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diff --git a/common/native/README.md b/common/native/README.md deleted file mode 100644 index 1f505c4d..00000000 --- a/common/native/README.md +++ /dev/null @@ -1,30 +0,0 @@ -# JNI -As a general rule, jarjar every static library dependency used in a mainline module into the -modules's namespace (especially if it is also used by other modules) - -Fully-qualified name of java class needs to be hard-coded into the JNI .so, because JNI_OnLoad -does not take any parameters. This means that there needs to be a different .so target for each -post-jarjared package, so for each module. - -This is the guideline to provide JNI library shared with modules: - -* provide a common java library in frameworks/libs/net with the Java class (e.g. BpfMap.java). - -* provide a common native library in frameworks/libs/net with the JNI and provide the native - register function with class_name parameter. See register_com_android_net_module_util_BpfMap - function in frameworks/libs/net/common/native/bpfmapjni/com_android_net_module_util_BpfMap.cpp - as an example. - -When you want to use JNI library from frameworks/lib/net: - -* Each module includes the java library (e.g. net-utils-device-common-bpf) and applies its jarjar - rules after build. - -* Each module creates a native library in their directory, which statically links against the - common native library (e.g. libnet_utils_device_common_bpf), and calls the native registered - function by hardcoding the post-jarjar class_name. Linkage *MUST* be static because common - functions in the file (e.g., `register_com_android_net_module_util_BpfMap`) will appear in the - library (`.so`) file, and different versions of the library loaded in the same process by - different modules will in general have different versions. It's important that each of these - libraries loads the common function from its own library. Static linkage should guarantee this - because static linkage resolves symbols at build time, not runtime.
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