</p> - <p>Since Erlang R12B, a Bin does not need to consist of a whole number of bytes.</p> + <p>A Bin does not need to consist of a whole number of bytes.</p> <p>A <em>bitstring</em> is a sequence of zero or more bits, where the number of bits does not need to be divisible by 8. If the number @@ -165,8 +167,9 @@ end.]]></code> separated by hyphens.</p> <taglist> <tag>Type</tag> - <item>The type can be <c>integer</c>, <c>float</c>, or - <c>binary</c>.</item> + <item>The most commonly used types are <c>integer</c>, <c>float</c>, and <c>binary</c>. + See <seealso marker="doc/reference_manual:expressions#bit_syntax">Bit Syntax Expressions in the Reference Manual</seealso> for a complete description. +</item> <tag>Signedness</tag> <item>The signedness specification can be either <c>signed</c> or <c>unsigned</c>. Notice that signedness only matters for @@ -181,7 +184,7 @@ end.]]></code> <item>The unit size is given as <c>unit:IntegerLiteral</c>. The allowed range is 1-256. It is multiplied by the <c>Size</c> specifier to give the effective size of - the segment. Since Erlang R12B, the unit size specifies the alignment + the segment. The unit size specifies the alignment for binary segments without size.</item> </taglist> <p><em>Example:</em></p> @@ -319,21 +322,15 @@ foo(<<A:8,Rest/bitstring>>) ->]]></code> <section> <title>Appending to a Binary</title> - <p>Since Erlang R12B, the following function for creating a binary out of - a list of triples of integers is efficient:</p> + <p>Appending to a binary in an efficient way can be done as follows:</p> <code type="none"><![CDATA[ triples_to_bin(T) -> triples_to_bin(T, <<>>). triples_to_bin([{X,Y,Z} | T], Acc) -> - triples_to_bin(T, <<Acc/binary,X:32,Y:32,Z:32>>); % inefficient before R12B + triples_to_bin(T, <<Acc/binary,X:32,Y:32,Z:32>>); triples_to_bin([], Acc) -> Acc.]]></code> - <p>In previous releases, this function was highly inefficient, because - the binary constructed so far (<c>Acc</c>) was copied in each recursion step. - That is no longer the case. For more information, see - <seealso marker="doc/efficiency_guide:introduction"> - Efficiency Guide</seealso>.</p> </section> </chapter> diff --git a/system/doc/reference_manual/distributed.xml b/system/doc/reference_manual/distributed.xml index 0a4a323fe9..01d78436c5 100644 --- a/system/doc/reference_manual/distributed.xml +++ b/system/doc/reference_manual/distributed.xml @@ -42,6 +42,19 @@ <p>The distribution mechanism is implemented using TCP/IP sockets. How to implement an alternative carrier is described in the <seealso marker="erts:alt_dist">ERTS User's Guide</seealso>.</p> + <warning> + <p> + Starting a distributed node without also specifying + <seealso marker="erts:erl#proto_dist"><c>-proto_dist inet_tls</c></seealso> + will expose the node to attacks that may give the attacker + complete access to the node and in extension the cluster. + When using un-secure distributed nodes, make sure that the + network is configured to keep potential attackers out. + See the <seealso marker="ssl:ssl_distribution"> + Using SSL for Erlang Distribution</seealso> User's Guide + for details on how to setup a secure distributed node. + </p> + </warning> </section> <section> |