#include "rust_internal.h"


// Upcalls.

#ifdef __GNUC__
#define LOG_UPCALL_ENTRY(task)                              \
    (task)->dom->get_log().reset_indent(0);                 \
    (task)->dom->log(rust_log::UPCALL,                      \
                     "upcall task: 0x%" PRIxPTR             \
                     " retpc: 0x%" PRIxPTR,                 \
                     (task), __builtin_return_address(0));  \
    (task)->dom->get_log().indent();
#else
#define LOG_UPCALL_ENTRY(task)                              \
    (task)->dom->get_log().reset_indent(0);                 \
    (task)->dom->log(rust_log::UPCALL,                      \
                     "upcall task: 0x%" PRIxPTR (task));    \
    (task)->dom->get_log().indent();
#endif

extern "C" CDECL char const *str_buf(rust_task *task, rust_str *s);

extern "C" void
upcall_grow_task(rust_task *task, size_t n_frame_bytes)
{
    LOG_UPCALL_ENTRY(task);
    task->grow(n_frame_bytes);
}

extern "C" CDECL void
upcall_log_int(rust_task *task, int32_t i)
{
    LOG_UPCALL_ENTRY(task);
    task->dom->log(rust_log::UPCALL|rust_log::ULOG,
                   "upcall log_int(0x%" PRIx32 " = %" PRId32 " = '%c')",
                   i, i, (char)i);
}

extern "C" CDECL void
upcall_log_str(rust_task *task, rust_str *str)
{
    LOG_UPCALL_ENTRY(task);
    const char *c = str_buf(task, str);
    task->dom->log(rust_log::UPCALL|rust_log::ULOG,
                   "upcall log_str(\"%s\")",
                   c);
}

extern "C" CDECL void
upcall_trace_word(rust_task *task, uintptr_t i)
{
    LOG_UPCALL_ENTRY(task);
    task->dom->log(rust_log::UPCALL|rust_log::TRACE,
                   "trace: 0x%" PRIxPTR "",
                   i, i, (char)i);
}

extern "C" CDECL void
upcall_trace_str(rust_task *task, char const *c)
{
    LOG_UPCALL_ENTRY(task);
    task->dom->log(rust_log::UPCALL|rust_log::TRACE,
                   "trace: %s",
                   c);
}

extern "C" CDECL rust_port*
upcall_new_port(rust_task *task, size_t unit_sz)
{
    LOG_UPCALL_ENTRY(task);
    rust_dom *dom = task->dom;
    dom->log(rust_log::UPCALL|rust_log::MEM|rust_log::COMM,
             "upcall_new_port(task=0x%" PRIxPTR ", unit_sz=%d)",
             (uintptr_t)task, unit_sz);
    return new (dom) rust_port(task, unit_sz);
}

extern "C" CDECL void
upcall_del_port(rust_task *task, rust_port *port)
{
    LOG_UPCALL_ENTRY(task);
    task->dom->log(rust_log::UPCALL|rust_log::MEM|rust_log::COMM,
                   "upcall del_port(0x%" PRIxPTR ")", (uintptr_t)port);
    I(task->dom, !port->refcnt);
    delete port;
}

extern "C" CDECL rust_chan*
upcall_new_chan(rust_task *task, rust_port *port)
{
    LOG_UPCALL_ENTRY(task);
    rust_dom *dom = task->dom;
    dom->log(rust_log::UPCALL|rust_log::MEM|rust_log::COMM,
             "upcall_new_chan(task=0x%" PRIxPTR ", port=0x%" PRIxPTR ")",
             (uintptr_t)task, port);
    I(dom, port);
    return new (dom) rust_chan(task, port);
}

extern "C" CDECL void
upcall_del_chan(rust_task *task, rust_chan *chan)
{
    LOG_UPCALL_ENTRY(task);
    rust_dom *dom = task->dom;
    dom->log(rust_log::UPCALL|rust_log::MEM|rust_log::COMM,
             "upcall del_chan(0x%" PRIxPTR ")", (uintptr_t)chan);
    I(dom, !chan->refcnt);
    delete chan;
}

