xref: /illumos-gate/usr/src/lib/libc/inc/asyncio.h (revision 4702be99a7621a425e53a63af8ae0ff7fe973b31)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #ifndef	_ASYNCIO_H
28 #define	_ASYNCIO_H
29 
30 #ifdef	__cplusplus
31 extern "C" {
32 #endif
33 
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <unistd.h>
37 #include <string.h>
38 #include <errno.h>
39 #include <sys/types.h>
40 #include <sys/stat.h>
41 #include <thread.h>
42 #include <pthread.h>
43 #include <setjmp.h>
44 #include <signal.h>
45 #include <siginfo.h>
46 #include <aio.h>
47 #include <limits.h>
48 #include <ucontext.h>
49 #include <sys/asynch.h>
50 #include <sys/mman.h>
51 
52 #if !defined(_LP64)
53 #define	AIOSTKSIZE	(64 * 1024)
54 #else
55 #define	AIOSTKSIZE	(128 * 1024)
56 #endif
57 
58 #define	SIGAIOCANCEL		SIGLWP	/* special aio cancelation signal */
59 
60 #define	AIO_WAITN_MAXIOCBS	32768	/* max. iocbs per system call */
61 
62 /*
63  * Declare structure types.  The structures themselves are defined below.
64  */
65 typedef struct aio_args		aio_args_t;
66 typedef struct aio_lio		aio_lio_t;
67 typedef struct notif_param	notif_param_t;
68 typedef struct aio_req		aio_req_t;
69 typedef struct aio_worker	aio_worker_t;
70 typedef struct aio_hash		aio_hash_t;
71 
72 struct aio_args {
73 	int		fd;
74 	caddr_t		buf;
75 	size_t		bufsz;
76 	offset_t	offset;
77 };
78 
79 /*
80  * list head for UFS list I/O
81  */
82 struct aio_lio {
83 	mutex_t		lio_mutex;	/* list mutex */
84 	cond_t		lio_cond_cv;	/* list notification for I/O done */
85 	aio_lio_t	*lio_next;	/* pointer to next on freelist */
86 	char		lio_mode;	/* LIO_WAIT/LIO_NOWAIT */
87 	char		lio_canned;	/* lio was canceled */
88 	char		lio_largefile;	/* largefile operation */
89 	char		lio_waiting;	/* waiting in __lio_listio() */
90 	int		lio_nent;	/* Number of list I/O's */
91 	int		lio_refcnt;	/* outstanding I/O's */
92 	int		lio_event;	/* Event number for notification */
93 	int		lio_port;	/* Port number for notification */
94 	int		lio_signo;	/* Signal number for notification */
95 	union sigval	lio_sigval;	/* Signal parameter */
96 	uintptr_t	lio_object;	/* for SIGEV_THREAD or SIGEV_PORT */
97 	struct sigevent	*lio_sigevent;	/* Notification function and attr. */
98 };
99 
100 /*
101  * Notification parameters
102  */
103 struct notif_param {
104 	int		np_signo;	/* SIGEV_SIGNAL */
105 	int		np_port;	/* SIGEV_THREAD or SIGEV_PORT */
106 	void		*np_user;
107 	int		np_event;
108 	uintptr_t	np_object;
109 	int		np_lio_signo;	/* listio: SIGEV_SIGNAL */
110 	int		np_lio_port;	/* listio: SIGEV_THREAD or SIGEV_PORT */
111 	void		*np_lio_user;
112 	int		np_lio_event;
113 	uintptr_t	np_lio_object;
114 };
115 
116 struct aio_req {
117 	/*
118 	 * fields protected by _aio_mutex lock.
119 	 */
120 	aio_req_t *req_link;		/* hash/freelist chain link */
121 	/*
122 	 * when req is on the doneq, then req_next is protected by
123 	 * the _aio_mutex lock. when the req is on a work q, then
124 	 * req_next is protected by a worker's work_qlock1 lock.
