mirror of
https://github.com/openssl/openssl.git
synced 2024-11-27 05:21:51 +08:00
157 lines
4.9 KiB
Plaintext
157 lines
4.9 KiB
Plaintext
=pod
|
|
|
|
=head1 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
|
|
|
|
=head1 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__)
|
|
|
|
=head1 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. Multi-threaded
|
|
applications will crash at random if it is not set.
|
|
|
|
locking_function() must be able to handle up to CRYPTO_num_locks()
|
|
different mutex locks. It sets the B<n>-th lock if B<mode> &
|
|
B<CRYPTO_LOCK>, and releases it otherwise.
|
|
|
|
B<file> and B<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 following
|
|
is required:
|
|
|
|
=over 4
|
|
|
|
=item *
|
|
Three additional callback function, dyn_create_function, dyn_lock_function
|
|
and dyn_destroy_function.
|
|
|
|
=item *
|
|
A structure defined with the data that each lock needs to handle.
|
|
|
|
=back
|
|
|
|
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
|
|
|
|
=head1 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.
|
|
|
|
=head1 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.
|
|
|
|
=head1 EXAMPLES
|
|
|
|
B<crypto/threads/mttest.c> shows examples of the callback functions on
|
|
Solaris, Irix and Win32.
|
|
|
|
=head1 HISTORY
|
|
|
|
CRYPTO_set_locking_callback() and CRYPTO_set_id_callback() are
|
|
available 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.
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<crypto(3)|crypto(3)>
|
|
|
|
=cut
|