extern "C" CDECL rust_chan *
upcall_clone_chan(rust_task *task, rust_task *owner, rust_chan *chan)
{
    LOG_UPCALL_ENTRY(task);
    rust_dom *dom = task->dom;
    dom->log(rust_log::UPCALL|rust_log::MEM|rust_log::COMM,
             "upcall clone_chan(owner 0x%" PRIxPTR ", chan 0x%" PRIxPTR ")",
             (uintptr_t)owner, (uintptr_t)chan);
    return new (owner->dom) rust_chan(owner, chan->port);
}


/*
 * Buffering protocol:
 *
 *   - Reader attempts to read:
 *     - Set reader to blocked-reading state.
 *     - If buf with data exists:
 *       - Attempt transmission.
 *
 *  - Writer attempts to write:
 *     - Set writer to blocked-writing state.
 *     - Copy data into chan.
 *     - Attempt transmission.
 *
 *  - Transmission:
 *       - Copy data from buf to reader
 *       - Decr buf
 *       - Set reader to running
 *       - If buf now empty and blocked writer:
 *         - Set blocked writer to running
 *
 */

static int
attempt_transmission(rust_dom *dom,
                     rust_chan *src,
                     rust_task *dst)
{
    I(dom, src);
    I(dom, dst);

    rust_port *port = src->port;
    if (!port) {
        dom->log(rust_log::COMM,
                 "src died, transmission incomplete");
        return 0;
    }

    circ_buf *buf = &src->buffer;
    if (buf->unread == 0) {
        dom->log(rust_log::COMM,
                 "buffer empty, transmission incomplete");
        return 0;
    }

    if (!dst->blocked_on(port)) {
        dom->log(rust_log::COMM,
                 "dst in non-reading state, transmission incomplete");
        return 0;
    }

    uintptr_t *dptr = dst->dptr;
    dom->log(rust_log::COMM,
             "receiving %d bytes into dst_task=0x%" PRIxPTR
             ", dptr=0x%" PRIxPTR,
             port->unit_sz, dst, dptr);
    buf->shift(dptr);

    // Wake up the sender if its waiting for the send operation.
    rust_task *sender = src->task;
    rust_token *token = &src->token;
    if (sender->blocked_on(token))
        sender->wakeup(token);

    // Wake up the receiver, there is new data.
    dst->wakeup(port);

    dom->log(rust_log::COMM, "transmission complete");
    return 1;
}

extern "C" CDECL void
upcall_yield(rust_task *task)
{
    LOG_UPCALL_ENTRY(task);
    rust_dom *dom = task->dom;
    dom->log(rust_log::UPCALL|rust_log::COMM, "upcall yield()");
    task->yield(1);
}

extern "C" CDECL void
upcall_join(rust_task *task, rust_task *other)
{
    LOG_UPCALL_ENTRY(task);
    rust_dom *dom = task->dom;
    dom->log(rust_log::UPCALL|rust_log::COMM,
             "upcall join(other=0x%" PRIxPTR ")",
             (uintptr_t)other);

    // If the other task is already dying, we dont have to wait for it.
    if (!other->dead()) {
        other->waiting_tasks.push(&task->alarm);
        task->block(other);
        task->yield(2);
    }
}

extern "C" CDECL void
upcall_send(rust_task *task, rust_chan *chan, void *sptr)
{
    LOG_UPCALL_ENTRY(task);
    rust_dom *dom = task->dom;
    dom->log(rust_log::UPCALL|rust_log::COMM,
             "upcall send(chan=0x%" PRIxPTR ", sptr=0x%" PRIxPTR ")",
             (uintptr_t)chan,
             (uintptr_t)sptr);

