Add the .event statement and the %wait instruction.

vvp/README.txt

@@ -1,7 +1,7 @@
 /*
  * Copyright (c) 2001 Stephen Williams (steve@icarus.com)
  *
- *  $Id: README.txt,v 1.8 2001/03/24 22:59:28 steve Exp $
+ *  $Id: README.txt,v 1.9 2001/03/26 04:00:39 steve Exp $
  */
 
 VVP SIMULATION ENGINE
@@ -186,6 +186,28 @@ position for that bit blank. Bits of .nets are initialized to
 z. Unconnected bits keep the value z throughout the simulation.
 
 
+EVENT STATEMENTS
+
+Threads need to interact with the functors of a netlist synchronously,
+as well as asynchronously. There are cases where the web of functors
+needs to wake up a waiting thread. The web of functors signals threads
+through .event objects, that are declare like so:
+
+	<label> .event <type>, <symbols_list>;
+	<label> .event "name";
+
+
+This event statement declares an object that a %waitfor instruction
+can take as an operand. When a thread executes a %waitfor, it puts
+itself in the notification list of the event and suspends. The
+<symbols_list> is a set of inputs that can trigger the event.
+
+The <type> describes the conditions needed to trigger the event. It
+may be posedge, negedge or edge. If the type is instead a "name"
+string, then this is a named event which receives events by the %set
+instruction instead of from the output of a functor.
+
+
 THREAD STATEMENTS:
 
 Thread statements create the initial threads for a simulation. These

vvp/codes.h

@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: codes.h,v 1.6 2001/03/25 03:54:26 steve Exp $"
+#ident "$Id: codes.h,v 1.7 2001/03/26 04:00:39 steve Exp $"
 #endif
 
 
@@ -46,6 +46,7 @@ extern bool of_JMP0XZ(vthread_t thr, vvp_code_t code);
 extern bool of_LOAD(vthread_t thr, vvp_code_t code);
 extern bool of_MOV(vthread_t thr, vvp_code_t code);
 extern bool of_SET(vthread_t thr, vvp_code_t code);
+extern bool of_WAIT(vthread_t thr, vvp_code_t code);
 extern bool of_NOOP(vthread_t thr, vvp_code_t code);
 extern bool of_VPI_CALL(vthread_t thr, vvp_code_t code);
 
@@ -92,6 +93,9 @@ extern void codespace_dump(FILE*fd);
 
 /*
  * $Log: codes.h,v $
+ * Revision 1.7  2001/03/26 04:00:39  steve
+ *  Add the .event statement and the %wait instruction.
+ *
  * Revision 1.6  2001/03/25 03:54:26  steve
  *  Add JMP0XZ and postpone net inputs when needed.
  *

vvp/compile.cc

@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: compile.cc,v 1.15 2001/03/25 19:38:23 steve Exp $"
+#ident "$Id: compile.cc,v 1.16 2001/03/26 04:00:39 steve Exp $"
 #endif
 
 # include  "compile.h"
@@ -75,6 +75,7 @@ const static struct opcode_table_s opcode_table[] = {
       { "%load",   of_LOAD,   2,  {OA_BIT1,     OA_FUNC_PTR, OA_NONE} },
       { "%mov",    of_MOV,    3,  {OA_BIT1,     OA_BIT2,     OA_NUMBER} },
       { "%set",    of_SET,    2,  {OA_FUNC_PTR, OA_BIT1,     OA_NONE} },
+      { "%wait",   of_WAIT,   1,  {OA_FUNC_PTR, OA_NONE,     OA_NONE} },
       { 0, of_NOOP, 0, {OA_NONE, OA_NONE, OA_NONE} }
 };
 
@@ -226,6 +227,7 @@ void compile_functor(char*label, char*type, unsigned init,
 
       obj->ival = init;
       obj->oval = 2;
+      obj->mode = 0;
 
       if (strcmp(type, "OR") == 0) {
 	    obj->table = ft_OR;
@@ -248,6 +250,71 @@ void compile_functor(char*label, char*type, unsigned init,
       free(type);
 }
 
