Merge bitcoin#21064: refactor: use std::shared_mutex & remove Boost T…

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060a2a6 ci: remove boost thread installation (fanquake)
06e1d7d build: don't build or use Boost Thread (fanquake)
7097add refactor: replace Boost shared_mutex with std shared_mutex in sigcache (fanquake)
8e55981 refactor: replace Boost shared_mutex with std shared_mutex in cuckoocache tests (fanquake)

Pull request description:

  This replaces `boost::shared_mutex` and `boost::unique_lock` with [`std::shared_mutex`](https://en.cppreference.com/w/cpp/thread/shared_mutex) & [`std::unique_lock`](https://en.cppreference.com/w/cpp/thread/unique_lock).

  Even though [some concerns were raised](bitcoin#16684 (comment)) in bitcoin#16684 with regard to `std::shared_mutex` being unsafe to use across some glibc versions, I still think this change is an improvement. As I mentioned in bitcoin#21022, I also think trying to restrict standard library feature usage based on bugs in glibc is not only hard to do, but it's not currently clear exactly how we do that in practice (does it also extend to patching out use in our dependencies, should we be implementing more runtime checks for features we are using, when do we consider an affected glibc "old enough" not to worry about? etc). If you take a look through the [glibc bug tracker](https://sourceware.org/bugzilla/describecomponents.cgi?product=glibc) you'll no doubt find plenty of (active) bug reports for standard library code we already using. Obviously not to say we shouldn't try and avoid buggy code where possible.

  Two other points:

  [Cory mentioned in bitcoin#21022](bitcoin#21022 (comment)):
  > It also seems reasonable to me to worry that boost hits the same underlying glibc bug, and we've just not happened to trigger the right conditions yet.

  Moving away from Boost to the standard library also removes the potential for differences related to Boosts configuration. Boost has multiple versions of `shared_mutex`, and what you end up using, and what it's backed by depends on:
  * The version of Boost.
  * The platform you're building for.
  * Which version of `BOOST_THREAD_VERSION` is defined: (2,3,4 or 5) default=2. (see [here](https://www.boost.org/doc/libs/1_70_0/doc/html/thread/build.html#thread.build.configuration) for some of the differences).
  * Is `BOOST_THREAD_V2_SHARED_MUTEX` defined? (not by default). If so, you might get the ["less performant, but more robust"](boostorg/thread#230 (comment)) version of `shared_mutex`.

  A lot of these factors are eliminated by our use of depends, but users will have varying configurations. It's also not inconceivable to think that a distro, or some package manager might start defining something like `BOOST_THREAD_VERSION=3`. Boost tried to change the default from 2 to 3 at one point.

  With this change, we no longer use Boost Thread, so this PR also removes it from depends, the build system, CI etc.

  Previous similar PRs were bitcoin#19183 & bitcoin#20922. The authors are included in the commits here.
  Also related to bitcoin#21022 - pthread sanity checking.

ACKs for top commit:
  laanwj:
    Code review ACK 060a2a6
  vasild:
    ACK 060a2a6

Tree-SHA512: 572d14d8c9de20bc434511f20d3f431836393ff915b2fe9de5a47a02dca76805ad5c3fc4cceecb4cd43f3ba939a0508178c4e60e62abdbaaa6b3e8db20b75b03

.fuzzbuzz.yml

@@ -5,7 +5,7 @@ environment:
   - CXXFLAGS=-fcoverage-mapping -fno-omit-frame-pointer -fprofile-instr-generate -gline-tables-only -O1
 setup:
   - sudo apt-get update
-  - sudo apt-get install -y autoconf bsdmainutils clang git libboost-all-dev libc++1 libc++abi1 libc++abi-dev libc++-dev libclang1 libclang-dev libdb5.3++ libevent-dev libllvm-ocaml-dev libomp5 libomp-dev libqt5core5a libqt5dbus5 libqt5gui5 libtool llvm llvm-dev llvm-runtime pkg-config qttools5-dev qttools5-dev-tools software-properties-common
+  - sudo apt-get install -y autoconf bsdmainutils clang git libboost-system-dev libboost-filesystem-dev libboost-test-dev libc++1 libc++abi1 libc++abi-dev libc++-dev libclang1 libclang-dev libdb5.3++ libevent-dev libllvm-ocaml-dev libomp5 libomp-dev libqt5core5a libqt5dbus5 libqt5gui5 libtool llvm llvm-dev llvm-runtime pkg-config qttools5-dev qttools5-dev-tools software-properties-common
   - ./autogen.sh
   - CC=clang CXX=clang++ ./configure --enable-fuzz --with-sanitizers=address,fuzzer,undefined --enable-danger-fuzz-link-all
   - make

ci/test/00_setup_env_native_asan.sh

@@ -6,7 +6,7 @@
 
 export LC_ALL=C.UTF-8
 
-export PACKAGES="clang llvm python3-zmq qtbase5-dev qttools5-dev-tools libevent-dev bsdmainutils libboost-filesystem-dev libboost-test-dev libboost-thread-dev libdb5.3++-dev libminiupnpc-dev libzmq3-dev libqrencode-dev"
+export PACKAGES="clang llvm python3-zmq qtbase5-dev qttools5-dev-tools libevent-dev bsdmainutils libboost-filesystem-dev libboost-test-dev libdb5.3++-dev libminiupnpc-dev libzmq3-dev libqrencode-dev"
 export NO_DEPENDS=1
 export FUNCTIONAL_TESTS_CONFIG="--exclude wallet_multiwallet.py" # Temporarily suppress ASan heap-use-after-free (see issue #14163)
 export RUN_BENCH=true

