#include "rust_internal.h"

// Upcalls.

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

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

inline bool
requires_message_passing(rust_task *sender, rust_task *receiver) {
    return sender->dom != receiver->dom;
}

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->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->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->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->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;
    task->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->log(rust_log::UPCALL | rust_log::MEM | rust_log::COMM,
              "upcall del_port(0x%" PRIxPTR ")", (uintptr_t) port);
    I(task->dom, !port->ref_count);
    delete port;
}

/**
 * Creates a new channel, pointed to a specified port.
 */
extern "C" CDECL rust_chan*
upcall_new_chan(rust_task *task, rust_port *port) {
    LOG_UPCALL_ENTRY(task);
    rust_dom *dom = task->dom;
    task->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);
}

/**
 * Called whenever the channel's ref count drops to zero.
 */
extern "C" CDECL void upcall_del_chan(rust_task *task, rust_chan *chan) {
    LOG_UPCALL_ENTRY(task);
    rust_dom *dom = task->dom;
    task->log(rust_log::UPCALL | rust_log::MEM | rust_log::COMM,
              "upcall del_chan(0x%" PRIxPTR ")", (uintptr_t) chan);
    I(dom, !chan->ref_count);
    delete chan;
}

/**
 * Clones a channel and stores it in the spawnee's domain. Each spawned task
 * has it's own copy of the channel.
 */
extern "C" CDECL rust_chan *
upcall_clone_chan(rust_task *task,
                  rust_proxy_delegate<rust_task> *spawnee_proxy,
                  rust_chan *chan) {
    LOG_UPCALL_ENTRY(task);
    rust_task *spawnee = spawnee_proxy->delegate();
    task->log(rust_log::UPCALL | rust_log::MEM | rust_log::COMM,
              "spawnee: 0x%" PRIxPTR ", chan: 0x%" PRIxPTR,
              (uintptr_t) spawnee, (uintptr_t) chan);
    return new (spawnee->dom) rust_chan(spawnee, 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;
//    }
//
//    circular_buffer *buf = &src->buffer;
//    if (buf->is_empty()) {
//        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->dequeue(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);
    task->log(rust_log::UPCALL | rust_log::COMM, "upcall yield()");
    task->yield(1);
}

extern "C" CDECL void upcall_join(rust_task *task,
                                  rust_proxy_delegate<rust_task> *proxy) {
    LOG_UPCALL_ENTRY(task);
    task->log(rust_log::UPCALL | rust_log::COMM,
                  "join proxy 0x%" PRIxPTR " -> task = 0x%" PRIxPTR,
                  proxy, proxy->delegate());

    rust_task *other = proxy->delegate();

    // If the other task is already dying, we don't have to wait for it.
    if (!other->dead()) {
        other->waiting_tasks.push(&task->alarm);
        task->block(other);
        task->yield(2);
    }
}

/**
 * Sends an chunk of data along the specified channel.
 *
 * sptr: pointer to a chunk of data to send
 */
extern "C" CDECL void
upcall_send(rust_task *task, rust_chan *chan, void *sptr) {
    LOG_UPCALL_ENTRY(task);
    task->log(rust_log::UPCALL | rust_log::COMM,
              "chan: 0x%" PRIxPTR ", sptr: 0x%" PRIxPTR ", size: %d",
              (uintptr_t) chan, (uintptr_t) sptr, chan->port->unit_sz);

    chan->buffer.enqueue(sptr);
    chan->transmit();
    task->log(rust_log::COMM, "=== WROTE DATA ===>");
}

extern "C" CDECL void
upcall_recv(rust_task *task, uintptr_t *dptr, rust_port *port) {
    LOG_UPCALL_ENTRY(task);
    task->log(rust_log::UPCALL | rust_log::COMM,
              "port: 0x%" PRIxPTR ", dptr: 0x%" PRIxPTR
              ", size: 0x%" PRIxPTR ", chan_no: %d",
              (uintptr_t) port, (uintptr_t) dptr, port->unit_sz,
              port->chans.length());

    for (uint32_t i = 0; i < port->chans.length(); i++) {
        rust_chan *chan = port->chans[i];
        if (chan->buffer.is_empty() == false) {
            chan->buffer.dequeue(dptr);
            task->log(rust_log::COMM, "<=== READ DATA ===");
            return;
        }
    }

    // No data was buffered on any incoming channel, so block this task
    // on the port. Remember the rendezvous location so that any sender
    // task can write to it before waking up this task.

    task->rendezvous_ptr = dptr;
    task->block(port);
    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->log(rust_log::UPCALL | rust_log::ERR,
              "upcall fail '%s', %s:%" PRIdPTR, expr, file, line);
    task->fail(4);
}

/**
 * Called whenever a task's ref count drops to zero.
 */
extern "C" CDECL void
upcall_kill(rust_task *task, rust_proxy_delegate<rust_task> *target_proxy) {
    LOG_UPCALL_ENTRY(task);
    rust_task *target_task = target_proxy->delegate();
    if (target_proxy != target_task) {
        task->dom->free(target_proxy);
    }
    task->log(rust_log::UPCALL | rust_log::TASK,
              "kill task 0x%" PRIxPTR ", ref count %d",
              target_task,
              target_task->ref_count);

    if (requires_message_passing(task, target_task)) {
        rust_dom *target_domain = target_task->dom;
        target_domain->send_message(
                new (target_domain)
                kill_task_message(target_domain, target_task));
    } else {
        target_task->kill();
    }
}

/**
 * Called by the exit glue when the task terminates.
 */
extern "C" CDECL void
upcall_exit(rust_task *task) {
    LOG_UPCALL_ENTRY(task);
    task->log(rust_log::UPCALL | rust_log::TASK,
              "task ref_count: %d", task->ref_count);
    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;
}

/**
 * Called whenever an object's ref count drops to zero.
 */
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;
    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);
    task->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);
    task->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;
    task->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->ref_count == 1) {

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

        // Second-fastest path: can at least realloc.
        task->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.
        task->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;

    task->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) {
        task->log(rust_log::UPCALL, " + %s", crate_rel(curr_crate, *c));
    }

    task->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");

    task->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) {
        task->log(rust_log::UPCALL | rust_log::CACHE,
                  "found-or-cached addr: 0x%" PRIxPTR, addr);
    } else {
        task->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);

    task->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) {
        task->log(rust_log::UPCALL | rust_log::CACHE,
                  "found-or-cached addr: 0x%" PRIxPTR, addr);
    } else {
        task->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);
    task->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);
    task->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.
    dom->start_main_loop();

    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_proxy_delegate<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);

    task->log(rust_log::UPCALL | rust_log::MEM,
              "upcall new_thread() = dom 0x%" PRIxPTR " task 0x%" PRIxPTR,
              new_dom, new_dom->root_task);
    rust_proxy<rust_task> *proxy =
            new (old_dom) rust_proxy<rust_task>(old_dom, new_dom->root_task);
    task->log(rust_log::UPCALL | rust_log::MEM,
              "new proxy = 0x%" PRIxPTR " -> task = 0x%" PRIxPTR,
              proxy, proxy->delegate());
    return proxy;
}

extern "C" CDECL rust_proxy_delegate<rust_task> *
upcall_start_thread(rust_task *spawner,
                    rust_proxy_delegate<rust_task> *root_task_proxy,
    uintptr_t exit_task_glue, uintptr_t spawnee_fn, size_t callsz) {
    LOG_UPCALL_ENTRY(spawner);

    rust_dom *dom = spawner->dom;
    rust_task *root_task = root_task_proxy->delegate();
    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 root_task_proxy;
}

//
// 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:
//