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34 .Nd register thread locking methods with the dynamic linker
40 .Fn dllockinit "void *context" "void *(*lock_create)(void *context)" "void (*rlock_acquire)(void *lock)" "void (*wlock_acquire)(void *lock)" "void (*lock_release)(void *lock)" "void (*lock_destroy)(void *lock)" "void (*context_destroy)(void *context)"
43 Due to enhancements in the dynamic linker, this interface is no longer
44 needed. It is deprecated and will be removed from future releases.
45 In current releases it still exists, but only as a stub which does nothing.
48 Threads packages can call
50 at initialization time to register locking functions for the dynamic
51 linker to use. This enables the dynamic linker to prevent multiple
52 threads from entering its critical sections simultaneously.
56 argument specifies an opaque context for creating locks. The
57 dynamic linker will pass it to the
59 function when creating the locks it needs. When the dynamic linker
60 is permanently finished using the locking functions (e.g., if the
61 program makes a subsequent call to
63 to register new locking functions) it will call
65 to destroy the context.
69 argument specifies a function for creating a read/write lock. It
70 must return a pointer to the new lock.
76 arguments specify functions which lock a lock for reading or
77 writing, respectively. The
79 argument specifies a function which unlocks a lock. Each of these
80 functions is passed a pointer to the lock.
84 argument specifies a function to destroy a lock. It may be
86 if locks do not need to be destroyed. The
88 argument specifies a function to destroy the context. It may be
90 if the context does not need to be destroyed.
94 is called, the dynamic linker protects its critical sections using
95 a default locking mechanism which works by blocking the
100 signals. This is sufficient for many application level threads
101 packages, which typically use one of these signals to implement
102 preemption. An application which has registered its own locking
105 can restore the default locking by calling
115 function first appeared in