X-Git-Url: http://plrg.eecs.uci.edu/git/?p=cdsspec-compiler.git;a=blobdiff_plain;f=action.cc;h=bd98f5ca2f490f4c3743641ee7018d8e178d72ec;hp=e88fceef66a8d173e851f4439afd55f1d96564f4;hb=d21164220a0d87ae931bf50d0e97ebf838742659;hpb=fab8621e4bf6acafc04dbaf786e2de6263d892f6 diff --git a/action.cc b/action.cc index e88fcee..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; @@ -97,11 +108,11 @@ bool ModelAction::is_wait() const { } bool ModelAction::is_notify() const { - return type==ATOMIC_NOTIFY_ONE || type==ATOMIC_NOTIFY_ALL; + return type == ATOMIC_NOTIFY_ONE || type == ATOMIC_NOTIFY_ALL; } bool ModelAction::is_notify_one() const { - return type==ATOMIC_NOTIFY_ONE; + return type == ATOMIC_NOTIFY_ONE; } bool ModelAction::is_unlock() const @@ -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; @@ -165,7 +181,7 @@ bool ModelAction::is_rmwc() const return type == ATOMIC_RMWC; } -bool ModelAction::is_fence() const +bool ModelAction::is_fence() const { return type == ATOMIC_FENCE; } @@ -206,20 +222,20 @@ 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) ) + 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 ) + } else if (is_wait()) { + if (((void *)value) == act->location) return true; - } else if ( act->is_wait() ) { - if ( location == ((void *)act->value) ) + } else if (act->is_wait()) { + if (location == ((void *)act->value)) return true; } } @@ -232,35 +248,72 @@ bool ModelAction::same_thread(const ModelAction *act) const return tid == act->tid; } -void ModelAction::copy_typeandorder(ModelAction * act) { +void ModelAction::copy_typeandorder(ModelAction * act) +{ this->type = act->type; this->order = act->order; } -/** 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. +/** + * 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; +} + +/** + * @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) { - 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; } } -/** 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 + * + * 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 is the action to consider exploring a reordering. - * @return tells whether we have to explore a reordering. + * @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 { @@ -274,17 +327,15 @@ bool ModelAction::could_synchronize_with(const ModelAction *act) const // 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()) + if ((could_be_write() || act->could_be_write() || is_fence() || act->is_fence()) && is_seqcst() && act->is_seqcst()) return true; - // Explore synchronizing read/write/fence pairs - if (is_acquire() && act->is_release() && (is_read() || is_fence()) && - (act->could_be_write() || act->is_fence())) + // Explore synchronizing read/write pairs + 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())) + if ((is_lock() || is_trylock()) && (act->is_unlock() || act->is_wait())) return true; // lock just acquired...we can fail to grab lock @@ -292,16 +343,16 @@ bool ModelAction::could_synchronize_with(const ModelAction *act) const return true; // other thread stalling on lock...we can release lock - if (is_unlock() && (act->is_trylock()||act->is_lock())) + if (is_unlock() && (act->is_trylock() || act->is_lock())) return true; - if (is_trylock() && (act->is_unlock()||act->is_wait())) + if (is_trylock() && (act->is_unlock() || act->is_wait())) return true; - if ( is_notify() && act->is_wait() ) + if (is_notify() && act->is_wait()) return true; - if ( is_wait() && act->is_notify() ) + if (is_wait() && act->is_notify()) return true; // Otherwise handle by reads_from relation @@ -313,11 +364,11 @@ bool ModelAction::is_conflicting_lock(const ModelAction *act) const // 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; @@ -345,11 +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 */ @@ -366,18 +473,32 @@ 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. * @param act The ModelAction to synchronize with * @return True if this is a valid synchronization; false otherwise */ -bool ModelAction::synchronize_with(const ModelAction *act) { +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); @@ -470,8 +591,6 @@ void ModelAction::print() const type_str = "unknown type"; } - uint64_t valuetoprint=type==ATOMIC_READ?(reads_from!=NULL?reads_from->value:VALUE_NONE):value; - switch (this->order) { case std::memory_order_relaxed: mo_str = "relaxed"; @@ -494,11 +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) { @@ -511,17 +636,60 @@ 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; - hash^=((unsigned int)this->order)<<3; - hash^=seq_number<<5; + 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()) { - if (reads_from) - hash^=reads_from->get_seq_number(); + 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; +}