[PATCH] Fix strace -T

[Jon TURNEY]

strace -T to toggle stracing of a process doesn't seem to work at the moment. 
Attached is a patch to make it work again.

2011-09-08  Jon TURNEY  <jon.tur...@dronecode.org.uk>

        * include/sys/strace.h (strace): Add toggle() method
        * strace.cc (toggle): Implement toggle() method
        * sigproc.cc (wait_sig): Use strace.toggle() in __SIGSTRACE


Fix 'strace -T -pid=<pid>'

Index: cygwin/include/sys/strace.h
===================================================================
--- cygwin/include/sys/strace.h.orig
+++ cygwin/include/sys/strace.h
@@ -40,6 +40,7 @@ class strace
   unsigned char _active;
 public:
   void activate ();
+  void toggle ();
   strace () {activate ();}
   int microseconds ();
   int version;
Index: cygwin/sigproc.cc
===================================================================
--- cygwin/sigproc.cc.orig
+++ cygwin/sigproc.cc
@@ -1194,7 +1194,7 @@ wait_sig (VOID *)
          talktome (&pack.si);
          break;
        case __SIGSTRACE:
-         strace.activate ();
+         strace.toggle ();
          strace.hello ();
          break;
        case __SIGPENDING:
Index: cygwin/strace.cc
===================================================================
--- cygwin/strace.cc.orig
+++ cygwin/strace.cc
@@ -43,6 +43,21 @@ strace::activate ()
 }
 
 void
+strace::toggle()
+{
+  if (active())
+    {
+      /* turn off stracing */
+      _active ^= 1;
+    }
+  else
+    {
+      /* announcing _STRACE_INTERFACE_ACTIVATE_ADDR makes the stracer turn on 
stracing */
+      activate ();
+    }
+}
+
+void
 strace::hello ()
 {
   if (active ())