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diff --git a/usr/man/man3/threads.3 b/usr/man/man3/threads.3 new file mode 100755 index 000000000..ea1322edc --- /dev/null +++ b/usr/man/man3/threads.3 @@ -0,0 +1,303 @@ +.\" Automatically generated by Pod::Man 2.28 (Pod::Simple 3.28) +.\" +.\" Standard preamble: +.\" ======================================================================== +.de Sp \" Vertical space (when we can't use .PP) +.if t .sp .5v +.if n .sp +.. +.de Vb \" Begin verbatim text +.ft CW +.nf +.ne \\$1 +.. +.de Ve \" End verbatim text +.ft R +.fi +.. +.\" Set up some character translations and predefined strings. \*(-- will +.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left +.\" double quote, and \*(R" will give a right double quote. \*(C+ will +.\" give a nicer C++. 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Always turn off hyphenation; it makes +.\" way too many mistakes in technical documents. +.if n .ad l +.nh +.SH "NAME" +CRYPTO_set_locking_callback, CRYPTO_set_id_callback, CRYPTO_num_locks, +CRYPTO_set_dynlock_create_callback, CRYPTO_set_dynlock_lock_callback, +CRYPTO_set_dynlock_destroy_callback, CRYPTO_get_new_dynlockid, +CRYPTO_destroy_dynlockid, CRYPTO_lock \- OpenSSL thread support +.SH "SYNOPSIS" +.IX Header "SYNOPSIS" +.Vb 1 +\& #include <openssl/crypto.h> +\& +\& void CRYPTO_set_locking_callback(void (*locking_function)(int mode, +\& int n, const char *file, int line)); +\& +\& void CRYPTO_set_id_callback(unsigned long (*id_function)(void)); +\& +\& int CRYPTO_num_locks(void); +\& +\& +\& /* struct CRYPTO_dynlock_value needs to be defined by the user */ +\& struct CRYPTO_dynlock_value; +\& +\& void CRYPTO_set_dynlock_create_callback(struct CRYPTO_dynlock_value * +\& (*dyn_create_function)(char *file, int line)); +\& void CRYPTO_set_dynlock_lock_callback(void (*dyn_lock_function) +\& (int mode, struct CRYPTO_dynlock_value *l, +\& const char *file, int line)); +\& void CRYPTO_set_dynlock_destroy_callback(void (*dyn_destroy_function) +\& (struct CRYPTO_dynlock_value *l, const char *file, int line)); +\& +\& int CRYPTO_get_new_dynlockid(void); +\& +\& void CRYPTO_destroy_dynlockid(int i); +\& +\& void CRYPTO_lock(int mode, int n, const char *file, int line); +\& +\& #define CRYPTO_w_lock(type) \e +\& CRYPTO_lock(CRYPTO_LOCK|CRYPTO_WRITE,type,_\|_FILE_\|_,_\|_LINE_\|_) +\& #define CRYPTO_w_unlock(type) \e +\& CRYPTO_lock(CRYPTO_UNLOCK|CRYPTO_WRITE,type,_\|_FILE_\|_,_\|_LINE_\|_) +\& #define CRYPTO_r_lock(type) \e +\& CRYPTO_lock(CRYPTO_LOCK|CRYPTO_READ,type,_\|_FILE_\|_,_\|_LINE_\|_) +\& #define CRYPTO_r_unlock(type) \e +\& CRYPTO_lock(CRYPTO_UNLOCK|CRYPTO_READ,type,_\|_FILE_\|_,_\|_LINE_\|_) +\& #define CRYPTO_add(addr,amount,type) \e +\& CRYPTO_add_lock(addr,amount,type,_\|_FILE_\|_,_\|_LINE_\|_) +.Ve +.SH "DESCRIPTION" +.IX Header "DESCRIPTION" +OpenSSL can safely be used in multi-threaded applications provided +that at least two callback functions are set. +.PP +locking_function(int mode, int n, const char *file, int line) is +needed to perform locking on shared data structures. +(Note that OpenSSL uses a number of global data structures that +will be implicitly shared whenever multiple threads use OpenSSL.) +Multi-threaded applications will crash at random if it is not set. +.PP +\&\fIlocking_function()\fR must be able to handle up to \fICRYPTO_num_locks()\fR +different mutex locks. It sets the \fBn\fR\-th lock if \fBmode\fR & +\&\fB\s-1CRYPTO_LOCK\s0\fR, and releases it otherwise. +.PP +\&\fBfile\fR and \fBline\fR are the file number of the function setting the +lock. They can be useful for debugging. +.PP +id_function(void) is a function that returns a thread \s-1ID,\s0 for example +\&\fIpthread_self()\fR if it returns an integer (see \s-1NOTES\s0 below). It isn't +needed on Windows nor on platforms where \fIgetpid()\fR returns a different +\&\s-1ID\s0 for each