Update files for OpenSSL-1.0.0f import.
[dragonfly.git] / secure / lib / libcrypto / man / threads.3
CommitLineData
e3261593 1.\" Automatically generated by Pod::Man 2.25 (Pod::Simple 3.19)
8b0cefbb
JR
2.\"
3.\" Standard preamble:
4.\" ========================================================================
8b0cefbb 5.de Sp \" Vertical space (when we can't use .PP)
984263bc
MD
6.if t .sp .5v
7.if n .sp
8..
8b0cefbb 9.de Vb \" Begin verbatim text
984263bc
MD
10.ft CW
11.nf
12.ne \\$1
13..
8b0cefbb 14.de Ve \" End verbatim text
984263bc 15.ft R
984263bc
MD
16.fi
17..
8b0cefbb
JR
18.\" Set up some character translations and predefined strings. \*(-- will
19.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
e257b235
PA
20.\" double quote, and \*(R" will give a right double quote. \*(C+ will
21.\" give a nicer C++. Capital omega is used to do unbreakable dashes and
22.\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff,
23.\" nothing in troff, for use with C<>.
24.tr \(*W-
8b0cefbb 25.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
984263bc 26.ie n \{\
8b0cefbb
JR
27. ds -- \(*W-
28. ds PI pi
29. if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
30. if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch
31. ds L" ""
32. ds R" ""
33. ds C` ""
34. ds C' ""
984263bc
MD
35'br\}
36.el\{\
8b0cefbb
JR
37. ds -- \|\(em\|
38. ds PI \(*p
39. ds L" ``
40. ds R" ''
984263bc 41'br\}
8b0cefbb 42.\"
e257b235
PA
43.\" Escape single quotes in literal strings from groff's Unicode transform.
44.ie \n(.g .ds Aq \(aq
45.el .ds Aq '
46.\"
8b0cefbb 47.\" If the F register is turned on, we'll generate index entries on stderr for
01185282 48.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
8b0cefbb
JR
49.\" entries marked with X<> in POD. Of course, you'll have to process the
50.\" output yourself in some meaningful fashion.
e257b235 51.ie \nF \{\
8b0cefbb
JR
52. de IX
53. tm Index:\\$1\t\\n%\t"\\$2"
984263bc 54..
8b0cefbb
JR
55. nr % 0
56. rr F
984263bc 57.\}
e257b235
PA
58.el \{\
59. de IX
60..
61.\}
aac4ff6f 62.\"
8b0cefbb
JR
63.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
64.\" Fear. Run. Save yourself. No user-serviceable parts.
65. \" fudge factors for nroff and troff
984263bc 66.if n \{\
8b0cefbb
JR
67. ds #H 0
68. ds #V .8m
69. ds #F .3m
70. ds #[ \f1
71. ds #] \fP
984263bc
MD
72.\}
73.if t \{\
8b0cefbb
JR
74. ds #H ((1u-(\\\\n(.fu%2u))*.13m)
75. ds #V .6m
76. ds #F 0
77. ds #[ \&
78. ds #] \&
984263bc 79.\}
8b0cefbb 80. \" simple accents for nroff and troff
984263bc 81.if n \{\
8b0cefbb
JR
82. ds ' \&
83. ds ` \&
84. ds ^ \&
85. ds , \&
86. ds ~ ~
87. ds /
984263bc
MD
88.\}
89.if t \{\
8b0cefbb
JR
90. ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
91. ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
92. ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
93. ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
94. ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
95. ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
984263bc 96.\}
8b0cefbb 97. \" troff and (daisy-wheel) nroff accents
984263bc
MD
98.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
99.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
100.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
101.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
102.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
103.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
104.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
105.ds ae a\h'-(\w'a'u*4/10)'e
106.ds Ae A\h'-(\w'A'u*4/10)'E
8b0cefbb 107. \" corrections for vroff
984263bc
MD
108.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
109.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
8b0cefbb 110. \" for low resolution devices (crt and lpr)
984263bc
MD
111.if \n(.H>23 .if \n(.V>19 \
112\{\
8b0cefbb
JR
113. ds : e
114. ds 8 ss
115. ds o a
116. ds d- d\h'-1'\(ga
117. ds D- D\h'-1'\(hy
118. ds th \o'bp'
119. ds Th \o'LP'
120. ds ae ae
121. ds Ae AE
984263bc
MD
122.\}
123.rm #[ #] #H #V #F C
8b0cefbb
JR
124.\" ========================================================================
125.\"
126.IX Title "threads 3"
e3261593 127.TH threads 3 "2012-01-04" "1.0.0f" "OpenSSL"
e257b235
PA
128.\" For nroff, turn off justification. Always turn off hyphenation; it makes
129.\" way too many mistakes in technical documents.
