asyncnss

At the deepest, lowest levels of the software stack, some functions - such as getaddrinfo() that performs name resolution - are ubiquitously used by applications, they are synchronous (they do not return until they have the full result), and they potentially make network calls, which may block for unbounded amounts of time. This is a problem when an application needs to make several calls to these functions: either they call them serially which compounds the waiting time, or they resort to workaround strategies which makes them significantly more complex. asyncnss solves this by providing an asynchronous API to a set of commonly used synchronous libc functions, with a mechanism that integrates seamlessly with classic Unix asynchronous event loops. It also isolates glibc's nsswitch module loading in a separate process, tightening the security of the client application.