Throughout change all calls of low_priority_sleep (0) to yield ().

* miscfuncs.cc (yield): Rename from low_priority_sleep.  Remove all of the
logic which called Sleep() and just use SwitchToThread.
* miscfuncs.h (yield): Rename from low_priority_sleep.
(SLEEP_0_STAY_LOW): Delete unused define.
* shared.cc (memory_init): Move heap_init() call directly after shared memory
initialization to more closely mimic long-standing program flow.
* tty.cc (tty_list::terminate): Replace call to low_priority_sleep with Sleep.

18 files changed, 48 insertions, 74 deletions

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index f7f1f50..e476c7e 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,15 @@
+2010-03-12  Christopher Faylor  <me+cygwin@cgf.cx>
+
+	Throughout change all calls of low_priority_sleep (0) to yield ().
+	* miscfuncs.cc (yield): Rename from low_priority_sleep.  Remove all of
+	the logic which called Sleep() and just use SwitchToThread.
+	* miscfuncs.h (yield): Rename from low_priority_sleep.
+	(SLEEP_0_STAY_LOW): Delete unused define.
+	* shared.cc (memory_init): Move heap_init() call directly after shared
+	memory initialization to more closely mimic long-standing program flow.
+	* tty.cc (tty_list::terminate): Replace call to low_priority_sleep with
+	Sleep.
+
 2010-03-10  Christopher Faylor  <me.cygwin@cgf.cx>
 
 	* shared.cc (memory_init): Fix comment.  Fix indentation.
diff --git a/winsup/cygwin/autoload.cc b/winsup/cygwin/autoload.cc
index eb16961..f5bdade 100644
--- a/winsup/cygwin/autoload.cc
+++ b/winsup/cygwin/autoload.cc
@@ -216,7 +216,7 @@ std_dll_init ()
     do
       {
 	InterlockedDecrement (&dll->here);
-	low_priority_sleep (0);
+	yield ();
       }
     while (InterlockedIncrement (&dll->here));
   else if (!dll->handle)
@@ -259,7 +259,7 @@ wsock_init ()
   while (InterlockedIncrement (&here))
     {
       InterlockedDecrement (&here);
-      low_priority_sleep (0);
+      yield ();
     }
 
   if (!wsock_started)
diff --git a/winsup/cygwin/cygthread.cc b/winsup/cygwin/cygthread.cc
index b0aea36..e747a2d 100644
--- a/winsup/cygwin/cygthread.cc
+++ b/winsup/cygwin/cygthread.cc
@@ -41,7 +41,7 @@ cygthread::callfunc (bool issimplestub)
     {
       /* Wait for main thread to assign 'h' */
       while (!h)
-	low_priority_sleep (0);
+	yield ();
       if (ev)
 	CloseHandle (ev);
       ev = h;
@@ -196,7 +196,7 @@ cygthread::cygthread (LPTHREAD_START_ROUTINE start, size_t n, void *param,
       if (ev)
 	ResetEvent (ev);
       while (!thread_sync)
-	low_priority_sleep (0);
+	yield ();
       SetEvent (thread_sync);
       thread_printf ("activated name '%s', thread_sync %p for thread %p", name, thread_sync, id);
       htobe = h;
@@ -217,7 +217,7 @@ cygthread::cygthread (LPTHREAD_START_ROUTINE start, size_t n, void *param,
   if (n)
     {
       while (!ev)
-	low_priority_sleep (0);
+	yield ();
       WaitForSingleObject (ev, INFINITE);
       ResetEvent (ev);
     }
@@ -256,7 +256,7 @@ cygthread::operator
 HANDLE ()
 {
   while (!ev)
-    low_priority_sleep (0);
+    yield ();
   return ev;
 }
 
@@ -287,7 +287,7 @@ cygthread::terminate_thread ()
   bool terminated = true;
   debug_printf ("thread '%s', id %p, inuse %d, stack_ptr %p", __name, id, inuse, stack_ptr);
   while (inuse && !stack_ptr)
-    low_priority_sleep (0);
+    yield ();
 
   if (!inuse)
     goto force_notterminated;
diff --git a/winsup/cygwin/dcrt0.cc b/winsup/cygwin/dcrt0.cc
index f85f297..5cee9f8 100644
--- a/winsup/cygwin/dcrt0.cc
+++ b/winsup/cygwin/dcrt0.cc
@@ -557,7 +557,7 @@ get_cygwin_startup_info ()
 	      {
 		res->ready (false);
 		for (unsigned i = 0; !being_debugged () && i < 10000; i++)
-		  low_priority_sleep (0);
+		  yield ();
 		strace.hello ();
 	      }
 	    break;
diff --git a/winsup/cygwin/exceptions.cc b/winsup/cygwin/exceptions.cc
index c416edc..39b56ea 100644
--- a/winsup/cygwin/exceptions.cc
+++ b/winsup/cygwin/exceptions.cc
@@ -440,7 +440,7 @@ try_to_debug (bool waitloop)
 	return dbg;
       SetThreadPriority (GetCurrentThread (), THREAD_PRIORITY_IDLE);
       while (!being_debugged ())
-	low_priority_sleep (0);
+	yield ();
       Sleep (2000);
     }
 
