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<![endif] [if lt IE 7]> <p class="chromeframe">You are using an <strong>outdated</strong> browser. Please <a href="http://browsehappy.com/">upgrade your browser</a> or <a href="http://www.google.com/chromeframe/?redirect=true">activate Google Chrome Frame</a> to improve your experience.</p> <![endif] Leandro Pereira Home About June 23, 2014 There are various ways to convert integers to their string representation. These conversions are rarely a bottleneck, but they often show up while profiling certain applications. For instance, they’re very common in Lwan while building the response headers. To use Lwan as an example: initially, snprintf() was used to convert numbers. Although this works, it is quite boring, performance-wise. The second approach was using the naïve algorithm, which basically divides the number by 10 in succession, writing ba...

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<![endif] [if lt IE 7]> <p class="chromeframe">You are using an <strong>outdated</strong> browser. Please <a href="http://browsehappy.com/">upgrade your browser</a> or <a href="http://www.google.com/chromeframe/?redirect=true">activate Google Chrome Frame</a> to improve your experience.</p> <![endif] Leandro Pereira Home About 20 July 2013 There are some functions in the standard C library that takes a function pointer to be used as a callback later on. Examples include atexit() and signal() . However, these functions can’t receive an arbitrary pointer (which could hold some important program state) in addition to the function pointer, so you’re left with pesky global variables: /* You have: */ atexit ( foo ); /* foo() will have to fetch program state from globals */ /* Instead of: */ static struct program_state state ; atexit ( foo , ...

<![endif] [if lt IE 7]> <p class="chromeframe">You are using an <strong>outdated</strong> browser. Please <a href="http://browsehappy.com/">upgrade your browser</a> or <a href="http://www.google.com/chromeframe/?redirect=true">activate Google Chrome Frame</a> to improve your experience.</p> <![endif] Leandro Pereira Home About 23 June 2014 Integer to string conversion There are various ways to convert integers to their string representation. These conversions are rarely a bottleneck, but they often show up while profiling certain applications. For instance, they’re very common in Lwan while building the response headers. To use Lwan as an example: initially, snprintf() was used to convert numbers. Although this works, it is quite boring, performance-wise. The second approach was using the naïve algorithm, which basically divides the number by ...

<![endif] [if lt IE 7]> <p class="chromeframe">You are using an <strong>outdated</strong> browser. Please <a href="http://browsehappy.com/">upgrade your browser</a> or <a href="http://www.google.com/chromeframe/?redirect=true">activate Google Chrome Frame</a> to improve your experience.</p> <![endif] Leandro Pereira Home About 20 July 2013 There are some functions in the standard C library that takes a function pointer to be used as a callback later on. Examples include atexit() and signal() . However, these functions can’t receive an arbitrary pointer (which could hold some important program state) in addition to the function pointer, so you’re left with pesky global variables: /* You have: */ atexit ( foo ); /* foo() will have to fetch program state from globals */ /* Instead of: */ static struct program_state state ; atexit ( foo , ...

<![endif] [if lt IE 7]> <p class="chromeframe">You are using an <strong>outdated</strong> browser. Please <a href="http://browsehappy.com/">upgrade your browser</a> or <a href="http://www.google.com/chromeframe/?redirect=true">activate Google Chrome Frame</a> to improve your experience.</p> <![endif] Leandro Pereira Home About 11 August 2012 Golang has a lot of nice features – and one I found pretty interesting is called deferred statements . This can be implemented in C++ pretty easily through RAII , but in C we’re pretty much out of luck. Or are we? In lwan , I’m using my own home-cooked coroutine implementation. All requests are handled by coroutines, so that it makes easy to condition the execution of deferred statements with the cleanup of a coroutine. And that’s what I did, by implementing coro_defer() , which adds hooks that will be called...