Author Archives: dmitriano

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05
05
20
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QT app is deactivated incorrectly on Android 10 in Gesture mode

Posted by | Android, QT |

If I enable Gesture mode on an Android 10 emulator by tapping System->Gestures->System Navigation->Gesture Navigation and then deactivate my app by swiping and reactivate it back, I get the following in the log:

adb logcat | grep "\ Lines"

05-04 21:52:36.389 11794 11939 D Lines   : Squircle::aboutToQuit()
05-04 21:52:36.389 11794 11939 D Lines   : InterstitialAdWrapper clear() called.
05-04 21:52:36.392 11794 11939 D Lines   : InterstitialAdWrapper InterstitialAd destructor called.
05-04 21:52:36.393 11794 11939 D Lines   : Squircle destructor called.
05-04 21:52:36.396 11794 11939 W Lines   : exit app 0
...
05-04 21:52:37.032 11794 11939 D Lines   : OslSoundPool destructor
05-04 21:52:37.117  2040  2134 W InputDispatcher: channel '8474831 net.geographx.LinesGame/net.geographx.MainActivity (server)' ~ Consumer closed input channel or an error occurred.  events=0x9
05-04 21:52:37.117  2040  2134 E InputDispatcher: channel '8474831 net.geographx.LinesGame/net.geographx.MainActivity (server)' ~ Channel is unrecoverably broken and will be disposed!
05-04 21:52:37.123  2040  3120 I WindowManager: WIN DEATH: Window{8474831 u0 net.geographx.LinesGame/net.geographx.MainActivity}
05-04 21:52:37.123  2040  3120 W InputDispatcher: Attempted to unregister already unregistered input channel '8474831 net.geographx.LinesGame/net.geographx.MainActivity (server)'
05-04 21:52:37.136  2040  3120 W ActivityManager: Scheduling restart of crashed service net.geographx.LinesGame/org.chromium.content.app.SandboxedProcessService0 in 1000ms
05-04 21:52:37.151  2040  2057 I ActivityManager: Process net.geographx.LinesGame (pid 11794) has died: cch CRE
05-04 21:52:38.034  2040  2057 I ActivityTaskManager: START u0 {act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10200000 cmp=net.geographx.LinesGame/net.geographx.MainActivity bnds=[37,882][238,1191]} from uid 10090
05-04 21:52:38.055  2040  2057 I chatty  : uid=1000(system) Binder:2040_2 identical 8 lines
05-04 21:52:38.099  2040  2072 I ActivityManager: Start proc 12702:net.geographx.LinesGame/u0a134 for activity {net.geographx.LinesGame/net.geographx.MainActivity}
05-04 21:52:38.101 12702 12702 W raphx.LinesGam: Unexpected CPU variant for X86 using defaults: x86
05-04 21:52:38.124 12702 12702 E raphx.LinesGam: Not starting debugger since process cannot load the jdwp agent.
...
05-04 21:52:38.966  2040  2069 I ActivityTaskManager: Displayed net.geographx.LinesGame/net.geographx.MainActivity: +931ms
05-04 21:52:39.062 12702 12826 D libLinesGameQt_x86.so: Translation file has been loaded successfully:  "LinesGame_en"
05-04 21:52:39.062 12702 12826 D Lines   : App version:  "2.5.11, #133"
05-04 21:52:39.072 12702 12826 D Lines   : QT/SysInfo: Device Pixel Ratio: 3  Screen DPI:  147.131
05-04 21:52:39.106 12702 12826 D Lines   : InterstitialAdWrapper  valid
05-04 21:52:39.185 12702 12826 D Lines   : qml: Registering adfree
05-04 21:52:39.189  7632  9145 W Finsky  : [672] gcs.d(23): net.geographx.LinesGame: No account found.
05-04 21:52:39.411 12702 12826 D Lines   : qml: adfree Component.onCompleted
05-04 21:52:39.413 12702 12826 D Lines   : InterstitialAdWrapper: calling Java method ' initializeInterstitialAd ' from C++
05-04 21:52:39.413 12702 12826 D Lines   : Starting the application event loop...
05-04 21:52:39.463 12702 12826 D Lines   : onApplicationStateChanged(Qt::ApplicationActive)
(more…)
25
04
20
 4 Comments

Why my QT app crashes at the destructor of std::thread on Android 10 devices?

Posted by | Android, C++ |

I did some research on why my QT app crashes at the destructor of std::thread on Android 10 devices at the user side with the following call stack:

#00 /apex/com.android.runtime/lib64/bionic/libc.so (abort+160)
#01 /system/lib64/libc++.so (abort_message+232)
#02 /system/lib64/libc++.so (demangling_terminate_handler()+44)
#03 /system/lib64/libc++.so (std::__terminate(void (*)())+12)
#04 /system/lib64/libc++.so (std::terminate()+52)
#05 /system/lib64/libc++.so (std::__1::thread::~thread()+20)
#06 /apex/com.android.runtime/lib64/bionic/libc.so (__cxa_finalize+212)
#07 /apex/com.android.runtime/lib64/bionic/libc.so (exit+24)
#08 /data/app/com.domain.myapp-Rs_sm5VrLR1Jj8QW6oYByA==/lib/arm64/libplugins_platforms_qtforandroid_arm64-v8a.so

and figured out that its likely because std::thread destructor is being invoked while the thread is still joinable at some point of the application execution (thanks to G. M. on stackoverflow.com).