125 	 */
126 	aio_req_t *req_next;		/* request/done queue link */
127 	aio_req_t *req_prev;		/* double linked list */
128 	/*
129 	 * fields protected by a worker's work_qlock1 lock.
130 	 */
131 	char		req_state;	/* AIO_REQ_QUEUED, ... */
132 	/*
133 	 * fields require no locking.
134 	 */
135 	char		req_type;	/* AIO_POSIX_REQ or not */
136 	char		req_largefile;	/* largefile operation */
137 	char		req_op;		/* AIOREAD, etc. */
138 	aio_worker_t	*req_worker;	/* associate request with worker */
139 	aio_result_t	*req_resultp;	/* address of result buffer */
140 	aio_args_t	req_args;	/* arglist */
141 	aio_lio_t	*req_head;	/* list head for LIO */
142 	struct sigevent	req_sigevent;
143 	void		*req_aiocbp;	/* ptr to aiocb or aiocb64 */
144 	notif_param_t	req_notify;	/* notification parameters */
145 };
146 
147 /* special lio type that destroys itself when lio refcnt becomes zero */
148 #define	LIO_FSYNC	LIO_WAIT+1
149 #define	LIO_DESTROY	LIO_FSYNC+1
150 
151 /* lio flags */
152 #define	LIO_FSYNC_CANCELED	0x1
153 
154 /* values for aio_state */
155 
156 #define	AIO_REQ_QUEUED		1
157 #define	AIO_REQ_INPROGRESS	2
158 #define	AIO_REQ_CANCELED	3
159 #define	AIO_REQ_DONE		4
160 #define	AIO_REQ_FREE		5
161 #define	AIO_REQ_DONEQ		6
162 
163 /* use KAIO in _aio_rw() */
164 #define	AIO_NO_KAIO		0x0
165 #define	AIO_KAIO		0x1
166 #define	AIO_NO_DUPS		0x2
167 
168 #define	AIO_POSIX_REQ		0x1
169 
170 #define	CHECK			1
171 #define	NOCHECK			2
172 #define	CHECKED			3
173 #define	USERAIO			4
174 #define	USERAIO_DONE		5
175 
176 /* values for _aio_flags */
177 
178 /* if set, _aiodone() notifies aio_waitn about done requests */
179 #define	AIO_WAIT_INPROGRESS	0x1
180 /* if set, _aiodone() wakes up functions waiting for completed I/Os */
181 #define	AIO_IO_WAITING		0x2
182 #define	AIO_LIB_WAITN		0x4	/* aio_waitn in progress */
183 #define	AIO_LIB_WAITN_PENDING	0x8	/* aio_waitn requests pending */
184 
185 /*
186  * Before a kaio() system call, the fd will be checked
187  * to ensure that kernel async. I/O is supported for this file.
188  * The only way to find out is if a kaio() call returns ENOTSUP,
189  * so the default will always be to try the kaio() call. Only in
190  * the specific instance of a kaio() call returning ENOTSUP
191  * will we stop submitting kaio() calls for that fd.
192  * If the fd is outside the array bounds, we will allow the kaio()
193  * call.
194  *
195  * The only way that an fd entry can go from ENOTSUP to supported
196  * is if that fd is freed up by a close(), and close will clear
197  * the entry for that fd.
198  *
199  * Each fd gets a bit in the array _kaio_supported[].
200  *
201  * uint32_t	_kaio_supported[MAX_KAIO_FDARRAY_SIZE];
202  *
203  * Array is MAX_KAIO_ARRAY_SIZE of 32-bit elements, for 8kb.
204  * If more than (MAX_KAIO_FDARRAY_SIZE * KAIO_FDARRAY_ELEM_SIZE)
205  * files are open, this can be expanded.
