/*
- * Copyright 2013 Facebook, Inc.
+ * Copyright 2013-present Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#pragma once
+#include <assert.h>
+#include <boost/noncopyable.hpp>
+#include <errno.h>
+#include <glog/logging.h>
#include <atomic>
#include <functional>
+#include <mutex>
#include <thread>
#include <unordered_set>
#include <vector>
-#include <boost/noncopyable.hpp>
-#include <semaphore.h>
-#include <errno.h>
-#include <assert.h>
#include <folly/ScopeGuard.h>
+#include <folly/concurrency/CacheLocality.h>
#include <folly/detail/Futex.h>
-
-namespace folly { namespace test {
+#include <folly/portability/Semaphore.h>
+#include <folly/synchronization/detail/AtomicUtils.h>
+
+namespace folly {
+namespace test {
+
+// This is ugly, but better perf for DeterministicAtomic translates
+// directly to more states explored and tested
+#define FOLLY_TEST_DSCHED_VLOG(...) \
+ do { \
+ if (false) { \
+ VLOG(2) << std::hex << std::this_thread::get_id() << ": " \
+ << __VA_ARGS__; \
+ } \
+ } while (false)
+
+/* signatures of user-defined auxiliary functions */
+using AuxAct = std::function<void(bool)>;
+using AuxChk = std::function<void(uint64_t)>;
/**
* DeterministicSchedule coordinates the inter-thread communication of a
* DeterministicSchedule::thread on a thread participating in this
* schedule) to participate in a deterministic schedule.
*/
- explicit DeterministicSchedule(const std::function<int(int)>& scheduler);
+ explicit DeterministicSchedule(
+ const std::function<size_t(size_t)>& scheduler);
/** Completes the schedule. */
~DeterministicSchedule();
* inter-thread communication are random variables following a poisson
* distribution.
*/
- static std::function<int(int)> uniform(long seed);
+ static std::function<size_t(size_t)> uniform(uint64_t seed);
/**
* Returns a scheduling function that chooses a subset of the active
* runnable thread. The subset is chosen with size n, and the choice
* is made every m steps.
*/
- static std::function<int(int)> uniformSubset(long seed, int n = 2,
- int m = 64);
+ static std::function<size_t(size_t)>
+ uniformSubset(uint64_t seed, size_t n = 2, size_t m = 64);
/** Obtains permission for the current thread to perform inter-thread
* communication. */
* communication. */
static void afterSharedAccess();
+ /** Calls a user-defined auxiliary function if any, and releases
+ * permission for the current thread to perform inter-thread
+ * communication. The bool parameter indicates the success of the
+ * shared access (if conditional, true otherwise). */
+ static void afterSharedAccess(bool success);
+
/** Launches a thread that will participate in the same deterministic
* schedule as the current thread. */
template <typename Func, typename... Args>
auto sched = tls_sched;
auto sem = sched ? sched->beforeThreadCreate() : nullptr;
auto child = std::thread([=](Args... a) {
- if (sched) sched->afterThreadCreate(sem);
- SCOPE_EXIT { if (sched) sched->beforeThreadExit(); };
+ if (sched) {
+ sched->afterThreadCreate(sem);
+ beforeSharedAccess();
+ FOLLY_TEST_DSCHED_VLOG("running");
+ afterSharedAccess();
+ }
+ SCOPE_EXIT {
+ if (sched) {
+ sched->beforeThreadExit();
+ }
+ };
func(a...);
}, args...);
if (sched) {
beforeSharedAccess();
sched->active_.insert(child.get_id());
+ FOLLY_TEST_DSCHED_VLOG("forked " << std::hex << child.get_id());
afterSharedAccess();
}
return child;
/** Calls sem_wait(sem) as part of a deterministic schedule. */
static void wait(sem_t* sem);
+ /** Used scheduler_ to get a random number b/w [0, n). If tls_sched is
+ * not set-up it falls back to std::rand() */
+ static size_t getRandNumber(size_t n);
+
+ /** Deterministic implemencation of getcpu */
+ static int getcpu(unsigned* cpu, unsigned* node, void* unused);
+
+ /** Sets up a thread-specific function for call immediately after
+ * the next shared access by the thread for managing auxiliary
+ * data. The function takes a bool parameter that indicates the
+ * success of the shared access (if it is conditional, true
+ * otherwise). The function is cleared after one use. */
+ static void setAuxAct(AuxAct& aux);
+
+ /** Sets up a function to be called after every subsequent shared
+ * access (until clearAuxChk() is called) for checking global
+ * invariants and logging. The function takes a uint64_t parameter
+ * that indicates the number of shared accesses so far. */
+ static void setAuxChk(AuxChk& aux);
+
+ /** Clears the function set by setAuxChk */
+ static void clearAuxChk();
+
private:
- static __thread sem_t* tls_sem;
- static __thread DeterministicSchedule* tls_sched;
+ static FOLLY_TLS sem_t* tls_sem;
+ static FOLLY_TLS DeterministicSchedule* tls_sched;
+ static FOLLY_TLS unsigned tls_threadId;
+ static thread_local AuxAct tls_aux_act;
+ static AuxChk aux_chk;
- std::function<int(int)> scheduler_;
+ std::function<size_t(size_t)> scheduler_;
std::vector<sem_t*> sems_;
std::unordered_set<std::thread::id> active_;
+ unsigned nextThreadId_;
+ /* step_ keeps count of shared accesses that correspond to user
+ * synchronization steps (atomic accesses for now).
