/*
- * Copyright 2016 Facebook, Inc.
+ * Copyright 2017 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
} \
} 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
* 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>
/** 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 int getRandNumber(int n);
+ 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 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);
};
/**
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();
+ 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);
+ }
};
/**
projects / folly.git / blobdiff