Make some globals static that can be
I wrote this patch as part of making a Bazel build system but it really is independent from that so I'm putting this as a separate PR.
External linkage does not help and just encourages sloppy dependencies (ie using symbols only declared in a cpp file in some other cpp file) and can lead to weird issues when there are name collisions.
To determine the default for `-par`, the number of script verification
threads, use [boost::thread::physical_concurrency()](http://www.boost.org/doc/libs/1_58_0/doc/html/thread/thread_management.html#thread.thread_management.thread.physical_concurrency)
which counts only physical cores, not virtual cores.
Virtual cores are roughly a set of cached registers to avoid context
switches while threading, they cannot actually perform work, so spawning
a verification thread for them could even reduce efficiency and will put
undue load on the system.
Should fix issue #6358, as well as some other reported system overload
issues, especially on Intel processors.
The function was only introduced in boost 1.56, so provide a utility
function `GetNumCores` to fall back for older Boost versions.
Add message directing users to security guide
Addresses #2142, which was blocking on updates to zcash/support/security.html. That page has now been added, so this message directing users to the site can be included.
It displays in the zcash-cli --help and --version message text, and on the zcashd metrics screen.
Prevents stomping on debug logs in datadirs that are locked by other
instances and lost parameter interaction messages that can get wiped by
ShrinkDebugFile().
The log is now opened explicitly and all emitted messages are buffered
until this open occurs. The version message and log cut have also been
moved to the earliest possible sensible location.
Closes#1097 so that zcash-cli displays license info like zcashd.
LicenseInfo is refactored from init.cpp to util.cpp so that the
bitcoin-cli makefile target does not need to be modified.
Previously the RPC interface allowed z_exportwallet, backupwallet and
dumpwallet to write data to an arbitrary filename. ZCA-009 demonstrates
how this is vulnerable. The resolution is to only allow data to
written when the -exportdir has been configured. Also filenames are
restricted to alphanumeric characters.
jl777