Mutex: Difference between revisions
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→{{header|Phix}}: added file locking, syntax colouring, marked p2js incompatible
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=={{header|Phix}}==
=== local mutexes ===
Exclusive-only and non-reentrant.
<!--<lang Phix>(notonline)-->
<span style="color: #008080;">without</span> <span style="color: #008080;">js</span> <span style="color: #000080;font-style:italic;">-- (critical sections)</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">cs</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">init_cs</span><span style="color: #0000FF;">()</span> <span style="color: #000080;font-style:italic;">-- Create a new critical section</span>
<span style="color: #0000FF;">...</span>
<span style="color: #7060A8;">enter_cs</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cs</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- Begin mutually exclusive execution</span>
<span style="color: #004080;">bool</span> <span style="color: #000000;">b</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">try_cs</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cs</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- As enter_cs, but yields false (0) if the lock cannot be obtained instantly</span>
<span style="color: #7060A8;">leave_cs</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cs</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- End mutually exclusive execution</span>
<span style="color: #0000FF;">...</span>
<span style="color: #000000;">delete_cs</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cs</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- Delete a critical section that you have no further use for</span>
<!--</lang>-->
=== global mutexes ===
Using file locking. Only shared locks are reentrant. Every call needs it's own bespoke retry logic.
<!--<lang Phix>(notonline)-->
<span style="color: #008080;">without</span> <span style="color: #008080;">js</span> <span style="color: #000080;font-style:italic;">-- (file i/o)</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">fn</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">open</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"log.txt"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"u"</span><span style="color: #0000FF;">),</span>
<span style="color: #0000FF;">...</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">count</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span>
<span style="color: #008080;">while</span> <span style="color: #008080;">not</span> <span style="color: #000000;">lock_file</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">,</span><span style="color: #000000;">LOCK_SHARED</span><span style="color: #0000FF;">,{})</span> <span style="color: #008080;">do</span>
<span style="color: #000080;font-style:italic;">--while not lock_file(fn,LOCK_EXCLUSIVE,{}) do</span>
<span style="color: #7060A8;">sleep</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">count</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">1</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">count</span><span style="color: #0000FF;">></span><span style="color: #000000;">5</span> <span style="color: #008080;">then</span>
<span style="color: #000080;font-style:italic;">-- message/abort/retry/...</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
<span style="color: #0000FF;">...</span>
<span style="color: #000000;">unlock_file</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">,{})</span>
<span style="color: #0000FF;">...</span>
<span style="color: #7060A8;">close</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">)</span>
<!--</lang>-->
=={{header|PicoLisp}}==
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