=head1 NAME
-CRYPTO_set_locking_callback, CRYPTO_set_id_callback,
-CRYPTO_set_idptr_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
+CRYPTO_THREAD_lock_new, CRYPTO_THREAD_read_lock, CRYPTO_THREAD_write_lock,
+CRYPTO_THREAD_unlock, CRYPTO_THREAD_lock_free, CRYPTO_atomic_add - 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));
+ CRYPTO_RWLOCK *CRYPTO_THREAD_lock_new(void);
+ int CRYPTO_THREAD_read_lock(CRYPTO_RWLOCK *lock);
+ int CRYPTO_THREAD_write_lock(CRYPTO_RWLOCK *lock);
+ int CRYPTO_THREAD_unlock(CRYPTO_RWLOCK *lock);
+ void CRYPTO_THREAD_lock_free(CRYPTO_RWLOCK *lock);
- void CRYPTO_set_id_callback(unsigned long (*id_function)(void));
-
- void CRYPTO_set_idptr_callback(void *(*idptr_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__)
+ int CRYPTO_atomic_add(int *val, int amount, int *ret, CRYPTO_RWLOCK *lock);
=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.
-(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.
-
-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.
+OpenSSL can be safely used in multi-threaded applications provided that
+support for the underlying OS threading API is built-in. Currently, OpenSSL
+supports the pthread and Windows APIs. OpenSSL can also be built without
+any multi-threading support, for example on platforms that don't provide
+any threading support or that provide a threading API that is not yet
+supported by OpenSSL.
-id_function(void) is a function that returns a numerical thread ID,
-for example pthread_self() if it returns an integer (see NOTES below).
-By OpenSSL's defaults, this is not needed on Windows nor on platforms
-where getpid() returns a different ID for each thread (see NOTES
-below).
-
-idptr_function(void) is a function that similarly returns a thread ID,
-but of type void *. This is not needed on platforms where &errno is
-different for each thread. OpenSSL assumes that it is in the same
-thread iff both the numerical and the pointer thread ID agree, so it
-suffices to define one of these two callback functions appropriately.
-
-Additionally, OpenSSL supports dynamic locks, and sometimes, some parts
-of OpenSSL need it for better performance. To enable this, the following
-is required:
+The following multi-threading function are provided:
=over 4
=item *
-Three additional callback function, dyn_create_function, dyn_lock_function
-and dyn_destroy_function.
+CRYPTO_THREAD_lock_new() allocates, initializes and returns a new read/write
+lock.
=item *
-A structure defined with the data that each lock needs to handle.
-
-=back
+CRYPTO_THREAD_read_lock() locks the provided B<lock> for reading.
-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.
+=item *
+CRYPTO_THREAD_write_lock() locks the provided B<lock> for writing.
-CRYPTO_get_new_dynlockid() is used to create locks. It will call
-dyn_create_function for the actual creation.
+=item *
+CRYPTO_THREAD_unlock() unlocks the previously locked B<lock>.
-CRYPTO_destroy_dynlockid() is used to destroy locks. It will call
-dyn_destroy_function for the actual destruction.
+=item *
+CRYPTO_THREAD_lock_frees() frees the provided B<lock>.
-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):
+=item *
+CRYPTO_atomic_add() atomically adds B<amount> to B<val> and returns the
+result of the operation in B<ret>. B<lock> will be locked, unless atomic
+operations are supported on the specific platform. Because of this, if a
+variable is modified by CRYPTO_atomic_add() then CRYPTO_atomic_add() must
+be the only way that the variable is modified.
- CRYPTO_LOCK 0x01
- CRYPTO_UNLOCK 0x02
- CRYPTO_READ 0x04
- CRYPTO_WRITE 0x08
+=back
=head1 RETURN VALUES
-CRYPTO_num_locks() returns the required number of locks.
+CRYPTO_THREAD_lock_new() returns the allocated lock, or NULL on error.
-CRYPTO_get_new_dynlockid() returns the index to the newly created lock.
+CRYPTO_THREAD_lock_frees() returns no value.
-The other functions return no values.
+The other functions return 1 on success or 0 on error.
=head1 NOTES
// no thread support
#endif
-Also, dynamic locks are currently not used internally by OpenSSL, but
-may do so in the future.
-
-Defining id_function(void) has it's own issues. Generally speaking,
-pthread_self() should be used, even on platforms where getpid() 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 getpid() returns a different value for each
-thread. Red Hat 9 Linux and later use NPTL, which is
-Posix-conformant, and has a getpid() 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 getpid() returning the same value for
-all threads.
-
-There is still the issue of platforms where pthread_self() returns
-something other than an integer. It is for cases like this that
-CRYPTO_set_idptr_callback() comes in handy. (E.g., call malloc(1)
-once in each thread, and have idptr_function() return a pointer to
-this object.)
-
-=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.
-
-CRYPTO_set_idptr_callback() was added in OpenSSL 0.9.9.
-
=head1 SEE ALSO
-L<crypto(3)|crypto(3)>
+L<crypto(3)>
=cut
projects / openssl.git / blobdiff