| … | |
… | |
| 559 | |
559 | |
| 560 | #define ECB_C (__STDC__+0) /* this assumes that __STDC__ is either empty or a number */ |
560 | #define ECB_C (__STDC__+0) /* this assumes that __STDC__ is either empty or a number */ |
| 561 | #define ECB_C99 (__STDC_VERSION__ >= 199901L) |
561 | #define ECB_C99 (__STDC_VERSION__ >= 199901L) |
| 562 | #define ECB_C11 (__STDC_VERSION__ >= 201112L) |
562 | #define ECB_C11 (__STDC_VERSION__ >= 201112L) |
| 563 | #define ECB_CPP (__cplusplus+0) |
563 | #define ECB_CPP (__cplusplus+0) |
| 564 | #define ECB_CPP98 (__cplusplus >= 199711L) |
|
|
| 565 | #define ECB_CPP11 (__cplusplus >= 201103L) |
564 | #define ECB_CPP11 (__cplusplus >= 201103L) |
| 566 | |
565 | |
| 567 | /*****************************************************************************/ |
566 | /*****************************************************************************/ |
| 568 | |
567 | |
| 569 | /* ECB_NO_THREADS - ecb is not used by multiple threads, ever */ |
568 | /* ECB_NO_THREADS - ecb is not used by multiple threads, ever */ |
| … | |
… | |
| 614 | #endif |
613 | #endif |
| 615 | #endif |
614 | #endif |
| 616 | |
615 | |
| 617 | #ifndef ECB_MEMORY_FENCE |
616 | #ifndef ECB_MEMORY_FENCE |
| 618 | #if ECB_GCC_VERSION(4,7) |
617 | #if ECB_GCC_VERSION(4,7) |
| 619 | /* see comment below about the C11 memory model. in short - avoid */ |
618 | /* see comment below (stdatomic.h) about the C11 memory model. */ |
| 620 | #define ECB_MEMORY_FENCE __atomic_thread_fence (__ATOMIC_SEQ_CST) |
619 | #define ECB_MEMORY_FENCE __atomic_thread_fence (__ATOMIC_SEQ_CST) |
| 621 | #elif defined __clang && __has_feature (cxx_atomic) |
620 | #elif defined __clang && __has_feature (cxx_atomic) |
| 622 | /* see above */ |
621 | /* see comment below (stdatomic.h) about the C11 memory model. */ |
| 623 | #define ECB_MEMORY_FENCE __c11_atomic_thread_fence (__ATOMIC_SEQ_CST) |
622 | #define ECB_MEMORY_FENCE __c11_atomic_thread_fence (__ATOMIC_SEQ_CST) |
| 624 | #elif ECB_GCC_VERSION(4,4) || defined __INTEL_COMPILER || defined __clang__ |
623 | #elif ECB_GCC_VERSION(4,4) || defined __INTEL_COMPILER || defined __clang__ |
| 625 | #define ECB_MEMORY_FENCE __sync_synchronize () |
624 | #define ECB_MEMORY_FENCE __sync_synchronize () |
| 626 | #elif _MSC_VER >= 1400 /* VC++ 2005 */ |
625 | #elif _MSC_VER >= 1400 /* VC++ 2005 */ |
| 627 | #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier) |
626 | #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier) |
| … | |
… | |
| 644 | #ifndef ECB_MEMORY_FENCE |
643 | #ifndef ECB_MEMORY_FENCE |
| 645 | #if ECB_C11 && !defined __STDC_NO_ATOMICS__ |
644 | #if ECB_C11 && !defined __STDC_NO_ATOMICS__ |
| 646 | /* we assume that these memory fences work on all variables/all memory accesses, */ |
645 | /* we assume that these memory fences work on all variables/all memory accesses, */ |
| 647 | /* not just C11 atomics and atomic accesses */ |
646 | /* not just C11 atomics and atomic accesses */ |
| 648 | #include <stdatomic.h> |
647 | #include <stdatomic.h> |
| 649 | /* unfortunately, the C11 memory model seems to be very limited, and unable to express */ |
648 | /* Unfortunately, neither gcc 4.7 nor clang 3.1 generate any instructions for */ |
| 650 | /* simple barrier semantics. That means we need to take out thor's hammer. */ |
649 | /* any fence other than seq_cst, which isn't very efficient for us. */ |
|
|
650 | /* Why that is, we don't know - either the C11 memory model is quite useless */ |
|
|
651 | /* for most usages, or gcc and clang have a bug */ |
|
|
652 | /* I *currently* lean towards the latter, and inefficiently implement */ |
|
|
653 | /* all three of ecb's fences as a seq_cst fence */ |
| 651 | #define ECB_MEMORY_FENCE atomic_thread_fence (memory_order_seq_cst) |
654 | #define ECB_MEMORY_FENCE atomic_thread_fence (memory_order_seq_cst) |
| 652 | #endif |
655 | #endif |
| 653 | #endif |
656 | #endif |
| 654 | |
657 | |
| 655 | #ifndef ECB_MEMORY_FENCE |
658 | #ifndef ECB_MEMORY_FENCE |
| … | |
… | |
| 3135 | backend_poll (EV_A_ waittime); |
3138 | backend_poll (EV_A_ waittime); |
| 3136 | assert ((loop_done = EVBREAK_CANCEL, 1)); /* assert for side effect */ |
3139 | assert ((loop_done = EVBREAK_CANCEL, 1)); /* assert for side effect */ |
| 3137 | |
3140 | |
| 3138 | pipe_write_wanted = 0; /* just an optimisation, no fence needed */ |
3141 | pipe_write_wanted = 0; /* just an optimisation, no fence needed */ |
| 3139 | |
3142 | |
| 3140 | MEMORY_FENCE_ACQUIRE; |
3143 | ECB_MEMORY_FENCE_ACQUIRE; |
| 3141 | if (pipe_write_skipped) |
3144 | if (pipe_write_skipped) |
| 3142 | { |
3145 | { |
| 3143 | assert (("libev: pipe_w not active, but pipe not written", ev_is_active (&pipe_w))); |
3146 | assert (("libev: pipe_w not active, but pipe not written", ev_is_active (&pipe_w))); |
| 3144 | ev_feed_event (EV_A_ &pipe_w, EV_CUSTOM); |
3147 | ev_feed_event (EV_A_ &pipe_w, EV_CUSTOM); |
| 3145 | } |
3148 | } |
