Thread-safety: initialization and tear-down should be automatic and thread-safe about oniguruma HOT 3 CLOSED

I should explain why this is important.

Libraries aren't used just by programs. Sometimes (often!) libraries are used by other libraries. Ensuring that there is only one call (or non-racing calls) to a library's initializer or finalizer is then impossible. The situation for finalizers is worse because a library might call another's finalizer in its own, but this might happen as a result of a last dlcose(), and if the lower-level library was still in use by other callers in the same process... boom.

For example, jq uses Oniguruma in its libjq.

from oniguruma.

For ONIG_STATE_DEC() question.
This is because it avoids that regexp recompile and regexp search rise at the same time.
Regexp recompile API existed in old GNU regex. I supported it for compatibility.
However, I do not support it now. (USE_RECOMPILE_API is not defined.)
So, ONIG_STATE_INC() etc... is empty declarations.

from oniguruma.

I have removed all THREAD_ macro in develop branch.

from oniguruma.