From f52356e8c8ea93cc050a64418c663fa171016352 Mon Sep 17 00:00:00 2001
From: "hyunghwan.chung" <hyunghwan.chung@c9d47f8d-4fed-4a2f-8cad-691f5fbe3904>
Date: Thu, 15 Oct 2015 14:40:08 +0000
Subject: [PATCH] added more code for process scheduling

---
 stix/kernel/Apex.st     |  70 +++++++++-----
 stix/kernel/Context.st  | 186 +++++++++++++++++++++++++++++++++++
 stix/kernel/Process.st  |  80 +++++++++++++++
 stix/kernel/Stix.st     | 210 +++++++---------------------------------
 stix/kernel/test-005.st |   2 +
 stix/lib/exec.c         | 151 +++++++++++++++--------------
 stix/lib/gc.c           |   2 +
 stix/lib/ignite.c       |  17 +++-
 stix/lib/proc.c         |  15 ++-
 stix/lib/stix.c         |  13 +++
 stix/lib/stix.h         |  25 ++++-
 11 files changed, 499 insertions(+), 272 deletions(-)
 create mode 100644 stix/kernel/Context.st
 create mode 100644 stix/kernel/Process.st

diff --git a/stix/kernel/Apex.st b/stix/kernel/Apex.st
index f63723f..0da1317 100644
--- a/stix/kernel/Apex.st
+++ b/stix/kernel/Apex.st
@@ -7,12 +7,12 @@
 
 	#method(#class) dump
 	{
-		<primitive: #dump>
+		<primitive: #_dump>
 	}
 
 	#method dump
 	{
-		<primitive: #dump>
+		<primitive: #_dump>
 	}
 
 	## -------------------------------------------------------
@@ -31,16 +31,39 @@
 	## -------------------------------------------------------
 	## -------------------------------------------------------
 
+	#method(#class) basicNew
+	{
+		<primitive: #_basic_new>
+		self primitiveFailed.
+	}
+
+	#method(#class) basicNew: anInteger
+	{
+		<primitive: #_basic_new_with_size>
+		self primitiveFailed.
+	}
+
 	#method(#class) new
 	{
-		<primitive: #new>
-		self primitiveFailed.
+		| x |
+		x := self basicNew.
+		x initialize. "TODO: assess if it's good to call 'initialize' from new."
+		^x.
 	}
 
 	#method(#class) new: anInteger
 	{
-		<primitive: #newWithSize>
-		self primitiveFailed.
+		| x |
+		x := self basicNew: anInteger.
+		x initialize. "TODO: assess if it's good to call 'initialize' from new."
+		^x.
+	}
+
+	#method initialize
+	{
+		"a subclass may override this method."
+		
+		^self.
 	}
 
 	## -------------------------------------------------------
@@ -48,12 +71,12 @@
 
 	#method class
 	{
-		<primitive: #class>
+		<primitive: #_class>
 	}
 
 	#method(#class) class
 	{
-		<primitive: #class>
+		<primitive: #_class>
 		^Class
 	}
 
@@ -62,37 +85,38 @@
 
 	#method basicSize
 	{
-		<primitive: #basicSize>
-		^0
+		<primitive: #_basic_size>
+		self primitiveFailed.
+	}
+
+	#method(#class) basicSize
+	{
+		<primitive: #_basic_size>
+		self primitiveFailed.
 	}
 
 	#method basicAt: anInteger
 	{
-		<primitive: #basicAt>
+		<primitive: #_basic_at>
 		self error: 'out of range'.
 	}
 
 	#method basicAt: anInteger put: anObject
 	{
-		<primitive: #basicAtPut>
+		<primitive: #_basic_at_put>
 		self error: 'out of range'.
 	}
 
-	#method(#class) basicSize
-	{
-		<primitive: #basicSize>
-		^0
-	}
 
 	#method(#class) basicAt: anInteger
 	{
-		<primitive: #basicAt>
+		<primitive: #_basic_at>
 		self error: 'out of range'.
 	}
 
 	#method(#class) basicAt: anInteger put: anObject
 	{
-		<primitive: #basicAtPut>
+		<primitive: #_basic_at_put>
 		self error: 'out of range'.
 	}
 
@@ -103,12 +127,12 @@
 	{
 		"check if the receiver is identical to anObject.
 		 this doesn't compare the contents"
-		<primitive: #identical>
+		<primitive: #_identical>
 	}
 
 	#method ~~ anObject
 	{
-		<primitive: #notIdentical>
+		<primitive: #_not_identical>
 		^(self == anObject) not.
 	}
 
