[ViewVC] Diff of: cvs/libev/ev

Comparing libev/ev_linuxaio.c (file contents):
Revision 1.42 by root, Mon Jul 1 20:47:38 2019 UTC vs.
Revision 1.47 by root, Mon Jul 8 02:45:43 2019 UTC

   unsigned header_length;  /* size of aio_ring */
   struct io_event io_events[0];
 };
-/*
- * define some syscall wrappers for common architectures
- * this is mostly for nice looks during debugging, not performance.
- * our syscalls return < 0, not == -1, on error. which is good
- * enough for linux aio.
- * TODO: arm is also common nowadays, maybe even mips and x86
- * TODO: after implementing this, it suddenly looks like overkill, but its hard to remove...
- */
-#if __GNUC__ && __linux && ECB_AMD64 && !defined __OPTIMIZE_SIZE__
-  /* the costly errno access probably kills this for size optimisation */
-  #define ev_syscall(nr,narg,arg1,arg2,arg3,arg4,arg5)                 \
-    ({                                                                 \
-        long res;                                                      \
-        register unsigned long r5 __asm__ ("r8" );                     \
-        register unsigned long r4 __asm__ ("r10");                     \
-        register unsigned long r3 __asm__ ("rdx");                     \
-        register unsigned long r2 __asm__ ("rsi");                     \
-        register unsigned long r1 __asm__ ("rdi");                     \
-        if (narg >= 5) r5 = (unsigned long)(arg5);                     \
-        if (narg >= 4) r4 = (unsigned long)(arg4);                     \
-        if (narg >= 3) r3 = (unsigned long)(arg3);                     \
-        if (narg >= 2) r2 = (unsigned long)(arg2);                     \
-        if (narg >= 1) r1 = (unsigned long)(arg1);                     \
-        __asm__ __volatile__ (                                         \
-          "syscall\n\t"                                                \
-          : "=a" (res)                                                 \
-          : "0" (nr), "r" (r1), "r" (r2), "r" (r3), "r" (r4), "r" (r5) \
-          : "cc", "r11", "cx", "memory");                              \
-        errno = -res;                                                  \
-        res;                                                           \
-    })
-#endif
-#ifdef ev_syscall
-  #define ev_syscall0(nr)                          ev_syscall (nr, 0,    0,    0,    0,    0,    0
-  #define ev_syscall1(nr,arg1)                     ev_syscall (nr, 1, arg1,    0,    0,    0,    0)
-  #define ev_syscall2(nr,arg1,arg2)                ev_syscall (nr, 2, arg1, arg2,    0,    0,    0)
-  #define ev_syscall3(nr,arg1,arg2,arg3)           ev_syscall (nr, 3, arg1, arg2, arg3,    0,    0)
-  #define ev_syscall4(nr,arg1,arg2,arg3,arg4)      ev_syscall (nr, 3, arg1, arg2, arg3, arg4,    0)
-  #define ev_syscall5(nr,arg1,arg2,arg3,arg4,arg5) ev_syscall (nr, 5, arg1, arg2, arg3, arg4, arg5)
-#else
-  #define ev_syscall0(nr)                          syscall (nr)
-  #define ev_syscall1(nr,arg1)                     syscall (nr, arg1)
-  #define ev_syscall2(nr,arg1,arg2)                syscall (nr, arg1, arg2)
-  #define ev_syscall3(nr,arg1,arg2,arg3)           syscall (nr, arg1, arg2, arg3)
-  #define ev_syscall4(nr,arg1,arg2,arg3,arg4)      syscall (nr, arg1, arg2, arg3, arg4)
-  #define ev_syscall5(nr,arg1,arg2,arg3,arg4,arg5) syscall (nr, arg1, arg2, arg3, arg4, arg5)
-#endif
 inline_size
 int
 evsys_io_setup (unsigned nr_events, aio_context_t *ctx_idp)
 {
   return ev_syscall2 (SYS_io_setup, nr_events, ctx_idp);
       /* we do it manually because the optimisations on epoll_modify won't do us any good */
       epoll_ctl (backend_fd, EPOLL_CTL_DEL, fd, 0);
       anfds [fd].emask = 0;
       iocb->io.aio_reqprio = 0;
     }
-  if (ecb_expect_false (iocb->io.aio_buf))
+  else if (ecb_expect_false (iocb->io.aio_buf))
     {
       /* iocb active, so cancel it first before resubmit */
       for (;;)
         {
           /* on all relevant kernels, io_cancel fails with EINPROGRESS on "success" */
           if (ecb_expect_true (errno == EINPROGRESS))
             break;
           /* the EINPROGRESS test is for nicer error message. clumsy. */
+          if (errno != EINTR)
+            {
-          assert (("libev: linuxaio unexpected io_cancel failed", errno != EINPROGRESS && errno != EINTR));
+              assert (("libev: linuxaio unexpected io_cancel failed", errno != EINTR && errno != EINPROGRESS));
+              break;
+            }
