Build by default with optimization level -O2 for GCC

before -O0 was used by default, that caused pretty bad performance.

Amd64, i6700k, 4200MHz, GNU/Linux (non-RT kernel), gcc 7.2.0

-------------------------------------
Optimization | EN/ENO |no EN/ENO |
-------------------------------------
default | 11 | 9.5 |
-O3 | 3.9 | 5.2 |
-O2 | 4 | 4.8 |
-Os | 4.1 | 3.5 |
-Ofast | 3.9 | 5.2 |
-------------------------------------

ARM, BBB Cortex-A8, 600Mhz, GNU/Linux, gcc 4.6.3

-------------------------------------
Optimization | EN/ENO |no EN/ENO |
-------------------------------------
default | 273 | 226 |
-O3 | 141.8 | 106.2 |
-O2 | 142 | 107 |
-Os | 152.5 | 112.2 |
-Ofast | 141.7 | 106.2 |
-------------------------------------

For embedded systems with size constaints (like Cortex-Mx, AVR and so
on) I usually use -Os. It gets pretty good results. For
GNU/Linux-based systems -O2 is usually a good choice, as you see the
test results.

     1

<?xml version='1.0' encoding='utf-8'?>

     2

<PyFile xmlns:xhtml="http://www.w3.org/1999/xhtml" xmlns:xsd="http://www.w3.org/2001/XMLSchema">

     3

  <variables/>

     4

  <globals>

     5

    <xhtml:p><![CDATA[import threading, time

     6

     7

MyT = None

     8

Stop = False

     9

    10

def StartLog():

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    global MyT

    12

    MyT=threading.Thread(target = DoLog)

    13

    MyT.start()

    14

    15

def DoLog():

    16

    global Stop

    17

    while not Stop:

    18

        PLCObject.LogMessage("Python side Logging (PLC is %s)"%PLCObject.PLCStatus)

    19

        time.sleep(0.3)

    20

    21

def StopLog():

    22

    global MyT,Stop

    23

    Stop=True

    24

    25

_runtime_init.append(StartLog)

    26

_runtime_cleanup.append(StopLog)

    27

]]></xhtml:p>

    28

  </globals>

    29

  <init>

    30

    <xhtml:p><![CDATA[]]></xhtml:p>

    31

  </init>

    32

  <cleanup>

    33

    <xhtml:p><![CDATA[]]></xhtml:p>

    34

  </cleanup>

    35

  <start>

    36

    <xhtml:p><![CDATA[]]></xhtml:p>

    37

  </start>

    38

  <stop>

    39

    <xhtml:p><![CDATA[]]></xhtml:p>

    40

  </stop>

    41

</PyFile>