X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=action.cc;h=bd98f5ca2f490f4c3743641ee7018d8e178d72ec;hb=5178739a27add5e59a1213c9ac90e73397c1a23d;hp=6a545d82a0badac66c25eb58cd124de6d8f892f0;hpb=6144dd79c2f94591ffdb10655322900629bb1b1e;p=model-checker.git diff --git a/action.cc b/action.cc index 6a545d8..bd98f5c 100644 --- a/action.cc +++ b/action.cc @@ -1,7 +1,6 @@ #include #define __STDC_FORMAT_MACROS #include -#include #include "model.h" #include "action.h" @@ -12,6 +11,12 @@ #define ACTION_INITIAL_CLOCK 0 +/** @brief A special value to represent a successful trylock */ +#define VALUE_TRYSUCCESS 1 + +/** @brief A special value to represent a failed trylock */ +#define VALUE_TRYFAILED 0 + /** * @brief Construct a new ModelAction * @@ -31,6 +36,7 @@ ModelAction::ModelAction(action_type_t type, memory_order order, void *loc, location(loc), value(value), reads_from(NULL), + reads_from_promise(NULL), last_fence_release(NULL), node(NULL), seq_number(ACTION_INITIAL_CLOCK), @@ -77,6 +83,11 @@ bool ModelAction::is_thread_start() const return type == THREAD_START; } +bool ModelAction::is_thread_join() const +{ + return type == THREAD_JOIN; +} + bool ModelAction::is_relseq_fixup() const { return type == MODEL_FIXUP_RELSEQ; @@ -150,6 +161,11 @@ bool ModelAction::could_be_write() const return is_write() || is_rmwr(); } +bool ModelAction::is_yield() const +{ + return type == THREAD_YIELD; +} + bool ModelAction::is_rmwr() const { return type == ATOMIC_RMWR; @@ -252,21 +268,28 @@ void ModelAction::copy_typeandorder(ModelAction * act) */ Thread * ModelAction::get_thread_operand() const { - if (type == THREAD_CREATE) - /* THREAD_CREATE uses (Thread *) for location */ - return (Thread *)get_location(); - else if (type == THREAD_JOIN) + 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: - * (1) a full RMW action in case of the completed write or - * (2) a READ action in case a failed action. +/** + * @brief Convert the read portion of an RMW + * + * Changes an existing read part of an RMW action into either: + * -# a full RMW action in case of the completed write or + * -# a READ action in case a failed action. + * * @todo If the memory_order changes, we may potentially need to update our * clock vector. + * + * @param act The second half of the RMW (either RMWC or RMW) */ void ModelAction::process_rmw(ModelAction *act) { @@ -279,14 +302,18 @@ void ModelAction::process_rmw(ModelAction *act) } } -/** The is_synchronizing method should only explore interleavings if: - * (1) the operations are seq_cst and don't commute or - * (2) the reordering may establish or break a synchronization relation. - * Other memory operations will be dealt with by using the reads_from - * relation. +/** + * @brief Check if this action should be backtracked with another, due to + * potential synchronization * - * @param act is the action to consider exploring a reordering. - * @return tells whether we have to explore a reordering. + * The is_synchronizing method should only explore interleavings if: + * -# the operations are seq_cst and don't commute or + * -# the reordering may establish or break a synchronization relation. + * + * Other memory operations will be dealt with by using the reads_from relation. + * + * @param act The action to consider exploring a reordering + * @return True, if we have to explore a reordering; otherwise false */ bool ModelAction::could_synchronize_with(const ModelAction *act) const { @@ -298,9 +325,9 @@ bool ModelAction::could_synchronize_with(const ModelAction *act) const if (!same_var(act)) return false; - // Explore interleavings of seqcst writes to guarantee total + // 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_seqcst() && act->is_seqcst()) + 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 @@ -369,11 +396,67 @@ void ModelAction::create_cv(const ModelAction *parent) cv = new ClockVector(NULL, this); } -void ModelAction::set_try_lock(bool obtainedlock) { - if (obtainedlock) - value = VALUE_TRYSUCCESS; +void ModelAction::set_try_lock(bool obtainedlock) +{ + value = obtainedlock ? VALUE_TRYSUCCESS : VALUE_TRYFAILED; +} + +/** + * @brief Get the value read by this load + * + * We differentiate this function from ModelAction::get_write_value and + * ModelAction::get_value for the purpose of