From b71dde8bd94985f5953a1647802ac312a798fe69 Mon Sep 17 00:00:00 2001 From: Rickard Green Date: Mon, 20 Jun 2016 15:51:25 +0200 Subject: Improve accuracy of timeouts using premature timeouts Improve accuracy of timeouts using a premature timeout then return to sleep with a shorter timeout just before requested timeout. This approach is only used on certain platforms where we know it improves the accuracy of the timeouts, e.g. MacOS X. --- erts/include/internal/erl_misc_utils.h | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) (limited to 'erts/include/internal') diff --git a/erts/include/internal/erl_misc_utils.h b/erts/include/internal/erl_misc_utils.h index a4a5d1d510..55566ddf74 100644 --- a/erts/include/internal/erl_misc_utils.h +++ b/erts/include/internal/erl_misc_utils.h @@ -56,4 +56,33 @@ int erts_map_win_error_to_errno(DWORD win_error); int erts_get_last_win_errno(void); #endif +#if defined(__APPLE__) && defined(__MACH__) && !defined(__DARWIN__) +#define __DARWIN__ 1 +#endif + +/* + * ERTS_PREMATURE_TIMEOUT() expects time units + * 1000 (millisec), 1000000 (microsec), or + * 1000000000 (nanosec). Might not work properly + * otherwise. + */ +#undef ERTS_USE_PREMATURE_TIMEOUT +#undef ERTS_PREMATURE_TIMEOUT + +#if defined(__DARWIN__) +#define ERTS_USE_PREMATURE_TIMEOUT 1 +#define ERTS_PREMATURE_TIMEOUT(TMO, TU) \ + ((TMO) >= 1 * ((TU) / 1000) \ + ? ((TMO) >= 20 * ((TU) / 1000) \ + ? 15 * ((TU) / 1000) \ + : ((TMO) >= 5 * ((TU) / 1000) \ + ? 3 * ((TU) / 1000) \ + : 5 * ((TU) / 10000))) \ + : 0) + +#else +#define ERTS_USE_PREMATURE_TIMEOUT 0 +#define ERTS_PREMATURE_TIMEOUT(TMO, TU) (0) +#endif + #endif /* #ifndef ERL_MISC_UTILS_H_ */ -- cgit v1.2.3