xref: /unit/src/nxt_thread.h (revision 2084:7d479274f334)
1 
2 /*
3  * Copyright (C) Igor Sysoev
4  * Copyright (C) NGINX, Inc.
5  */
6 
7 #ifndef _NXT_UNIX_THREAD_H_INCLUDED_
8 #define _NXT_UNIX_THREAD_H_INCLUDED_
9 
10 
11 /*
12  * Thread Specific Data
13  *
14  * The interface unifies two TSD implementations: the __thread storage
15  * class and pthread specific data.  It works also in non-threaded mode.
16  * The interface is optimized for the __thread storage class and non-threaded
17  * mode, since the __thread storage is faster and is supported in modern
18  * versions of Linux, FreeBSD, Solaris, and MacOSX.  Pthread specific data
19  * is considered as a fallback option.
20  *
21  * The underlining interfaces are different: pthread data must be allocated
22  * by hand and may be accessed only by using pointers whereas __thread data
23  * allocation is transparent and it is accessed directly.
24  *
25  * pthread_getspecific() is usually faster than pthread_setspecific()
26  * (much faster on MacOSX), so there is no nxt_thread_set_data() interface
27  * for this reason.  It is better to store frequently alterable thread
28  * log pointer in nxt_thread_t, but not in a dedicated key.
29  */
30 
31 #if (NXT_HAVE_THREAD_STORAGE_CLASS)
32 
33 #define nxt_thread_extern_data(type, tsd)                                     \
34     NXT_EXPORT extern __thread type  tsd
35 
36 #define nxt_thread_declare_data(type, tsd)                                    \
37     __thread type  tsd
38 
39 #define nxt_thread_init_data(tsd)
40 
41 #define nxt_thread_get_data(tsd)                                              \
42     &tsd
43 
44 
45 #else /* NXT_HAVE_PTHREAD_SPECIFIC_DATA */
46 
47 /*
48  * nxt_thread_get_data() is used as
49  *    p = nxt_thread_get_data(tsd),
50  * but the tsd address is actually required.  This could be resolved by macro
51  *    #define nxt_thread_get_data(tsd)  nxt_thread_get_data_addr(&tsd)
52  * or by definition nxt_thread_specific_data_t as an array.
53  *
54  * On Linux and Solaris pthread_key_t is unsigned integer.
55  * On FreeBSD, NetBSD, OpenBSD, and HP-UX pthread_key_t is integer.
56  * On MacOSX and AIX pthread_key_t is unsigned long integer.
57  * On Cygwin pthread_key_t is pointer to void.
58  */
59 
60 typedef struct {
61     nxt_atomic_t             key;
62     size_t                   size;
63 } nxt_thread_specific_data_t[1];
64 
65 
66 #define nxt_thread_extern_data(type, tsd)                                     \
67     NXT_EXPORT extern nxt_thread_specific_data_t  tsd
68 
69 #define nxt_thread_declare_data(type, tsd)                                    \
70     nxt_thread_specific_data_t tsd = { { (nxt_atomic_int_t) -1, sizeof(type) } }
71 
72 NXT_EXPORT void nxt_thread_init_data(nxt_thread_specific_data_t tsd);
73 
74 #define nxt_thread_get_data(tsd)                                              \
75     pthread_getspecific((pthread_key_t) tsd->key)
76 
77 #endif
78 
79 
80 typedef void (*nxt_thread_start_t)(void *data);
81 
82 typedef struct {
83     nxt_thread_start_t       start;
84     nxt_event_engine_t       *engine;
85     nxt_work_t               work;
86 } nxt_thread_link_t;
87 
88 
89 NXT_EXPORT nxt_int_t nxt_thread_create(nxt_thread_handle_t *handle,
90     nxt_thread_link_t *link);
91 NXT_EXPORT nxt_thread_t *nxt_thread_init(void);
92 NXT_EXPORT void nxt_thread_exit(nxt_thread_t *thr);
93 NXT_EXPORT void nxt_thread_cancel(nxt_thread_handle_t handle);
94 NXT_EXPORT void nxt_thread_wait(nxt_thread_handle_t handle);
95 
96 
97 #define nxt_thread_handle()                                                   \
98     pthread_self()
99 
100 
101 typedef pthread_mutex_t      nxt_thread_mutex_t;
102 
103 NXT_EXPORT nxt_int_t nxt_thread_mutex_create(nxt_thread_mutex_t *mtx);
104 NXT_EXPORT void nxt_thread_mutex_destroy(nxt_thread_mutex_t *mtx);
105 NXT_EXPORT nxt_int_t nxt_thread_mutex_lock(nxt_thread_mutex_t *mtx);
106 NXT_EXPORT nxt_bool_t nxt_thread_mutex_trylock(nxt_thread_mutex_t *mtx);
107 NXT_EXPORT nxt_int_t nxt_thread_mutex_unlock(nxt_thread_mutex_t *mtx);
108 
109 
110 typedef pthread_cond_t       nxt_thread_cond_t;
111 
112 NXT_EXPORT nxt_int_t nxt_thread_cond_create(nxt_thread_cond_t *cond);
113 NXT_EXPORT void nxt_thread_cond_destroy(nxt_thread_cond_t *cond);
114 NXT_EXPORT nxt_int_t nxt_thread_cond_signal(nxt_thread_cond_t *cond);
115 NXT_EXPORT nxt_err_t nxt_thread_cond_wait(nxt_thread_cond_t *cond,
116     nxt_thread_mutex_t *mtx, nxt_nsec_t timeout);
117 
118 
119 #if (NXT_HAVE_PTHREAD_YIELD)
120 #define nxt_thread_yield()                                                    \
121     pthread_yield()
122 
123 #elif (NXT_HAVE_PTHREAD_YIELD_NP)
124 #define nxt_thread_yield()                                                    \
125     pthread_yield_np()
126 
127 #else
128 #define nxt_thread_yield()                                                    \
129     nxt_sched_yield()
130 
131 #endif
132 
133 
134 struct nxt_thread_s {
135     nxt_log_t                *log;
136     nxt_log_t                main_log;
137 
138     nxt_task_t               *task;
139 
140     nxt_tid_t                tid;
141     nxt_thread_handle_t      handle;
142     nxt_thread_link_t        *link;
143     nxt_thread_pool_t        *thread_pool;
144 
145     nxt_thread_time_t        time;
146 
147     nxt_runtime_t            *runtime;
148     nxt_event_engine_t       *engine;
149     void                     *data;
150 
151 #if 0
152     /*
153      * Although pointer to a current fiber should be a property of
154      * engine->fibers, its placement here eliminates 2 memory accesses.
155      */
156     nxt_fiber_t              *fiber;
157 #endif
158 
159     nxt_random_t             random;
160 };
161 
162 
163 #endif /* _NXT_UNIX_THREAD_H_INCLUDED_ */
164