+ * The reason for keeping track of this here and not just with
+ * auxiliary data is to provide users with warning signs (e.g.,
+ * skipped steps) if they inadvertently forget to set up aux
+ * functions for some shared accesses. */
+ uint64_t step_;
sem_t* beforeThreadCreate();
void afterThreadCreate(sem_t*);
void beforeThreadExit();
+ /** Calls user-defined auxiliary function (if any) */
+ void callAux(bool);
};
-
/**
* DeterministicAtomic<T> is a drop-in replacement std::atomic<T> that
* cooperates with DeterministicSchedule.
DeterministicAtomic() = default;
~DeterministicAtomic() = default;
- DeterministicAtomic(DeterministicAtomic<T> const &) = delete;
- DeterministicAtomic<T>& operator= (DeterministicAtomic<T> const &) = delete;
+ DeterministicAtomic(DeterministicAtomic<T> const&) = delete;
+ DeterministicAtomic<T>& operator=(DeterministicAtomic<T> const&) = delete;
constexpr /* implicit */ DeterministicAtomic(T v) noexcept : data(v) {}
- bool is_lock_free() const noexcept {
- return data.is_lock_free();
- }
+ bool is_lock_free() const noexcept { return data.is_lock_free(); }
bool compare_exchange_strong(
- T& v0, T v1,
- std::memory_order mo = std::memory_order_seq_cst) noexcept {
+ T& v0,
+ T v1,
+ std::memory_order mo = std::memory_order_seq_cst) noexcept {
+ return compare_exchange_strong(
+ v0, v1, mo, detail::default_failure_memory_order(mo));
+ }
+ bool compare_exchange_strong(
+ T& v0,
+ T v1,
+ std::memory_order success,
+ std::memory_order failure) noexcept {
DeterministicSchedule::beforeSharedAccess();
- bool rv = data.compare_exchange_strong(v0, v1, mo);
- DeterministicSchedule::afterSharedAccess();
+ auto orig = v0;
+ bool rv = data.compare_exchange_strong(v0, v1, success, failure);
+ FOLLY_TEST_DSCHED_VLOG(this << ".compare_exchange_strong(" << std::hex
+ << orig << ", " << std::hex << v1 << ") -> "
+ << rv << "," << std::hex << v0);
+ DeterministicSchedule::afterSharedAccess(rv);
return rv;
}
bool compare_exchange_weak(
- T& v0, T v1,
- std::memory_order mo = std::memory_order_seq_cst) noexcept {
+ T& v0,
+ T v1,
+ std::memory_order mo = std::memory_order_seq_cst) noexcept {
+ return compare_exchange_weak(
+ v0, v1, mo, detail::default_failure_memory_order(mo));
+ }
+ bool compare_exchange_weak(
+ T& v0,
+ T v1,
+ std::memory_order success,
+ std::memory_order failure) noexcept {
DeterministicSchedule::beforeSharedAccess();
- bool rv = data.compare_exchange_weak(v0, v1, mo);
- DeterministicSchedule::afterSharedAccess();
+ auto orig = v0;
+ bool rv = data.compare_exchange_weak(v0, v1, success, failure);
+ FOLLY_TEST_DSCHED_VLOG(this << ".compare_exchange_weak(" << std::hex << orig
+ << ", " << std::hex << v1 << ") -> " << rv
+ << "," << std::hex << v0);
+ DeterministicSchedule::afterSharedAccess(rv);
return rv;
}
T exchange(T v, std::memory_order mo = std::memory_order_seq_cst) noexcept {
DeterministicSchedule::beforeSharedAccess();
T rv = data.exchange(v, mo);
- DeterministicSchedule::afterSharedAccess();
+ FOLLY_TEST_DSCHED_VLOG(this << ".exchange(" << std::hex << v << ") -> "
+ << std::hex << rv);
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
- /* implicit */ operator T () const noexcept {
+ /* implicit */ operator T() const noexcept {
DeterministicSchedule::beforeSharedAccess();
T rv = data;
- DeterministicSchedule::afterSharedAccess();
+ FOLLY_TEST_DSCHED_VLOG(this << "() -> " << std::hex << rv);
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
T load(std::memory_order mo = std::memory_order_seq_cst) const noexcept {
DeterministicSchedule::beforeSharedAccess();