+void compile_event(char*label, char*type,
+		   unsigned argc, struct symb_s*argv)
+{
+      vvp_ipoint_t fdx = functor_allocate(1);
+      functor_t obj = functor_index(fdx);
+
+      { symbol_value_t val;
+        val.num = fdx;
+	sym_set_value(sym_functors, label, val);
+      }
+
+      assert(argc <= 4);
+
+	/* Run through the arguments looking for the functors that are
+	   connected to my input ports. For each source functor that I
+	   find, connect the output of that functor to the indexed
+	   input by inserting myself (complete with the port number in
+	   the vvp_ipoint_t) into the list that the source heads.
+
+	   If the source functor is not declared yet, then don't do
+	   the link yet. Save the reference to be resolved later. */
+
+      for (unsigned idx = 0 ;  idx < argc ;  idx += 1) {
+	    symbol_value_t val = sym_get_value(sym_functors, argv[idx].text);
+	    vvp_ipoint_t tmp = val.num;
+
+	    if (tmp) {
+		  tmp = ipoint_index(tmp, argv[idx].idx);
+		  functor_t fport = functor_index(tmp);
+		  obj->port[idx] = fport->out;
+		  fport->out = ipoint_make(fdx, idx);
+
+		  free(argv[idx].text);
+
+	    } else {
+		  postpone_functor_input(ipoint_make(fdx, idx),
+					 argv[idx].text,
+					 argv[idx].idx);
+
+	    }
+      }
+
+      free(argv);
+
+      obj->ival = 0xaa;
+      obj->oval = 2;
+      obj->mode = 1;
+
+      obj->event = (struct vvp_event_s*) malloc(sizeof (struct vvp_event_s));
+      obj->event->threads = 0;
+      obj->event->ival = obj->ival;
+
+      if (strcmp(type,"posedge") == 0)
+	    obj->event->vvp_edge_tab = vvp_edge_posedge;
+      else if (strcmp(type,"negedge") == 0)
+	    obj->event->vvp_edge_tab = vvp_edge_negedge;
+      else if (strcmp(type,"edge") == 0)
+	    obj->event->vvp_edge_tab = vvp_edge_anyedge;
+      else
+	    obj->event->vvp_edge_tab = 0;
+
+      free(type);
+      free(label);
+}
+
 /*
  * The parser uses this function to compile an link an executable
  * opcode. I do this by looking up the opcode in the opcode_table. The
@@ -453,6 +520,7 @@ void compile_variable(char*label, char*name, int msb, int lsb)
 	    obj->table = ft_var;
 	    obj->ival  = 0x22;
 	    obj->oval  = 0x02;
+	    obj->mode  = 0;
       }
 
 	/* Make the vpiHandle for the reg. */
@@ -477,6 +545,7 @@ void compile_net(char*label, char*name, int msb, int lsb,
 	    obj->table = ft_var;
 	    obj->ival  = 0x22;
 	    obj->oval  = 0x02;
+	    obj->mode  = 0;
       }
 
       assert(argc == wid);
@@ -593,6 +662,9 @@ void compile_dump(FILE*fd)
 
 /*
  * $Log: compile.cc,v $
+ * Revision 1.16  2001/03/26 04:00:39  steve
+ *  Add the .event statement and the %wait instruction.
+ *
  * Revision 1.15  2001/03/25 19:38:23  steve
  *  Support NOR and NOT gates.
  *

vvp/compile.h

@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: compile.h,v 1.10 2001/03/25 00:35:35 steve Exp $"
+#ident "$Id: compile.h,v 1.11 2001/03/26 04:00:39 steve Exp $"
 #endif
 
 # include  <stdio.h>
@@ -65,6 +65,15 @@ extern void compile_functor(char*label, char*type, unsigned init,
 extern void compile_vpi_symbol(const char*label, vpiHandle obj);
 extern vpiHandle compile_vpi_lookup(const char*label);
 
