Merge bitcoin/bitcoin#26292: util: move threadinterrupt into util/

b89530483d util: move threadinterrupt into util (fanquake)

Pull request description:

  Alongside thread and threadnames. It's part of libbitcoin_util.

ACKs for top commit:
  ryanofsky:
    Code review ACK b89530483d. No changes since last review other than rebase
  theuni:
    ACK b89530483d.

Tree-SHA512: 0421f4d1881ec295272446804b27d16bf63e6b62b272f8bb52bfecde9ae6605e8109ed16294690d3e3ce4b15cc5e7c4046f99442df73adb10bdf069d3fb165aa

src/util/sock.cpp

@@ -4,11 +4,11 @@
 
 #include <compat/compat.h>
 #include <logging.h>
-#include <threadinterrupt.h>
 #include <tinyformat.h>
 #include <util/sock.h>
 #include <util/syserror.h>
 #include <util/system.h>
+#include <util/threadinterrupt.h>
 #include <util/time.h>
 
 #include <memory>

src/util/sock.h

@@ -6,7 +6,7 @@
 #define BITCOIN_UTIL_SOCK_H
 
 #include <compat/compat.h>
-#include <threadinterrupt.h>
+#include <util/threadinterrupt.h>
 #include <util/time.h>
 
 #include <chrono>

src/util/threadinterrupt.cpp

@@ -0,0 +1,35 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <util/threadinterrupt.h>
+
+#include <sync.h>
+
+CThreadInterrupt::CThreadInterrupt() : flag(false) {}
+
+CThreadInterrupt::operator bool() const
+{
+    return flag.load(std::memory_order_acquire);
+}
+
+void CThreadInterrupt::reset()
+{
+    flag.store(false, std::memory_order_release);
+}
+
+void CThreadInterrupt::operator()()
+{
+    {
+        LOCK(mut);
+        flag.store(true, std::memory_order_release);
+    }
+    cond.notify_all();
+}
+
+bool CThreadInterrupt::sleep_for(Clock::duration rel_time)
+{
+    WAIT_LOCK(mut, lock);
+    return !cond.wait_for(lock, rel_time, [this]() { return flag.load(std::memory_order_acquire); });
+}

src/util/threadinterrupt.h

@@ -0,0 +1,36 @@
+// Copyright (c) 2016-2021 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_UTIL_THREADINTERRUPT_H
+#define BITCOIN_UTIL_THREADINTERRUPT_H
+
+#include <sync.h>
+#include <threadsafety.h>
+
+#include <atomic>
+#include <chrono>
+#include <condition_variable>
+
+/*
+    A helper class for interruptible sleeps. Calling operator() will interrupt
+    any current sleep, and after that point operator bool() will return true
+    until reset.
+*/
+class CThreadInterrupt
+{
+public:
+    using Clock = std::chrono::steady_clock;
+    CThreadInterrupt();
+    explicit operator bool() const;
+    void operator()() EXCLUSIVE_LOCKS_REQUIRED(!mut);
+    void reset();
+    bool sleep_for(Clock::duration rel_time) EXCLUSIVE_LOCKS_REQUIRED(!mut);
+
+private:
+    std::condition_variable cond;
+    Mutex mut;
+    std::atomic<bool> flag;
+};
+
+#endif // BITCOIN_UTIL_THREADINTERRUPT_H