130.if n .ad l
131.nh
984263bc 132.SH "NAME"
01185282
PA
133CRYPTO_THREADID_set_callback, CRYPTO_THREADID_get_callback,
134CRYPTO_THREADID_current, CRYPTO_THREADID_cmp, CRYPTO_THREADID_cpy,
135CRYPTO_THREADID_hash, CRYPTO_set_locking_callback, CRYPTO_num_locks,
984263bc
MD
136CRYPTO_set_dynlock_create_callback, CRYPTO_set_dynlock_lock_callback,
137CRYPTO_set_dynlock_destroy_callback, CRYPTO_get_new_dynlockid,
138CRYPTO_destroy_dynlockid, CRYPTO_lock \- OpenSSL thread support
139.SH "SYNOPSIS"
8b0cefbb 140.IX Header "SYNOPSIS"
984263bc
MD
141.Vb 1
142\& #include <openssl/crypto.h>
e257b235 143\&
01185282
PA
144\& /* Don\*(Aqt use this structure directly. */
145\& typedef struct crypto_threadid_st
146\& {
147\& void *ptr;
148\& unsigned long val;
149\& } CRYPTO_THREADID;
150\& /* Only use CRYPTO_THREADID_set_[numeric|pointer]() within callbacks */
151\& void CRYPTO_THREADID_set_numeric(CRYPTO_THREADID *id, unsigned long val);
152\& void CRYPTO_THREADID_set_pointer(CRYPTO_THREADID *id, void *ptr);
153\& int CRYPTO_THREADID_set_callback(void (*threadid_func)(CRYPTO_THREADID *));
154\& void (*CRYPTO_THREADID_get_callback(void))(CRYPTO_THREADID *);
155\& void CRYPTO_THREADID_current(CRYPTO_THREADID *id);
156\& int CRYPTO_THREADID_cmp(const CRYPTO_THREADID *a,
157\& const CRYPTO_THREADID *b);
158\& void CRYPTO_THREADID_cpy(CRYPTO_THREADID *dest,
159\& const CRYPTO_THREADID *src);
160\& unsigned long CRYPTO_THREADID_hash(const CRYPTO_THREADID *id);
e257b235 161\&
984263bc 162\& int CRYPTO_num_locks(void);
e257b235 163\&
984263bc
MD
164\& /* struct CRYPTO_dynlock_value needs to be defined by the user */
165\& struct CRYPTO_dynlock_value;
e257b235 166\&
984263bc
MD
167\& void CRYPTO_set_dynlock_create_callback(struct CRYPTO_dynlock_value *
168\& (*dyn_create_function)(char *file, int line));
169\& void CRYPTO_set_dynlock_lock_callback(void (*dyn_lock_function)
170\& (int mode, struct CRYPTO_dynlock_value *l,
171\& const char *file, int line));
172\& void CRYPTO_set_dynlock_destroy_callback(void (*dyn_destroy_function)
173\& (struct CRYPTO_dynlock_value *l, const char *file, int line));
e257b235 174\&
984263bc 175\& int CRYPTO_get_new_dynlockid(void);
e257b235 176\&
984263bc 177\& void CRYPTO_destroy_dynlockid(int i);
e257b235 178\&
984263bc 179\& void CRYPTO_lock(int mode, int n, const char *file, int line);
e257b235 180\&
984263bc 181\& #define CRYPTO_w_lock(type) \e
e257b235 182\& CRYPTO_lock(CRYPTO_LOCK|CRYPTO_WRITE,type,_\|_FILE_\|_,_\|_LINE_\|_)
984263bc 183\& #define CRYPTO_w_unlock(type) \e
e257b235 184\& CRYPTO_lock(CRYPTO_UNLOCK|CRYPTO_WRITE,type,_\|_FILE_\|_,_\|_LINE_\|_)
984263bc 185\& #define CRYPTO_r_lock(type) \e
e257b235 186\& CRYPTO_lock(CRYPTO_LOCK|CRYPTO_READ,type,_\|_FILE_\|_,_\|_LINE_\|_)
984263bc 187\& #define CRYPTO_r_unlock(type) \e
e257b235 188\& CRYPTO_lock(CRYPTO_UNLOCK|CRYPTO_READ,type,_\|_FILE_\|_,_\|_LINE_\|_)
984263bc 189\& #define CRYPTO_add(addr,amount,type) \e
e257b235 190\& CRYPTO_add_lock(addr,amount,type,_\|_FILE_\|_,_\|_LINE_\|_)
984263bc
MD
191.Ve
192.SH "DESCRIPTION"
8b0cefbb 193.IX Header "DESCRIPTION"
984263bc 194OpenSSL can safely be used in multi-threaded applications provided
01185282
PA
195that at least two callback functions are set, locking_function and
196threadid_func.
