#pragma once
+// This needs to be above semaphore.h due to the windows
+// libevent implementation needing mode_t to be defined,
+// but defining it differently than our portability
+// headers do.
+#include <folly/portability/SysTypes.h>
+
+#include <assert.h>
+#include <boost/noncopyable.hpp>
+#include <errno.h>
+#include <glog/logging.h>
+#include <semaphore.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 <glog/logging.h>
#include <folly/ScopeGuard.h>
#include <folly/detail/CacheLocality.h>
// This is ugly, but better perf for DeterministicAtomic translates
// directly to more states explored and tested
-#define FOLLY_TEST_DSCHED_VLOG(msg...) \
- do { \
- if (false) { \
- VLOG(2) << std::hex << std::this_thread::get_id() << ": " << msg; \
- } \
+#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
* set of threads under test, so that despite concurrency the execution is
* 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>
/** 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 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::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);
};
/**
FOLLY_TEST_DSCHED_VLOG(this << ".compare_exchange_strong(" << std::hex
<< orig << ", " << std::hex << v1 << ") -> "
<< rv << "," << std::hex << v0);
- DeterministicSchedule::afterSharedAccess();
+ DeterministicSchedule::afterSharedAccess(rv);
return rv;
}
FOLLY_TEST_DSCHED_VLOG(this << ".compare_exchange_weak(" << std::hex << orig
<< ", " << std::hex << v1 << ") -> " << rv
<< "," << std::hex << v0);
- DeterministicSchedule::afterSharedAccess();
+ DeterministicSchedule::afterSharedAccess(rv);
return rv;
}
T rv = data.exchange(v, mo);
FOLLY_TEST_DSCHED_VLOG(this << ".exchange(" << std::hex << v << ") -> "
<< std::hex << rv);
- DeterministicSchedule::afterSharedAccess();
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
DeterministicSchedule::beforeSharedAccess();
T rv = data;
FOLLY_TEST_DSCHED_VLOG(this << "() -> " << std::hex << rv);
- DeterministicSchedule::afterSharedAccess();
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
DeterministicSchedule::beforeSharedAccess();
T rv = data.load(mo);
FOLLY_TEST_DSCHED_VLOG(this << ".load() -> " << std::hex << rv);
- DeterministicSchedule::afterSharedAccess();
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
DeterministicSchedule::beforeSharedAccess();
T rv = (data = v);
FOLLY_TEST_DSCHED_VLOG(this << " = " << std::hex << v);
- DeterministicSchedule::afterSharedAccess();
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
DeterministicSchedule::beforeSharedAccess();
data.store(v, mo);
FOLLY_TEST_DSCHED_VLOG(this << ".store(" << std::hex << v << ")");
- DeterministicSchedule::afterSharedAccess();
+ DeterministicSchedule::afterSharedAccess(true);
}
T operator++() noexcept {
DeterministicSchedule::beforeSharedAccess();
T rv = ++data;
FOLLY_TEST_DSCHED_VLOG(this << " pre++ -> " << std::hex << rv);
- DeterministicSchedule::afterSharedAccess();
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
DeterministicSchedule::beforeSharedAccess();
T rv = data++;
FOLLY_TEST_DSCHED_VLOG(this << " post++ -> " << std::hex << rv);
- DeterministicSchedule::afterSharedAccess();
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
DeterministicSchedule::beforeSharedAccess();
T rv = --data;
FOLLY_TEST_DSCHED_VLOG(this << " pre-- -> " << std::hex << rv);
- DeterministicSchedule::afterSharedAccess();
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
DeterministicSchedule::beforeSharedAccess();
T rv = data--;
FOLLY_TEST_DSCHED_VLOG(this << " post-- -> " << std::hex << rv);
- DeterministicSchedule::afterSharedAccess();
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
T rv = (data += v);
FOLLY_TEST_DSCHED_VLOG(this << " += " << std::hex << v << " -> " << std::hex
<< rv);
- DeterministicSchedule::afterSharedAccess();
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
data += v;
FOLLY_TEST_DSCHED_VLOG(this << ".fetch_add(" << std::hex << v << ") -> "
<< std::hex << rv);
- DeterministicSchedule::afterSharedAccess();
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
T rv = (data -= v);
FOLLY_TEST_DSCHED_VLOG(this << " -= " << std::hex << v << " -> " << std::hex
<< rv);
- DeterministicSchedule::afterSharedAccess();
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
data -= v;
FOLLY_TEST_DSCHED_VLOG(this << ".fetch_sub(" << std::hex << v << ") -> "
<< std::hex << rv);
- DeterministicSchedule::afterSharedAccess();
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
T rv = (data &= v);
FOLLY_TEST_DSCHED_VLOG(this << " &= " << std::hex << v << " -> " << std::hex
<< rv);
- DeterministicSchedule::afterSharedAccess();
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
data &= v;
FOLLY_TEST_DSCHED_VLOG(this << ".fetch_and(" << std::hex << v << ") -> "
<< std::hex << rv);
- DeterministicSchedule::afterSharedAccess();
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
T rv = (data |= v);
FOLLY_TEST_DSCHED_VLOG(this << " |= " << std::hex << v << " -> " << std::hex
<< rv);
- DeterministicSchedule::afterSharedAccess();
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
data |= v;
FOLLY_TEST_DSCHED_VLOG(this << ".fetch_or(" << std::hex << v << ") -> "
<< std::hex << rv);
- DeterministicSchedule::afterSharedAccess();
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
T rv = (data ^= v);
FOLLY_TEST_DSCHED_VLOG(this << " ^= " << std::hex << v << " -> " << std::hex
<< rv);
- DeterministicSchedule::afterSharedAccess();
+ DeterministicSchedule::afterSharedAccess(true);
return rv;
}
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 folly::test
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