    I(dom, chan);
    I(dom, sptr);

    rust_port *port = chan->port;
    dom->log(rust_log::MEM|rust_log::COMM,
             "send to port", (uintptr_t)port);
    I(dom, port);

    rust_token *token = &chan->token;
    dom->log(rust_log::MEM|rust_log::COMM,
             "sending via token 0x%" PRIxPTR,
             (uintptr_t)token);

    if (port->task) {
        chan->buffer.push(sptr);
        task->block(token);
        attempt_transmission(dom, chan, port->task);
        if (chan->buffer.unread && !token->pending())
            token->submit();
    } else {
        dom->log(rust_log::COMM|rust_log::ERR,
                 "port has no task (possibly throw?)");
    }

    if (!task->running())
        task->yield(3);
}

extern "C" CDECL void
upcall_recv(rust_task *task, uintptr_t *dptr, rust_port *port)
{
    LOG_UPCALL_ENTRY(task);
    rust_dom *dom = task->dom;
    dom->log(rust_log::UPCALL|rust_log::COMM,
             "upcall recv(dptr=0x%" PRIxPTR ", port=0x%" PRIxPTR ")",
             (uintptr_t)dptr,
             (uintptr_t)port);

    I(dom, port);
    I(dom, port->task);
    I(dom, task);
    I(dom, port->task == task);

    task->block(port);

    if (port->writers.length() > 0) {
        I(dom, task->dom);
        size_t i = rand(&dom->rctx);
        i %= port->writers.length();
        rust_token *token = port->writers[i];
        rust_chan *chan = token->chan;
        if (attempt_transmission(dom, chan, task))
            token->withdraw();
    } else {
        dom->log(rust_log::COMM,
                 "no writers sending to port", (uintptr_t)port);
    }

    if (!task->running()) {
        task->dptr = dptr;
        task->yield(3);
    }
}

extern "C" CDECL void
upcall_fail(rust_task *task, char const *expr, char const *file, size_t line)
{
    LOG_UPCALL_ENTRY(task);
    task->dom->log(rust_log::UPCALL|rust_log::ERR,
                   "upcall fail '%s', %s:%" PRIdPTR,
                   expr, file, line);
    task->fail(4);
}

extern "C" CDECL void
upcall_kill(rust_task *task, rust_task *target)
{
    LOG_UPCALL_ENTRY(task);
    task->dom->log(rust_log::UPCALL|rust_log::TASK,
                   "upcall kill target=0x%" PRIxPTR, target);
    target->kill();
}

extern "C" CDECL void
upcall_exit(rust_task *task)
{
    LOG_UPCALL_ENTRY(task);

    rust_dom *dom = task->dom;
    dom->log(rust_log::UPCALL|rust_log::TASK, "upcall exit");
    task->die();
    task->notify_waiting_tasks();
    task->yield(1);
}

extern "C" CDECL uintptr_t
upcall_malloc(rust_task *task, size_t nbytes, type_desc *td)
{
    LOG_UPCALL_ENTRY(task);

    task->dom->log(rust_log::UPCALL|rust_log::MEM,
                   "upcall malloc(%" PRIdPTR ", 0x%" PRIxPTR ")"
                   " with gc-chain head = 0x%" PRIxPTR,
                   nbytes, td, task->gc_alloc_chain);
    void *p = task->malloc(nbytes, td);
    task->dom->log(rust_log::UPCALL|rust_log::MEM,
                   "upcall malloc(%" PRIdPTR ", 0x%" PRIxPTR
                   ") = 0x%" PRIxPTR
                   " with gc-chain head = 0x%" PRIxPTR,
                   nbytes, td, (uintptr_t)p, task->gc_alloc_chain);
    return (uintptr_t) p;
}

extern "C" CDECL void
upcall_free(rust_task *task, void* ptr, uintptr_t is_gc)
{
    LOG_UPCALL_ENTRY(task);

    rust_dom *dom = task->dom;
    dom->log(rust_log::UPCALL|rust_log::MEM,
             "upcall free(0x%" PRIxPTR ")",
             (uintptr_t)ptr);
    task->free(ptr, (bool) is_gc);
}

