rust/src/rt/rust_kernel.cpp

// A workaround that makes INTPTR_MAX be visible
#ifdef __FreeBSD__
#define __STDC_LIMIT_MACROS 1
#endif

#include <vector>
#include "rust_internal.h"
#include "rust_util.h"
#include "rust_scheduler.h"

#define KLOG_(...)                              \
    KLOG(this, kern, __VA_ARGS__)
#define KLOG_ERR_(field, ...)                   \
    KLOG_LVL(this, field, log_err, __VA_ARGS__)

rust_kernel::rust_kernel(rust_srv *srv) :
    _region(srv, true),
    _log(srv, NULL),
    srv(srv),
    live_tasks(0),
    max_task_id(0),
    rval(0),
    live_schedulers(0),
    max_sched_id(0),
    env(srv->env)
{
}

void
rust_kernel::log(uint32_t level, char const *fmt, ...) {
    char buf[BUF_BYTES];
    va_list args;
    va_start(args, fmt);
    vsnprintf(buf, sizeof(buf), fmt, args);
    _log.trace_ln(NULL, level, buf);
    va_end(args);
}

void
rust_kernel::fatal(char const *fmt, ...) {
    char buf[BUF_BYTES];
    va_list args;
    va_start(args, fmt);
    vsnprintf(buf, sizeof(buf), fmt, args);
    _log.trace_ln(NULL, (uint32_t)0, buf);
    exit(1);
    va_end(args);
}

void *
rust_kernel::malloc(size_t size, const char *tag) {
    return _region.malloc(size, tag);
}

void *
rust_kernel::realloc(void *mem, size_t size) {
    return _region.realloc(mem, size);
}

void rust_kernel::free(void *mem) {
    _region.free(mem);
}

rust_sched_id
rust_kernel::create_scheduler(size_t num_threads) {
    I(this, !sched_lock.lock_held_by_current_thread());
    rust_sched_id id;
    rust_scheduler *sched;
    {
        scoped_lock with(sched_lock);
        id = max_sched_id++;
        K(srv, id != INTPTR_MAX, "Hit the maximum scheduler id");
        sched = new (this, "rust_scheduler")
            rust_scheduler(this, srv, num_threads, id);
        bool is_new = sched_table
            .insert(std::pair<rust_sched_id, rust_scheduler*>(id, sched)).second;
        A(this, is_new, "Reusing a sched id?");
        live_schedulers++;
    }
    sched->start_task_threads();
    return id;
}

rust_scheduler *
rust_kernel::get_scheduler_by_id(rust_sched_id id) {
    I(this, !sched_lock.lock_held_by_current_thread());
    scoped_lock with(sched_lock);
    sched_map::iterator iter = sched_table.find(id);
    if (iter != sched_table.end()) {
        return iter->second;
    } else {
        return NULL;
    }
}

void
rust_kernel::release_scheduler_id(rust_sched_id id) {
    I(this, !sched_lock.lock_held_by_current_thread());
    scoped_lock with(sched_lock);
    sched_map::iterator iter = sched_table.find(id);
    I(this, iter != sched_table.end());
    rust_scheduler *sched = iter->second;
    sched_table.erase(iter);
    delete sched;
    live_schedulers--;
    if (live_schedulers == 0) {
        // We're all done. Tell the main thread to continue
        sched_lock.signal();
    }
}

int
rust_kernel::wait_for_schedulers()
{
    I(this, !sched_lock.lock_held_by_current_thread());
    scoped_lock with(sched_lock);
    // Schedulers could possibly have already exited
    if (live_schedulers != 0) {
        sched_lock.wait();
    }
    return rval;
}

// FIXME: Fix all these FIXMEs
void
rust_kernel::fail() {
    // FIXME: On windows we're getting "Application has requested the
    // Runtime to terminate it in an unusual way" when trying to shutdown
    // cleanly.
    set_exit_status(PROC_FAIL_CODE);
#if defined(__WIN32__)
    exit(rval);
#endif
    // Copy the list of schedulers so that we don't hold the lock while
    // running kill_all_tasks.
    // FIXME: There's a lot that happens under kill_all_tasks, and I don't
    // know that holding sched_lock here is ok, but we need to hold the
    // sched lock to prevent the scheduler from being destroyed while
    // we are using it. Probably we need to make rust_scheduler atomicly
    // reference counted.
    std::vector<rust_scheduler*> scheds;
    {
        scoped_lock with(sched_lock);
        for (sched_map::iterator iter = sched_table.begin();
             iter != sched_table.end(); iter++) {
            scheds.push_back(iter->second);
        }
    }

    // FIXME: This is not a foolproof way to kill all tasks while ensuring
    // that no new tasks or schedulers are created in the meantime that
    // keep the scheduler alive.
    for (std::vector<rust_scheduler*>::iterator iter = scheds.begin();
         iter != scheds.end(); iter++) {
        (*iter)->kill_all_tasks();
    }
}

void
rust_kernel::register_task(rust_task *task) {
    uintptr_t new_live_tasks;
    {
        scoped_lock with(task_lock);
        task->user.id = max_task_id++;
        task_table.put(task->user.id, task);
        new_live_tasks = ++live_tasks;
    }
    K(srv, task->user.id != INTPTR_MAX, "Hit the maximum task id");
    KLOG_("Registered task %" PRIdPTR, task->user.id);
    KLOG_("Total outstanding tasks: %d", new_live_tasks);
}

void
rust_kernel::release_task_id(rust_task_id id) {
    KLOG_("Releasing task %" PRIdPTR, id);
    uintptr_t new_live_tasks;
    {
        scoped_lock with(task_lock);
        task_table.remove(id);
        new_live_tasks = --live_tasks;
    }
    KLOG_("Total outstanding tasks: %d", new_live_tasks);
}

rust_task *
rust_kernel::get_task_by_id(rust_task_id id) {
    scoped_lock with(task_lock);
    rust_task *task = NULL;
    // get leaves task unchanged if not found.
    task_table.get(id, &task);
    if(task) {
        if(task->get_ref_count() == 0) {
            // this means the destructor is running, since the destructor
            // grabs the kernel lock to unregister the task. Pretend this
            // doesn't actually exist.
            return NULL;
        }
        else {
            task->ref();
        }
    }
    return task;
}

#ifdef __WIN32__
void
rust_kernel::win32_require(LPCTSTR fn, BOOL ok) {
    if (!ok) {
        LPTSTR buf;
        DWORD err = GetLastError();
        FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
                      FORMAT_MESSAGE_FROM_SYSTEM |
                      FORMAT_MESSAGE_IGNORE_INSERTS,
                      NULL, err,
                      MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
                      (LPTSTR) &buf, 0, NULL );
        KLOG_ERR_(dom, "%s failed with error %ld: %s", fn, err, buf);
        LocalFree((HLOCAL)buf);
        I(this, ok);
    }
}
#endif

void
rust_kernel::set_exit_status(int code) {
    scoped_lock with(rval_lock);
    // If we've already failed then that's the code we're going to use
    if (rval != PROC_FAIL_CODE) {
        rval = code;
    }
}

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//