diff --git a/winsup/cygwin/cygtls.cc b/winsup/cygwin/cygtls.cc
index afaee8e977..b8b5a01498 100644
--- a/winsup/cygwin/cygtls.cc
+++ b/winsup/cygwin/cygtls.cc
@@ -64,6 +64,7 @@ _cygtls::init_thread (void *x, DWORD (*func) (void *, void *))
   initialized = CYGTLS_INITIALIZED;
   errno_addr = &(local_clib._errno);
   locals.cw_timer = NULL;
+  locals.cw_timer_inuse = false;
   locals.pathbufs.clear ();
 
   if ((void *) func == (void *) cygthread::stub
@@ -85,6 +86,7 @@ _cygtls::fixup_after_fork ()
   signal_arrived = NULL;
   locals.select.sockevt = NULL;
   locals.cw_timer = NULL;
+  locals.cw_timer_inuse = false;
   locals.pathbufs.clear ();
   wq.thread_ev = NULL;
 }
diff --git a/winsup/cygwin/cygwait.cc b/winsup/cygwin/cygwait.cc
index dbbe1db6e1..bb653f6b7c 100644
--- a/winsup/cygwin/cygwait.cc
+++ b/winsup/cygwin/cygwait.cc
@@ -58,16 +58,20 @@ cygwait (HANDLE object, PLARGE_INTEGER timeout, unsigned mask)
     }
 
   DWORD timeout_n;
+  HANDLE local_timer = NULL;
+  HANDLE &wait_timer =
+    _my_tls.locals.cw_timer_inuse ? local_timer : _my_tls.locals.cw_timer;
   if (!timeout)
     timeout_n = WAIT_TIMEOUT + 1;
   else
     {
+      if (!_my_tls.locals.cw_timer_inuse)
+	_my_tls.locals.cw_timer_inuse = true;
       timeout_n = WAIT_OBJECT_0 + num++;
-      if (!_my_tls.locals.cw_timer)
-	NtCreateTimer (&_my_tls.locals.cw_timer, TIMER_ALL_ACCESS, NULL,
-		       NotificationTimer);
-      NtSetTimer (_my_tls.locals.cw_timer, timeout, NULL, NULL, FALSE, 0, NULL);
-      wait_objects[timeout_n] = _my_tls.locals.cw_timer;
+      if (!wait_timer)
+	NtCreateTimer (&wait_timer, TIMER_ALL_ACCESS, NULL, NotificationTimer);
+      NtSetTimer (wait_timer, timeout, NULL, NULL, FALSE, 0, NULL);
+      wait_objects[timeout_n] = wait_timer;
     }
 
   while (1)
@@ -100,7 +104,7 @@ cygwait (HANDLE object, PLARGE_INTEGER timeout, unsigned mask)
     {
       TIMER_BASIC_INFORMATION tbi;
 
-      NtQueryTimer (_my_tls.locals.cw_timer, TimerBasicInformation, &tbi,
+      NtQueryTimer (wait_timer, TimerBasicInformation, &tbi,
 		    sizeof tbi, NULL);
       /* if timer expired, TimeRemaining is negative and represents the
 	  system uptime when signalled */
@@ -108,7 +112,11 @@ cygwait (HANDLE object, PLARGE_INTEGER timeout, unsigned mask)
 	timeout->QuadPart = tbi.SignalState || tbi.TimeRemaining.QuadPart < 0LL
                             ? 0LL : tbi.TimeRemaining.QuadPart;
       }
-      NtCancelTimer (_my_tls.locals.cw_timer, NULL);
+      NtCancelTimer (wait_timer, NULL);
+      if (local_timer)
+	NtClose(local_timer);
+      else
+	_my_tls.locals.cw_timer_inuse = false;
     }
 
   if (res == WAIT_CANCELED && is_cw_cancel_self)
diff --git a/winsup/cygwin/exceptions.cc b/winsup/cygwin/exceptions.cc
index 469052a98a..1cce7c8498 100644
--- a/winsup/cygwin/exceptions.cc
+++ b/winsup/cygwin/exceptions.cc
@@ -1420,7 +1420,7 @@ api_fatal_debug ()
 