@@ -901,7 +901,7 @@ setup_handler (int sig, void *handler, struct sigaction& siga, _cygtls *tls)
 	break;
 
       sigproc_printf ("couldn't interrupt.  trying again.");
-      low_priority_sleep (0);
+      yield ();
     }
 
 out:
diff --git a/winsup/cygwin/fhandler_fifo.cc b/winsup/cygwin/fhandler_fifo.cc
index d24c731..b4a78d4 100644
--- a/winsup/cygwin/fhandler_fifo.cc
+++ b/winsup/cygwin/fhandler_fifo.cc
@@ -46,7 +46,7 @@ fhandler_fifo::open_nonserver (const char *npname, unsigned low_flags,
       if (h != INVALID_HANDLE_VALUE || GetLastError () != ERROR_PIPE_NOT_CONNECTED)
 	return h;
       if (&_my_tls != _main_tls)
-	low_priority_sleep (0);
+	yield ();
       else if (WaitForSingleObject (signal_arrived, 0) == WAIT_OBJECT_0)
 	{
 	  set_errno (EINTR);
diff --git a/winsup/cygwin/fhandler_proc.cc b/winsup/cygwin/fhandler_proc.cc
index bfbf64d..de55797 100644
--- a/winsup/cygwin/fhandler_proc.cc
+++ b/winsup/cygwin/fhandler_proc.cc
@@ -616,7 +616,7 @@ format_proc_cpuinfo (void *, char *&destbuf)
 	debug_printf ("SetThreadAffinityMask failed %E");
       // I'm not sure whether the thread changes processor immediately
       // and I'm not sure whether this function will cause the thread to be rescheduled
-      low_priority_sleep (0);
+      yield ();
 
       bool has_cpuid = false;
 
diff --git a/winsup/cygwin/gendef b/winsup/cygwin/gendef
index 9c17010..8899e85 100755
--- a/winsup/cygwin/gendef
+++ b/winsup/cygwin/gendef
@@ -126,8 +126,7 @@ __sigfe:
 	movl	%eax,$tls::spinning(%ebx)		# flag if we are waiting for lock
 	testl	%eax,%eax				# it will be zero
 	jz	2f					#  if so
-	xorl	%eax,%eax				# nope.  It was not zero
-	call	_low_priority_sleep			# should be a short-time thing, so
+	call	_yield			# should be a short-time thing, so
 	jmp	1b					# sleep and loop
 2:	movl	\$4,%eax				# have the lock, now increment the
 	xadd	%eax,$tls::stackptr(%ebx)		#  stack pointer and get pointer
@@ -151,8 +150,7 @@ __sigbe:						# return here after cygwin syscall
 	movl	%eax,$tls::spinning(%ebx)		# flag if we are waiting for lock
 	testl	%eax,%eax				# it will be zero
 	jz	2f					#  if so
-	xorl	%eax,%eax				# nope.  not zero
-	call	_low_priority_sleep			# sleep
+	call	_yield			# sleep
 	jmp	1b					#  and loop
 2:	movl	\$-4,%eax				# now decrement aux stack
 	xadd	%eax,$tls::stackptr(%ebx)		#  and get pointer
@@ -177,8 +175,7 @@ _sigreturn:
 	movl	%eax,$tls::spinning(%ebx)		# flag if we are waiting for lock
 	testl	%eax,%eax				# it will be zero
 	jz	2f					#  if so
-	xorl	%eax,%eax				# nope.  not zero
-	call	_low_priority_sleep			# sleep
+	call	_yield			# sleep
 	jmp	1b					#  and loop
 2:	popl	%edx					# saved errno
 	testl	%edx,%edx				# Is it < 0
@@ -258,8 +255,7 @@ __ZN7_cygtls4lockEv:
 	lock	xchgl %eax,$tls::pstacklock(%ebx)
 	testl	%eax,%eax
 	jz	2f
-	xorl	%eax,%eax
-	call	_low_priority_sleep
+	call	_yield
 	jmp	1b
 2:	popl	%ebx
 	ret
@@ -283,8 +279,7 @@ stabilize_sig_stack:
 	movl	%eax,$tls::spinning(%ebx)		# flag if we are waiting for lock
 	testl	%eax,%eax
 	jz	2f
-	xorl	%eax,%eax
-	call	_low_priority_sleep
+	call	_yield
 	jmp	1b
 2:	cmpl	\$0,$tls::sig(%ebx)
 	jz	3f
diff --git a/winsup/cygwin/miscfuncs.cc b/winsup/cygwin/miscfuncs.cc
index 29b8159..c7099dc 100644
--- a/winsup/cygwin/miscfuncs.cc
+++ b/winsup/cygwin/miscfuncs.cc
@@ -228,43 +228,11 @@ check_iovec (const struct iovec *iov, int iovcnt, bool forwrite)
   return (ssize_t) tot;
 }
 