T rv = data.load(mo);
- DeterministicSchedule::afterSharedAccess();
+ FOLLY_TEST_DSCHED_VLOG(this << ".load() -> " << std::hex << rv);
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
- T operator= (T v) noexcept {
+ T operator=(T v) noexcept {
DeterministicSchedule::beforeSharedAccess();
T rv = (data = v);
- DeterministicSchedule::afterSharedAccess();
+ FOLLY_TEST_DSCHED_VLOG(this << " = " << std::hex << v);
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
void store(T v, std::memory_order mo = std::memory_order_seq_cst) noexcept {
DeterministicSchedule::beforeSharedAccess();
data.store(v, mo);
- DeterministicSchedule::afterSharedAccess();
+ FOLLY_TEST_DSCHED_VLOG(this << ".store(" << std::hex << v << ")");
+ DeterministicSchedule::afterSharedAccess(true);
}
- T operator++ () noexcept {
+ T operator++() noexcept {
DeterministicSchedule::beforeSharedAccess();
T rv = ++data;
- DeterministicSchedule::afterSharedAccess();
+ FOLLY_TEST_DSCHED_VLOG(this << " pre++ -> " << std::hex << rv);
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
- T operator++ (int postDummy) noexcept {
+ T operator++(int /* postDummy */) noexcept {
DeterministicSchedule::beforeSharedAccess();
T rv = data++;
- DeterministicSchedule::afterSharedAccess();
+ FOLLY_TEST_DSCHED_VLOG(this << " post++ -> " << std::hex << rv);
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
- T operator-- () noexcept {
+ T operator--() noexcept {
DeterministicSchedule::beforeSharedAccess();
T rv = --data;
- DeterministicSchedule::afterSharedAccess();
+ FOLLY_TEST_DSCHED_VLOG(this << " pre-- -> " << std::hex << rv);
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
- T operator-- (int postDummy) noexcept {
+ T operator--(int /* postDummy */) noexcept {
DeterministicSchedule::beforeSharedAccess();
T rv = data--;
- DeterministicSchedule::afterSharedAccess();
+ FOLLY_TEST_DSCHED_VLOG(this << " post-- -> " << std::hex << rv);
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
- T operator+= (T v) noexcept {
+ T operator+=(T v) noexcept {
DeterministicSchedule::beforeSharedAccess();
T rv = (data += v);
- DeterministicSchedule::afterSharedAccess();
+ FOLLY_TEST_DSCHED_VLOG(this << " += " << std::hex << v << " -> " << std::hex
+ << rv);
+ DeterministicSchedule::afterSharedAccess(true);
+ return rv;
+ }
+
+ T fetch_add(T v,
+ std::memory_order /* mo */ = std::memory_order_seq_cst) noexcept {
+ DeterministicSchedule::beforeSharedAccess();
+ T rv = data;
+ data += v;
+ FOLLY_TEST_DSCHED_VLOG(this << ".fetch_add(" << std::hex << v << ") -> "
+ << std::hex << rv);
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
- T operator-= (T v) noexcept {
+ T operator-=(T v) noexcept {
DeterministicSchedule::beforeSharedAccess();
T rv = (data -= v);
- DeterministicSchedule::afterSharedAccess();
+ FOLLY_TEST_DSCHED_VLOG(this << " -= " << std::hex << v << " -> " << std::hex
+ << rv);
+ DeterministicSchedule::afterSharedAccess(true);
+ return rv;
+ }
+
+ T fetch_sub(T v,
+ std::memory_order /* mo */ = std::memory_order_seq_cst) noexcept {
+ DeterministicSchedule::beforeSharedAccess();
+ T rv = data;
+ data -= v;
+ FOLLY_TEST_DSCHED_VLOG(this << ".fetch_sub(" << std::hex << v << ") -> "
+ << std::hex << rv);
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
- T operator&= (T v) noexcept {
+ T operator&=(T v) noexcept {
DeterministicSchedule::beforeSharedAccess();
T rv = (data &= v);
- DeterministicSchedule::afterSharedAccess();
+ FOLLY_TEST_DSCHED_VLOG(this << " &= " << std::hex << v << " -> " << std::hex
+ << rv);