 /* Attempt to carefully handle SIGCONT when we are stopped. */
 void
-_cygtls::handle_SIGCONT (threadlist_t * &tl_entry)
+_cygtls::handle_SIGCONT ()
 {
   if (NOTSTATE (myself, PID_STOPPED))
     return;
@@ -1431,23 +1431,17 @@ _cygtls::handle_SIGCONT (threadlist_t * &tl_entry)
      Make sure that any pending signal is handled before trying to
      send a new one.  Then make sure that SIGCONT has been recognized
      before exiting the loop.  */
-  bool sigsent = false;
-  while (1)
-    if (sig)		/* Assume that it's ok to just test sig outside of a
-			   lock since setup_handler does it this way.  */
-      {
-	cygheap->unlock_tls (tl_entry);
-	yield ();	/* Attempt to schedule another thread.  */
-	tl_entry = cygheap->find_tls (_main_tls);
-      }
-    else if (sigsent)
-      break;		/* SIGCONT has been recognized by other thread */
-    else
-      {
-	sig = SIGCONT;
-	set_signal_arrived (); /* alert sig_handle_tty_stop */
-	sigsent = true;
-      }
+  while (sig)  /* Assume that it's ok to just test sig outside of a */
+    yield ();  /* lock since setup_handler does it this way.  */
+
+  lock ();
+  sig = SIGCONT;
+  set_signal_arrived (); /* alert sig_handle_tty_stop */
+  unlock ();
+
+  while (sig == SIGCONT)
+    yield ();
+
   /* Clear pending stop signals */
   sig_clear (SIGSTOP, false);
   sig_clear (SIGTSTP, false);
@@ -1479,11 +1473,7 @@ sigpacket::process ()
   myself->rusage_self.ru_nsignals++;
 
   if (si.si_signo == SIGCONT)
-    {
-      tl_entry = cygheap->find_tls (_main_tls);
-      _main_tls->handle_SIGCONT (tl_entry);
-      cygheap->unlock_tls (tl_entry);
-    }
+    _main_tls->handle_SIGCONT ();
 
   /* SIGKILL is special.  It always goes through.  */
   if (si.si_signo == SIGKILL)
diff --git a/winsup/cygwin/local_includes/cygtls.h b/winsup/cygwin/local_includes/cygtls.h
index e4e3889aff..328912f1ec 100644
--- a/winsup/cygwin/local_includes/cygtls.h
+++ b/winsup/cygwin/local_includes/cygtls.h
@@ -135,6 +135,7 @@ struct _local_storage
 
   /* thread.cc */
   HANDLE cw_timer;
+  bool cw_timer_inuse;
 