-extern "C" int
-low_priority_sleep (DWORD secs)
+void
+yield ()
 {
-  HANDLE thisthread = GetCurrentThread ();
-  int curr_prio = GetThreadPriority (thisthread);
-  bool staylow;
-  if (secs != INFINITE)
-    staylow = false;
-  else
-    {
-      secs = 0;
-      staylow = true;
-    }
-
-  if (!secs)
-    {
-      for (int i = 0; i < 3; i++)
-	SwitchToThread ();
-    }
-  else
-    {
-      int new_prio;
-      if (GetCurrentThreadId () == cygthread::main_thread_id)
-	new_prio = THREAD_PRIORITY_LOWEST;
-      else
-	new_prio = GetThreadPriority (hMainThread);
-
-      if (curr_prio != new_prio)
-	/* Force any threads in normal priority to be scheduled */
-	SetThreadPriority (thisthread, new_prio);
-      Sleep (secs);
-
-      if (!staylow && curr_prio != new_prio)
-	SetThreadPriority (thisthread, curr_prio);
-    }
-
-  return curr_prio;
+  for (int i = 0; i < 3; i++)
+    SwitchToThread ();
 }
 
 /* Get a default value for the nice factor.  When changing these values,
diff --git a/winsup/cygwin/miscfuncs.h b/winsup/cygwin/miscfuncs.h
index 489f8b7..1dcb924 100644
--- a/winsup/cygwin/miscfuncs.h
+++ b/winsup/cygwin/miscfuncs.h
@@ -18,8 +18,7 @@ bool __stdcall create_pipe (PHANDLE, PHANDLE, LPSECURITY_ATTRIBUTES, DWORD)
   __attribute__ ((regparm (3)));
 #define CreatePipe create_pipe
 
-extern "C" int low_priority_sleep (DWORD) __attribute__ ((regparm (1)));
-#define SLEEP_0_STAY_LOW INFINITE
+extern "C" void yield ();
 
 void backslashify (const char *, char *, bool);
 void slashify (const char *, char *, bool);
diff --git a/winsup/cygwin/net.cc b/winsup/cygwin/net.cc
index ac83d4e..ad1735f 100644
--- a/winsup/cygwin/net.cc
+++ b/winsup/cygwin/net.cc
@@ -2775,7 +2775,7 @@ cygwin_bindresvport_sa (int fd, struct sockaddr *sa)
   for (int i = 0; i < NUM_PORTS; i++)
     {
       while ((myport = InterlockedExchange (&cygwin_shared->last_used_bindresvport, -1)) == -1)
-	low_priority_sleep (0);
+	yield ();
       if (myport == 0 || --myport < PORT_LOW)
 	myport = PORT_HIGH;
       InterlockedExchange (&cygwin_shared->last_used_bindresvport, myport);
diff --git a/winsup/cygwin/pinfo.cc b/winsup/cygwin/pinfo.cc
index af081ba..cdc801d 100644
--- a/winsup/cygwin/pinfo.cc
+++ b/winsup/cygwin/pinfo.cc
@@ -258,7 +258,7 @@ pinfo::init (pid_t n, DWORD flag, HANDLE h0)
 	      mapaddr = NULL;
 	    }
 	  debug_printf ("MapViewOfFileEx h0 %p, i %d failed, %E", h0, i);
-	  low_priority_sleep (0);
+	  yield ();
 	  continue;
 	}
 
@@ -313,7 +313,7 @@ pinfo::init (pid_t n, DWORD flag, HANDLE h0)
     loop:
       release ();
       if (h0)
-	low_priority_sleep (0);
+	yield ();
     }
 
   if (h)
@@ -978,7 +978,7 @@ _pinfo::sync_proc_pipe ()
 {
   if (wr_proc_pipe && wr_proc_pipe != INVALID_HANDLE_VALUE)
     while (wr_proc_pipe_owner != GetCurrentProcessId ())
-      low_priority_sleep (0);
+      yield ();
 }
 
