libressl-CRYPTO_lock - thread support

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CRYPTO_LOCK(3) Library Functions Manual CRYPTO_LOCK(3)

NAME

CRYPTO_lock, CRYPTO_w_lock, CRYPTO_w_unlock, CRYPTO_r_lock, CRYPTO_r_unlock, CRYPTO_add — thread support

SYNOPSIS

library “libcrypto” #include <openssl/crypto.h>

void

CRYPTO_lock(int mode, int type, const char *file, int line);

int

CRYPTO_add(int *p, int amount, int type);

	#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__)

DESCRIPTION

These functions are obsolete.

CRYPTO_lock() locks or unlocks a mutex lock.

mode is a bitfield describing what should be done with the lock. For each call, either CRYPTO_LOCK or CRYPTO_UNLOCK must be included. In the LibreSSL implementation, CRYPTO_READ and CRYPTO_WRITE are ignored.

type is a number in the range 0 <= type < CRYPTO_NUM_LOCKS identifying a particular lock. Currently, the value of CRYPTO_NUM_LOCKS is 41.

The file and line arguments are ignored.

In the LibreSSL implementation, CRYPTO_lock() is a wrapper around pthread_mutex_lock(3) and pthread_mutex_unlock(3).

CRYPTO_add() locks the lock number type, adds amount to *p, and unlocks the lock number type again.

RETURN VALUES

CRYPTO_add() returns the new value of *p.

SEE ALSO

crypto(3)

HISTORY

CRYPTO_lock(), CRYPTO_w_lock(), CRYPTO_w_unlock(), CRYPTO_r_lock(), and CRYPTO_r_unlock() first appeared in SSLeay 0.6.0. CRYPTO_add() first appeared in SSLeay 0.6.2. These functions have been available since OpenBSD 2.4. GNU June 8, 2025 CRYPTO_LOCK(3)

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