On Wed, 30 Mar 2022 13:21:41 GMT, Jaikiran Pai <[email protected]> wrote:
>> A small improvement to `RawNativeLibraries`. `RawNativeLibraries::load`
>> returns the same `NativeLibrary` instance of a given path if it's called
>> multiple times. This means that multiple clients have to coordinate that the
>> last one using the loaded library is the one to close the library by calling
>> `RawNativeLibraries::unload`; otherwise, an exception may be thrown.
>>
>> This patch changes `RawNativeLibraries::load` to delegate to the underlying
>> platform-specific library loading mechanism e.g. dlopen/dlclose that keeps
>> the reference count. So each call to `RawNativeLibraries::load` and
>> `unload` is simply a call to dlopen and dlclose respectively. Each client
>> of calling `RawNativeLibraries::load` is responsible for calling
>> `RawNativeLibraries::unload`. This will be consistent with the current
>> behavior when you call `load` and `unload` with a different
>> `RawNativeLibraries` instance.
>
> src/java.base/share/classes/jdk/internal/loader/RawNativeLibraries.java line
> 49:
>
>> 47: public final class RawNativeLibraries {
>> 48: final Set<RawNativeLibraryImpl> libraries =
>> ConcurrentHashMap.newKeySet();
>> 49: final Class<?> caller;
>
> Hello Mandy,
> Apart from the `caller` being used for checks while constructing a
> `RawNativeLibraries` in `RawNativeLibraries.newInstance(MethodHandles.Lookup
> trustedCaller)`, I don't see this instance member being used anywhere. Do you
> think we need to store this as an instance member?
I keep it as a record and for debugging use in case.
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PR: https://git.openjdk.java.net/jdk/pull/8022