+/*
+ * The compile_event function takes the parts of the event statement
+ * and makes the various objects needed to simulate it. This includes
+ * the functor that receives the signals and the event_t that holds
+ * the threads.
+ */
+extern void compile_event(char*label, char*type,
+			  unsigned argc, struct symb_s*argv);
+
 /*
  * A code statement is a label, an opcode and up to 3 operands. There
  * are a few lexical types that the parser recognizes of the operands,
@@ -123,6 +132,9 @@ extern void compile_dump(FILE*fd);
 
 /*
  * $Log: compile.h,v $
+ * Revision 1.11  2001/03/26 04:00:39  steve
+ *  Add the .event statement and the %wait instruction.
+ *
  * Revision 1.10  2001/03/25 00:35:35  steve
  *  Add the .net statement.
  *

vvp/examples/edge.vvp

@@ -0,0 +1,52 @@
+:vpi_module "system";
+
+; Copyright (c) 2001  Stephen Williams (steve@icarus.com)
+;
+;    This source code is free software; you can redistribute it
+;    and/or modify it in source code form under the terms of the GNU
+;    General Public License as published by the Free Software
+;    Foundation; either version 2 of the License, or (at your option)
+;    any later version.
+;
+;    This program is distributed in the hope that it will be useful,
+;    but WITHOUT ANY WARRANTY; without even the implied warranty of
+;    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;    GNU General Public License for more details.
+;
+;    You should have received a copy of the GNU General Public License
+;    along with this program; if not, write to the Free Software
+;    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+
+
+; This example tests the operation of a simple posedge event. The module
+; that would generate code like this would be:
+;
+;    module main;
+;        reg a;
+;
+;        initial begin
+;          a = 0;
+;          #1 a = 1;
+;        end
+;
+;        always @(posedge a) $display("Got a posedge.");
+;
+;    endmodule
+;
+
+main	.scope "main";
+
+V_main.a	.var "a", 0, 0;
+V_main.b	.event posedge, V_main.a;
+
+code
+	%set V_main.a, 0;
+	%delay 1;
+	%set V_main.a, 1;
+	%end; 
+	.thread	code;
+
+loop	%wait V_main.b;
+	%vpi_call "$display", "Got a posedge.";
+	%jmp loop;
+	.thread loop;

vvp/functor.cc

@@ -17,11 +17,12 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: functor.cc,v 1.6 2001/03/25 00:35:35 steve Exp $"
+#ident "$Id: functor.cc,v 1.7 2001/03/26 04:00:39 steve Exp $"
 #endif
 
 # include  "functor.h"
 # include  "schedule.h"
+# include  "vthread.h"
 # include  <assert.h>
 
 /*
@@ -131,6 +132,63 @@ functor_t functor_index(vvp_ipoint_t point)
       return functor_table[point]->table[index1]->table + index0;
 }
 
+static void functor_set_mode0(vvp_ipoint_t ptr, functor_t fp)
+{
+	/* Locate the new output value in the table. */
+      unsigned char out = fp->table[fp->ival >> 2];
+      out >>= 2 * (fp->ival&0x03);
+      out &= 0x03;
+
+	/* If the output changes, then create a propagation event. */
+      if (out != fp->oval) {
+	    fp->oval = out;
+	    schedule_functor(ptr, 0);
+      }
+}
+
+const unsigned char vvp_edge_posedge[16] = {
+      0, 1, 1, 1, // 0 -> ...
+      0, 0, 0, 0, // 1 -> ...
+      0, 1, 0, 0, // x -> ...
+      0, 1, 0, 0  // z -> ...
+};
+
+const unsigned char vvp_edge_negedge[16] = {
+      0, 0, 0, 0, // 0 -> ...
+      1, 0, 1, 1, // 1 -> ...
+      1, 0, 0, 0, // x -> ...
+      1, 0, 0, 0  // z -> ...
+};
+
+const unsigned char vvp_edge_anyedge[16] = {
+      0, 1, 1, 1, // 0 -> ...
+      1, 0, 1, 1, // 1 -> ...
+      1, 1, 0, 1, // x -> ...
+      1, 1, 1, 0  // z -> ...
+};
+
+static void functor_set_mode1(functor_t fp)
+{
+      vvp_event_t ep = fp->event;
+
+      for (unsigned idx = 0 ;  ep->threads && (idx < 4) ;  idx += 1) {
+	    unsigned oval = (ep->ival >> 2*idx) & 3;
+	    unsigned nval = (fp->ival >> 2*idx) & 3;
+
+	    unsigned val = (oval << 2) | nval;
+	    unsigned char edge_p = ep->vvp_edge_tab[val];
+
+	    if (edge_p) {
+		  vthread_t tmp = ep->threads;
+		  ep->threads = 0;
+		  vthread_schedule_list(tmp);
+	    }
+      }
+
+	/* the new value is the new old value. */
+      ep->ival = fp->ival;
+}
+
 /*
  * Set the addressed bit of the functor, and recalculate the
  * output. If the output changes any, then generate the necessary
@@ -148,15 +206,13 @@ void functor_set(vvp_ipoint_t ptr, unsigned bit)
       unsigned char mask = mask_table[pp];
       fp->ival = (fp->ival & mask) | (bit << (2*pp));
 
