On Thu, Apr 2, 2015 at 3:21 AM, Rasmus Lerdorf <ras...@lerdorf.com> wrote:
> On 04/01/2015 09:15 AM, Dan Ackroyd wrote: > > Hi, > > > > I'd like to get people's feedback for the idea of making setlocale be > > either deprecated and to be removed eventually or just increasing the > > warning level against people using it. > > > > The short version of why we should do this is that setlocale breaks > > things. It is a process wide operation, that is not thread safe on > > most platforms. Although people use it to alter the way strings are > > output, it also breaks libraries that are assuming that they are > > running in a "C" locale. > > The PHP setlocale() wrapper can be made threadsafe in a portable manner > via newlocale()/uselocale(), so that part isn't an issue. Someone just > needs to write the code for the threaded SAPIs. It hasn't been a high > priority due to how few people use non-Windows ZTS mode so far. > > Obviously within the same process there may be issues with changing a > locale to something unexpected by subsequent code, but that is really a > bug in that code then. If some library function expects and only works > in the "C" locale, it should make sure it is in that locale before doing > anything and then restoring the locale back appropriately. And with a > bit of symbol trickery libraries that do actually call setlocale to > change it and restore it can be made to use our newlocale/uselocale > thread-local locale mechanism. > > setlocale() is used quite a bit and for non-threaded, which is the bulk > of php usage, it tends to work quite well. It is annoying that it is > process-wide and as you noted that can cause issues, sure, and that the > current implementation isn't threadsafe, but it isn't something that is > technically unsolvable. Rather than throwing our hands in the air and > just pulling the rug out from under people using it, we should take a > look at fixing the problems associated with it instead. > > -Rasmus > > To Rasmus's point, here's a PR for HHVM to provide a thread-safe setlocale implementation: https://github.com/facebook/hhvm/pull/4736/files It should be fairly easy to refactor the thread-safe-setlocale.(h/cpp) files for Zend.
