easy_profiler/README.md

# easy_profiler [![1.0.3](https://img.shields.io/badge/version-1.0.3-009688.svg)](https://github.com/yse/easy_profiler/releases)

[![Build Status](https://travis-ci.org/yse/easy_profiler.svg?branch=develop)](https://travis-ci.org/yse/easy_profiler)

[![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
[![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://www.apache.org/licenses/LICENSE-2.0)


1. [About](#about)
2. [Key features](#key-features)
3. [Usage](#usage)
    - [Prepare build system](#prepare-build-system)
       - [General build system](#general)
       - [CMake](#build-with-cmake)
    - [Add profiling blocks](#add-profiling-blocks)
    - [Collect blocks](#collect-blocks)
        - [Collect via network](#collect-via-network)
        - [Collect via file](#collect-via-file)
        - [Note about context-switch](#note-about-context-switch)
4. [Build](#build)
    - [Linux](#linux)
    - [Windows](#windows)
5. [License](#license)

# About
Lightweight cross-platform profiler library for c++

You can profile any function in you code. Furthermore this library provide measuring time of any block of code.
For example, information for 12 millions of blocks is using less than 300Mb of memory.
Working profiler slows your application execution for only 1-2%.

![Block time](https://hsto.org/files/3e4/afe/8b7/3e4afe8b77ac4ad3a6f8c805be4b7f13.png)
_Average overhead per block is about 15ns/block (tested on Intel Core i7-5930K 3.5GHz, Win7)_

Disabled profiler will not affect your application execution in any way. You can leave it in your Release build
and enable it at run-time at any moment during application launch to see what is happening at the moment.

Also the library can capture system's context switch events between threads. Context switch information includes
duration, target thread id, thread owner process id, thread owner process name.

You can see the results of measuring in simple GUI application which provides full statistics and renders beautiful time-line.

![GUI screenshot](https://cloud.githubusercontent.com/assets/10530007/21056780/2383d472-be48-11e6-8b35-d1a32e64b910.png)

# Key features

- Extremely low overhead
- Low additional memory usage
- Cross-platform
- Measuring over network
- Capture thread context-switch events
- Fully remove integration via defines

# Usage

## Prepare build system

### General

First of all you can specify path to include directory which contains `include/profiler` directory and define macro `BUILD_WITH_EASY_PROFILER`.
For linking with easy_profiler you can specify path to library.

### Build with cmake

If you are using `cmake` set `CMAKE_PREFIX_PATH` to `lib/cmake/easy_profiler` directory (from [release](https://github.com/yse/easy_profiler/releases) package) and use function `find_package(easy_profiler)` with `target_link_libraries(... easy_profiler)`. Example:

``` cmake
project(app_for_profiling)

set(SOURCES
    main.cpp
)

#CMAKE_PREFIX_PATH should be set to <easy_profiler-release_dir>/lib/cmake/easy_profiler
find_package(easy_profiler REQUIRED)

add_executable(app_for_profiling ${SOURCES})

target_link_libraries(app_for_profiling easy_profiler)
```

## Add profiling blocks

Example of usage.

This code snippet will generate block with function name and Magenta color:
```cpp
#include <easy/profiler.h>

void frame() {
    EASY_FUNCTION(profiler::colors::Magenta); // Magenta block with name "frame"
    prepareRender();
    calculatePhysics();
}
```

To profile any block you may do this as following.
You can specify these blocks also with Google material design colors or just set name of the block
(in this case it will have default color which is `Amber100`):
```cpp
#include <easy/profiler.h>

void foo() {
    // some code
    EASY_BLOCK("Calculating sum"); // Block with default color
    int sum = 0;
    for (int i = 0; i < 10; ++i) {
        EASY_BLOCK("Addition", profiler::colors::Red); // Scoped red block (no EASY_END_BLOCK needed)
        sum += i;
    }
    EASY_END_BLOCK; // This ends "Calculating sum" block

    EASY_BLOCK("Calculating multiplication", profiler::colors::Blue500); // Blue block
    int mul = 1;
    for (int i = 1; i < 11; ++i)
        mul *= i;
    //EASY_END_BLOCK; // This is not needed because all blocks are ended on destructor when closing braces met
}
```

You can also use your own colors. easy_profiler is using standard 32-bit ARGB color format.
Example:
```cpp
#include <easy/profiler.h>

void bar() {
    EASY_FUNCTION(0xfff080aa); // Function block with custom color
    // some code
}
```
## Collect blocks

There are two ways to cature blocks

### Collect via network

It's most prefered and convenient approach in many case.

1. Initialize listening by `profiler::startListen()`. It's start new thread to listen on `28077` port the start-capture-signal from gui-application.
2. To stop listening you can call `profiler::stopListen()` function. 

### Collect via file

1. Enable profiler by `EASY_PROFILER_ENABLE` macro
2. Dump blocks to file in any place you want by `profiler::dumpBlocksToFile("test_profile.prof")` function

Example:
```cpp
int main()
{
    EASY_PROFILER_ENABLE;
    /* do work*/
    profiler::dumpBlocksToFile("test_profile.prof");
}
```

### Note about context-switch

To capture a thread context-switch event you need:

- On Windows: run profiling application "as administrator"
- On linux: you can run special `systemtap` script with root privileges as follow (example on Fedora):
```bash
#stap -o /tmp/cs_profiling_info.log scripts/context_switch_logger.stp name APPLICATION_NAME
```
APPLICATION_NAME - name of profiling application

# Build

## Prerequisites

For core:
* compiler with c++11 support
* cmake 3.0 or higher

For GUI:
* Qt 5.3.0 or higher

## Linux

```bash
$ mkdir build
$ cd build
$ cmake ..
$ make
```

## Windows

If you are using QtCreator IDE you can just open `CMakeLists.txt` file in root directory.
If you are using Visual Studio you can generate solution by cmake generator command.
Examples shows how to generate Win64 solution for Visual Studio 2013. To generate for another version use proper cmake generator (-G "name of generator").

### Way 1
Specify path to cmake scripts in Qt5 dir (usually in lib/cmake subdir) and execute cmake generator command,
for example:
```batch
$ mkdir build
$ cd build
$ cmake -DCMAKE_PREFIX_PATH="C:\Qt\5.3\msvc2013_64\lib\cmake" .. -G "Visual Studio 12 2013 Win64"
```

### Way 2
Create system variable "Qt5Widgets_DIR" and set it's value to "[path-to-Qt5-binaries]\lib\cmake\Qt5Widgets".
For example, "C:\Qt\5.3\msvc2013_64\lib\cmake\Qt5Widgets".
And then run cmake generator as follows:
```batch
$ mkdir build
$ cd build
$ cmake .. -G "Visual Studio 12 2013 Win64"
```

# License

Licensed under either of
- MIT license ([LICENSE.MIT](LICENSE.MIT) or http://opensource.org/licenses/MIT)
- Apache License, Version 2.0, ([LICENSE.APACHE](LICENSE.APACHE) or http://www.apache.org/licenses/LICENSE-2.0)

at your option.