@@ -116,12 +140,12 @@
 	{
 		"check if the receiver is identical to anObject.
 		 this doesn't compare the contents"
-		<primitive: #identical>
+		<primitive: #_identical>
 	}
 
 	#method(#class) ~~ anObject
 	{
-		<primitive: #notIdentical>
+		<primitive: #_not_identical>
 		^(self == anObject) not.
 	}
 
diff --git a/stix/kernel/Context.st b/stix/kernel/Context.st
new file mode 100644
index 0000000..6cc6c39
--- /dev/null
+++ b/stix/kernel/Context.st
@@ -0,0 +1,186 @@
+#class(#pointer) Context(Apex)
+{
+}
+
+#class(#pointer) MethodContext(Context)
+{
+	#dcl sender ip sp ntmprs method receiver home origin.
+
+	#method pc
+	{
+		^ip
+	}
+
+	#method pc: anInteger
+	{
+		ip := anInteger.
+		"sp := sp - 1."  "whould this always work??? "
+	}
+
+	#method sp
+	{
+		^sp.
+
+	}
+	#method sp: anInteger
+	{
+		sp := anInteger.
+	}
+
+	#method pc: aPC sp: aSP
+	{
+		ip := aPC.
+		sp := aSP.
+		##sp := sp - 1.
+	}
+}
+
+#class(#pointer) BlockContext(Context)
+{
+	#dcl caller ip sp ntmprs nargs source  home origin.
+
+	#method fork
+	{
+		"crate a new process in the runnable state"
+## TODO
+	}
+
+	#method newProcess
+	{
+		"create a new process in the suspended state"
+## TODO
+	}
+
+	#method newProcessWith: anArray
+	{
+		"create a new process in the suspended state passing the elements
+		 of anArray as block arguments"
+## TODO
+	}
+
+	#method value
+	{
+		<primitive: #_block_value>
+	}
+
+	#method value: a 
+	{
+		<primitive: #_block_value>
+	}
+
+	#method value: a value: b
+	{
+		<primitive: #_block_value>
+	}
+
+	#method value: a value: b value: c
+	{
+		<primitive: #_block_value>
+	}
+
+	#method ifTrue: aBlock
+	{
+		^(self value) ifTrue: aBlock.
+	}
+
+	#method ifFalse: aBlock
+	{
+		^(self value) ifFalse: aBlock.
+	}
+
+	#method ifTrue: trueBlock ifFalse: falseBlock
+	{
+		^(self value) ifTrue: trueBlock ifFalse: falseBlock
+	}
+
+	#method whileTrue: aBlock
+	{
+## http://stackoverflow.com/questions/2500483/is-there-a-way-in-a-message-only-language-to-define-a-whiletrue-message-without
+
+## ----------------------------------------------------------------------------
+
+##		^(self value) ifTrue: [aBlock value. self whileTrue: aBlock].
+
+## ----------------------------------------------------------------------------
+
+		## less block context before whileTrue: is recursively sent.
+		## whileTrue: is sent in a method context.
+##		(self value) ifFalse: [^nil].
+##		aBlock value. 
+##		self whileTrue: aBlock.
+
+## ----------------------------------------------------------------------------
+
+## ----------------------------------------------------------------------------
+		| pc sp xsp |
+
+		sp := thisContext sp.
+		sp := sp - 1. "decrement sp by 1 becuase thisContext pushed above affects the sp method"
+		pc := thisContext pc.
+		self value ifFalse: [ ^nil "^self" ].
+		aBlock value.
+		##thisContext pc: pc - 3 sp: sp.
+		##thisContext pc: pc + 2 sp: sp.   
+		thisContext pc: pc + 1 sp: sp.   
+		## this +2 or - 3 above is dependent on the byte code instruction size used for 'store'  
+		## +2 to skip STORE_INTO_TEMP(pc) and POP_STACKTOP.
+		## TODO: make it independent of the byte code size 
+
+## ----------------------------------------------------------------------------
+
+##        #<label>:
+##		thisContext pc: #<label> sp: sp.
+##
+##		| pc |
+##		pc := thisContext pc.
+##		^self value ifTrue: [aBlock value. thisContext pc: pc]
+
+## ----------------------------------------------------------------------------
+
+##		self value ifTrue: [ aBlock value. thisContext restart. ].
+	}
+
+	#method pc
+	{
+		^ip
+	}
+
+	#method pc: anInteger
+	{
+		ip := anInteger.
+	}
+	
+	#method sp
+	{
+		^sp
+	}
+
+	#method sp: anInteger
+	{
+		sp := anInteger.
+	}
+
+	#method restart
+	{
+		ip := source pc.
+	}
+
+
+
+	"------ TODO: -------------------------------------"
+	#method on: anError do: anExceptionBlock
+	{
+		"TODO: handle if anError is an ErrorSet .."
+	}
+
+	#method ensure: aBlock
+	{
+	}
+
+	#method ifCurtailed: aBlock
+	{
+	}
+
+	"------ TODO: -------------------------------------"
+}
+
diff --git a/stix/kernel/Process.st b/stix/kernel/Process.st
new file mode 100644
index 0000000..4137802
--- /dev/null
+++ b/stix/kernel/Process.st
@@ -0,0 +1,80 @@
+#class(#pointer) Process(Object)
+{
+	#dcl sp state prev next.
+
+	#method prev
+	{
+		^self.prev.
+	}
+
+	#method next
+	{
+		^self.next.
+	}
+
+	#method next: aProcess
+	{
+		self.next := aProcess.
+	}
+
+	#method prev: aProcess
+	{
+		self.prev := aProcess.
+	}
+}
+
+#class ProcessScheduler(Object)
+{
+	#dcl tally head tail active.
+
+	#method new
+	{
+		"instantiation is not allowed"
+		^nil. "TODO: raise an exception"
+	}
+
+	#method activeProcess
+	{
+		^self.active.
+	}
+
+	#method add: aProcess
+	{
+		<primitive: #_scheduler_add>
+
+		(self.tally = 0)
+			ifTrue: [
+				self.head := aProcess.
+				self.tail := aProcess.
+				self.tally := 1.
+			]
+			ifFalse: [
+				aProcess next: self.head.
+				self.head prev: aProcess.
+				self.head := aProcess.
+				self.tally := self.tally + 1.
+			].
+	}
+
+	#method remove: aProcess
+	{
+		"<primitive: #_scheduler_remove>"
+
+"TODO: "
+
+	}
+
+	"
+	#method yield
+	{
+		<primitive: #processYield>
+		self primitiveFailed
+	}
+
+	#method enter: aContext
+	{
+		<primitive: #processEnter>
+		self primitiveFailed
+	}
+	"
+}
diff --git a/stix/kernel/Stix.st b/stix/kernel/Stix.st
index bc0a5fa..b8f314b 100644
--- a/stix/kernel/Stix.st
+++ b/stix/kernel/Stix.st
@@ -29,41 +29,61 @@
 