-	/* Locate the new output value in the table. */
+      switch (fp->mode) {
-      unsigned char out = fp->table[fp->ival >> 2];
+	  case 0:
-      out >>= 2 * (fp->ival&0x03);
+	    functor_set_mode0(ptr, fp);
-      out &= 0x03;
+	    break;
-
+	  case 1:
-	/* If the output changes, then create a propagation event. */
+	    functor_set_mode1(fp);
-      if (out != fp->oval) {
+	    break;
-	    fp->oval = out;
-	    schedule_functor(ptr, 0);
       }
 }
 
@@ -226,6 +282,9 @@ const unsigned char ft_var[16] = {
 
 /*
  * $Log: functor.cc,v $
+ * Revision 1.7  2001/03/26 04:00:39  steve
+ *  Add the .event statement and the %wait instruction.
+ *
  * Revision 1.6  2001/03/25 00:35:35  steve
  *  Add the .net statement.
  *

vvp/functor.h

@@ -19,13 +19,12 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: functor.h,v 1.5 2001/03/25 19:38:23 steve Exp $"
+#ident "$Id: functor.h,v 1.6 2001/03/26 04:00:39 steve Exp $"
 #endif
 
 # include  "pointers.h"
 # include  <stdio.h>
 
-typedef const unsigned char*vvp_truth_t;
 
 /*
  * The vvp_ipoint_t is an integral type that is 32bits. The low 2 bits
@@ -45,11 +44,25 @@ typedef const unsigned char*vvp_truth_t;
  *	1'b1  : 01
  *	1'bx  : 10
  *	1'bz  : 11
+ *
+ * The function of the functor is defined by the table/event
+ * union. Normally, the truth table is the behavior and the functor
+ * output value is picked from the lookup table that the table pointer
+ * points to.
+ *
+ * If the functor is an event functor, however, the event member
+ * points to an extended structure where thread state is stored.
+ *
+ * The major mode is selected by the mode parameter.
  */
 
 struct functor_s {
 	/* This is the truth table for the device */
+      union {
 	    vvp_truth_t table;
+	    vvp_event_t event;
+      };
+
 	/* This is the output for the device. */
       vvp_ipoint_t out;
 	/* These are the input ports. */
@@ -57,10 +70,26 @@ struct functor_s {
 	/* These are the input values. */
       unsigned char ival;
       unsigned char oval;
+	/* functor mode:  0 == table ;  1 == event */
+      unsigned char mode;
 };
 
 typedef struct functor_s *functor_t;
 
+/*
+ * If functor mode is 1, the event member is valid and the vvp_event_s
+ * points to the extended event information.
+ */
+extern const unsigned char vvp_edge_posedge[16];
+extern const unsigned char vvp_edge_negedge[16];
+extern const unsigned char vvp_edge_anyedge[16];
+
+struct vvp_event_s {
+      vthread_t threads;
+      unsigned char ival;
+      const unsigned char*vvp_edge_tab;
+};
+
 /*
  * Initialize the functors address space. This function must be called
  * exactly once before any of the other functor functions may be
@@ -115,6 +144,9 @@ extern const unsigned char ft_var[];
 