thread (see \s-1NOTES\s0 below). +.PP +Additionally, OpenSSL supports dynamic locks, and sometimes, some parts +of OpenSSL need it for better performance. To enable this, the following +is required: +.IP "\(bu" 4 +Three additional callback function, dyn_create_function, dyn_lock_function +and dyn_destroy_function. +.IP "\(bu" 4 +A structure defined with the data that each lock needs to handle. +.PP +struct CRYPTO_dynlock_value has to be defined to contain whatever structure +is needed to handle locks. +.PP +dyn_create_function(const char *file, int line) is needed to create a +lock. Multi-threaded applications might crash at random if it is not set. +.PP +dyn_lock_function(int mode, CRYPTO_dynlock *l, const char *file, int line) +is needed to perform locking off dynamic lock numbered n. Multi-threaded +applications might crash at random if it is not set. +.PP +dyn_destroy_function(CRYPTO_dynlock *l, const char *file, int line) is +needed to destroy the lock l. Multi-threaded applications might crash at +random if it is not set. +.PP +\&\fICRYPTO_get_new_dynlockid()\fR is used to create locks. It will call +dyn_create_function for the actual creation. +.PP +\&\fICRYPTO_destroy_dynlockid()\fR is used to destroy locks. It will call +dyn_destroy_function for the actual destruction. +.PP +\&\fICRYPTO_lock()\fR is used to lock and unlock the locks. mode is a bitfield +describing what should be done with the lock. n is the number of the +lock as returned from \fICRYPTO_get_new_dynlockid()\fR. mode can be combined +from the following values. These values are pairwise exclusive, with +undefined behaviour if misused (for example, \s-1CRYPTO_READ\s0 and \s-1CRYPTO_WRITE\s0 +should not be used together): +.PP +.Vb 4 +\& CRYPTO_LOCK 0x01 +\& CRYPTO_UNLOCK 0x02 +\& CRYPTO_READ 0x04 +\& CRYPTO_WRITE 0x08 +.Ve +.SH "RETURN VALUES" +.IX Header "RETURN VALUES" +\&\fICRYPTO_num_locks()\fR returns the required number of locks. +.PP +\&\fICRYPTO_get_new_dynlockid()\fR returns the index to the newly created lock. +.PP +The other functions return no values. +.SH "NOTES" +.IX Header "NOTES" +You can find out if OpenSSL was configured with thread support: +.PP +.Vb 7 +\& #define OPENSSL_THREAD_DEFINES +\& #include <openssl/opensslconf.h> +\& #if defined(OPENSSL_THREADS) +\& // thread support enabled +\& #else +\& // no thread support +\& #endif +.Ve +.PP +Also, dynamic locks are currently not used internally by OpenSSL, but +may do so in the future. +.PP +Defining id_function(void) has it's own issues. Generally speaking, +\&\fIpthread_self()\fR should be used, even on platforms where \fIgetpid()\fR gives +different answers in each thread, since that may depend on the machine +the program is run on, not the machine where the program is being +compiled. For instance, Red Hat 8 Linux and earlier used +LinuxThreads, whose \fIgetpid()\fR returns a different value for each +thread. Red Hat 9 Linux and later use \s-1NPTL,\s0 which is +Posix-conformant, and has a \fIgetpid()\fR that returns the same value for +all threads in a process. A program compiled on Red Hat 8 and run on +Red Hat 9 will therefore see \fIgetpid()\fR returning the same value for +all threads. +.PP +There is still the issue of platforms where \fIpthread_self()\fR returns +something other than an integer. This is a bit unusual, and this +manual has no cookbook solution for that case. +.SH "EXAMPLES" +.IX Header "EXAMPLES" +\&\fBcrypto/threads/mttest.c\fR shows examples of the callback functions on +Solaris, Irix and Win32. +.SH "HISTORY" +.IX Header "HISTORY" +\&\fICRYPTO_set_locking_callback()\fR and \fICRYPTO_set_id_callback()\fR are +available in all versions of SSLeay and OpenSSL. +\&\fICRYPTO_num_locks()\fR was added in OpenSSL 0.9.4. +All functions dealing with dynamic locks were added in OpenSSL 0.9.5b\-dev. +.SH "SEE ALSO" +.IX Header "SEE ALSO" +\&\fIcrypto\fR\|(3) |