rt: Remove rust_timer. Unused

mk/rt.mk

@@ -50,7 +50,6 @@ RUNTIME_CS_$(1) := \
               rt/rust_uv.cpp \
               rt/rust_uvtmp.cpp \
               rt/rust_log.cpp \
-              rt/rust_timer.cpp \
               rt/circular_buffer.cpp \
               rt/isaac/randport.cpp \
               rt/rust_srv.cpp \

src/rt/rust_internal.h

@@ -220,27 +220,6 @@ public:
 #include "rust_kernel.h"
 #include "rust_scheduler.h"
 
-struct rust_timer {
-    // FIXME: This will probably eventually need replacement
-    // with something more sophisticated and integrated with
-    // an IO event-handling library, when we have such a thing.
-    // For now it's just the most basic "thread that can interrupt
-    // its associated domain-thread" device, so that we have
-    // *some* form of task-preemption.
-    rust_scheduler *sched;
-    uintptr_t exit_flag;
-
-#if defined(__WIN32__)
-    HANDLE thread;
-#else
-    pthread_attr_t attr;
-    pthread_t thread;
-#endif
-
-    rust_timer(rust_scheduler *sched);
-    ~rust_timer();
-};
-
 typedef void CDECL (glue_fn)(void *, void *,
                              const type_desc **, void *);
 typedef void CDECL (cmp_glue_fn)(void *, void *,

src/rt/rust_scheduler.cpp

@@ -244,13 +244,6 @@ void
 rust_scheduler::start_main_loop() {
     lock.lock();
 
-    // Make sure someone is watching, to pull us out of infinite loops.
-    //
-    // FIXME: time-based interruption is not presently working; worked
-    // in rustboot and has been completely broken in rustc.
-    //
-    // rust_timer timer(this);
-
     DLOG(this, dom, "started domain loop %d", id);
 
     while (kernel->live_tasks > 0) {

src/rt/rust_timer.cpp

@@ -1,90 +0,0 @@
-#include "rust_internal.h"
-#include "vg/valgrind.h"
-
-// The mechanism in this file is very crude; every domain (thread) spawns its
-// own secondary timer thread, and that timer thread *never idles*. It
-// sleep-loops interrupting the domain.
-//
-// This will need replacement, particularly in order to achieve an actual
-// state of idling when we're waiting on the outside world.  Though that might
-// be as simple as making a secondary waitable start/stop-timer signalling
-// system between the domain and its timer thread. We'll see.
-//
-// On the other hand, we don't presently have the ability to idle domains *at
-// all*, and without the timer thread we're unable to otherwise preempt rust
-// tasks. So ... one step at a time.
-//
-// The implementation here is "lockless" in the sense that it only involves
-// one-directional signaling of one-shot events, so the event initiator just
-// writes a nonzero word to a prederermined location and waits for the
-// receiver to see it show up in their memory.
-
-#if defined(__WIN32__)
-static DWORD WINAPI
-#elif defined(__GNUC__)
-static void *
-#else
-#error "Platform not supported"
-#endif
-timer_loop(void *ptr) {
-    // We were handed the rust_timer that owns us.
-    rust_timer *timer = (rust_timer *)ptr;
-    rust_scheduler *sched = timer->sched;
-    DLOG(sched, timer, "in timer 0x%" PRIxPTR, (uintptr_t)timer);
-    size_t ms = TIME_SLICE_IN_MS;
-
-    while (!timer->exit_flag) {
-#if defined(__WIN32__)
-        Sleep(ms);
-#else
-        usleep(ms * 1000);
-#endif
-        DLOG(sched, timer, "timer 0x%" PRIxPTR
-        " interrupting schedain 0x%" PRIxPTR, (uintptr_t) timer,
-                 (uintptr_t) sched);
-        sched->interrupt_flag = 1;
-    }
-#if defined(__WIN32__)
-    ExitThread(0);
-#else
-    pthread_exit(NULL);
-#endif
-    return 0;
-}
-
-rust_timer::rust_timer(rust_scheduler *sched) :
-    sched(sched), exit_flag(0) {
-    DLOG(sched, timer, "creating timer for domain 0x%" PRIxPTR, sched);
-#if defined(__WIN32__)
-    thread = CreateThread(NULL, 0, timer_loop, this, 0, NULL);
-    sched->kernel->win32_require("CreateThread", thread != NULL);
-    if (RUNNING_ON_VALGRIND)
-        Sleep(10);
-#else
-    pthread_attr_init(&attr);
-    pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
-    pthread_create(&thread, &attr, timer_loop, (void *)this);
-#endif
-}
-
-rust_timer::~rust_timer() {
-    exit_flag = 1;
-#if defined(__WIN32__)
-    sched->kernel->win32_require("WaitForSingleObject",
-                               WaitForSingleObject(thread, INFINITE) ==
-                               WAIT_OBJECT_0);
-#else
-    pthread_join(thread, NULL);
-#endif
-}
-
-//
-// 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 $RBUILD 2>&1 | sed -e 's/\\/x\\//x:\\//g'";
-// End:
-//