extern "C" CDECL uintptr_t
upcall_mark(rust_task *task, void* ptr)
{
    LOG_UPCALL_ENTRY(task);

    rust_dom *dom = task->dom;
    if (ptr) {
        gc_alloc *gcm = (gc_alloc*) (((char*)ptr) - sizeof(gc_alloc));
        uintptr_t marked = (uintptr_t) gcm->mark();
        dom->log(rust_log::UPCALL|rust_log::MEM|rust_log::GC,
                 "upcall mark(0x%" PRIxPTR ") = %" PRIdPTR,
                 (uintptr_t)gcm, marked);
        return marked;
    }
    return 0;
}

extern "C" CDECL rust_str *
upcall_new_str(rust_task *task, char const *s, size_t fill)
{
    LOG_UPCALL_ENTRY(task);
    rust_dom *dom = task->dom;
    dom->log(rust_log::UPCALL|rust_log::MEM,
             "upcall new_str('%s', %" PRIdPTR ")", s, fill);
    size_t alloc = next_power_of_two(sizeof(rust_str) + fill);
    void *mem = dom->malloc(alloc);
    if (!mem) {
        task->fail(3);
        return NULL;
    }
    rust_str *st = new (mem) rust_str(dom, alloc, fill, (uint8_t const *)s);
    dom->log(rust_log::UPCALL|rust_log::MEM,
             "upcall new_str('%s', %" PRIdPTR ") = 0x%" PRIxPTR,
             s, fill, st);
    return st;
}

extern "C" CDECL rust_vec *
upcall_new_vec(rust_task *task, size_t fill, type_desc *td)
{
    LOG_UPCALL_ENTRY(task);
    rust_dom *dom = task->dom;
    dom->log(rust_log::UPCALL|rust_log::MEM,
             "upcall new_vec(%" PRIdPTR ")",
             fill);
    size_t alloc = next_power_of_two(sizeof(rust_vec) + fill);
    void *mem = task->malloc(alloc, td);
    if (!mem) {
        task->fail(3);
        return NULL;
    }
    rust_vec *v = new (mem) rust_vec(dom, alloc, 0, NULL);
    dom->log(rust_log::UPCALL|rust_log::MEM,
             "upcall new_vec(%" PRIdPTR ") = 0x%" PRIxPTR,
             fill, v);
    return v;
}


extern "C" CDECL rust_str *
upcall_vec_grow(rust_task *task, rust_vec *v, size_t n_bytes, uintptr_t is_gc)
{
    LOG_UPCALL_ENTRY(task);
    rust_dom *dom = task->dom;
    dom->log(rust_log::UPCALL|rust_log::MEM,
             "upcall vec_grow(%" PRIxPTR ", %" PRIdPTR
             "), alloc=%" PRIdPTR ", fill=%" PRIdPTR,
             v, n_bytes, v->alloc, v->fill);
    size_t alloc = next_power_of_two(sizeof(rust_vec) + v->fill + n_bytes);
    if (v->refcnt == 1) {

        // Fastest path: already large enough.
        if (v->alloc >= alloc) {
            dom->log(rust_log::UPCALL|rust_log::MEM, "no-growth path");
            return v;
        }

        // Second-fastest path: can at least realloc.
        dom->log(rust_log::UPCALL|rust_log::MEM, "realloc path");
        v = (rust_vec*)dom->realloc(v, alloc);
        if (!v) {
            task->fail(4);
            return NULL;
        }
        v->alloc = alloc;

