merge from trunk

3 files changed, 78 insertions, 26 deletions

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 474767ebccb..b839897bb9e 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,6 +1,18 @@
 2003-04-04  Christopher Faylor  <cgf@redhat.com>
 
-	* cygthread.cc (operator new): Be more defensive when messing with
+	* cygthread.h (cygthread::avail): Make LONG for easier use with
+	Interlocked* functions.
+	* cygthread.cc (cygthread::init): Eliminate unneeded muto.
+	(cygthread::operator new): Don't lock.  Instead change use of avail
+	variable into tri-state: available (1), not available (-1),
+	uninitialized (0).
+	(cygthread::terminate_thread): Set avail to uninitialized.
+	(cygthread::detach): Eliminate local 'avail'.  Always set avail to 1
+	unless signalled.
+
+2003-04-04  Christopher Faylor  <cgf@redhat.com>
+
+	* cygthread.cc (cygthread::operator new): Be more defensive when messing with
 	threads that are marked "unavailable".
 
 2003-04-03  Christopher Faylor  <cgf@redhat.com>
diff --git a/winsup/cygwin/cygthread.cc b/winsup/cygwin/cygthread.cc
index fd946e4ad7d..bc6c8bc9eaf 100644
--- a/winsup/cygwin/cygthread.cc
+++ b/winsup/cygwin/cygthread.cc
@@ -94,12 +94,10 @@ cygthread::simplestub (VOID *arg)
   ExitThread (0);
 }
 
-static NO_COPY muto *cygthread_protect;
 /* Start things going.  Called from dll_crt0_1. */
 void
 cygthread::init ()
 {
-  new_muto (cygthread_protect);
   main_thread_id = GetCurrentThreadId ();
 }
 
@@ -129,29 +127,27 @@ cygthread::freerange ()
 void * cygthread::operator
 new (size_t)
 {
-  DWORD id;
+  LONG is_avail;
   cygthread *info;
 
-  cygthread_protect->acquire ();
-
   /* Search the threads array for an empty slot to use */
   for (info = threads; info < threads + NTHREADS; info++)
-    if ((LONG) (id = (DWORD) InterlockedExchange ((LPLONG) &info->avail, -1)) < 0)
-      /* being considered */;
-    else if (id > 0)
+    if ((is_avail = InterlockedExchange (&info->avail, -1)) < 0)
+      /* in use */;
+    else if (is_avail > 0)
       {
+	/* available */
 #ifdef DEBUGGING
 	if (info->__name)
-	  api_fatal ("name not NULL? id %p, i %d", id, info - threads);
+	  api_fatal ("name not NULL? id %p, i %d", info->id, info - threads);
 	if (!info->h)
-	  api_fatal ("h not set? id %p, i %d", id, info - threads);
+	  api_fatal ("h not set? id %p, i %d", info->id, info - threads);
 #endif
 	goto out;
       }
-    else if (info->id)
-      InterlockedExchange ((LPLONG) &info->avail, 0);
     else
       {
+	/* Uninitialized.  Available as soon as thread is created */
 	info->h = CreateThread (&sec_none_nih, 0, cygthread::stub, info,
 				CREATE_SUSPENDED, &info->id);
 	goto out;
@@ -159,15 +155,13 @@ new (size_t)
 
 #ifdef DEBUGGING
   char buf[1024];
-  if (!GetEnvironmentVariable ("CYGWIN_NOFREERANGE_NOCHECK", buf, sizeof (buf)))
+  if (!GetEnvironmentVariable ("CYGWIN_FREERANGE_NOCHECK", buf, sizeof (buf)))
     api_fatal ("Overflowed cygwin thread pool");
 #endif
 
   info = freerange ();	/* exhausted thread pool */
 
 out:
-  InterlockedExchange ((LPLONG) &info->avail, 0);
-  cygthread_protect->release ();
   return info;
 }
 
@@ -269,21 +263,21 @@ cygthread::terminate_thread ()
   thread_sync = ev = h = NULL;
   __name = NULL;
   id = 0;
+  (void) InterlockedExchange (&avail, 0); /* No longer initialized */
 }
 
 /* Detach the cygthread from the current thread.  Note that the
    theory is that cygthreads are only associated with one thread.
-   So, there should be no problems with multiple threads doing waits
-   on the one cygthread. */
+   So, there should be never be multiple threads doing waits
+   on the same cygthread. */
 bool
 cygthread::detach (HANDLE sigwait)
 {
   bool signalled = false;
-  if (avail)
-    system_printf ("called detach on available thread %d?", avail);
+  if (avail >= 0)
+    system_printf ("called detach but avail %d, thread %d?", avail, id);
   else
     {
-      DWORD newavail = id;
       DWORD res;
 
       if (!sigwait)
@@ -303,18 +297,17 @@ cygthread::detach (HANDLE sigwait)
 	    res = WaitForSingleObject (*this, INFINITE);
 	  else
 	    {
+	      signalled = true;
 	      terminate_thread ();
 	      set_sig_errno (EINTR);	/* caller should be dealing with return
 					   values. */
-	      newavail = 0;
-	      signalled = true;
 	    }
 	}
 
       thread_printf ("%s returns %d, id %p", sigwait ? "WFMO" : "WFSO",
 		     res, id);
 
-      if (!newavail)
+      if (signalled)
 	/* already handled */;
       else if (is_freerange)
 	{
@@ -324,8 +317,8 @@ cygthread::detach (HANDLE sigwait)
       else
 	{
 	  ResetEvent (*this);
-	  /* Mark the thread as available by setting avail to non-zero */
-	  (void) InterlockedExchange ((LPLONG) &avail, newavail);
+	  /* Mark the thread as available by setting avail to positive value */
+	  (void) InterlockedExchange (&avail, 1);
 	}
     }
   return signalled;
diff --git a/winsup/cygwin/cygthread.h b/winsup/cygwin/cygthread.h
new file mode 100644
index 00000000000..3226f2a02e7
--- /dev/null
+++ b/winsup/cygwin/cygthread.h
@@ -0,0 +1,47 @@
+/* cygthread.h
+
+   Copyright 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
+
+This software is a copyrighted work licensed under the terms of the
+Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
+details. */
+
+class cygthread
+{
+  LONG avail;	/* 1: available, 0: ininitialized, -1: not available */
+  DWORD id;
+  HANDLE h;
+  HANDLE ev;
+  HANDLE thread_sync;
+  void *stack_ptr;
+  const char *__name;
+  LPTHREAD_START_ROUTINE func;
+  VOID *arg;
+  bool is_freerange;
+  static DWORD main_thread_id;
+  static bool exiting;
+  static DWORD WINAPI stub (VOID *);
+  static DWORD WINAPI simplestub (VOID *);
+ public:
+  static const char * name (DWORD = 0);
+  cygthread (LPTHREAD_START_ROUTINE, LPVOID, const char *);
+  cygthread () {};
+  static void init ();
+  bool detach (HANDLE = NULL);
+  operator HANDLE ();
+  static bool is ();
+  void * operator new (size_t);
+  static cygthread *freerange ();
+  void exit_thread ();
+  void terminate_thread ();
+  static void terminate ();
+  bool SetThreadPriority (int nPriority) {return ::SetThreadPriority (h, nPriority);}
+  void zap_h ()
+  {
+    (void) CloseHandle (h);
+    h = NULL;
+  }
+
+};
+
+#define cygself NULL