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33 .Nd register thread locking methods with the dynamic linker
39 .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)"
42 Due to enhancements in the dynamic linker, this interface is no longer
43 needed. It is deprecated and will be removed from future releases.
44 In current releases it still exists, but only as a stub which does nothing.
47 Threads packages can call
49 at initialization time to register locking functions for the dynamic
50 linker to use. This enables the dynamic linker to prevent multiple
51 threads from entering its critical sections simultaneously.
55 argument specifies an opaque context for creating locks. The
56 dynamic linker will pass it to the
58 function when creating the locks it needs. When the dynamic linker
59 is permanently finished using the locking functions (e.g., if the
60 program makes a subsequent call to
62 to register new locking functions) it will call
64 to destroy the context.
68 argument specifies a function for creating a read/write lock. It
69 must return a pointer to the new lock.
75 arguments specify functions which lock a lock for reading or
76 writing, respectively. The
78 argument specifies a function which unlocks a lock. Each of these
79 functions is passed a pointer to the lock.
83 argument specifies a function to destroy a lock. It may be
85 if locks do not need to be destroyed. The
87 argument specifies a function to destroy the context. It may be
89 if the context does not need to be destroyed.
93 is called, the dynamic linker protects its critical sections using
94 a default locking mechanism which works by blocking the
99 signals. This is sufficient for many application level threads
100 packages, which typically use one of these signals to implement
101 preemption. An application which has registered its own locking
104 can restore the default locking by calling
114 function first appeared in