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Diffstat (limited to 'src/corelib/doc/snippets/qtracer/ftracer.cpp')
| -rw-r--r-- | src/corelib/doc/snippets/qtracer/ftracer.cpp | 180 |
1 files changed, 0 insertions, 180 deletions
diff --git a/src/corelib/doc/snippets/qtracer/ftracer.cpp b/src/corelib/doc/snippets/qtracer/ftracer.cpp deleted file mode 100644 index b12e3ed9c3..0000000000 --- a/src/corelib/doc/snippets/qtracer/ftracer.cpp +++ /dev/null @@ -1,180 +0,0 @@ -/**************************************************************************** -** -** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies). -** Contact: http://www.qt-project.org/legal -** -** This file is part of the examples of the Qt Toolkit. -** -** $QT_BEGIN_LICENSE:BSD$ -** You may use this file under the terms of the BSD license as follows: -** -** "Redistribution and use in source and binary forms, with or without -** modification, are permitted provided that the following conditions are -** met: -** * Redistributions of source code must retain the above copyright -** notice, this list of conditions and the following disclaimer. -** * Redistributions in binary form must reproduce the above copyright -** notice, this list of conditions and the following disclaimer in -** the documentation and/or other materials provided with the -** distribution. -** * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names -** of its contributors may be used to endorse or promote products derived -** from this software without specific prior written permission. -** -** -** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS -** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT -** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR -** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT -** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, -** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT -** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, -** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY -** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT -** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE -** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." -** -** $QT_END_LICENSE$ -** -****************************************************************************/ - -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <fcntl.h> -#include <unistd.h> - -#include <QCoreApplication> -#include <QLoggingCategory> - - -//![1] -QLoggingCategory theFooArea("foo"); -QLoggingCategory theBarArea("bar"); -QLoggingCategory theBazArea("baz"); -//![1] - -// Note: These locations are Ubuntu specific. - -// Note: To make the example work with user permissions, make sure -// the files are user-writable and the path leading there accessible. - -const char traceSwitch[] = "/sys/kernel/debug/tracing/tracing_on"; -const char traceSink[] = "/sys/kernel/debug/tracing/trace_marker"; - -// The base class only serves as a facility to share code -// between the "single line" data logging aspect and the -// scoped "measuring" aspect. - -// Both aspects and the base class could be combined into -// a single tracer serving both purposes, but are split -// here for clarity. - -// Error handling is left as an exercise. - -//![2] -class MyTracerBase : public QTracer -{ -public: - MyTracerBase() { - enable = ::open(traceSwitch, O_WRONLY); - marker = ::open(traceSink, O_WRONLY); - } - - ~MyTracerBase() { - ::close(enable); - ::close(marker); - } - -protected: - int enable; - int marker; -}; -//![2] - - -//![2] -class MyTracer : public MyTracerBase -{ -public: - void start() { ::write(marker, "B", 1); } - void end() { ::write(marker, "E", 1); } -}; -//![2] - - -//![3] -class MyDataLogger : public MyTracerBase -{ -public: - MyDataLogger() { - buf[0] = 0; - pos = 0; - } - - void record(int i) { pos += sprintf(buf + pos, "%d", i); } - void record(const char *msg) { pos += sprintf(buf + pos, "%s", msg); } - void end() { ::write(marker, buf, pos); pos = 0; } - -private: - char buf[100]; - int pos; -}; -//![3] - -// Simplest possible example for "measuring". -//![4] -int foo(int i) -{ - qCTraceGuard(theFooArea); - // Here could be some lengthy code. - return i * i; -} -//![4] - -// We can switch on/off tracing dynamically. -// The tracer will be temporarily switched off at the third call -// and re-enabled at the eighth. -//![5] -int bar(int i) -{ - static int n = 0; - ++n; - if (n == 3) - theBarArea.setEnabled(QtTraceMsg, false); - if (n == 8) - theBarArea.setEnabled(QtTraceMsg, true); - - qCTraceGuard(theBarArea); - return i * i; -} -//![5] - -// An example to create "complex" log messages. -//![6] -int baz(int i) -{ - qCTrace(theBazArea) << 32 << "some stuff"; - - return i * i; -} -//![6] - - - -//![7] -namespace { -static struct Init -{ - Init() { - tracer.addToCategory(theFooArea); - tracer.addToCategory(theBarArea); - logger.addToCategory(theBazArea); - } - - MyTracer tracer; - MyDataLogger logger; - -} initializer; -} -//![7] |