1 /* $MirOS: src/lib/libc/include/thread_private.h,v 1.4 2010/09/12 15:51:03 tg Exp $ */
2 /* $OpenBSD: thread_private.h,v 1.16 2004/06/07 21:11:23 marc Exp $ */
3 
4 /* needs <sys/time.h> for some functions */
5 
6 /* PUBLIC DOMAIN: No Rights Reserved. Marco S Hyman <marc@snafu.org> */
7 
8 #ifndef _THREAD_PRIVATE_H_
9 #define _THREAD_PRIVATE_H_
10 
11 /*
12  * This file defines the thread library interface to libc.  Thread
13  * libraries must implement the functions described here for proper
14  * inter-operation with libc.   libc contains weak versions of the
15  * described functions for operation in a non-threaded environment.
16  */
17 
18 /*
19  * This variable is 0 until a second thread is created.
20  */
21 extern int __isthreaded;
22 
23 /*
24  * Weak symbols are used in libc so that the thread library can
25  * efficiently wrap libc functions.
26  *
27  * Use WEAK_NAME(n) to get a libc-private name for n (_weak_n),
28  *     WEAK_ALIAS(n) to generate the weak symbol n pointing to _weak_n,
29  *     WEAK_PROTOTYPE(n) to generate a prototype for _weak_n (based on n).
30  */
31 #define WEAK_NAME(name)		__CONCAT(_weak_,name)
32 #define WEAK_ALIAS(name)	__weak_alias(name, WEAK_NAME(name))
33 #ifdef __GNUC__
34 #define WEAK_PROTOTYPE(name)	__typeof__(name) WEAK_NAME(name)
35 #else
36 #define WEAK_PROTOTYPE(name)	/* typeof() only in gcc */
37 #endif
38 
39 /*
40  * helper macro to make unique names in the thread namespace
41  */
42 #define __THREAD_NAME(name)	__CONCAT(_thread_tagname_,name)
43 
44 /*
45  * helper functions that exist as (weak) null functions in libc and
46  * (strong) functions in the thread library.   These functions:
47  *
48  * _thread_tag_lock:
49  *	lock the mutex associated with the given tag.   If the given
50  *	tag is NULL a tag is first allocated.
51  *
52  * _thread_tag_unlock:
53  *	unlock the mutex associated with the given tag.   If the given
54  *	tag is NULL a tag is first allocated.
55  *
56  * _thread_tag_storage:
57  *	return a pointer to per thread instance of data associated
58  *	with the given tag.  If the given tag is NULL a tag is first
59  *	allocated.
60  */
61 void	_thread_tag_lock(void **);
62 void	_thread_tag_unlock(void **);
63 void   *_thread_tag_storage(void **, void *, size_t, void *);
64 
65 /*
66  * Macros used in libc to access thread mutex, keys, and per thread storage.
67  * _THREAD_PRIVATE_KEY and _THREAD_PRIVATE_MUTEX are different macros for
68  * historical reasons.   They do the same thing, define a static variable
69  * keyed by 'name' that identifies a mutex and a key to identify per thread
70  * data.
71  */
72 #define _THREAD_PRIVATE_KEY(name)					\
73 	static void *__THREAD_NAME(name)
74 #define _THREAD_PRIVATE_MUTEX(name)					\
75 	static void *__THREAD_NAME(name)
76 #define _THREAD_PRIVATE_MUTEX_LOCK(name)				\
77 	_thread_tag_lock(&(__THREAD_NAME(name)))
78 #define _THREAD_PRIVATE_MUTEX_UNLOCK(name)				\
79 	_thread_tag_unlock(&(__THREAD_NAME(name)))
80 #define _THREAD_PRIVATE(keyname, storage, error)			\
81 	_thread_tag_storage(&(__THREAD_NAME(keyname)), &(storage),	\
82 			    sizeof (storage), error)
83 /*
84  * Resolver code is special cased in that it uses global keys.
85  */
86 extern void *__THREAD_NAME(_res);
87 extern void *__THREAD_NAME(_res_ext);
88 extern void *__THREAD_NAME(serv_mutex);
89 
90 /*
91  * File descriptor locking definitions.
92  */
93 #define FD_READ		0x1
94 #define FD_WRITE	0x2
95 #define FD_RDWR		(FD_READ | FD_WRITE)
96 
97 #ifdef _SYS_TIME_H_
98 int	_thread_fd_lock(int, int, struct timespec *);
99 #endif
100 void	_thread_fd_unlock(int, int);
101 
102 /*
103  * Macros are used in libc code for historical (debug) reasons.
104  * Define them here.
105  */
106 #define _FD_LOCK(_fd,_type,_ts)	_thread_fd_lock(_fd, _type, _ts)
107 #define _FD_UNLOCK(_fd,_type)	_thread_fd_unlock(_fd, _type)
108 
109 
110 /*
111  * malloc lock/unlock prototypes and definitions
112  */
113 void	_thread_malloc_init(void);
114 void	_thread_malloc_lock(void);
115 void	_thread_malloc_unlock(void);
116 
117 #define _MALLOC_LOCK()		do {					\
118 					if (__isthreaded)		\
119 						_thread_malloc_lock();	\
120 				} while (0)
121 #define _MALLOC_UNLOCK()	do {					\
122 					if (__isthreaded)		\
123 						_thread_malloc_unlock();\
124 				} while (0)
125 #define _MALLOC_LOCK_INIT()	do {					\
126 					if (__isthreaded)		\
127 						_thread_malloc_init();\
128 				} while (0)
129 
130 #define _ARC4_LOCK()		/* nothing; for now */
131 #define _ARC4_UNLOCK()		/* nothing; for now */
132 
133 /* copied from pthread_private.h with a twist */
134 #ifdef _LIBC_IN_ABORT
135 int     _thread_sys_sigprocmask(int, const void *, void *);
136 #endif
137 
138 #endif /* _THREAD_PRIVATE_H_ */
139