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/cvs/libev/ev_linuxaio.c
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Comparing libev/ev_linuxaio.c (file contents):
Revision 1.6 by root, Fri Jun 21 03:52:29 2019 UTC vs.
Revision 1.7 by root, Sat Jun 22 16:25:53 2019 UTC

… …
110} 110}
111 111
112/*****************************************************************************/ 112/*****************************************************************************/
113/* actual backed implementation */ 113/* actual backed implementation */
114 114
115/* we use out own wrapper structure in acse we ever want to do something "clever" */
115typedef struct aniocb 116typedef struct aniocb
116{ 117{
117 struct iocb io; 118 struct iocb io;
118 /*int inuse;*/ 119 /*int inuse;*/
119} *ANIOCBP; 120} *ANIOCBP;
120 121
121inline_size 122inline_size
122void 123void
123linuxaio_array_needsize_iocbp (ANIOCBP *base, int count) 124linuxaio_array_needsize_iocbp (ANIOCBP *base, int count)
124{ 125{
125 /* TODO: quite the overhead to allocate every iocb separately */ 126 /* TODO: quite the overhead to allocate every iocb separately, maybe use our own alocator? */
126 while (count--) 127 while (count--)
127 { 128 {
128 *base = (ANIOCBP)ev_malloc (sizeof (**base)); 129 *base = (ANIOCBP)ev_malloc (sizeof (**base));
129 /* TODO: full zero initialize required? */ 130 /* TODO: full zero initialize required? */
130 memset (*base, 0, sizeof (**base)); 131 memset (*base, 0, sizeof (**base));
131 /* would be nice to initialize fd/data as well */ 132 /* would be nice to initialize fd/data as well, but array_needsize API doesn't support that */
132 (*base)->io.aio_lio_opcode = IOCB_CMD_POLL; 133 (*base)->io.aio_lio_opcode = IOCB_CMD_POLL;
133 ++base; 134 ++base;
134 } 135 }
135} 136}
136 137
… …
212 unsigned tail = *(volatile unsigned *)&ring->tail; 213 unsigned tail = *(volatile unsigned *)&ring->tail;
213 214
214 if (head == tail) 215 if (head == tail)
215 return 0; 216 return 0;
216 217
218 /* bail out if the ring buffer doesn't match the expected layout */
217 if (ecb_expect_false (ring->magic != AIO_RING_MAGIC) 219 if (ecb_expect_false (ring->magic != AIO_RING_MAGIC)
218 || ring->incompat_features != AIO_RING_INCOMPAT_FEATURES 220 || ring->incompat_features != AIO_RING_INCOMPAT_FEATURES
219 || ring->header_length != sizeof (struct aio_ring)) /* TODO: or use it to find io_event[0]? */ 221 || ring->header_length != sizeof (struct aio_ring)) /* TODO: or use it to find io_event[0]? */
220 return 0; 222 return 0;
221 223
… …
244 246
245 if (linuxaio_get_events_from_ring (EV_A)) 247 if (linuxaio_get_events_from_ring (EV_A))
246 return; 248 return;
247 249
248 /* no events, so wait for at least one, then poll ring buffer again */ 250 /* no events, so wait for at least one, then poll ring buffer again */
249 /* this degraded to one event per loop iteration */ 251 /* this degrades to one event per loop iteration */
250 /* if the ring buffer changes layout, but so be it */ 252 /* if the ring buffer changes layout, but so be it */
251 253
252 ts.tv_sec = (long)timeout; 254 ts.tv_sec = (long)timeout;
253 ts.tv_nsec = (long)((timeout - ts.tv_sec) * 1e9); 255 ts.tv_nsec = (long)((timeout - ts.tv_sec) * 1e9);
254 256
… …
283 { 285 {
284 /* This happens when the ring buffer is full, at least. I assume this means 286 /* This happens when the ring buffer is full, at least. I assume this means
285 * that the event was queued synchronously during io_submit, and thus 287 * that the event was queued synchronously during io_submit, and thus
286 * the buffer overflowd. 288 * the buffer overflowd.
287 * In this case, we just try next loop iteration. 289 * In this case, we just try next loop iteration.
290 * This should not result in a few fds taking priority, as the interface
291 * is one-shot, and we submit iocb's in a round-robin fashion.
288 */ 292 */
289 memmove (linuxaio_submits, linuxaio_submits + submitted, (linuxaio_submitcnt - submitted) * sizeof (*linuxaio_submits)); 293 memmove (linuxaio_submits, linuxaio_submits + submitted, (linuxaio_submitcnt - submitted) * sizeof (*linuxaio_submits));
290 linuxaio_submitcnt -= submitted; 294 linuxaio_submitcnt -= submitted;
291 timeout = 0; 295 timeout = 0;
292 break; 296 break;
293 } 297 }
294 else 298 else
295 /* TODO: we get EAGAIN when the ring buffer is full for some reason */
296 /* TODO: should we always just try next time? */
297 ev_syserr ("(libev) io_submit"); 299 ev_syserr ("(libev) io_submit");
298 300
299 submitted += res; 301 submitted += res;
300 } 302 }
301 303
… …
342 344
343inline_size 345inline_size
344void 346void
345linuxaio_fork (EV_P) 347linuxaio_fork (EV_P)
346{ 348{
347 /* TODO: verify and test */
348
349 /* this frees all iocbs, which is very heavy-handed */ 349 /* this frees all iocbs, which is very heavy-handed */
350 linuxaio_destroy (EV_A); 350 linuxaio_destroy (EV_A);
351 linuxaio_submitcnt = 0; /* all pointers were invalidated */ 351 linuxaio_submitcnt = 0; /* all pointers were invalidated */
352 352
353 linuxaio_ctx = 0; 353 linuxaio_ctx = 0;

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