 /* function to send a "signal" to the parent when something interesting happens
diff --git a/winsup/cygwin/sched.cc b/winsup/cygwin/sched.cc
index 08f9683..eae493b 100644
--- a/winsup/cygwin/sched.cc
+++ b/winsup/cygwin/sched.cc
@@ -483,7 +483,7 @@ sched_setscheduler (pid_t pid, int policy,
 int
 sched_yield ()
 {
-  low_priority_sleep (0);
+  yield ();
   return 0;
 }
 }
diff --git a/winsup/cygwin/shared.cc b/winsup/cygwin/shared.cc
index 4a24892..fcca6f4 100644
--- a/winsup/cygwin/shared.cc
+++ b/winsup/cygwin/shared.cc
@@ -318,7 +318,7 @@ user_shared_initialize ()
   else
     {
       while (!user_shared->cb)
-	low_priority_sleep (0);	// Should be hit only very very rarely
+	yield ();	// Should be hit only very very rarely
       if (user_shared->version != sversion)
 	multiple_cygwin_problem ("user shared memory version", user_shared->version, sversion);
       else if (user_shared->cb != sizeof (*user_shared))
@@ -423,7 +423,7 @@ memory_init (bool init_cygheap)
       LONG smi = InterlockedExchange (&shared_mem_inited, -1);
       if (smi < 0)
 	{
-	  low_priority_sleep (0);
+	  yield ();
 	  continue;
 	}
 
@@ -431,12 +431,13 @@ memory_init (bool init_cygheap)
 	/* Initialize installation root dir */
 	init_installation_root ();
 
-      /* Installation root dir has been globally initialized */
       cygwin_shared = (shared_info *) open_shared (L"shared",
 						   CYGWIN_VERSION_SHARED_DATA,
 						   cygwin_shared_h,
 						   sizeof (*cygwin_shared),
 						   SH_CYGWIN_SHARED);
+      heap_init ();
+
       if (!smi)
 	{
 	  cygwin_shared->initialize ();
@@ -451,7 +452,6 @@ memory_init (bool init_cygheap)
       InterlockedExchange (&shared_mem_inited, smi);
       break;
     }
-  heap_init ();
   user_shared_create (false);
 }
 
diff --git a/winsup/cygwin/sigproc.cc b/winsup/cygwin/sigproc.cc
index e940ebe..9408b0c 100644
--- a/winsup/cygwin/sigproc.cc
+++ b/winsup/cygwin/sigproc.cc
@@ -583,7 +583,7 @@ sig_send (_pinfo *p, siginfo_t& si, _cygtls *tls)
       HANDLE dupsig;
       DWORD dwProcessId;
       for (int i = 0; !p->sendsig && i < 10000; i++)
-	low_priority_sleep (0);
+	yield ();
       if (p->sendsig)
 	{
 	  dupsig = p->sendsig;
@@ -1011,7 +1011,7 @@ remove_proc (int ci)
 	 the proc_waiter thread has already done this by the time we
 	 get here.  */
       while (!procs[nprocs].waiter_ready)
-	low_priority_sleep (0);
+	yield ();
       procs[ci] = procs[nprocs];
     }
   return 0;
diff --git a/winsup/cygwin/sync.cc b/winsup/cygwin/sync.cc
index 8fa0d93..b62c6bc 100644
--- a/winsup/cygwin/sync.cc
+++ b/winsup/cygwin/sync.cc
@@ -36,7 +36,7 @@ muto::init (const char *s)
   char *already_exists = (char *) InterlockedExchangePointer (&name, s);
   if (already_exists)
     while (!bruteforce)
-      low_priority_sleep (0);
+      yield ();
   else
     {
       waiters = -1;
diff --git a/winsup/cygwin/thread.cc b/winsup/cygwin/thread.cc
index 20eb95d..5681aad 100644
--- a/winsup/cygwin/thread.cc
+++ b/winsup/cygwin/thread.cc
@@ -456,7 +456,7 @@ pthread::create (void *(*func) (void *), pthread_attr *newattr,
     {
       postcreate ();
       while (!cygtls)
-	low_priority_sleep (0);
+	yield ();
     }
   retval = magic;
   mutex.unlock ();
diff --git a/winsup/cygwin/tty.cc b/winsup/cygwin/tty.cc
index 624805f..e701810 100644
--- a/winsup/cygwin/tty.cc
+++ b/winsup/cygwin/tty.cc
@@ -160,7 +160,7 @@ tty_list::terminate ()
 	      i = 0;
 	    }
 
-	  low_priority_sleep (200);
+	  Sleep (200);
 	}
 
       lock_ttys here ();