Opaque data structure that holds context information (precomputed tables etc.).
The purpose of context structures is to cache large precomputed data tables
that are expensive to construct, and also to maintain the randomization data
for blinding.
Do not create a new context object for each operation, as construction is
far slower than all other API calls (~100 times slower than an ECDSA
verification).
A constructed context can safely be used from multiple threads
simultaneously, but API calls that take a non-const pointer to a context
need exclusive access to it. In particular this is the case for
secp256k1_context_destroy, secp256k1_context_preallocated_destroy,
and secp256k1_context_randomize.
Regarding randomization, either do it once at creation time (in which case
you do not need any locking for the other calls), or use a read-write lock.
Opaque data structure that holds context information (precomputed tables etc.).
The purpose of context structures is to cache large precomputed data tables that are expensive to construct, and also to maintain the randomization data for blinding.
Do not create a new context object for each operation, as construction is far slower than all other API calls (~100 times slower than an ECDSA verification).
A constructed context can safely be used from multiple threads simultaneously, but API calls that take a non-const pointer to a context need exclusive access to it. In particular this is the case for secp256k1_context_destroy, secp256k1_context_preallocated_destroy, and secp256k1_context_randomize.
Regarding randomization, either do it once at creation time (in which case you do not need any locking for the other calls), or use a read-write lock.