X-Git-Url: http://plrg.eecs.uci.edu/git/?p=model-checker.git;a=blobdiff_plain;f=action.cc;h=81f447a5b13f9d8e3db3e352e4be49f4659559b0;hp=e5c9afe46f4cd81fff20555344b669c23c9b4bb1;hb=f5029d07e4fad5921f60108f5632fb2a5e4a52fb;hpb=d1930060e483b841f0a9c35c5041035dbdf6de4a diff --git a/action.cc b/action.cc index e5c9afe..81f447a 100644 --- a/action.cc +++ b/action.cc @@ -7,50 +7,135 @@ #include "action.h" #include "clockvector.h" #include "common.h" +#include "threads-model.h" +#include "nodestack.h" -ModelAction::ModelAction(action_type_t type, memory_order order, void *loc, uint64_t value) : +#define ACTION_INITIAL_CLOCK 0 + +/** + * @brief Construct a new ModelAction + * + * @param type The type of action + * @param order The memory order of this action. A "don't care" for non-ATOMIC + * actions (e.g., THREAD_* or MODEL_* actions). + * @param loc The location that this action acts upon + * @param value (optional) A value associated with the action (e.g., the value + * read or written). Defaults to a given macro constant, for debugging purposes. + * @param thread (optional) The Thread in which this action occurred. If NULL + * (default), then a Thread is assigned according to the scheduler. + */ +ModelAction::ModelAction(action_type_t type, memory_order order, void *loc, + uint64_t value, Thread *thread) : type(type), order(order), location(loc), value(value), reads_from(NULL), - cv(NULL) + reads_from_promise(NULL), + last_fence_release(NULL), + node(NULL), + seq_number(ACTION_INITIAL_CLOCK), + cv(NULL), + sleep_flag(false) { - Thread *t = thread_current(); + /* References to NULL atomic variables can end up here */ + ASSERT(loc || type == ATOMIC_FENCE || type == MODEL_FIXUP_RELSEQ); + + Thread *t = thread ? thread : thread_current(); this->tid = t->get_id(); - this->seq_number = model->get_next_seq_num(); } +/** @brief ModelAction destructor */ ModelAction::~ModelAction() { - if (cv) - delete cv; + /** + * We can't free the clock vector: + * Clock vectors are snapshotting state. When we delete model actions, + * they are at the end of the node list and have invalid old clock + * vectors which have already been rolled back to an unallocated state. + */ + + /* + if (cv) + delete cv; */ +} + +void ModelAction::copy_from_new(ModelAction *newaction) +{ + seq_number = newaction->seq_number; } -bool ModelAction::is_mutex_op() const { - return type == ATOMIC_LOCK || type == ATOMIC_TRYLOCK || type == ATOMIC_UNLOCK; +void ModelAction::set_seq_number(modelclock_t num) +{ + /* ATOMIC_UNINIT actions should never have non-zero clock */ + ASSERT(!is_uninitialized()); + ASSERT(seq_number == ACTION_INITIAL_CLOCK); + seq_number = num; } -bool ModelAction::is_lock() const { +bool ModelAction::is_thread_start() const +{ + return type == THREAD_START; +} + +bool ModelAction::is_relseq_fixup() const +{ + return type == MODEL_FIXUP_RELSEQ; +} + +bool ModelAction::is_mutex_op() const +{ + return type == ATOMIC_LOCK || type == ATOMIC_TRYLOCK || type == ATOMIC_UNLOCK || type == ATOMIC_WAIT || type == ATOMIC_NOTIFY_ONE || type == ATOMIC_NOTIFY_ALL; +} + +bool ModelAction::is_lock() const +{ return type == ATOMIC_LOCK; } -bool ModelAction::is_unlock() const { +bool ModelAction::is_wait() const { + return type == ATOMIC_WAIT; +} + +bool ModelAction::is_notify() const { + return type == ATOMIC_NOTIFY_ONE || type == ATOMIC_NOTIFY_ALL; +} + +bool ModelAction::is_notify_one() const { + return type == ATOMIC_NOTIFY_ONE; +} + +bool ModelAction::is_unlock() const +{ return type == ATOMIC_UNLOCK; } -bool ModelAction::is_trylock() const { +bool ModelAction::is_trylock() const +{ return type == ATOMIC_TRYLOCK; } -bool ModelAction::is_success_lock() const { +bool ModelAction::is_success_lock() const +{ return type == ATOMIC_LOCK || (type == ATOMIC_TRYLOCK && value == VALUE_TRYSUCCESS); } -bool ModelAction::is_failed_trylock() const { +bool