984263bc 197.PP
8b0cefbb 198locking_function(int mode, int n, const char *file, int line) is
984263bc
MD
199needed to perform locking on shared data structures.
200(Note that OpenSSL uses a number of global data structures that
201will be implicitly shared whenever multiple threads use OpenSSL.)
202Multi-threaded applications will crash at random if it is not set.
203.PP
8b0cefbb 204\&\fIlocking_function()\fR must be able to handle up to \fICRYPTO_num_locks()\fR
984263bc 205different mutex locks. It sets the \fBn\fR\-th lock if \fBmode\fR &
8b0cefbb 206\&\fB\s-1CRYPTO_LOCK\s0\fR, and releases it otherwise.
984263bc 207.PP
8b0cefbb 208\&\fBfile\fR and \fBline\fR are the file number of the function setting the
984263bc
MD
209lock. They can be useful for debugging.
210.PP
01185282
PA
211threadid_func(\s-1CRYPTO_THREADID\s0 *id) is needed to record the currently-executing
212thread's identifier into \fBid\fR. The implementation of this callback should not
213fill in \fBid\fR directly, but should use \fICRYPTO_THREADID_set_numeric()\fR if thread
214IDs are numeric, or \fICRYPTO_THREADID_set_pointer()\fR if they are pointer-based.
215If the application does not register such a callback using
216\&\fICRYPTO_THREADID_set_callback()\fR, then a default implementation is used \- on
217Windows and BeOS this uses the system's default thread identifying APIs, and on
218all other platforms it uses the address of \fBerrno\fR. The latter is satisfactory
219for thread-safety if and only if the platform has a thread-local error number
220facility.
221.PP
222Once \fIthreadid_func()\fR is registered, or if the built-in default implementation is
223to be used;
224.IP "\(bu" 4
225\&\fICRYPTO_THREADID_current()\fR records the currently-executing thread \s-1ID\s0 into the
226given \fBid\fR object.
227.IP "\(bu" 4
228\&\fICRYPTO_THREADID_cmp()\fR compares two thread IDs (returning zero for equality, ie.
229the same semantics as \fImemcmp()\fR).
230.IP "\(bu" 4
231\&\fICRYPTO_THREADID_cpy()\fR duplicates a thread \s-1ID\s0 value,
232.IP "\(bu" 4
233\&\fICRYPTO_THREADID_hash()\fR returns a numeric value usable as a hash-table key. This
234is usually the exact numeric or pointer-based thread \s-1ID\s0 used internally, however
235this also handles the unusual case where pointers are larger than 'long'
236variables and the platform's thread IDs are pointer-based \- in this case, mixing
237is done to attempt to produce a unique numeric value even though it is not as
238wide as the platform's true thread IDs.
984263bc
MD
239.PP
240Additionally, OpenSSL supports dynamic locks, and sometimes, some parts
241of OpenSSL need it for better performance. To enable this, the following
242is required:
e257b235
PA
243.IP "\(bu" 4
244Three additional callback function, dyn_create_function, dyn_lock_function
245and dyn_destroy_function.
246.IP "\(bu" 4
247A structure defined with the data that each lock needs to handle.