(more…)
31
03
20
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Shrinking MySQL database

Posted by | MS SQL |

Calculating disk space usage per MySQL DB:

sudo du -h /var/lib/mysql/

932M    /var/lib/mysql/beauty
179M    /var/lib/mysql/slogpost
485M    /var/lib/mysql/omegauto
8.0K    /var/lib/mysql/test
676K    /var/lib/mysql/sys
22G     /var/lib/mysql/bot
79M     /var/lib/mysql/master
11M     /var/lib/mysql/mysql
176K    /var/lib/mysql/phpmyadmin
21M     /var/lib/mysql/shar
127M    /var/lib/mysql/mike
1.1M    /var/lib/mysql/performance_schema
79M     /var/lib/mysql/devnote
12M     /var/lib/mysql/mike1
48K     /var/lib/mysql/game
24G     /var/lib/mysql/
(more…)
29
02
20
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C++ binary serialization speed is comparable with std::memmove

Posted by | C++ | Tagged |

Measuring std::memmove speed

I wrote a simple test that outputs std::memmove speed to the console:

AWT_ATTRIBUTE(size_t, element_count, 1000000);

std::unique_ptr<uint8_t> p_src(new uint8_t[element_count]);
std::memset(p_src.get(), 25u, element_count);

std::unique_ptr<uint8_t> p_dst(new uint8_t[element_count]);

context.out << _T("std::memmove: ");

awl::StopWatch w;

std::memmove(p_dst.get(), p_src.get(), element_count);

ReportSpeed(context, w, element_count);

context.out << std::endl;

And the similar tests for std::memset and std::vector::insert.

(more…)
21
02
20
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A funny example of C++ code that MS can compile :)

Posted by | C++ |

In the code below, static_assert operates on the addresses of local variables, but however MS compiles it and the assertion does not fail:

#include <tuple>
#include <string>
 
struct A
{
    int a;
    double b;
    std::string c;
};
 
void f()
{
    A a{ 1, 3.0, "abc" };
    constexpr auto t1 = std::tie(a.a, a.b, a.c);
    static_assert(&std::get<0>(t1) == &a.a);
}

Use the following command to compile this example:

cl /std:c++17 /EHsc a.cpp
(more…)
21
02
20
 3 Comments

How I solved “This version of the application is not configured for billing through Google Play”

Posted by | Android |

I created an unlockable product in Google Play, added billing permission to the manifest:

<uses-permission android:name="com.android.vending.BILLING"/>

and implemented billing in my application, but when I attempted to purchase the product first time I got error ‘This version of the application is not configured for billing through Google Play‘:

This version of the application is not configured for billing through Google Play
(more…)
18
02
20
 2 Comments

Basic ideas of version tolerant serialization in C++

Posted by | C++ | Tagged |

Consider the following scenario: there was structure A in an old version of a C++ application:

struct A
{
    double a;
    int b;
    std::string c;
};

An instance of A was serialized into a file in a binary format and after that the application was updated to a new version.

But in the new version of the application structure A was modified by adding fields d and e and deleting field a:

struct A
{
    int b;
    std::vector<int> d;
    bool e;
    std::string c;
};

and the new version of the application needs to deserialize an instance of its new structure A from the file containing old version of A.

(more…)
16
02
20
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Packaging QT application into Android App Bundle (AAB)

Posted by | Android, QT |

In Qt Creator 4.11.0 on Projects page check “Build .aab”:

This will create .aab file.

(more…)
10
02
20
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Setting up Oracle Database for development

Posted by | Oracle |

To set up an Oracle Database for development I install the database in a docker container and then modify password policies in the default user profile as follows:

ALTER PROFILE DEFAULT LIMIT COMPOSITE_LIMIT UNLIMITED
  PASSWORD_LIFE_TIME UNLIMITED
  PASSWORD_REUSE_TIME UNLIMITED
  PASSWORD_REUSE_MAX UNLIMITED
  PASSWORD_VERIFY_FUNCTION NULL
  PASSWORD_LOCK_TIME UNLIMITED
  PASSWORD_GRACE_TIME UNLIMITED
  FAILED_LOGIN_ATTEMPTS UNLIMITED;

this prevents passwords from expiring and users from being locked.

(more…)
06
02
20
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A simple C++ serialization framework

Posted by | C++ | Tagged |

I implemented a simple C++ binary serialization framework that makes a structure or class serializable by adding a macro that usually takes one line of code as shown in the example below:

struct A
{
    bool x;
    int y;

    AWL_SERIALIZABLE(x, y)
};

There is also a macro that makes a structure or a class equatable:

AWL_MEMBERWISE_EQUATABLE(A)
(more…)
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