+ DeterministicSchedule::afterSharedAccess(true);
+ return rv;
+ }
+
+ T fetch_and(T v,
+ std::memory_order /* mo */ = std::memory_order_seq_cst) noexcept {
+ DeterministicSchedule::beforeSharedAccess();
+ T rv = data;
+ data &= v;
+ FOLLY_TEST_DSCHED_VLOG(this << ".fetch_and(" << std::hex << v << ") -> "
+ << std::hex << rv);
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
- T operator|= (T v) noexcept {
+ T operator|=(T v) noexcept {
DeterministicSchedule::beforeSharedAccess();
T rv = (data |= v);
- DeterministicSchedule::afterSharedAccess();
+ FOLLY_TEST_DSCHED_VLOG(this << " |= " << std::hex << v << " -> " << std::hex
+ << rv);
+ DeterministicSchedule::afterSharedAccess(true);
+ return rv;
+ }
+
+ T fetch_or(T v,
+ std::memory_order /* mo */ = std::memory_order_seq_cst) noexcept {
+ DeterministicSchedule::beforeSharedAccess();
+ T rv = data;
+ data |= v;
+ FOLLY_TEST_DSCHED_VLOG(this << ".fetch_or(" << std::hex << v << ") -> "
+ << std::hex << rv);
+ DeterministicSchedule::afterSharedAccess(true);
+ return rv;
+ }
+
+ T operator^=(T v) noexcept {
+ DeterministicSchedule::beforeSharedAccess();
+ T rv = (data ^= v);
+ FOLLY_TEST_DSCHED_VLOG(this << " ^= " << std::hex << v << " -> " << std::hex
+ << rv);
+ DeterministicSchedule::afterSharedAccess(true);
+ return rv;
+ }
+
+ T fetch_xor(T v,
+ std::memory_order /* mo */ = std::memory_order_seq_cst) noexcept {
+ DeterministicSchedule::beforeSharedAccess();
+ T rv = data;
+ data ^= v;
+ FOLLY_TEST_DSCHED_VLOG(this << ".fetch_xor(" << std::hex << v << ") -> "
+ << std::hex << rv);
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
+
+ /** Read the value of the atomic variable without context switching */
+ T load_direct() const noexcept {
+ return data.load(std::memory_order_relaxed);
+ }
};
-}}
+/**
+ * DeterministicMutex is a drop-in replacement of std::mutex that
+ * cooperates with DeterministicSchedule.
+ */
+struct DeterministicMutex {
+ std::mutex m;
+
+ DeterministicMutex() = default;
+ ~DeterministicMutex() = default;
+ DeterministicMutex(DeterministicMutex const&) = delete;
+ DeterministicMutex& operator=(DeterministicMutex const&) = delete;
+
+ void lock() {
+ FOLLY_TEST_DSCHED_VLOG(this << ".lock()");
+ while (!try_lock()) {
+ // Not calling m.lock() in order to avoid deadlock when the
+ // mutex m is held by another thread. The deadlock would be
+ // between the call to m.lock() and the lock holder's wait on
+ // its own tls_sem scheduling semaphore.
+ }
+ }
+
+ bool try_lock() {
+ DeterministicSchedule::beforeSharedAccess();
+ bool rv = m.try_lock();
+ FOLLY_TEST_DSCHED_VLOG(this << ".try_lock() -> " << rv);
+ DeterministicSchedule::afterSharedAccess();
+ return rv;
+ }
+
+ void unlock() {
+ FOLLY_TEST_DSCHED_VLOG(this << ".unlock()");
+ m.unlock();
+ }
+};
+} // namespace test
+} // namespace folly
-namespace folly { namespace detail {
+/* Specialization declarations */
-template<>
-bool Futex<test::DeterministicAtomic>::futexWait(uint32_t expected,
- uint32_t waitMask);
+namespace folly {
+namespace detail {
-template<>
+template <>
int Futex<test::DeterministicAtomic>::futexWake(int count, uint32_t wakeMask);
-}}
+template <>
+FutexResult Futex<test::DeterministicAtomic>::futexWaitImpl(
+ uint32_t expected,
+ std::chrono::time_point<std::chrono::system_clock>* absSystemTime,
+ std::chrono::time_point<std::chrono::steady_clock>* absSteadyTime,
+ uint32_t waitMask);
+} // namespace detail
+
+template <>
+Getcpu::Func AccessSpreader<test::DeterministicAtomic>::pickGetcpuFunc();
+
+} // namespace folly
projects / folly.git / blobdiff