   tls_pathbuf pathbufs;
   char ttybuf[32];
@@ -180,7 +181,7 @@ class _cygtls
   siginfo_t *sigwait_info;
   HANDLE signal_arrived;
   bool will_wait_for_signal;
-#if 0
+#if 1
   long __align;			/* Needed to align context to 16 byte. */
 #endif
   /* context MUST be aligned to 16 byte, otherwise RtlCaptureContext fails.
@@ -194,7 +195,7 @@ class _cygtls
   class cygthread *_ctinfo;
   class san *andreas;
   waitq wq;
-  int sig;
+  volatile int sig;
   unsigned incyg;
   volatile unsigned spinning;
   volatile unsigned stacklock;
@@ -275,7 +276,7 @@ class _cygtls
   {
     will_wait_for_signal = false;
   }
-  void handle_SIGCONT (threadlist_t * &);
+  void handle_SIGCONT ();
   static void cleanup_early(struct _reent *);
 private:
   void call2 (DWORD (*) (void *, void *), void *, void *);
diff --git a/winsup/cygwin/release/3.5.6 b/winsup/cygwin/release/3.5.6
deleted file mode 100644
index 643d58e585..0000000000
--- a/winsup/cygwin/release/3.5.6
+++ /dev/null
@@ -1,5 +0,0 @@
-Fixes:
-------
-
-- Fix zsh hang at startup.
-  Addresses: https://cygwin.com/pipermail/cygwin/2024-December/256954.html
diff --git a/winsup/cygwin/select.cc b/winsup/cygwin/select.cc
index 2c09b14d1c..95c12ef52a 100644
--- a/winsup/cygwin/select.cc
+++ b/winsup/cygwin/select.cc
@@ -385,10 +385,14 @@ next_while:;
      to create the timer once per thread.  Since WFMO checks the handles
      in order, we append the timer as last object, otherwise it's preferred
      over actual events on the descriptors. */
-  HANDLE &wait_timer = _my_tls.locals.cw_timer;
+  HANDLE local_timer = NULL;
+  HANDLE &wait_timer =
+    _my_tls.locals.cw_timer_inuse ? local_timer : _my_tls.locals.cw_timer;
   if (us > 0LL)
     {
       NTSTATUS status;
+      if (!_my_tls.locals.cw_timer_inuse)
+	_my_tls.locals.cw_timer_inuse = true;
       if (!wait_timer)
 	{
 	  status = NtCreateTimer (&wait_timer, TIMER_ALL_ACCESS, NULL,
@@ -431,6 +435,10 @@ next_while:;
     {
       BOOLEAN current_state;
       NtCancelTimer (wait_timer, &current_state);
+      if (local_timer)
+	NtClose (local_timer);
+      else
+	_my_tls.locals.cw_timer_inuse = false;
     }
 
   wait_states res;
diff --git a/winsup/cygwin/sigproc.cc b/winsup/cygwin/sigproc.cc
index c2985277fc..858a7fd12d 100644
--- a/winsup/cygwin/sigproc.cc
+++ b/winsup/cygwin/sigproc.cc
@@ -742,6 +742,9 @@ sig_send (_pinfo *p, siginfo_t& si, _cygtls *tls)
       memcpy (p, si._si_commune._si_str, n); p += n;
     }
 
+  unsigned cw_mask;
+  cw_mask = pack.si.si_signo == __SIGFLUSHFAST ? 0 : cw_sig_restart;
+
   DWORD nb;
   BOOL res;
   /* Try multiple times to send if packsize != nb since that probably
@@ -751,14 +754,9 @@ sig_send (_pinfo *p, siginfo_t& si, _cygtls *tls)
       res = WriteFile (sendsig, leader, packsize, &nb, NULL);
       if (!res || packsize == nb)
 	break;
-      if (cygwait (NULL, 10, cw_sig_eintr) == WAIT_SIGNALED
-	  && pack.si.si_signo != __SIGFLUSHFAST)
-	_my_tls.call_signal_handler ();
+      cygwait (NULL, 10, cw_mask);
       res = 0;
     }
-  /* Re-assert signal_arrived which has been cleared in cygwait(). */
-  if (_my_tls.sig)
-    _my_tls.set_signal_arrived ();
 
   if (!res)
     {
@@ -789,16 +787,7 @@ sig_send (_pinfo *p, siginfo_t& si, _cygtls *tls)
   if (wait_for_completion)
     {
       sigproc_printf ("Waiting for pack.wakeup %p", pack.wakeup);
-      do
-	{
-	  rc = cygwait (pack.wakeup, WSSC, cw_sig_eintr);
-	  if (rc == WAIT_SIGNALED && pack.si.si_signo != __SIGFLUSHFAST)
-	    _my_tls.call_signal_handler ();
-	}
-      while (rc != WAIT_OBJECT_0 && rc != WAIT_TIMEOUT);
-      /* Re-assert signal_arrived which has been cleared in cygwait(). */
-      if (_my_tls.sig)
-	_my_tls.set_signal_arrived ();
+      rc = cygwait (pack.wakeup, WSSC, cw_mask);
       ForceCloseHandle (pack.wakeup);
     }
   else