X-Git-Url: http://plrg.eecs.uci.edu/git/?p=c11tester.git;a=blobdiff_plain;f=threads.cc;h=dc2db2d9bfefcab57458035f3f4bc815b75b5fc5;hp=399472c9ac60b5b578ea0af88ea05bcf7da06c9f;hb=dfb6b1724a592f7a5376336d653b93d9010833c4;hpb=5e3720f6a6dccf2af670e4ab30660130f2a57c8f diff --git a/threads.cc b/threads.cc index 399472c9..dc2db2d9 100644 --- a/threads.cc +++ b/threads.cc @@ -2,30 +2,32 @@ * @brief Thread functions. */ +#include -#include "libthreads.h" +#include #include "common.h" -#include "threads.h" +#include "threads-model.h" /* global "model" object */ #include "model.h" -#define STACK_SIZE (1024 * 1024) - +/** Allocate a stack for a new thread. */ static void * stack_allocate(size_t size) { - return malloc(size); + return snapshot_malloc(size); } +/** Free a stack for a terminated thread. */ static void stack_free(void *stack) { - free(stack); + snapshot_free(stack); } +/** Return the currently executing thread. */ Thread * thread_current(void) { ASSERT(model); - return model->scheduler->get_current_thread(); + return model->get_current_thread(); } /** @@ -35,8 +37,8 @@ Thread * thread_current(void) * @todo We should make the START event always immediately follow the * CREATE event, so we don't get redundant traces... */ - -void thread_startup() { +void thread_startup() +{ Thread * curr_thread = thread_current(); /* Add dummy "start" action, just to create a first clock vector */ @@ -44,8 +46,16 @@ void thread_startup() { /* Call the actual thread function */ curr_thread->start_routine(curr_thread->arg); + + /* Finish thread properly */ + model->switch_to_master(new ModelAction(THREAD_FINISH, std::memory_order_seq_cst, curr_thread)); } +/** + * Create a thread context for a new thread so we can use + * setcontext/getcontext/swapcontext to swap it out. + * @return 0 on success; otherwise, non-zero error condition + */ int Thread::create_context() { int ret; @@ -65,32 +75,86 @@ int Thread::create_context() return 0; } +/** + * Swaps the current context to another thread of execution. This form switches + * from a user Thread to a system context. + * @param t Thread representing the currently-running thread. The current + * context is saved here. + * @param ctxt Context to which we will swap. Must hold a valid system context. + * @return Does not return, unless we return to Thread t's context. See + * swapcontext(3) (returns 0 for success, -1 for failure). + */ int Thread::swap(Thread *t, ucontext_t *ctxt) { return swapcontext(&t->context, ctxt); } +/** + * Swaps the current context to another thread of execution. This form switches + * from a system context to a user Thread. + * @param ctxt System context variable to which to save the current context. + * @param t Thread to which we will swap. Must hold a valid user context. + * @return Does not return, unless we return to the system context (ctxt). See + * swapcontext(3) (returns 0 for success, -1 for failure). + */ int Thread::swap(ucontext_t *ctxt, Thread *t) { return swapcontext(ctxt, &t->context); } + +/** Terminate a thread and free its stack. */ void Thread::complete() { - if (state != THREAD_COMPLETED) { - DEBUG("completed thread %d\n", get_id()); + if (!is_complete()) { + DEBUG("completed thread %d\n", id_to_int(get_id())); state = THREAD_COMPLETED; if (stack) stack_free(stack); } } +/** + * @brief Construct a new model-checker Thread + * + * A model-checker Thread is used for accounting purposes only. It will never + * have its own stack, and it should never be inserted into the Scheduler. + * + * @param tid The thread ID to assign + */ +Thread::Thread(thread_id_t tid) : + parent(NULL), + creation(NULL), + pending(NULL), + start_routine(NULL), + arg(NULL), + stack(NULL), + user_thread(NULL), + id(tid), + state(THREAD_READY), /* Thread is always ready? */ + wait_list(), + last_action_val(0), + model_thread(true) +{ + memset(&context, 0, sizeof(context)); +} + +/** + * Construct a new thread. + * @param t The thread identifier of the newly created thread. + * @param func The function that the thread will call. + * @param a The parameter to pass to this function. + */ Thread::Thread(thrd_t *t, void (*func)(void *), void *a) : + creation(NULL), + pending(NULL), start_routine(func), arg(a), user_thread(t), state(THREAD_CREATED), - last_action_val(VALUE_NONE) + wait_list(), + last_action_val(VALUE_NONE), + model_thread(false) { int ret; @@ -104,12 +168,14 @@ Thread::Thread(thrd_t *t, void (*func)(void *), void *a) : parent = thread_current(); } +/** Destructor */ Thread::~Thread() { complete(); model->remove_thread(this); } +/** @return The thread_id_t corresponding to this Thread object. */ thread_id_t Thread::get_id() { return id;