 /*
  * $Log: functor.h,v $
+ * Revision 1.6  2001/03/26 04:00:39  steve
+ *  Add the .event statement and the %wait instruction.
+ *
  * Revision 1.5  2001/03/25 19:38:23  steve
  *  Support NOR and NOT gates.
  *

vvp/lexor.lex

@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: lexor.lex,v 1.8 2001/03/25 19:36:45 steve Exp $"
+#ident "$Id: lexor.lex,v 1.9 2001/03/26 04:00:39 steve Exp $"
 #endif
 
 # include  "parse_misc.h"
@@ -48,6 +48,7 @@
 
 
   /* These are some keywords that are recognized. */
+".event"   { return K_EVENT; }
 ".functor" { return K_FUNCTOR; }
 ".net"     { return K_NET; }
 ".scope"   { return K_SCOPE; }
@@ -104,6 +105,9 @@ int yywrap()
 
 /*
  * $Log: lexor.lex,v $
+ * Revision 1.9  2001/03/26 04:00:39  steve
+ *  Add the .event statement and the %wait instruction.
+ *
  * Revision 1.8  2001/03/25 19:36:45  steve
  *  Accept <> characters in labels and symbols.
  *

vvp/opcodes.txt

@@ -1,7 +1,7 @@
 /*
  * Copyright (c) 2001 Stephen Williams (steve@icarus.com)
  *
- *  $Id: opcodes.txt,v 1.5 2001/03/22 05:08:00 steve Exp $
+ *  $Id: opcodes.txt,v 1.6 2001/03/26 04:00:39 steve Exp $
  */
 
 
@@ -115,7 +115,7 @@ declared using VPI. The operands are compiled down to a vpiHandle for
 the call. The instruction contains only the vpiHandle for the
 call. See the vpi.txt file for more on system task/function calls.
 
-* %waitfor <functor-label>
+* %wait <functor-label>
 
 When a thread executes this instruction, it places itself in the
 sensitive list for the addressed functor. The functor holds all the

vvp/parse.y

@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: parse.y,v 1.12 2001/03/25 00:35:35 steve Exp $"
+#ident "$Id: parse.y,v 1.13 2001/03/26 04:00:39 steve Exp $"
 #endif
 
 # include  "parse_misc.h"
@@ -49,7 +49,7 @@ extern FILE*yyin;
 };
 
 
-%token K_FUNCTOR K_NET K_SCOPE K_THREAD K_VAR K_vpi_call
+%token K_EVENT K_FUNCTOR K_NET K_SCOPE K_THREAD K_VAR K_vpi_call
 %token K_vpi_module
 
 %token <text> T_INSTR
@@ -106,6 +106,14 @@ statement
 	| T_LABEL K_FUNCTOR T_SYMBOL','  T_NUMBER ';'
 		{ compile_functor($1, $3, $5, 0, 0); }
 
+  /* Event statements take a label, a type (the first T_SYMBOL) and a
+     list of inputs. */
+
+	| T_LABEL K_EVENT T_SYMBOL ',' symbols ';'
+		{ struct symbv_s obj = $5;
+		  compile_event($1, $3, obj.cnt, obj.vect);
+		}
+
   /* Instructions may have a label, and have zero or more
      operands. The meaning of and restrictions on the operands depends
      on the specific instruction. */
@@ -295,6 +303,9 @@ int compile_design(const char*path)
 
 /*
  * $Log: parse.y,v $
+ * Revision 1.13  2001/03/26 04:00:39  steve
+ *  Add the .event statement and the %wait instruction.
+ *
  * Revision 1.12  2001/03/25 00:35:35  steve
  *  Add the .net statement.
  *

vvp/pointers.h

@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: pointers.h,v 1.2 2001/03/20 06:16:24 steve Exp $"
+#ident "$Id: pointers.h,v 1.3 2001/03/26 04:00:39 steve Exp $"
 #endif
 
