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Comparing libev/ev.c (file contents):
Revision 1.438 by root, Tue May 29 21:03:44 2012 UTC vs.
Revision 1.444 by root, Fri Jun 1 22:01:13 2012 UTC

… …
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 */
570/* ECB_NO_SMP - ecb might be used in multiple threads, but only on a single cpu */ 569/* ECB_NO_SMP - ecb might be used in multiple threads, but only on a single cpu */
571 570
572#if ECB_NO_THREADS 571#if ECB_NO_THREADS
573# define ECB_NO_SMP 1 572 #define ECB_NO_SMP 1
574#endif 573#endif
575 574
576#if ECB_NO_SMP 575#if ECB_NO_SMP
577 #define ECB_MEMORY_FENCE do { } while (0) 576 #define ECB_MEMORY_FENCE do { } while (0)
578#endif 577#endif
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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 /*#define ECB_MEMORY_FENCE_ACQUIRE ({ char dummy = 0; __sync_lock_test_and_set (&dummy, 1); }) */
627 /*#define ECB_MEMORY_FENCE_RELEASE ({ char dummy = 1; __sync_lock_release (&dummy ); }) */
628 #elif _MSC_VER >= 1400 /* VC++ 2005 */ 625 #elif _MSC_VER >= 1400 /* VC++ 2005 */
629 #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier) 626 #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
630 #define ECB_MEMORY_FENCE _ReadWriteBarrier () 627 #define ECB_MEMORY_FENCE _ReadWriteBarrier ()
631 #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */ 628 #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */
632 #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier () 629 #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier ()
… …
646#ifndef ECB_MEMORY_FENCE 643#ifndef ECB_MEMORY_FENCE
647 #if ECB_C11 && !defined __STDC_NO_ATOMICS__ 644 #if ECB_C11 && !defined __STDC_NO_ATOMICS__
648 /* 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, */
649 /* not just C11 atomics and atomic accesses */ 646 /* not just C11 atomics and atomic accesses */
650 #include <stdatomic.h> 647 #include <stdatomic.h>
651 /* 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 */
652 /* 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 */
653 #define ECB_MEMORY_FENCE atomic_thread_fence (memory_order_seq_cst) 654 #define ECB_MEMORY_FENCE atomic_thread_fence (memory_order_seq_cst)
654 #endif
655 #endif 655 #endif
656#endif 656#endif
657 657
658#ifndef ECB_MEMORY_FENCE 658#ifndef ECB_MEMORY_FENCE
659 #if !ECB_AVOID_PTHREADS 659 #if !ECB_AVOID_PTHREADS
… …
2550 EV_WIN32_CLOSE_FD (evpipe [1]); 2550 EV_WIN32_CLOSE_FD (evpipe [1]);
2551 } 2551 }
2552 2552
2553#if EV_SIGNAL_ENABLE || EV_ASYNC_ENABLE 2553#if EV_SIGNAL_ENABLE || EV_ASYNC_ENABLE
2554 evpipe_init (EV_A); 2554 evpipe_init (EV_A);
2555 /* now iterate over everything, in case we missed something */ 2555 /* iterate over everything, in case we missed something before */
2556 pipecb (EV_A_ &pipe_w, EV_READ); 2556 ev_feed_event (EV_A_ &pipe_w, EV_CUSTOM);
2557#endif 2557#endif
2558 } 2558 }
2559 2559
2560 postfork = 0; 2560 postfork = 0;
2561} 2561}
… …
2736} 2736}
2737 2737
2738void 2738void
2739ev_loop_fork (EV_P) EV_THROW 2739ev_loop_fork (EV_P) EV_THROW
2740{ 2740{
2741 postfork = 1; /* must be in line with ev_default_fork */ 2741 postfork = 1;
2742} 2742}
2743 2743
2744/*****************************************************************************/ 2744/*****************************************************************************/
2745 2745
2746void 2746void
… …
3138 backend_poll (EV_A_ waittime); 3138 backend_poll (EV_A_ waittime);
3139 assert ((loop_done = EVBREAK_CANCEL, 1)); /* assert for side effect */ 3139 assert ((loop_done = EVBREAK_CANCEL, 1)); /* assert for side effect */
3140 3140
3141 pipe_write_wanted = 0; /* just an optimisation, no fence needed */ 3141 pipe_write_wanted = 0; /* just an optimisation, no fence needed */
3142 3142
3143 ECB_MEMORY_FENCE_ACQUIRE;
3143 if (pipe_write_skipped) 3144 if (pipe_write_skipped)
3144 { 3145 {
3145 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)));
3146 ev_feed_event (EV_A_ &pipe_w, EV_CUSTOM); 3147 ev_feed_event (EV_A_ &pipe_w, EV_CUSTOM);
3147 } 3148 }
… …
3176 && !(flags & (EVRUN_ONCE | EVRUN_NOWAIT)) 3177 && !(flags & (EVRUN_ONCE | EVRUN_NOWAIT))
3177 )); 3178 ));
3178 3179
3179 if (loop_done == EVBREAK_ONE) 3180 if (loop_done == EVBREAK_ONE)
3180 loop_done = EVBREAK_CANCEL; 3181 loop_done = EVBREAK_CANCEL;
3182
3183 /* pendingpri is normally -1 here, which is not a good */
3184 /* value when returning to an ev_invoke_pending */
3185 pendingpri = NUMPRI - 1;
3181 3186
3182#if EV_FEATURE_API 3187#if EV_FEATURE_API
3183 --loop_depth; 3188 --loop_depth;
3184#endif 3189#endif
3185 3190

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