RMW's, which may have both a + * 'read' and a 'write' value. + * + * Note: 'this' must be a load. + * + * @return The value read by this load + */ +uint64_t ModelAction::get_reads_from_value() const +{ + ASSERT(is_read()); + if (reads_from) + return reads_from->get_write_value(); + else if (reads_from_promise) + return reads_from_promise->get_value(); + return VALUE_NONE; /* Only for new actions with no reads-from */ +} + +/** + * @brief Get the value written by this store + * + * We differentiate this function from ModelAction::get_reads_from_value and + * ModelAction::get_value for the purpose of RMW's, which may have both a + * 'read' and a 'write' value. + * + * Note: 'this' must be a store. + * + * @return The value written by this store + */ +uint64_t ModelAction::get_write_value() const +{ + ASSERT(is_write()); + return value; +} + +/** + * @brief Get the value returned by this action + * + * For atomic reads (including RMW), an operation returns the value it read. + * For atomic writes, an operation returns the value it wrote. For other + * operations, the return value varies (sometimes is a "don't care"), but the + * value is simply stored in the "value" field. + * + * @return This action's return value + */ +uint64_t ModelAction::get_return_value() const +{ + if (is_read()) + return get_reads_from_value(); + else if (is_write()) + return get_write_value(); else - value = VALUE_TRYFAILED; + return value; } /** @return The Node associated with this ModelAction */ @@ -390,11 +473,24 @@ Node * ModelAction::get_node() const */ void ModelAction::set_read_from(const ModelAction *act) { + ASSERT(act); reads_from = act; - if (act && act->is_uninitialized()) + reads_from_promise = NULL; + if (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. @@ -495,12 +591,6 @@ void ModelAction::print() const type_str = "unknown type"; } - uint64_t valuetoprint; - if (type == ATOMIC_READ && reads_from != NULL) - valuetoprint = reads_from->value; - else - valuetoprint = value; - switch (this->order) { case std::memory_order_relaxed: mo_str = "relaxed"; @@ -523,11 +613,17 @@ void ModelAction::print() const } 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); + seq_number, id_to_int(tid), type_str, mo_str, location, get_return_value()); if (is_read()) { if (reads_from) model_print(" Rf: %-3d", reads_from->get_seq_number()); - else + 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) { @@ -540,7 +636,7 @@ void ModelAction::print() const model_print("\n"); } -/** @brief Print nicely-formatted info about this ModelAction */ +/** @brief Get a (likely) unique hash for this ModelAction */ unsigned int ModelAction::hash() const { unsigned int hash = (unsigned int)this->type; @@ -548,7 +644,52 @@ unsigned int ModelAction::hash() const hash ^= seq_number << 5; hash ^= id_to_int(tid) << 6; - if (is_read() && reads_from) - hash ^= reads_from->get_seq_number(); + if (is_read()) { + if (reads_from) + hash ^= reads_from->get_seq_number(); + else if (reads_from_promise) + hash ^= model->get_promise_number(reads_from_promise); + hash ^= get_reads_from_value(); + } return hash; } + +/** + * @brief Checks the NodeStack to see if a ModelAction is in our may-read-from set + * @param write The ModelAction to check for + * @return True if the ModelAction is found; false otherwise + */ +bool ModelAction::may_read_from(const ModelAction *write) const +{ + for (int i = 0; i < node->get_read_from_past_size(); i++) + if (node->get_read_from_past(i) == write) + return true; + return false; +} + +/** + * @brief Checks the NodeStack to see if a Promise is in our may-read-from set + * @param promise The Promise to check for + * @return True if the Promise is found; false otherwise + */ +bool ModelAction::may_read_from(const Promise *promise) const +{ + for (int i = 0; i < node->get_read_from_promise_size(); i++) + if (node->get_read_from_promise(i) == promise) + return true; + return false; +} + +/** + * Only valid for LOCK, TRY_LOCK, UNLOCK, and WAIT operations. + * @return The mutex operated on by this action, if any; otherwise NULL + */ +std::mutex * ModelAction::get_mutex() const +{ + if (is_trylock() || is_lock() || is_unlock()) + return (std::mutex *)get_location(); + else if (is_wait()) + return (std::mutex *)get_value(); + else + return NULL; +}