CRYPTO_set_locking_callback man page on OpenDarwin

Man page or keyword search:  
man Server   3202 pages
apropos Keyword Search (all sections)
Output format
OpenDarwin logo
[printable version]

threads(3)			    OpenSSL			    threads(3)

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

SYNOPSIS
	#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)    \
	       CRYPTO_lock(CRYPTO_LOCK⎪CRYPTO_WRITE,type,__FILE__,__LINE__)
	#define CRYPTO_w_unlock(type)  \
	       CRYPTO_lock(CRYPTO_UNLOCK⎪CRYPTO_WRITE,type,__FILE__,__LINE__)
	#define CRYPTO_r_lock(type)    \
	       CRYPTO_lock(CRYPTO_LOCK⎪CRYPTO_READ,type,__FILE__,__LINE__)
	#define CRYPTO_r_unlock(type)  \
	       CRYPTO_lock(CRYPTO_UNLOCK⎪CRYPTO_READ,type,__FILE__,__LINE__)
	#define CRYPTO_add(addr,amount,type)   \
	       CRYPTO_add_lock(addr,amount,type,__FILE__,__LINE__)

DESCRIPTION
       OpenSSL can safely be used in multi-threaded applications provided that
       at least two callback functions are set.

       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 when‐
       ever multiple threads use OpenSSL.)  Multi-threaded applications will
       crash at random if it is not set.

       locking_function() must be able to handle up to CRYPTO_num_locks() dif‐
       ferent mutex locks. It sets the n-th lock if mode & CRYPTO_LOCK, and
       releases it otherwise.

       file and line are the file number of the function setting the lock.
       They can be useful for debugging.

       id_function(void) is a function that returns a thread ID. It is not
       needed on Windows nor on platforms where getpid() returns a different
       ID for each thread (most notably Linux).

       Additionally, OpenSSL supports dynamic locks, and sometimes, some parts
       of OpenSSL need it for better performance.  To enable this, the follow‐
       ing is required:

       * Three additional callback function, dyn_create_function,
       dyn_lock_function and dyn_destroy_function.
       * A structure defined with the data that each lock needs to handle.

       struct CRYPTO_dynlock_value has to be defined to contain whatever
       structure is needed to handle locks.

       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.

       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.

       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.

       CRYPTO_get_new_dynlockid() is used to create locks.  It will call
       dyn_create_function for the actual creation.

       CRYPTO_destroy_dynlockid() is used to destroy locks.  It will call
       dyn_destroy_function for the actual destruction.

       CRYPTO_lock() 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 CRYPTO_get_new_dynlockid().  mode can be combined
       from the following values.  These values are pairwise exclusive, with
       undefined behaviour if misused (for example, CRYPTO_READ and
       CRYPTO_WRITE should not be used together):

	       CRYPTO_LOCK     0x01
	       CRYPTO_UNLOCK   0x02
	       CRYPTO_READ     0x04
	       CRYPTO_WRITE    0x08

RETURN VALUES
       CRYPTO_num_locks() returns the required number of locks.

       CRYPTO_get_new_dynlockid() returns the index to the newly created lock.

       The other functions return no values.

NOTE
       You can find out if OpenSSL was configured with thread support:

	#define OPENSSL_THREAD_DEFINES
	#include <openssl/opensslconf.h>
	#if defined(THREADS)
	  // thread support enabled
	#else
	  // no thread support
	#endif

       Also, dynamic locks are currently not used internally by OpenSSL, but
       may do so in the future.

EXAMPLES
       crypto/threads/mttest.c shows examples of the callback functions on
       Solaris, Irix and Win32.

HISTORY
       CRYPTO_set_locking_callback() and CRYPTO_set_id_callback() are avail‐
       able in all versions of SSLeay and OpenSSL.  CRYPTO_num_locks() was
       added in OpenSSL 0.9.4.	All functions dealing with dynamic locks were
       added in OpenSSL 0.9.5b-dev.

SEE ALSO
       crypto(3)

0.9.7d				  2003-11-20			    threads(3)
[top]

List of man pages available for OpenDarwin

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net