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Library: fix spurious wake-up from (non)timed wait

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A classical carry-over of dirty values...
Problem arises, when starting an unconditional wait on the same object monitor,
which previously conducted a timed wait. Then the obsolete timeout from the previous
wait remained in place, causing our Sync-Wrapper (erroneously) to assume a timed wait
and then pthread to return immediately from this timed wait.

The result was permanent idle looping in the ProcDispatcher, after the first command was processed
This commit is contained in:
Fischlurch 2018-11-17 17:00:39 +01:00
parent bc1cf3a0b5
commit a49d79ffbd
2 changed files with 23 additions and 5 deletions
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6
src/lib/sync.hpp
View file

@ -238,7 +238,9 @@ namespace lib {
struct Timeout
: timespec
{
Timeout() { tv_sec=tv_nsec=0; }
Timeout() { reset(); }
void reset() { tv_sec=tv_nsec=0; }
/** initialise to NOW() + offset (in milliseconds) */
Timeout&
@ -254,6 +256,8 @@ namespace lib {
tv_sec += tv_nsec / 1000000000;
tv_nsec %= 1000000000;
} }
else
reset();
return *this;
}

22
wiki/thinkPad.ichthyo.mm
View file

@ -44602,18 +44602,32 @@
<icon BUILTIN="flag-yellow"/>
</node>
</node>
<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1544310988414" ID="ID_134908056" MODIFIED="1544311003084" TEXT="ProcDispatcher macht idle-Loop">
<node COLOR="#435e98" CREATED="1544310988414" FOLDED="true" ID="ID_134908056" MODIFIED="1544320824720" TEXT="ProcDispatcher macht idle-Loop">
<icon BUILTIN="messagebox_warning"/>
<node CREATED="1544311004661" ID="ID_1064987345" MODIFIED="1544311012720" TEXT="Symptom: CPU-Last im Ruhezustand"/>
<node CREATED="1544311014140" ID="ID_392351205" MODIFIED="1544311027390" TEXT="Grund: f&#xe4;llt sofort wieder aus timed wait"/>
<node BACKGROUND_COLOR="#fdfdcf" COLOR="#ff0000" CREATED="1544311029042" ID="ID_15647077" MODIFIED="1544311046170" TEXT="Ursache: Sync.hpp -- Timeout-Struct nicht korrekt initialisiert">
<icon BUILTIN="flag-pink"/>
<node CREATED="1544311014140" ID="ID_392351205" MODIFIED="1544320819468" TEXT="Grund: f&#xe4;llt sofort wieder aus timed wait">
<icon BUILTIN="idea"/>
</node>
<node COLOR="#338800" CREATED="1544311029042" ID="ID_15647077" MODIFIED="1544320803272" TEXT="Ursache: Sync.hpp -- Timeout-Struct nicht korrekt initialisiert">
<icon BUILTIN="button_ok"/>
<node CREATED="1544311051503" ID="ID_1872128038" MODIFIED="1544311082817" TEXT="bool-Operator vergleicht auf 0">
<icon BUILTIN="info"/>
</node>
<node CREATED="1544311064725" ID="ID_1179966941" MODIFIED="1544311079804" TEXT="finde aber im Debugger irgendwelche Werte.">
<icon BUILTIN="idea"/>
</node>
<node CREATED="1544320706921" ID="ID_50250235" MODIFIED="1544320717897" TEXT="genauer: Werte werden nicht aufger&#xe4;umt">
<node CREATED="1544320719053" ID="ID_1185228058" MODIFIED="1544320755043" TEXT="Konvention ist: sekunden == 0 ==&gt; kein Timeout">
<icon BUILTIN="info"/>
</node>
<node CREATED="1544320761671" ID="ID_1421942136" MODIFIED="1544320772577" TEXT="pthread findet timeout in der Vergangenheit"/>
<node CREATED="1544320773286" ID="ID_256879540" MODIFIED="1544320782737" TEXT="...und kehr damit sofort zur&#xfc;ck aus dem wait">
<icon BUILTIN="ksmiletris"/>
</node>
</node>
<node COLOR="#338800" CREATED="1544320791339" ID="ID_536822312" MODIFIED="1544320800480" TEXT="Fix: else-Zweig, reset()">
<icon BUILTIN="button_ok"/>
</node>
</node>
</node>
</node>