    } else {
        // Slowest path: make a new vec.
        dom->log(rust_log::UPCALL|rust_log::MEM, "new vec path");
        void *mem = dom->malloc(alloc);
        if (!mem) {
            task->fail(4);
            return NULL;
        }
        v->deref();
        v = new (mem) rust_vec(dom, alloc, v->fill, &v->data[0]);
    }
    I(dom, sizeof(rust_vec) + v->fill <= v->alloc);
    return v;
}


static rust_crate_cache::c_sym *
fetch_c_sym(rust_task *task,
            rust_crate const *curr_crate,
            size_t lib_num,
            size_t c_sym_num,
            char const *library,
            char const *symbol)
{
    rust_crate_cache *cache = task->get_crate_cache(curr_crate);
    rust_crate_cache::lib *l = cache->get_lib(lib_num, library);
    return cache->get_c_sym(c_sym_num, l, symbol);
}

extern "C" CDECL uintptr_t
upcall_require_rust_sym(rust_task *task,
                        rust_crate const *curr_crate,
                        size_t lib_num,      // # of lib
                        size_t c_sym_num,    // # of C sym "rust_crate" in lib
                        size_t rust_sym_num, // # of rust sym
                        char const *library,
                        char const **path)
{
    LOG_UPCALL_ENTRY(task);
    rust_dom *dom = task->dom;

    dom->log(rust_log::UPCALL|rust_log::CACHE,
             "upcall require rust sym: lib #%" PRIdPTR
             " = %s, c_sym #%" PRIdPTR
             ", rust_sym #%" PRIdPTR
             ", curr_crate = 0x%" PRIxPTR,
             lib_num, library, c_sym_num, rust_sym_num,
             curr_crate);
    for (char const **c = crate_rel(curr_crate, path); *c; ++c) {
        dom->log(rust_log::UPCALL, " + %s", crate_rel(curr_crate, *c));
    }

    dom->log(rust_log::UPCALL|rust_log::CACHE,
             "require C symbol 'rust_crate' from lib #%" PRIdPTR,lib_num);
    rust_crate_cache::c_sym *c =
        fetch_c_sym(task, curr_crate, lib_num, c_sym_num,
                    library, "rust_crate");

    dom->log(rust_log::UPCALL|rust_log::CACHE,
             "require rust symbol inside crate");
    rust_crate_cache::rust_sym *s =
        task->cache->get_rust_sym(rust_sym_num, dom, curr_crate, c, path);

    uintptr_t addr = s->get_val();
    if (addr) {
        dom->log(rust_log::UPCALL|rust_log::CACHE,
                 "found-or-cached addr: 0x%" PRIxPTR, addr);
    } else {
        dom->log(rust_log::UPCALL|rust_log::CACHE,
                 "failed to resolve symbol");
        task->fail(7);
    }
    return addr;
}

extern "C" CDECL uintptr_t
upcall_require_c_sym(rust_task *task,
                     rust_crate const *curr_crate,
                     size_t lib_num,      // # of lib
                     size_t c_sym_num,    // # of C sym
                     char const *library,
                     char const *symbol)
{
    LOG_UPCALL_ENTRY(task);
    rust_dom *dom = task->dom;

    dom->log(rust_log::UPCALL|rust_log::CACHE,
             "upcall require c sym: lib #%" PRIdPTR
             " = %s, c_sym #%" PRIdPTR
             " = %s"
             ", curr_crate = 0x%" PRIxPTR,
             lib_num, library, c_sym_num, symbol, curr_crate);

    rust_crate_cache::c_sym *c =
        fetch_c_sym(task, curr_crate, lib_num, c_sym_num, library, symbol);

    uintptr_t addr = c->get_val();
    if (addr) {
        dom->log(rust_log::UPCALL|rust_log::CACHE,
                 "found-or-cached addr: 0x%" PRIxPTR, addr);
    } else {
        dom->log(rust_log::UPCALL|rust_log::CACHE,
                 "failed to resolve symbol");
        task->fail(6);
    }
    return addr;
}

extern "C" CDECL type_desc *
upcall_get_type_desc(rust_task *task,
                     rust_crate const *curr_crate,
                     size_t size,
                     size_t align,
                     size_t n_descs,
                     type_desc const **descs)
{
    LOG_UPCALL_ENTRY(task);
    rust_dom *dom = task->dom;
    dom->log(rust_log::UPCALL|rust_log::CACHE,
             "upcall get_type_desc with size=%" PRIdPTR
             ", align=%" PRIdPTR ", %" PRIdPTR " descs",
             size, align, n_descs);
    rust_crate_cache *cache = task->get_crate_cache(curr_crate);
    type_desc *td = cache->get_type_desc(size, align, n_descs, descs);
    dom->log(rust_log::UPCALL|rust_log::CACHE,
             "returning tydesc 0x%" PRIxPTR, td);
    return td;
}


