X-Git-Url: http://plrg.eecs.uci.edu/git/?p=c11tester.git;a=blobdiff_plain;f=threads.cc;h=ca4b28b1bc850c9ea5bcab709e2d27a9e74e2581;hp=e3aed76d2e756f564411796fef2e3e3e5cc990cc;hb=af25bde59ce05189adee92825ecc03fbb83e675b;hpb=a02d0bed3bc5ab757c3ed30a9589c53b05919688 diff --git a/threads.cc b/threads.cc index e3aed76d..ca4b28b1 100644 --- a/threads.cc +++ b/threads.cc @@ -1,3 +1,7 @@ +/** @file threads.cc + * @brief Thread functions. + */ + #include "libthreads.h" #include "common.h" #include "threads.h" @@ -5,42 +9,51 @@ /* 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(); } /** * Provides a startup wrapper for each thread, allowing some initial * model-checking data to be recorded. This method also gets around makecontext * not being 64-bit clean + * @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(); - /* TODO -- we should make this event always immediately follow the - CREATE event, so we don't get redundant traces... */ - /* Add dummy "start" action, just to create a first clock vector */ - model->switch_to_master(new ModelAction(THREAD_START, memory_order_seq_cst, curr_thread)); + model->switch_to_master(new ModelAction(THREAD_START, std::memory_order_seq_cst, curr_thread)); /* 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; @@ -60,31 +73,59 @@ 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); } } +/** + * 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), + wait_list(), last_action_val(VALUE_NONE) { int ret; @@ -99,12 +140,14 @@ 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;