206  */
207 
208 #define	MAX_KAIO_FDARRAY_SIZE		2048
209 #define	KAIO_FDARRAY_ELEM_SIZE		WORD_BIT	/* uint32_t */
210 
211 #define	MAX_KAIO_FDS	(MAX_KAIO_FDARRAY_SIZE * KAIO_FDARRAY_ELEM_SIZE)
212 
213 #define	VALID_FD(fdes)		((fdes) >= 0 && (fdes) < MAX_KAIO_FDS)
214 
215 #define	KAIO_SUPPORTED(fdes)						\
216 	(!VALID_FD(fdes) ||						\
217 		((_kaio_supported[(fdes) / KAIO_FDARRAY_ELEM_SIZE] &	\
218 		(uint32_t)(1 << ((fdes) % KAIO_FDARRAY_ELEM_SIZE))) == 0))
219 
220 #define	SET_KAIO_NOT_SUPPORTED(fdes)					\
221 	if (VALID_FD(fdes))						\
222 		_kaio_supported[(fdes) / KAIO_FDARRAY_ELEM_SIZE] |=	\
223 		(uint32_t)(1 << ((fdes) % KAIO_FDARRAY_ELEM_SIZE))
224 
225 #define	CLEAR_KAIO_SUPPORTED(fdes)					\
226 	if (VALID_FD(fdes))						\
227 		_kaio_supported[(fdes) / KAIO_FDARRAY_ELEM_SIZE] &=	\
228 		~(uint32_t)(1 << ((fdes) % KAIO_FDARRAY_ELEM_SIZE))
229 
230 struct aio_worker {
231 	aio_worker_t *work_forw;	/* forward link in list of workers */
232 	aio_worker_t *work_backw;	/* backwards link in list of workers */
233 	mutex_t work_qlock1;		/* lock for work queue 1 */
234 	cond_t work_idle_cv;		/* place to sleep when idle */
235 	aio_req_t *work_head1;		/* head of work request queue 1 */
236 	aio_req_t *work_tail1;		/* tail of work request queue 1 */
237 	aio_req_t *work_next1;		/* work queue one's next pointer */
238 	aio_req_t *work_prev1;		/* last request done from queue 1 */
239 	aio_req_t *work_req;		/* active work request */
240 	thread_t work_tid;		/* worker's thread-id */
241 	int work_count1;		/* length of work queue one */
242 	int work_done1;			/* number of requests done */
243 	int work_minload1;		/* min length of queue */
244 	int work_idleflg;		/* when set, worker is idle */
245 	sigjmp_buf work_jmp_buf;	/* cancellation point */
246 };
247 
248 struct aio_hash {			/* resultp hash table */
249 	mutex_t		hash_lock;
250 	aio_req_t	*hash_ptr;
251 #if !defined(_LP64)
252 	void		*hash_pad;	/* ensure sizeof (aio_hash_t) == 32 */
253 #endif
254 };
255 
256 extern aio_hash_t *_aio_hash;
257 
258 #define	HASHSZ			2048	/* power of 2 */
259 #define	AIOHASH(resultp)	((((uintptr_t)(resultp) >> 17) ^ \
260 				((uintptr_t)(resultp) >> 2)) & (HASHSZ - 1))
261 #define	POSIX_AIO(x)		((x)->req_type == AIO_POSIX_REQ)
262 
263 extern int __uaio_init(void);
264 extern void _kaio_init(void);
265 extern intptr_t _kaio(int, ...);
266 extern int _aiorw(int, caddr_t, int, offset_t, int, aio_result_t *, int);
267 extern int _aio_rw(aiocb_t *, aio_lio_t *, aio_worker_t **, int, int);
268 #if !defined(_LP64)
269 extern int _aio_rw64(aiocb64_t *, aio_lio_t *, aio_worker_t **, int, int);
270 #endif
271 extern int _aio_create_worker(aio_req_t *, int);
272 extern int _aio_cancel_req(aio_worker_t *, aio_req_t *, int *, int *);
273 extern int aiocancel_all(int);
274 extern void aio_panic(const char *) __NORETURN;
275 extern aio_req_t *_aio_hash_find(aio_result_t *);
276 extern aio_req_t *_aio_hash_del(aio_result_t *);
277 extern void _aio_req_mark_done(aio_req_t *);
278 extern void _aio_waitn_wakeup(void);
279 extern aio_worker_t *_aio_worker_alloc(void);
280 extern void _aio_worker_free(void *);