        }
     }
   iocb->io.aio_buf =
       (nev & EV_READ ? POLLIN : 0)
 /* get any events from ring buffer, return true if any were handled */
 static int
 linuxaio_get_events_from_ring (EV_P)
 {
   struct aio_ring *ring = (struct aio_ring *)linuxaio_ctx;
+  unsigned head, tail;
   /* the kernel reads and writes both of these variables, */
   /* as a C extension, we assume that volatile use here */
   /* both makes reads atomic and once-only */
-  unsigned head = *(volatile unsigned *)&ring->head;
+  head = *(volatile unsigned *)&ring->head;
+  ECB_MEMORY_FENCE_ACQUIRE;
-  unsigned tail = *(volatile unsigned *)&ring->tail;
+  tail = *(volatile unsigned *)&ring->tail;
   if (head == tail)
     return 0;
-  /* make sure the events up to tail are visible */
-  ECB_MEMORY_FENCE_ACQUIRE;
   /* parse all available events, but only once, to avoid starvation */
-  if (tail > head) /* normal case around */
+  if (ecb_expect_true (tail > head)) /* normal case around */
     linuxaio_parse_events (EV_A_ ring->io_events + head, tail - head);
   else /* wrapped around */
     {
       linuxaio_parse_events (EV_A_ ring->io_events + head, ring->nr - head);
       linuxaio_parse_events (EV_A_ ring->io_events, tail);
     {
       int res;
       EV_RELEASE_CB;
-      ts.tv_sec  = (long)timeout;
+      EV_TS_SET (ts, timeout);
-      ts.tv_nsec = (long)((timeout - ts.tv_sec) * 1e9);
       res = evsys_io_getevents (linuxaio_ctx, 1, want, ioev, &ts);
       EV_ACQUIRE_CB;
       if (res < 0)
             }
             ++linuxaio_iteration;
             if (linuxaio_io_setup (EV_A) < 0)
               {
+                /* TODO: rearm all and recreate epoll backend from scratch */
+                /* TODO: might be more prudent? */
                 /* to bad, we can't get a new aio context, go 100% epoll */
                 linuxaio_free_iocbp (EV_A);
                 ev_io_stop (EV_A_ &linuxaio_epoll_w);
                 ev_ref (EV_A);
                 linuxaio_ctx = 0;
+                backend        = EVBACKEND_EPOLL;
                 backend_modify = epoll_modify;
                 backend_poll   = epoll_poll;
               }
             timeout = 0;
             res = 1; /* skip this iocb */
           }
         else if (errno == EINTR) /* not seen in reality, not documented */
           res = 0; /* silently ignore and retry */
         else
+          {
-          ev_syserr ("(libev) linuxaio io_submit");
+            ev_syserr ("(libev) linuxaio io_submit");
+            res = 0;
+          }
       submitted += res;
     }
   linuxaio_submitcnt = 0;
   ev_io_init  (EV_A_ &linuxaio_epoll_w, linuxaio_epoll_cb, backend_fd, EV_READ);
   ev_set_priority (&linuxaio_epoll_w, EV_MAXPRI);
   ev_io_start (EV_A_ &linuxaio_epoll_w);
   ev_unref (EV_A); /* watcher should not keep loop alive */
-  backend_modify  = linuxaio_modify;
+  backend_modify = linuxaio_modify;
-  backend_poll    = linuxaio_poll;
+  backend_poll   = linuxaio_poll;
   linuxaio_iocbpmax = 0;
   linuxaio_iocbps = 0;
   linuxaio_submits = 0;
   epoll_destroy (EV_A);
   linuxaio_free_iocbp (EV_A);
   evsys_io_destroy (linuxaio_ctx); /* fails in child, aio context is destroyed */
 }
-inline_size
+ecb_cold
-void
+static void
 linuxaio_fork (EV_P)
 {
-  /* this frees all iocbs, which is very heavy-handed */
-  linuxaio_destroy (EV_A);
   linuxaio_submitcnt = 0; /* all pointers were invalidated */
+  linuxaio_free_iocp (EV_A); /* this frees all iocbs, which is very heavy-handed */
+  evsys_io_destroy (linuxaio_ctx); /* fails in child, aio context is destroyed */
   linuxaio_iteration = 0; /* we start over in the child */
   while (linuxaio_io_setup (EV_A) < 0)
     ev_syserr ("(libev) linuxaio io_setup");
   /* forking epoll should also effectively unregister all fds from the backend */
   epoll_fork (EV_A);
+  /* epoll_fork already did this. hopefully */
+  /*fd_rearm_all (EV_A);*/
   ev_io_stop  (EV_A_ &linuxaio_epoll_w);
   ev_io_set   (EV_A_ &linuxaio_epoll_w, backend_fd, EV_READ);
   ev_io_start (EV_A_ &linuxaio_epoll_w);
-  /* epoll_fork already did this. hopefully */
-  /*fd_rearm_all (EV_A);*/
 }

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Comparing libev/ev_linuxaio.c (file contents): Revision 1.42 by root, Mon Jul 1 20:47:38 2019 UTC vs. Revision 1.47 by root, Mon Jul 8 02:45:43 2019 UTC

Diff Legend

Comparing libev/ev_linuxaio.c (file contents):
Revision 1.42 by root, Mon Jul 1 20:47:38 2019 UTC vs.
Revision 1.47 by root, Mon Jul 8 02:45:43 2019 UTC