On Tue, 25 Jan 2022 17:22:54 GMT, Yumin Qi <mi...@openjdk.org> wrote:
>> I'm curious, under what circumstances would, before >> https://bugs.openjdk.java.net/browse/JDK-8237750, we ever hit the >> LoadLibrary in imageDecompressor.cpp? Did this ever work? Was there ever a >> scenario where the JVM was not involved and hence the zip.dll was not loaded >> already? >> >> For me, the code looks good unless I miss a scenario where we don't have the >> JVM loaded already at this point. > >> I'm curious, under what circumstances would, before >> https://bugs.openjdk.java.net/browse/JDK-8237750, we ever hit the >> LoadLibrary in imageDecompressor.cpp? Did this ever work? Was there ever a >> scenario where the JVM was not involved and hence the zip.dll was not loaded >> already? >> >> For me, the code looks good unless I miss a scenario where we don't have the >> JVM loaded already at this point. > > Thanks for review. Before 8237750, the zip library is always loaded so > jimage just get the handle of the loaded zip by calling . After that, zip is > loaded at need, so if jvm does not use zip, it will not be loaded. > Unfortunately, it does not realize that jimage is using this zip, so it > failed to get the handle. But there exists a case, if the zip is in PATH, the > following fix 8244495 used LoadLibrary("zip.dll") for a rescue. If zip.dll > is not in PATH, the call still failed to load zip. This is the current issue. > > So far, if user loaded zip from native code before jimage code is executed ( > I could not image a scenario how it can happen), the > GetModuleHandle("zip.dll") may return the handle to it, but it does not > surely it is for the "zip.dll" --- if multiple instances exist, the returned > handle is not guaranteed the one you want. > > With this change, if user loads zip from native code (with different > version), JVM does not sense that, it will still load zip from $JDK or $JRE, > and jimage still uses handle returned from JVM. The only case is JVM failed > to load zip library: > > if (_zip_handle == NULL) { > vm_exit_during_initialization("Unable to load zip library", path); > } > > You cannot make any progress on the failure. Thanks for the explanation, @yminqi. Change looks good. ------------- PR: https://git.openjdk.java.net/jdk/pull/7206