ci/test/00_setup_env_native_fuzz.sh

@@ -8,7 +8,7 @@ export LC_ALL=C.UTF-8
 
 export DOCKER_NAME_TAG="ubuntu:20.04"
 export CONTAINER_NAME=ci_native_fuzz
-export PACKAGES="clang llvm python3 libevent-dev bsdmainutils libboost-filesystem-dev libboost-test-dev libboost-thread-dev"
+export PACKAGES="clang llvm python3 libevent-dev bsdmainutils libboost-filesystem-dev libboost-test-dev"
 export DEP_OPTS="NO_UPNP=1 DEBUG=1"
 export CPPFLAGS="-DDEBUG_LOCKORDER -DENABLE_DASH_DEBUG -DARENA_DEBUG"
 export CXXFLAGS="-Werror -Wno-unused-command-line-argument -Wno-unused-value -Wno-deprecated-builtins"

ci/test/00_setup_env_native_fuzz_with_valgrind.sh

@@ -8,7 +8,7 @@ export LC_ALL=C.UTF-8
 
 export DOCKER_NAME_TAG="ubuntu:20.04"
 export CONTAINER_NAME=ci_native_fuzz_valgrind
-export PACKAGES="clang llvm python3 libevent-dev bsdmainutils libboost-system-dev libboost-filesystem-dev libboost-test-dev libboost-thread-dev valgrind"
+export PACKAGES="clang llvm python3 libevent-dev bsdmainutils libboost-system-dev libboost-filesystem-dev libboost-test-dev valgrind"
 export NO_DEPENDS=1
 export RUN_UNIT_TESTS=false
 export RUN_FUNCTIONAL_TESTS=false

ci/test/00_setup_env_native_valgrind.sh

@@ -6,7 +6,7 @@
 
 export LC_ALL=C.UTF-8
 
-export PACKAGES="valgrind clang llvm python3-zmq libevent-dev bsdmainutils libboost-system-dev libboost-filesystem-dev libboost-test-dev libboost-thread-dev libdb5.3++-dev libminiupnpc-dev libzmq3-dev"
+export PACKAGES="valgrind clang llvm python3-zmq libevent-dev bsdmainutils libboost-system-dev libboost-filesystem-dev libboost-test-dev libdb5.3++-dev libminiupnpc-dev libzmq3-dev"
 export USE_VALGRIND=1
 export NO_DEPENDS=1
 export TEST_RUNNER_EXTRA="--exclude rpc_bind"  # Excluded for now, see https://github.com/bitcoin/bitcoin/issues/17765#issuecomment-602068547

configure.ac

@@ -693,7 +693,7 @@ case $host in
        AC_MSG_ERROR("windres not found")
      fi
 
-     CPPFLAGS="$CPPFLAGS -D_MT -DWIN32 -D_WINDOWS -DBOOST_THREAD_USE_LIB -D_WIN32_WINNT=0x0601 -D_WIN32_IE=0x0501 -DWIN32_LEAN_AND_MEAN"
+     CPPFLAGS="$CPPFLAGS -D_MT -DWIN32 -D_WINDOWS -D_WIN32_WINNT=0x0601 -D_WIN32_IE=0x0501 -DWIN32_LEAN_AND_MEAN"
 
      dnl libtool insists upon adding -nostdlib and a list of objects/libs to link against.
      dnl That breaks our ability to build dll's with static libgcc/libstdc++/libssp. Override
@@ -1421,7 +1421,6 @@ if test x$want_boost = xno; then
     AC_MSG_ERROR([[only libdashconsensus can be built without boost]])
 fi
 AX_BOOST_FILESYSTEM
-AX_BOOST_THREAD
 
 if test x$suppress_external_warnings != xno; then
     dnl Prevent use of std::unary_function, which was removed in C++17,
@@ -1432,7 +1431,7 @@ if test x$suppress_external_warnings != xno; then
     BOOST_CPPFLAGS=SUPPRESS_WARNINGS($BOOST_CPPFLAGS)
 fi
 
-BOOST_LIBS="$BOOST_LDFLAGS $BOOST_SYSTEM_LIB $BOOST_FILESYSTEM_LIB $BOOST_THREAD_LIB"
+BOOST_LIBS="$BOOST_LDFLAGS $BOOST_SYSTEM_LIB $BOOST_FILESYSTEM_LIB"
 fi
 
 if test x$use_reduce_exports = xyes; then

depends/packages/boost.mk

@@ -30,7 +30,7 @@ endif
 else
 $(package)_toolset_$(host_os)=gcc
 endif
-$(package)_config_libraries=filesystem,thread,test
+$(package)_config_libraries=filesystem,test
 $(package)_cxxflags=-std=c++17 -fvisibility=hidden
 $(package)_cxxflags_linux=-fPIC
 $(package)_cxxflags_freebsd=-fPIC

doc/build-unix.md

@@ -74,7 +74,7 @@ Build requirements:
 
 Now, you can either build from self-compiled [depends](/depends/README.md) or install the required dependencies:
 
-    sudo apt-get libevent-dev libboost-system-dev libboost-filesystem-dev libboost-test-dev libboost-thread-dev
+    sudo apt-get libevent-dev libboost-system-dev libboost-filesystem-dev libboost-test-dev
 
 Berkeley DB is required for the wallet.