984263bc
MD
248.PP
249struct CRYPTO_dynlock_value has to be defined to contain whatever structure
250is needed to handle locks.
251.PP
8b0cefbb 252dyn_create_function(const char *file, int line) is needed to create a
984263bc
MD
253lock. Multi-threaded applications might crash at random if it is not set.
254.PP
8b0cefbb 255dyn_lock_function(int mode, CRYPTO_dynlock *l, const char *file, int line)
984263bc
MD
256is needed to perform locking off dynamic lock numbered n. Multi-threaded
257applications might crash at random if it is not set.
258.PP
8b0cefbb 259dyn_destroy_function(CRYPTO_dynlock *l, const char *file, int line) is
984263bc
MD
260needed to destroy the lock l. Multi-threaded applications might crash at
261random if it is not set.
262.PP
8b0cefbb 263\&\fICRYPTO_get_new_dynlockid()\fR is used to create locks. It will call
984263bc
MD
264dyn_create_function for the actual creation.
265.PP
8b0cefbb 266\&\fICRYPTO_destroy_dynlockid()\fR is used to destroy locks. It will call
984263bc
MD
267dyn_destroy_function for the actual destruction.
268.PP
8b0cefbb 269\&\fICRYPTO_lock()\fR is used to lock and unlock the locks. mode is a bitfield
984263bc
MD
270describing what should be done with the lock. n is the number of the
271lock as returned from \fICRYPTO_get_new_dynlockid()\fR. mode can be combined
272from the following values. These values are pairwise exclusive, with
273undefined behaviour if misused (for example, \s-1CRYPTO_READ\s0 and \s-1CRYPTO_WRITE\s0
274should not be used together):
275.PP
276.Vb 4
277\& CRYPTO_LOCK 0x01
278\& CRYPTO_UNLOCK 0x02
279\& CRYPTO_READ 0x04
280\& CRYPTO_WRITE 0x08
281.Ve
282.SH "RETURN VALUES"
8b0cefbb
JR
283.IX Header "RETURN VALUES"
284\&\fICRYPTO_num_locks()\fR returns the required number of locks.
984263bc 285.PP
8b0cefbb 286\&\fICRYPTO_get_new_dynlockid()\fR returns the index to the newly created lock.
984263bc
MD
287.PP
288The other functions return no values.
a561f9ff
SS
289.SH "NOTES"
290.IX Header "NOTES"
984263bc
MD
291You can find out if OpenSSL was configured with thread support:
292.PP
293.Vb 7
294\& #define OPENSSL_THREAD_DEFINES
295\& #include <openssl/opensslconf.h>
a561f9ff 296\& #if defined(OPENSSL_THREADS)
984263bc
MD
297\& // thread support enabled
298\& #else
299\& // no thread support
300\& #endif
301.Ve
8b0cefbb 302.PP
984263bc
MD
303Also, dynamic locks are currently not used internally by OpenSSL, but
304may do so in the future.
305.SH "EXAMPLES"
8b0cefbb
JR
306.IX Header "EXAMPLES"
307\&\fBcrypto/threads/mttest.c\fR shows examples of the callback functions on
984263bc
MD
308Solaris, Irix and Win32.
309.SH "HISTORY"
8b0cefbb 310.IX Header "HISTORY"
01185282 311\&\fICRYPTO_set_locking_callback()\fR is
984263bc 312available in all versions of SSLeay and OpenSSL.
8b0cefbb
JR
313\&\fICRYPTO_num_locks()\fR was added in OpenSSL 0.9.4.
314All functions dealing with dynamic locks were added in OpenSSL 0.9.5b\-dev.
01185282
PA
315\&\fB\s-1CRYPTO_THREADID\s0\fR and associated functions were introduced in OpenSSL 1.0.0
316to replace (actually, deprecate) the previous \fICRYPTO_set_id_callback()\fR,
317\&\fICRYPTO_get_id_callback()\fR, and \fICRYPTO_thread_id()\fR functions which assumed
318thread IDs to always be represented by 'unsigned long'.
984263bc 319.SH "SEE ALSO"
74dab6c2 320.IX Header "SEE ALSO"
8b0cefbb 321\&\fIcrypto\fR\|(3)