qt - why QOpenGLFunctions_2_0::initializeOpenGLFunctions is so slow on Mac 10.10? -


i need create hundreds of objects call qopenglfunctions_2_0::initializeopenglfunctions(). found initializeopenglfunctions() slow when built qt app on mac 10.10.

details:

to reproduce issue, built qt opengl example on both mac 10.10 , mac 10.11. , found 1 built on mac 10.10 40 times slower 1 10.11. no matter ran on 10.10 mac or 10.11 mac.

to measure time, printed timestamps in openglwindow.cpp

    qdebug() << qdatetime::currentmsecssinceepoch() << ":" << __line__;     initializeopenglfunctions();     qdebug() << qdatetime::currentmsecssinceepoch() << ":" << __line__;     initialize();

and outputs are:

// built on mac 10.11 1503009550512 : 88 1503009550514 : 90  // built on mac 10.10 (40 times slower) 1503009508921 : 88 1503009509007 : 90

more details of build environments:

qt 5.6.2  macos 10.11.6 apple llvm version 7.3.0 (clang-703.0.31) target: x86_64-apple-darwin15.6.0 thread model: posix  mac 10.10. apple llvm version 6.1.0 (clang-602.0.53) (based on llvm 3.6.0svn) target: x86_64-apple-darwin14.5.0 thread model: posix

any suggestion?


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