File 1030-erlang-module-doc-preciser-description-of-... of Package erlang

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File 1030-erlang-module-doc-preciser-description-of-erlang-yie.patch of Package erlang

From a01ec2f8bb07dd566b95bf845a916a111c661d64 Mon Sep 17 00:00:00 2001
From: Kjell Winblad <kjellwinblad@gmail.com>
Date: Thu, 17 Sep 2020 11:40:26 +0200
Subject: [PATCH 20/39] erlang module doc: preciser description of
 erlang:yield()

---
 erts/doc/src/erlang.xml       | 22 ++++++++++++++--------
 erts/preloaded/src/erlang.erl |  2 ++
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml
index 45b37db10d..2e8c9f5247 100644
--- a/erts/doc/src/erlang.xml
+++ b/erts/doc/src/erlang.xml
@@ -12155,16 +12155,22 @@ true</pre>
 <name name="yield" arity="0"/>
 <fsummary>Let other processes get a chance to execute.</fsummary>
 <desc>
- Voluntarily lets other processes (if any) get a chance to
- execute. Using this function is similar to
- <c>receive after 1 -> true end</c>, except that <c>yield()</c>
- is faster.
+ Tries to give other processes with the same or
+ higher priority (if any) a chance to execute before
+ returning. There is no guarantee that any other process runs
+ between the invocation and return of <c>erlang:yield/0</c>.
+
+ See the documentation for <seealso
+ marker="system/reference_manual:expressions#receive"><c>receive-after</c>
+ expressions</seealso> for how to make the current process
+ sleep for a specific number of milliseconds.
 <warning>
- There is seldom or never any need to use this BIF,
- especially in the SMP emulator, as other processes have a
- chance to run in another scheduler thread anyway.
+ There is seldom or never any need to use this BIF.
 Using this BIF without a thorough grasp of how the scheduler
- works can cause performance degradation.
+ works can cause performance degradation. The current implementation
+ of this function puts the current process last in the current
+ scheduler's queue for processes of the same priority as the
+ current process.
 </warning>
 </desc>
 </func>
diff --git a/erts/preloaded/src/erlang.erl b/erts/preloaded/src/erlang.erl
index 700b84bf25..60caad2b1e 100644
--- a/erts/preloaded/src/erlang.erl
+++ b/erts/preloaded/src/erlang.erl
@@ -3335,6 +3335,8 @@ spawn_request_abandon(_ReqId) ->
 
 -spec erlang:yield() -> 'true'.
 yield() ->
+ % This is not an infinite loop because erlang:yield() is
+ % translated to an instruction by the loader
 erlang:yield().
 
 -spec nodes() -> Nodes when
-- 
2.26.2

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File 1030-erlang-module-doc-preciser-description-of-erlang-yie.patch of Package erlang

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