ModelAction::is_failed_trylock() const +{ return (type == ATOMIC_TRYLOCK && value == VALUE_TRYFAILED); } +/** @return True if this operation is performed on a C/C++ atomic variable */ +bool ModelAction::is_atomic_var() const +{ + return is_read() || could_be_write(); +} + +bool ModelAction::is_uninitialized() const +{ + return type == ATOMIC_UNINIT; +} + bool ModelAction::is_read() const { return type == ATOMIC_READ || type == ATOMIC_RMWR || type == ATOMIC_RMW; @@ -58,7 +143,12 @@ bool ModelAction::is_read() const bool ModelAction::is_write() const { - return type == ATOMIC_WRITE || type == ATOMIC_RMW || type == ATOMIC_INIT; + return type == ATOMIC_WRITE || type == ATOMIC_RMW || type == ATOMIC_INIT || type == ATOMIC_UNINIT; +} + +bool ModelAction::could_be_write() const +{ + return is_write() || is_rmwr(); } bool ModelAction::is_rmwr() const @@ -76,7 +166,7 @@ bool ModelAction::is_rmwc() const return type == ATOMIC_RMWC; } -bool ModelAction::is_fence() const +bool ModelAction::is_fence() const { return type == ATOMIC_FENCE; } @@ -86,6 +176,11 @@ bool ModelAction::is_initialization() const return type == ATOMIC_INIT; } +bool ModelAction::is_relaxed() const +{ + return order == std::memory_order_relaxed; +} + bool ModelAction::is_acquire() const { switch (order) { @@ -112,11 +207,24 @@ bool ModelAction::is_release() const bool ModelAction::is_seqcst() const { - return order==std::memory_order_seq_cst; + return order == std::memory_order_seq_cst; } bool ModelAction::same_var(const ModelAction *act) const { + if (act->is_wait() || is_wait()) { + if (act->is_wait() && is_wait()) { + if (((void *)value) == ((void *)act->value)) + return true; + } else if (is_wait()) { + if (((void *)value) == act->location) + return true; + } else if (act->is_wait()) { + if (location == ((void *)act->value)) + return true; + } + } + return location == act->location; } @@ -125,9 +233,35 @@ bool ModelAction::same_thread(const ModelAction *act) const return tid == act->tid; } -void ModelAction::copy_typeandorder(ModelAction * act) { - this->type=act->type; - this->order=act->order; +void ModelAction::copy_typeandorder(ModelAction * act) +{ + this->type = act->type; + this->order = act->order; +} + +/** + * Get the Thread which is the operand of this action. This is only valid for + * THREAD_* operations (currently only for THREAD_CREATE and THREAD_JOIN). Note + * that this provides a central place for determining the conventions of Thread + * storage in ModelAction, where we generally aren't very type-safe (e.g., we + * store object references in a (void *) address. + * + * For THREAD_CREATE, this yields the Thread which is created. + * For THREAD_JOIN, this yields the Thread we are joining with. + * + * @return The Thread which this action acts on, if exists; otherwise NULL + */ +Thread * ModelAction::get_thread_operand() const +{ + if (type == THREAD_CREATE) { + /* THREAD_CREATE stores its (Thread *) in a thrd_t::priv */ + thrd_t *thrd = (thrd_t *)get_location(); + return thrd->priv; + } else if (type == THREAD_JOIN) + /* THREAD_JOIN uses (Thread *) for location */ + return (Thread *)get_location(); + else + return NULL; } /** This method changes an existing read part of an RMW action into either: @@ -136,13 +270,14 @@ void ModelAction::copy_typeandorder(ModelAction * act) { * @todo If the memory_order changes, we may potentially need to update our * clock vector. */ -void ModelAction::process_rmw(ModelAction * act) { - this->order=act->order; +void ModelAction::process_rmw(ModelAction *act) +{ + this->order = act->order; if (act->is_rmwc()) - this->type=ATOMIC_READ; + this->type = ATOMIC_READ; else if (act->is_rmw()) { - this->type=ATOMIC_RMW; - this->value=act->value; + this->type = ATOMIC_RMW; + this->value = act->value; } } @@ -155,9 +290,9 @@ void ModelAction::process_rmw(ModelAction * act) { * @param act is the action