Struct mupdf_sys::fz_locks_context

#[repr(C)]
pub struct fz_locks_context {
    pub user: *mut c_void,
    pub lock: Option<unsafe extern "C" fn(user: *mut c_void, lock: c_int)>,
    pub unlock: Option<unsafe extern "C" fn(user: *mut c_void, lock: c_int)>,
}

Locking functions

MuPDF is kept deliberately free of any knowledge of particular threading systems. As such, in order for safe multi-threaded operation, we rely on callbacks to client provided functions.

A client is expected to provide FZ_LOCK_MAX number of mutexes, and a function to lock/unlock each of them. These may be recursive mutexes, but do not have to be.

If a client does not intend to use multiple threads, then it may pass NULL instead of a lock structure.

In order to avoid deadlocks, we have one simple rule internally as to how we use locks: We can never take lock n when we already hold any lock i, where 0 <= i <= n. In order to verify this, we have some debugging code, that can be enabled by defining FITZ_DEBUG_LOCKING.

Fields

user: *mut c_void

lock: Option<unsafe extern "C" fn(user: *mut c_void, lock: c_int)>

unlock: Option<unsafe extern "C" fn(user: *mut c_void, lock: c_int)>

Trait Implementations

impl Clone for fz_locks_context

fn clone(&self) -> fz_locks_context

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for fz_locks_context

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Copy for fz_locks_context