Make empth_wakeup() and empth_terminate() wake up empth_sleep(), and

empth_sleep() return whether that happened:
[EMPTH_LWP] (lwpWakeupSleep): New, factored out of lwpSelect().
[EMPTH_LWP] (lwpSelect): Use it.
[EMPTH_LWP] (lwpWakeup): New.  Call lwpWakeupFd() if sleeping in
lwpSleepFd(), lwpWakeupSleep() if sleeping in lwpSleepUntil().
[EMPTH_LWP] (lwpTerminate, empth_wakeup): Use it rather than
lwpWakeupFd().
[EMPTH_LWP] (lwpWakeupFd): Internal linkage.
[EMPTH_LWP] (lwpSleepUntil): Reset member runtime, so that lwpWakeup()
can test it reliably.  Return how sleep woke up.
[EMPTH_LWP] (empth_sleep): Return value of lwpSleepUntil().
[EMPTH_POSIX] (EMPTH_INTR): New.
[EMPTH_POSIX] (empth_wakeup): Set state to it.
[EMPTH_POSIX] (empth_restorectx): Clear state.
[EMPTH_POSIX] (empth_sleep): Don't re-seleep when state is not clear,
i.e. thread was woken up prematurely.  Return how sleep woke up.
[EMPTH_W32] (empth_sleep): Implement by waiting on hThreadEvent with a
timeout rather than a straight Sleep().  Return how sleep woke up.

src/lib/empthread/lwp.c

@@ -101,13 +101,13 @@ empth_select(int fd, int flags)
 void
 empth_wakeup(empth_t *a)
 {
-    lwpWakeupFd(a);
+    lwpWakeup(a);
 }
 
-void
+int
 empth_sleep(time_t until)
 {
-    lwpSleepUntil(until);
+    return lwpSleepUntil(until);
 }
 
 int

src/lib/empthread/ntthread.c

@@ -599,21 +599,25 @@ empth_wakeup(empth_t *pThread)
  *
  * Put the given thread to sleep...
  */
-void
+int
 empth_sleep(time_t until)
 {
     long lSec;
+    empth_t *pThread = TlsGetValue(dwTLSIndex);
+    int iReturn = 0;
 
-    loc_BlockThisThread();
+    if ((lSec = until - time(0)) > 0) {
+	loc_BlockThisThread();
+	loc_debug("going to sleep %ld sec", lSec);
 
-    while ((lSec = until - time(0)) > 0) {
-        loc_debug("going to sleep %ld sec", lSec);
-	Sleep(lSec * 1000L);
+	if (WaitForSingleObject(pThread->hThreadEvent, lSec * 1000L) !=
+	    WAIT_TIMEOUT)
+	    iReturn = -1;
+
+	loc_debug("sleep done. Waiting to run.");
+	loc_RunThisThread(NULL);
     }
-
-    loc_debug("sleep done. Waiting to run.");
-
-    loc_RunThisThread(NULL);
+    return iReturn;
 }
 
 /************************

src/lib/empthread/pthread.c

@@ -58,6 +58,7 @@
 #include "prototypes.h"
 
 #define EMPTH_KILLED  1
+#define EMPTH_INTR 2
 
 struct empth_t {
     char *name;			/* thread name */
@@ -252,6 +253,7 @@ empth_restorectx(void)
 	empth_status("i am dead");
 	empth_exit();
     }
+    ctx_ptr->state = 0;
     empth_status("context restored");
 }
 
@@ -355,33 +357,37 @@ empth_alarm(int sig)
 {
     /*
      * Nothing to do --- we handle this signal just to let
-     * empth_wakeup() interrupt system calls.
+     * empth_wakeup() and empth_terminate() interrupt system calls.
      */
-    empth_status("got alarm signal");
 }
 
 void
 empth_wakeup(empth_t *a)
 {
     empth_status("waking up thread %s", a->name);
+    if (a->state == 0)
+	a->state = EMPTH_INTR;
     pthread_kill(a->id, SIGALRM);
 }
 
-void
+int
 empth_sleep(time_t until)
 {
+    empth_t *ctx = pthread_getspecific(ctx_key);
     struct timeval tv;
+    int res;
 
     empth_status("going to sleep %ld sec", until - time(0));
     pthread_mutex_unlock(&mtx_ctxsw);
-    tv.tv_sec = until - time(NULL);
-    tv.tv_usec = 0;
     do {
-	select(0, NULL, NULL, NULL, &tv);
-    } while ((tv.tv_sec = until - time(NULL)) > 0);
+	tv.tv_sec = until - time(NULL);
+	tv.tv_usec = 0;
+	res = select(0, NULL, NULL, NULL, &tv);
+    } while (res < 0 && ctx->state == 0);
     empth_status("sleep done. Waiting for lock");
     pthread_mutex_lock(&mtx_ctxsw);
     empth_restorectx();
+    return res;
 }
 
 int