to consider exploring a reordering. * @return tells whether we have to explore a reordering. */ -bool ModelAction::is_synchronizing(const ModelAction *act) const +bool ModelAction::could_synchronize_with(const ModelAction *act) const { - //Same thread can't be reordered + // Same thread can't be reordered if (same_thread(act)) return false; @@ -165,26 +300,71 @@ bool ModelAction::is_synchronizing(const ModelAction *act) const if (!same_var(act)) return false; - // Explore interleavings of seqcst writes to guarantee total order - // of seq_cst operations that don't commute - if (is_write() && is_seqcst() && act->is_write() && act->is_seqcst()) + // Explore interleavings of seqcst writes/fences to guarantee total + // order of seq_cst operations that don't commute + if ((could_be_write() || act->could_be_write() || is_fence() || act->is_fence()) && is_seqcst() && act->is_seqcst()) return true; // Explore synchronizing read/write pairs - if (is_read() && is_acquire() && act->is_write() && act->is_release()) + if (is_acquire() && act->is_release() && is_read() && act->could_be_write()) + return true; + + // lock just released...we can grab lock + if ((is_lock() || is_trylock()) && (act->is_unlock() || act->is_wait())) + return true; + + // lock just acquired...we can fail to grab lock + if (is_trylock() && act->is_success_lock()) + return true; + + // other thread stalling on lock...we can release lock + if (is_unlock() && (act->is_trylock() || act->is_lock())) + return true; + + if (is_trylock() && (act->is_unlock() || act->is_wait())) return true; - if (is_write() && is_release() && act->is_read() && act->is_acquire()) + + if (is_notify() && act->is_wait()) + return true; + + if (is_wait() && act->is_notify()) return true; // Otherwise handle by reads_from relation return false; } -void ModelAction::create_cv(const ModelAction *parent) +bool ModelAction::is_conflicting_lock(const ModelAction *act) const { - if (cv) - delete cv; + // Must be different threads to reorder + if (same_thread(act)) + return false; + // Try to reorder a lock past a successful lock + if (act->is_success_lock()) + return true; + + // Try to push a successful trylock past an unlock + if (act->is_unlock() && is_trylock() && value == VALUE_TRYSUCCESS) + return true; + + // Try to push a successful trylock past a wait + if (act->is_wait() && is_trylock() && value == VALUE_TRYSUCCESS) + return true; + + return false; +} + +/** + * Create a new clock vector for this action. Note that this function allows a + * user to clobber (and leak) a ModelAction's existing clock vector. A user + * should ensure that the vector has already either been rolled back + * (effectively "freed") or freed. + * + * @param parent A ModelAction from which to inherit a ClockVector + */ +void ModelAction::create_cv(const ModelAction *parent) +{ if (parent) cv = new ClockVector(parent->cv, this); else @@ -193,38 +373,60 @@ void ModelAction::create_cv(const ModelAction *parent) void ModelAction::set_try_lock(bool obtainedlock) { if (obtainedlock) - value=VALUE_TRYSUCCESS; + value = VALUE_TRYSUCCESS; else - value=VALUE_TRYFAILED; + value = VALUE_TRYFAILED; } -/** Update the model action's read_from action */ -void ModelAction::read_from(const ModelAction *act) +/** @return The Node associated with this ModelAction */ +Node * ModelAction::get_node() const +{ + /* UNINIT actions do not have a Node */ + ASSERT(!is_uninitialized()); + return node; +} + +/** + * Update the model action's read_from action + * @param act The action to read from; should be a write + */ +void ModelAction::set_read_from(const ModelAction *act) { - ASSERT(cv); reads_from = act; - if (act != NULL && this->is_acquire()) { - rel_heads_list_t release_heads; - model->get_release_seq_heads(this, &release_heads); - for (unsigned int i = 0; i < release_heads.size(); i++) - synchronize_with(release_heads[i]); - } + reads_from_promise = NULL; + if (act && act->is_uninitialized()) + model->assert_bug("May read from uninitialized atomic\n"); +} + +/** + * Set this action's read-from promise + * @param promise The promise to read from + */ +void ModelAction::set_read_from_promise(Promise *promise) +{ + ASSERT(is_read()); + reads_from_promise = promise; + reads_from = NULL; } /** * Synchronize the current thread with the thread corresponding to the * ModelAction parameter. * @param act The ModelAction to synchronize with + * @return True if this is a valid synchronization; false otherwise */ -void ModelAction::synchronize_with(const ModelAction *act) { - ASSERT(*act < *this || type == THREAD_JOIN || type == ATOMIC_LOCK ); - model->check_promises(cv, act->cv); +bool ModelAction::synchronize_with(const ModelAction *act) +{ + if (*this < *act && type != THREAD_JOIN && type != ATOMIC_LOCK) + return false; + model->check_promises(act->get_tid(), cv, act->cv); cv->merge(act->cv); + return true; } bool ModelAction::has_synchronized_with(const ModelAction *act) const { - return cv->has_synchronized_with(act->cv); + return cv->synchronized_since(act); } /** @@ -238,10 +440,14 @@ bool ModelAction::happens_before(const ModelAction *act) const return act->cv->synchronized_since(this); } -void ModelAction::print(void) const +/** @brief Print nicely-formatted info about this ModelAction */ +void ModelAction::print() const { const char *type_str, *mo_str; switch (this->type) { + case MODEL_FIXUP_RELSEQ: + type_str = "relseq fixup"; + break; case THREAD_CREATE: type_str = "thread create"; break; @@ -257,6 +463,9 @@ void ModelAction::print(void) const case THREAD_FINISH: type_str = "thread finish"; break; + case ATOMIC_UNINIT: + type_str = "uninitialized"; + break; case ATOMIC_READ: type_str = "atomic read"; break; @@ -278,11 +487,35 @@ void ModelAction::print(void) const case ATOMIC_INIT: type_str = "init atomic"; break; + case ATOMIC_LOCK: + type_str = "lock"; + break; + case ATOMIC_UNLOCK: + type_str = "unlock"; + break; + case ATOMIC_TRYLOCK: + type_str = "trylock"; + break; + case ATOMIC_WAIT: + type_str = "wait"; + break; + case ATOMIC_NOTIFY_ONE: + type_str = "notify one"; + break; + case ATOMIC_NOTIFY_ALL: + type_str = "notify all"; + break; default: type_str = "unknown type"; } - uint64_t valuetoprint=type==ATOMIC_READ?(reads_from!=NULL?reads_from->value:VALUE_NONE):value; + uint64_t valuetoprint; + if (is_read() && reads_from) + valuetoprint = reads_from->value; + else if (is_read() && reads_from_promise) + valuetoprint = reads_from_promise->get_value(); + else + valuetoprint = value; switch (this->order) { case std::memory_order_relaxed: @@ -305,17 +538,39 @@ void ModelAction::print(void) const break; } - printf("(%3d) Thread: %-2d Action: %-13s MO: %7s Loc: %14p Value: %-12" PRIu64, + model_print("(%4d) Thread: %-2d Action: %-13s MO: %7s Loc: %14p Value: %-#18" PRIx64, seq_number, id_to_int(tid), type_str, mo_str, location, valuetoprint); if (is_read()) { if (reads_from) - printf(" Rf: %d", reads_from->get_seq_number()); - else - printf(" Rf: ?"); + model_print(" Rf: %-3d", reads_from->get_seq_number()); + else if (reads_from_promise) { + int idx = model->get_promise_number(reads_from_promise); + if (idx >= 0) + model_print(" Rf: P%-2d", idx); + else + model_print(" RF: P? "); + } else + model_print(" Rf: ? "); } if (cv) { - printf("\t"); + if (is_read()) + model_print(" "); + else + model_print(" "); cv->print(); } else - printf("\n"); + model_print("\n"); +} + +/** @brief Get a (likely) unique hash for this ModelAction */ +unsigned int ModelAction::hash() const +{ + unsigned int hash = (unsigned int)this->type; + hash ^= ((unsigned int)this->order) << 3; + hash ^= seq_number << 5; + hash ^= id_to_int(tid) << 6; + + if (is_read() && reads_from) + hash ^= reads_from->get_seq_number(); + return hash; }