CRYPTO_LOCK(3)

💅 CRYPTO_LOCK(3) 💅

Okay bestie, this is the Library Functions Manual page for CRYPTO_LOCK(3) — thread-support lore, but make it make sense. 🧵✨

🌸 NAME 🌸

CRYPTO_lock, CRYPTO_w_lock, CRYPTO_w_unlock, CRYPTO_r_lock, CRYPTO_r_unlock, CRYPTO_add — thread support. That's the whole little squad, no cap.

✨ SYNOPSIS ✨

       #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. Like, yes, we're still documenting them, but they 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) — the related page, bestie.

⭐ 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.

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Source/version: Debian; date: March 14, 2024; manual: CRYPTO_LOCK(3). Bye bestie, mwah 💋💖