Module threads 

Threading support (§57, §93, §85 Phase 1).

Thread-local state, concurrent parsing, concurrent transformation, shared immutable dictionaries, callback isolation.

UPSTREAM-PARITY

libxml2’s threading support provides:

• xmlInitThreads() / xmlCleanupThreads() — lifecycle
• xmlLockLibrary() / xmlUnlockLibrary() — global lock
• Thread-local storage for error state and parser contexts

In modern libxml2 (2.12+), threading is initialized automatically by xmlInitParser. The explicit thread functions exist for backward compatibility.

In Rust, we use standard thread-safe primitives and thread_local! for thread-local storage. The global lock is a no-op since Rust’s type system prevents data races at compile time.

Phase 1 status

Complete — all threading support is implemented.

Functions

cleanup_threads

Clean up threading support.

free_mutex^⚠

Free a simple mutex (upstream threads.h xmlFreeMutex).

free_rmutex^⚠

Free a recursive mutex (upstream threads.h xmlFreeRMutex).

get_thread_count

Get the number of active threads (for compatibility).

init_threads

Initialize threading support.

lock_library

Lock the library (global mutex).

mutex_lock^⚠

Lock a simple mutex (upstream threads.h xmlMutexLock).

mutex_unlock^⚠

Unlock a simple mutex (upstream threads.h xmlMutexUnlock).

new_mutex

Create a simple mutex (upstream threads.h xmlNewMutex).

new_rmutex

Create a recursive mutex (upstream threads.h xmlNewRMutex).

rmutex_lock^⚠

Lock a recursive mutex (upstream threads.h xmlRMutexLock).

rmutex_unlock^⚠

Unlock a recursive mutex (upstream threads.h xmlRMutexUnlock).

threads_initialized

Check whether threading has been initialized.

unlock_library

Unlock the library.