#if defined(__WIN32__)
static DWORD WINAPI rust_thread_start(void *ptr)
#elif defined(__GNUC__)
static void *rust_thread_start(void *ptr)
#else
#error "Platform not supported"
#endif
{
    // We were handed the domain we are supposed to run.
    rust_dom *dom = (rust_dom *)ptr;

    // Start a new rust main loop for this thread.
    rust_main_loop(dom);

    rust_srv *srv = dom->srv;
    delete dom;
    delete srv;

    return 0;
}

extern "C" CDECL rust_task *
upcall_new_task(rust_task *spawner)
{
    LOG_UPCALL_ENTRY(spawner);

    rust_dom *dom = spawner->dom;
    rust_task *task = new (dom) rust_task(dom, spawner);
    dom->log(rust_log::UPCALL|rust_log::MEM|rust_log::TASK,
             "upcall new_task(spawner 0x%" PRIxPTR ") = 0x%" PRIxPTR,
             spawner, task);
    return task;
}

extern "C" CDECL rust_task *
upcall_start_task(rust_task *spawner,
                  rust_task *task,
                  uintptr_t exit_task_glue,
                  uintptr_t spawnee_fn,
                  size_t callsz)
{
    LOG_UPCALL_ENTRY(spawner);

    rust_dom *dom = spawner->dom;
    dom->log(rust_log::UPCALL|rust_log::MEM|rust_log::TASK,
             "upcall start_task(task 0x%" PRIxPTR
             " exit_task_glue 0x%" PRIxPTR
             ", spawnee 0x%" PRIxPTR
             ", callsz %" PRIdPTR ")",
             task, exit_task_glue, spawnee_fn, callsz);
    task->start(exit_task_glue, spawnee_fn, spawner->rust_sp, callsz);
    return task;
}

extern "C" CDECL rust_task *
upcall_new_thread(rust_task *task)
{
    LOG_UPCALL_ENTRY(task);

    rust_dom *old_dom = task->dom;
    rust_dom *new_dom = new rust_dom(old_dom->srv->clone(),
                                     old_dom->root_crate);
    new_dom->log(rust_log::UPCALL|rust_log::MEM,
                 "upcall new_thread() = 0x%" PRIxPTR,
                 new_dom->root_task);
    return new_dom->root_task;
}

extern "C" CDECL rust_task *
upcall_start_thread(rust_task *spawner,
                    rust_task *root_task,
                    uintptr_t exit_task_glue,
                    uintptr_t spawnee_fn,
                    size_t callsz)
{
    LOG_UPCALL_ENTRY(spawner);

    rust_dom *dom = spawner->dom;
    dom->log(rust_log::UPCALL|rust_log::MEM|rust_log::TASK,
             "upcall start_thread(exit_task_glue 0x%" PRIxPTR
             ", spawnee 0x%" PRIxPTR
             ", callsz %" PRIdPTR ")",
             exit_task_glue, spawnee_fn, callsz);
    root_task->start(exit_task_glue, spawnee_fn, spawner->rust_sp, callsz);

#if defined(__WIN32__)
    HANDLE thread;
    thread = CreateThread(NULL, 0, rust_thread_start, root_task->dom,
                          0, NULL);
    dom->win32_require("CreateThread", thread != NULL);
#else
    pthread_t thread;
    pthread_create(&thread, &dom->attr, rust_thread_start,
                   (void *)root_task->dom);
#endif

    return 0;
}

//
// Local Variables:
// mode: C++
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// compile-command: "make -k -C .. 2>&1 | sed -e 's/\\/x\\//x:\\//g'";
// End:
//