Re: RFR: 8283060: RawNativeLibraries should allow multiple clients to load/unload the same library
On Wed, 30 Mar 2022 13:21:41 GMT, Jaikiran Pai 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 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.
-
PR: https://git.openjdk.java.net/jdk/pull/8022
Re: RFR: 8283060: RawNativeLibraries should allow multiple clients to load/unload the same library
On Tue, 29 Mar 2022 20:05:50 GMT, Mandy Chung 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 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?
-
PR: https://git.openjdk.java.net/jdk/pull/8022
Re: RFR: 8283060: RawNativeLibraries should allow multiple clients to load/unload the same library
On Tue, 29 Mar 2022 20:05:50 GMT, Mandy Chung 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. Marked as reviewed by jvernee (Reviewer). - PR: https://git.openjdk.java.net/jdk/pull/8022
Re: RFR: 8283060: RawNativeLibraries should allow multiple clients to load/unload the same library
On Tue, 29 Mar 2022 20:05:50 GMT, Mandy Chung 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. LGTM - Marked as reviewed by sundar (Reviewer). PR: https://git.openjdk.java.net/jdk/pull/8022
RFR: 8283060: RawNativeLibraries should allow multiple clients to load/unload the same library
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. - Commit messages: - 8283060: RawNativeLibraries should allow multiple clients to load/unload the same library Changes: https://git.openjdk.java.net/jdk/pull/8022/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk=8022=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8283060 Stats: 66 lines in 3 files changed: 43 ins; 10 del; 13 mod Patch: https://git.openjdk.java.net/jdk/pull/8022.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/8022/head:pull/8022 PR: https://git.openjdk.java.net/jdk/pull/8022
