xref: /freebsd/sys/contrib/openzfs/lib/libtpool/thread_pool_impl.h (revision 271171e0d97b88ba2a7c3bf750c9672b484c1c13)
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 https://opensource.org/licenses/CDDL-1.0.
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 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #ifndef _THREAD_POOL_IMPL_H
28 #define	_THREAD_POOL_IMPL_H
29 
30 #include <thread_pool.h>
31 
32 #ifdef	__cplusplus
33 extern "C" {
34 #endif
35 
36 /*
37  * Thread pool implementation definitions.
38  * See <thread_pool.h> for interface declarations.
39  */
40 
41 /*
42  * FIFO queued job
43  */
44 typedef struct tpool_job tpool_job_t;
45 struct tpool_job {
46 	tpool_job_t	*tpj_next;		/* list of jobs */
47 	void		(*tpj_func)(void *);	/* function to call */
48 	void		*tpj_arg;		/* its argument */
49 };
50 
51 /*
52  * List of active threads, linked through their stacks.
53  */
54 typedef struct tpool_active tpool_active_t;
55 struct tpool_active {
56 	tpool_active_t	*tpa_next;	/* list of active threads */
57 	pthread_t	tpa_tid;	/* active thread id */
58 };
59 
60 /*
61  * The thread pool.
62  */
63 struct tpool {
64 	tpool_t		*tp_forw;	/* circular list of all thread pools */
65 	tpool_t		*tp_back;
66 	pthread_mutex_t	tp_mutex;	/* protects the pool data */
67 	pthread_cond_t	tp_busycv;	/* synchronization in tpool_dispatch */
68 	pthread_cond_t	tp_workcv;	/* synchronization with workers */
69 	pthread_cond_t	tp_waitcv;	/* synchronization in tpool_wait() */
70 	tpool_active_t	*tp_active;	/* threads performing work */
71 	tpool_job_t	*tp_head;	/* FIFO job queue */
72 	tpool_job_t	*tp_tail;
73 	pthread_attr_t	tp_attr;	/* attributes of the workers */
74 	int		tp_flags;	/* see below */
75 	uint_t		tp_linger;	/* seconds before idle workers exit */
76 	int		tp_njobs;	/* number of jobs in job queue */
77 	int		tp_minimum;	/* minimum number of worker threads */
78 	int		tp_maximum;	/* maximum number of worker threads */
79 	int		tp_current;	/* current number of worker threads */
80 	int		tp_idle;	/* number of idle workers */
81 };
82 
83 /* tp_flags */
84 #define	TP_WAIT		0x01		/* waiting in tpool_wait() */
85 #define	TP_SUSPEND	0x02		/* pool is being suspended */
86 #define	TP_DESTROY	0x04		/* pool is being destroyed */
87 #define	TP_ABANDON	0x08		/* pool is abandoned (auto-destroy) */
88 
89 #ifdef	__cplusplus
90 }
91 #endif
92 
93 #endif /* _THREAD_POOL_IMPL_H */
94