src: implement per-process native Debug() printer and use it in mkcodecache #31884

joyeecheung · 2020-02-20T10:03:16Z

src: make aliased_buffer.h self-contained

aliased_buffer.h uses MultiplyWithOverflowCheck() implemented
in util-inl.h

src: refactor debug category parsing

Move the debug category parsing into a new EnabledDebugList class,
so that it can be reused outside of Environment.

src: implement per-process native Debug() printer

This patch adds a per-process native Debug() printer that can be
called when an Environment is not available.

tools: use per-process native Debug() printer in mkcodecache

Checklist

make -j4 test (UNIX), or vcbuild test (Windows) passes
tests and/or benchmarks are included
documentation is changed or added
commit message follows commit guidelines

aliased_buffer.h uses MultiplyWithOverflowCheck() implemented in util-inl.h

Move the debug category parsing into a new EnabledDebugList class, so that it can be reused outside of Environment.

This patch adds a per-process native Debug() printer that can be called when an Environment is not available.

src/debug_utils.h

addaleax · 2020-02-20T11:49:51Z

src/env.h

-  bool debug_enabled_[static_cast<int>(DebugCategory::CATEGORY_COUNT)] = {
-      false};
-
+  std::unique_ptr<EnabledDebugList> enabled_debug_list_;


Is there any reason that this would need to be a pointer? I don’t think that’s necessary, and it comes with one additional layer of indirection for each debug check. One of the goals for the Debug() implementation was to have as close to zero overhead as possible, and I think this might get in the way of it…

Mostly to avoid the circular dependency - but I guess this can also be achieved by moving more things from debug_utils.h to debug_utils-inl.h so that env.h can just include debug_utils.h and debug_utils.h do not need to include env.h ?

If that works, then that would be great – otherwise we might need to move more things into env.h…

hmm, looks like if we want to keep the initialization in the constructor, then it needs to be a pointer since we'd need the environment pointer with initialized env_vars for credentials::SafeGetenv(). So I just moved the initialization into EnableDebugList::Parse(), and call it in InitializeOncePerProcess (and separately, in mkcodecache since it does not need InitializeOncePerProcess()), this also means that for now the printer is not usable until node::Start() is called in the default binary, but I guess that's fine, compared to reordering the whole initialization sequence to work around pointers.

Fwiw, what I had in mind is to use the trivial copy constructor to re-initialize it later, e.g. enabled_debug_list_ = EnabledDebugList(...);, but I guess ::Parse() works just as well :)

src/node_env_var.cc

joyeecheung · 2020-02-25T10:53:36Z

node.gyp

@@ -1225,6 +1225,16 @@
      ],

      'conditions': [
+        [ 'node_use_openssl=="true"', {


Just realized that these are necessary for the headers (esp. enums) to match in mkcodecache and node_mksnapshot binaries - hopefully all these cruft can be cleaned up when #31074 is addressed, though the last time I tried SmartOS wouldn't link, sigh.

aliased_buffer.h uses MultiplyWithOverflowCheck() implemented in util-inl.h PR-URL: #31884 Reviewed-By: Anna Henningsen <anna@addaleax.net>

Move the debug category parsing into a new EnabledDebugList class, so that it can be reused outside of Environment. PR-URL: #31884 Reviewed-By: Anna Henningsen <anna@addaleax.net>

This patch adds a per-process native Debug() printer that can be called when an Environment is not available. PR-URL: #31884 Reviewed-By: Anna Henningsen <anna@addaleax.net>

PR-URL: #31884 Reviewed-By: Anna Henningsen <anna@addaleax.net>

joyeecheung · 2020-03-10T01:07:18Z

Landed in bb6125b...192cb72, thanks!

For posterity - if you encounter linking issues after this patch please re-run configure as this patch has changed the build flags of mkcodecache and mksnapshot