diff packages/kernel/current/include/flag.hxx @ 0:3111d98ba7b3 ecos-v1_1-release

Initial commit of eCos version 1.1
author jlarmour
date Tue, 11 May 1999 11:16:07 +0000
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children 443894e2e912
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+++ b/packages/kernel/current/include/flag.hxx
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+#ifndef CYGONCE_KERNEL_FLAG_HXX
+#define CYGONCE_KERNEL_FLAG_HXX
+
+//==========================================================================
+//
+//	flag.hxx
+//
+//	Flag object class declarations
+//
+//==========================================================================
+//####COPYRIGHTBEGIN####
+//
+// -------------------------------------------
+// The contents of this file are subject to the Cygnus eCos Public License
+// Version 1.0 (the "License"); you may not use this file except in
+// compliance with the License.  You may obtain a copy of the License at
+// http://sourceware.cygnus.com/ecos
+// 
+// Software distributed under the License is distributed on an "AS IS"
+// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See the
+// License for the specific language governing rights and limitations under
+// the License.
+// 
+// The Original Code is eCos - Embedded Cygnus Operating System, released
+// September 30, 1998.
+// 
+// The Initial Developer of the Original Code is Cygnus.  Portions created
+// by Cygnus are Copyright (C) 1998 Cygnus Solutions.  All Rights Reserved.
+// -------------------------------------------
+//
+//####COPYRIGHTEND####
+//==========================================================================
+//#####DESCRIPTIONBEGIN####
+//
+// Author(s): 	hmt
+// Contributors:	hmt
+// Date:	1998-02-10
+// Purpose:	Define Flag class interfaces
+// Description:	The classes defined here provide the APIs for flags.
+// Usage:	#include <cyg/kernel/flag.hxx>
+//		
+//
+//####DESCRIPTIONEND####
+//
+//==========================================================================
+
+#include <cyg/kernel/ktypes.h>
+#include <cyg/infra/cyg_ass.h>                     // assertion macros
+#include <cyg/kernel/thread.hxx>                   // Cyg_Thread
+
+// -------------------------------------------------------------------------
+
+// Flag object.  This class implements a queue of threads waiting for a
+// boolean expression of the flag value (an integer) to become true; all
+// relevant threads are awoken, not just the first.  A variant on this is
+// the single-bit flag, which is implemented by means of default arguments.
+
+#ifdef CYGIMP_FLAGS_16BIT
+typedef cyg_uint16 Cyg_FlagValue;
+#define CYG_FLAGS_SIZE 16
+#endif
+#ifdef CYGIMP_FLAGS_32BIT
+typedef cyg_uint32 Cyg_FlagValue;
+#define CYG_FLAGS_SIZE 32
+#endif
+#ifdef CYGIMP_FLAGS_64BIT
+typedef cyg_uint64 Cyg_FlagValue;
+#define CYG_FLAGS_SIZE 64
+#endif
+
+#ifndef CYG_FLAGS_SIZE
+typedef cyg_uint32 Cyg_FlagValue;
+#define CYG_FLAGS_SIZE 32
+#endif
+
+
+
+class Cyg_Flag
+{
+private:
+    Cyg_FlagValue value;
+
+    class FlagWaitInfo
+    {
+    public:
+        Cyg_FlagValue	allmask;        // these are separate words to
+        Cyg_FlagValue	anymask;        // save time in wakeup.
+        Cyg_FlagValue	value_out;      // return the value that satisfied
+        cyg_bool	do_clear;
+
+        FlagWaitInfo() { value_out = 0; }
+    };
+
+    Cyg_ThreadQueue     queue;          // Queue of waiting threads
+
+public:
+
+    CYGDBG_DEFINE_CHECK_THIS
+    
+    Cyg_Flag( Cyg_FlagValue init = 0 ); // Constructor
+    ~Cyg_Flag();                        // Destructor
+        
+    void
+    setbits( Cyg_FlagValue arg = ~0 );  // -OR- the arg in
+    // not inlined; this function awakens affected threads.
+
+    void
+    maskbits( Cyg_FlagValue arg = 0 );  // -AND- it in
+    // this is not inlined because it needs to lock the scheduler;
+    // it only really does value &= arg; nobody can be awoken in consequence.
+
+    typedef cyg_uint8 WaitMode;
+    // These values are chosen to map directly to uITRON for emulation
+    // purposes:
+    static const WaitMode AND = 0;      // all specified bits must be set
+    static const WaitMode OR  = 2;      // any specified bit must be set
+    static const WaitMode CLR = 1;      // clear value when satisfied
+    static const WaitMode MASK= 3;      // might be useful
+
+    // Wait for a match on our pattern, according to the flags given.
+    // Return the matching value, or zero if interrupted.
+    Cyg_FlagValue
+    wait( Cyg_FlagValue pattern, WaitMode mode );
+
+    // Wait for a match on our pattern, with an absolute timeout.
+    // Return the matching value, or zero if timed out/interrupted.
+    // (zero cannot match any pattern).
+#ifdef CYGFUN_KERNEL_THREADS_TIMER
+    Cyg_FlagValue
+    wait( Cyg_FlagValue pattern, WaitMode mode,
+          cyg_tick_count abs_timeout );
+#endif
+    // Test for a match on our pattern, according to the flags given.
+    // Return the matching value if success, else zero.
+    Cyg_FlagValue
+    poll( Cyg_FlagValue pattern, WaitMode mode ); 
+
+    inline Cyg_FlagValue
+    peek()                              // Get current value
+    {
+        return value;                   // NOT atomic wrt threads
+    }
+
+    inline cyg_bool
+    waiting()                           // Any threads waiting?
+    {
+        return !queue.empty();
+    }
+};
+
+
+
+// -------------------------------------------------------------------------
+#endif // ifndef CYGONCE_KERNEL_FLAG_HXX
+// EOF flag.hxx