ntp_worker.h revision 293896 
1/*
2 * ntp_worker.h
3 */
4
5#ifndef NTP_WORKER_H
6#define NTP_WORKER_H
7
8#include "ntp_workimpl.h"
9
10#ifdef WORKER
11# if defined(WORK_THREAD) && defined(WORK_PIPE)
12#  ifdef HAVE_SEMAPHORE_H
13#   include <semaphore.h>
14#  endif
15# endif
16#include "ntp_stdlib.h"
17
18/* #define TEST_BLOCKING_WORKER */	/* ntp_config.c ntp_intres.c */
19
20typedef enum blocking_work_req_tag {
21	BLOCKING_GETNAMEINFO,
22	BLOCKING_GETADDRINFO,
23} blocking_work_req;
24
25typedef void (*blocking_work_callback)(blocking_work_req, void *, size_t, void *);
26
27typedef enum blocking_magic_sig_e {
28	BLOCKING_REQ_MAGIC  = 0x510c7ecf,
29	BLOCKING_RESP_MAGIC = 0x510c7e54,
30} blocking_magic_sig;
31
32/*
33 * The same header is used for both requests to and responses from
34 * the child.  In the child, done_func and context are opaque.
35 */
36typedef struct blocking_pipe_header_tag {
37	size_t			octets;
38	blocking_magic_sig	magic_sig;
39	blocking_work_req	rtype;
40	u_int			child_idx;
41	blocking_work_callback	done_func;
42	void *			context;
43} blocking_pipe_header;
44
45# ifdef WORK_THREAD
46#  ifdef SYS_WINNT
47typedef struct { HANDLE thnd; } thread_type;
48typedef struct { HANDLE shnd; } sema_type;
49#  else
50typedef pthread_t	thread_type;
51typedef sem_t		sema_type;
52#  endif
53typedef thread_type	*thr_ref;
54typedef sema_type	*sem_ref;
55# endif
56
57/*
58 *
59 */
60#if defined(WORK_FORK)
61
62typedef struct blocking_child_tag {
63	int	reusable;
64	int	pid;
65	int	req_write_pipe;		/* parent */
66	int	resp_read_pipe;
67	void *	resp_read_ctx;
68	int	req_read_pipe;		/* child */
69	int	resp_write_pipe;
70	int	ispipe;
71} blocking_child;
72
73#elif defined(WORK_THREAD)
74
75typedef struct blocking_child_tag {
76/*
77 * blocking workitems and blocking_responses are dynamically-sized
78 * one-dimensional arrays of pointers to blocking worker requests and
79 * responses.
80 *
81 * IMPORTANT: This structure is shared between threads, and all access
82 * that is not atomic (especially queue operations) must hold the
83 * 'accesslock' semaphore to avoid data races.
84 *
85 * The resource management (thread/semaphore creation/destruction)
86 * functions and functions just testing a handle are safe because these
87 * are only changed by the main thread when no worker is running on the
88 * same data structure.
89 */
90	int			reusable;
91	sem_ref			accesslock;	/* shared access lock */
92	thr_ref			thread_ref;	/* thread 'handle' */
93
94	/* the reuest queue */
95	blocking_pipe_header ** volatile
96				workitems;
97	volatile size_t		workitems_alloc;
98	size_t			head_workitem;		/* parent */
99	size_t			tail_workitem;		/* child */
100	sem_ref			workitems_pending;	/* signalling */
101
102	/* the response queue */
103	blocking_pipe_header ** volatile
104				responses;
105	volatile size_t		responses_alloc;
106	size_t			head_response;		/* child */
107	size_t			tail_response;		/* parent */
108
109	/* event handles / sem_t pointers */
110	sem_ref			wake_scheduled_sleep;
111
112	/* some systems use a pipe for notification, others a semaphore.
113	 * Both employ the queue above for the actual data transfer.
114	 */
115#ifdef WORK_PIPE
116	int			resp_read_pipe;		/* parent */
117	int			resp_write_pipe;	/* child */
118	int			ispipe;
119	void *			resp_read_ctx;		/* child */
120#else
121	sem_ref			responses_pending;	/* signalling */
122#endif
123	sema_type		sem_table[4];
124	thread_type		thr_table[1];
125} blocking_child;
126
127#endif	/* WORK_THREAD */
128
129extern	blocking_child **	blocking_children;
130extern	size_t			blocking_children_alloc;
131extern	int			worker_per_query;	/* boolean */
132extern	int			intres_req_pending;
133
134extern	u_int	available_blocking_child_slot(void);
135extern	int	queue_blocking_request(blocking_work_req, void *,
136				       size_t, blocking_work_callback,
137				       void *);
138extern	int	queue_blocking_response(blocking_child *,
139					blocking_pipe_header *, size_t,
140					const blocking_pipe_header *);
141extern	void	process_blocking_resp(blocking_child *);
142extern	int	send_blocking_req_internal(blocking_child *,
143					   blocking_pipe_header *,
144					   void *);
145extern	int	send_blocking_resp_internal(blocking_child *,
146					    blocking_pipe_header *);
147extern	blocking_pipe_header *
148		receive_blocking_req_internal(blocking_child *);
149extern	blocking_pipe_header *
150		receive_blocking_resp_internal(blocking_child *);
151extern	int	blocking_child_common(blocking_child *);
152extern	void	exit_worker(int)
153			__attribute__ ((__noreturn__));
154extern	int	worker_sleep(blocking_child *, time_t);
155extern	void	worker_idle_timer_fired(void);
156extern	void	interrupt_worker_sleep(void);
157extern	int	req_child_exit(blocking_child *);
158#ifndef HAVE_IO_COMPLETION_PORT
159extern	int	pipe_socketpair(int fds[2], int *is_pipe);
160extern	void	close_all_beyond(int);
161extern	void	close_all_except(int);
162extern	void	kill_asyncio	(int);
163#endif
164
165# ifdef WORK_PIPE
166typedef	void	(*addremove_io_fd_func)(int, int, int);
167extern	addremove_io_fd_func		addremove_io_fd;
168# else
169extern	void	handle_blocking_resp_sem(void *);
170typedef	void	(*addremove_io_semaphore_func)(sem_ref, int);
171extern	addremove_io_semaphore_func	addremove_io_semaphore;
172# endif
173
174# ifdef WORK_FORK
175extern	int				worker_process;
176# endif
177
178#endif	/* WORKER */
179
180#if defined(HAVE_DROPROOT) && defined(WORK_FORK)
181extern void	fork_deferred_worker(void);
182#else
183# define	fork_deferred_worker()	do {} while (0)
184#endif
185
186#endif	/* !NTP_WORKER_H */
187