From bc5818cfdd56e19a16357f4443d80a56426aa134 Mon Sep 17 00:00:00 2001 From: Rickard Green Date: Mon, 10 Oct 2011 21:03:10 +0200 Subject: Replace system block with thread progress block The ERTS internal system block functionality has been replaced by new functionality for blocking the system. The old system block functionality had contention issues and complexity issues. The new functionality piggy-backs on thread progress tracking functionality needed by newly introduced lock-free synchronization in the runtime system. When the functionality for blocking the system isn't used there is more or less no overhead at all. This since the functionality for tracking thread progress is there and needed anyway. --- erts/emulator/sys/unix/sys.c | 31 ++++++++++++++----------------- 1 file changed, 14 insertions(+), 17 deletions(-) (limited to 'erts/emulator/sys/unix/sys.c') diff --git a/erts/emulator/sys/unix/sys.c b/erts/emulator/sys/unix/sys.c index 15e110a6cc..8e8d4cce61 100644 --- a/erts/emulator/sys/unix/sys.c +++ b/erts/emulator/sys/unix/sys.c @@ -52,6 +52,7 @@ #define ERTS_WANT_GOT_SIGUSR1 #define WANT_NONBLOCKING /* must define this to pull in defs from sys.h */ #include "sys.h" +#include "erl_thr_progress.h" #if defined(__APPLE__) && defined(__MACH__) && !defined(__DARWIN__) #define __DARWIN__ 1 @@ -2425,11 +2426,7 @@ void erts_do_break_handling(void) * therefore, make sure that all threads but this one are blocked before * proceeding! */ - erts_smp_block_system(0); - /* - * NOTE: since we allow gc we are not allowed to lock - * (any) process main locks while blocking system... - */ + erts_smp_thr_progress_block(); /* during break we revert to initial settings */ /* this is done differently for oldshell */ @@ -2457,7 +2454,7 @@ void erts_do_break_handling(void) tcsetattr(0,TCSANOW,&temp_mode); } - erts_smp_release_system(); + erts_smp_thr_progress_unblock(); } /* Fills in the systems representation of the jam/beam process identifier. @@ -2868,7 +2865,7 @@ erl_sys_schedule(int runnable) { #ifdef ERTS_SMP ERTS_CHK_IO(!runnable); - ERTS_SMP_LC_ASSERT(!ERTS_LC_IS_BLOCKING); + ERTS_SMP_LC_ASSERT(!erts_thr_progress_is_blocking()); #else if (runnable) { ERTS_CHK_IO(0); /* Poll for I/O */ @@ -2937,15 +2934,15 @@ signal_dispatcher_thread_func(void *unused) * to other threads. * * NOTE 2: The signal dispatcher thread is not a blockable - * thread (i.e., it hasn't called - * erts_register_blockable_thread()). This is - * intentional. We want to be able to interrupt - * writing of a crash dump by hitting C-c twice. - * Since it isn't a blockable thread it is important - * that it doesn't change the state of any data that - * a blocking thread expects to have exclusive access - * to (unless the signal dispatcher itself explicitly - * is blocking all blockable threads). + * thread (i.e., not a thread managed by the + * erl_thr_progress module). This is intentional. + * We want to be able to interrupt writing of a crash + * dump by hitting C-c twice. Since it isn't a + * blockable thread it is important that it doesn't + * change the state of any data that a blocking thread + * expects to have exclusive access to (unless the + * signal dispatcher itself explicitly is blocking all + * blockable threads). */ switch (buf[i]) { case 0: /* Emulator initialized */ @@ -2985,7 +2982,7 @@ signal_dispatcher_thread_func(void *unused) buf[i]); } } - ERTS_SMP_LC_ASSERT(!ERTS_LC_IS_BLOCKING); + ERTS_SMP_LC_ASSERT(!erts_thr_progress_is_blocking()); } return NULL; } -- cgit v1.2.3