 /*
@@ -77,8 +77,26 @@ inline unsigned ipoint_port(vvp_ipoint_t func)
 
 typedef unsigned vvp_cpoint_t;
 
+/*
+ * The truth table that functors point to are addressed with this
+ * typedef. 
+ */
+typedef const unsigned char*vvp_truth_t;
+
+/*
+ * The functor event mode uses a pointer of this type to point to the
+ * extended event data.
+ */
+typedef struct vvp_event_s *vvp_event_t;
+
+
+typedef struct vthread_s*vthread_t;
+
 /*
  * $Log: pointers.h,v $
+ * Revision 1.3  2001/03/26 04:00:39  steve
+ *  Add the .event statement and the %wait instruction.
+ *
  * Revision 1.2  2001/03/20 06:16:24  steve
  *  Add support for variable vectors.
  *

vvp/vthread.cc

@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: vthread.cc,v 1.11 2001/03/25 03:54:26 steve Exp $"
+#ident "$Id: vthread.cc,v 1.12 2001/03/26 04:00:39 steve Exp $"
 #endif
 
 # include  "vthread.h"
@@ -34,6 +34,8 @@ struct vthread_s {
       unsigned long pc;
       unsigned char *bits;
       unsigned short nbits;
+	/* This is used for keeping wait queues. */
+      struct vthread_s*next;
 };
 
 static void thr_check_addr(struct vthread_s*thr, unsigned addr)
@@ -76,6 +78,7 @@ vthread_t v_newthread(unsigned long pc)
       thr->pc = pc;
       thr->bits = (unsigned char*)malloc(16);
       thr->nbits = 16*4;
+      thr->next = 0;
 
       thr_put_bit(thr, 0, 0);
       thr_put_bit(thr, 1, 1);
@@ -106,6 +109,15 @@ void vthread_run(vthread_t thr)
       }
 }
 
+void vthread_schedule_list(vthread_t thr)
+{
+      while (thr) {
+	    vthread_t tmp = thr;
+	    thr = thr->next;
+	    schedule_vthread(tmp, 0);
+      }
+}
+
 bool of_ASSIGN(vthread_t thr, vvp_code_t cp)
 {
       unsigned char bit_val = thr_get_bit(thr, cp->bit_idx2);
@@ -249,8 +261,26 @@ bool of_VPI_CALL(vthread_t thr, vvp_code_t cp)
       return schedule_finished()? false : true;
 }
 
+/*
+ * Implement the wait by locating the functor for the event, and
+ * adding this thread to the threads list for the event.
+ */
+bool of_WAIT(vthread_t thr, vvp_code_t cp)
+{
+      functor_t fp = functor_index(cp->iptr);
+      assert(fp->mode == 1);
+      vvp_event_t ep = fp->event;
+      thr->next = ep->threads;
+      ep->threads = thr;
+
+      return false;
+}
+
 /*
  * $Log: vthread.cc,v $
+ * Revision 1.12  2001/03/26 04:00:39  steve
+ *  Add the .event statement and the %wait instruction.
+ *
  * Revision 1.11  2001/03/25 03:54:26  steve
  *  Add JMP0XZ and postpone net inputs when needed.
  *

vvp/vthread.h

@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: vthread.h,v 1.1 2001/03/11 00:29:39 steve Exp $"
+#ident "$Id: vthread.h,v 1.2 2001/03/26 04:00:39 steve Exp $"
 #endif
 
 /*
@@ -48,8 +48,19 @@ extern vthread_t v_newthread(unsigned long sa);
  */
 extern void vthread_run(vthread_t thr);
 
+/*
+ * This function schedules all the threads in the list to be scheduled
+ * for execution with delay 0. the thr pointer is taken to be the head
+ * of a list.
+ */
+extern void vthread_schedule_list(vthread_t thr);
+
+
 /*
  * $Log: vthread.h,v $
+ * Revision 1.2  2001/03/26 04:00:39  steve
+ *  Add the .event statement and the %wait instruction.
+ *
  * Revision 1.1  2001/03/11 00:29:39  steve
  *  Add the vvp engine to cvs.
  *