281 extern aio_req_t *_aio_req_alloc(void);
282 extern void _aio_req_free(aio_req_t *);
283 extern aio_lio_t *_aio_lio_alloc(void);
284 extern void _aio_lio_free(aio_lio_t *);
285 extern int _aio_idle(aio_worker_t *);
286 extern void *_aio_do_request(void *);
287 extern void *_aio_do_notify(void *);
288 extern void _lio_remove(aio_req_t *);
289 extern aio_req_t *_aio_req_remove(aio_req_t *);
290 extern int _aio_get_timedelta(timespec_t *, timespec_t *);
291 extern aio_result_t *_aio_req_done(void);
292 extern void _aio_set_result(aio_req_t *, ssize_t, int);
293 extern int _aio_sigev_thread_init(struct sigevent *);
294 extern int _aio_sigev_thread(aiocb_t *);
295 #if !defined(_LP64)
296 extern int _aio_sigev_thread64(aiocb64_t *);
297 #endif
298 
299 extern aio_worker_t *_kaiowp;		/* points to kaio cleanup thread */
300 extern aio_worker_t *__workers_rw;	/* list of all rw workers */
301 extern aio_worker_t *__nextworker_rw;	/* worker chosen for next rw request */
302 extern int __rw_workerscnt;		/* number of rw workers */
303 extern aio_worker_t *__workers_no;	/* list of all notification workers */
304 extern aio_worker_t *__nextworker_no;	/* worker chosen, next notification */
305 extern int __no_workerscnt;		/* number of notification workers */
306 extern mutex_t __aio_initlock;		/* makes aio initialization atomic */
307 extern cond_t __aio_initcv;
308 extern int __aio_initbusy;
309 extern mutex_t __aio_mutex;		/* global aio lock */
310 extern cond_t _aio_iowait_cv;		/* wait for userland I/Os */
311 extern cond_t _aio_waitn_cv;		/* wait for end of aio_waitn */
312 extern int _max_workers;		/* max number of workers permitted */
313 extern int _min_workers;		/* min number of workers */
314 extern sigset_t _worker_set;		/* worker's signal mask */
315 extern int _aio_worker_cnt;		/* number of AIO workers */
316 extern int _sigio_enabled;		/* when set, send SIGIO signal */
317 extern pid_t __pid;			/* process's PID */
318 extern int __uaio_ok;			/* indicates if aio is initialized */
319 extern int _kaio_ok;			/* indicates if kaio is initialized */
320 extern pthread_key_t _aio_key;		/* for thread-specific data */
321 extern aio_req_t *_aio_done_tail;	/* list of done requests */
322 extern aio_req_t *_aio_done_head;
323 extern aio_req_t *_aio_doneq;
324 extern int _aio_freelist_cnt;
325 extern int _aio_allocated_cnt;
326 extern int _aio_donecnt;
327 extern int _aio_doneq_cnt;
328 extern int _aio_waitncnt;		/* # of requests for aio_waitn */
329 extern int _aio_outstand_cnt;		/* # of outstanding requests */
330 extern int _kaio_outstand_cnt;		/* # of outstanding kaio requests */
331 extern int _aio_req_done_cnt;		/* req. done but not in "done queue" */
332 extern int _aio_kernel_suspend;		/* active kernel kaio calls */
333 extern int _aio_suscv_cnt;		/* aio_suspend calls waiting on cv's */
334 extern int _aiowait_flag;		/* when set, aiowait() is inprogress */
335 extern int _aio_flags;			/* see defines, above */
336 extern uint32_t *_kaio_supported;
337 
338 extern const sigset_t maskset;		/* all maskable signals */
339 
340 #ifdef	__cplusplus
341 }
342 #endif
343 
344 #endif	/* _ASYNCIO_H */
345