 #class Number(Magnitude)
 {
-	#method add: aNumber
-	{
-		<primitive: #integerAdd>
-	}
-
 	#method + aNumber
 	{
-		<primitive: #integerAdd>
+		<primitive: #_integer_add>
+		self primitiveFailed.
 	}
 
 	#method - aNumber
 	{
-		<primitive: #integerSub>
+		<primitive: #_integer_sub>
+		self primitiveFailed.
 	}
 
 	#method * aNumber
 	{
-		<primitive: #integerMul>
+		<primitive: #_integer_mul>
+		self primitiveFailed.
 	}
 
 	#method = aNumber
 	{
-		<primitive: #integerEQ>
+		<primitive: #_integer_eq>
+		self primitiveFailed.
+	}
+
+	#method ~= aNumber
+	{
+		<primitive: #_integer_ne>
+		self primitiveFailed.
 	}
 
 	#method < aNumber
 	{
-		<primitive: #integerLT>
+		<primitive: #_integer_lt>
+		self primitiveFailed.
 	}
 
 	#method > aNumber
 	{
-		<primitive: #integerGT>
+		<primitive: #_integer_gt>
+		self primitiveFailed.
 	}
 
+	#method <= aNumber
+	{
+		<primitive: #_integer_le>
+		self primitiveFailed.
+	}
+
+	#method >= aNumber
+	{
+		<primitive: #_integer_ge>
+		self primitiveFailed.
+	}
+
+
 
 	#method to: end by: step do: aBlock
 	{
@@ -100,169 +120,13 @@
 #include 'Collection-Array.st'.
 #include 'Collection-Set.st'.
 
-
-#class(#pointer) Context(Apex)
-{
-}
-
-#class(#pointer) MethodContext(Context)
-{
-	#dcl sender ip sp ntmprs method receiver home origin.
-
-	#method pc
-	{
-		^ip
-	}
-
-	#method pc: anInteger
-	{
-		ip := anInteger.
-		"sp := sp - 1."  "whould this always work??? "
-	}
-
-	#method sp
-	{
-		^sp.
-
-	}
-	#method sp: anInteger
-	{
-		sp := anInteger.
-	}
-
-	#method pc: aPC sp: aSP
-	{
-		ip := aPC.
-		sp := aSP.
-		##sp := sp - 1.
-	}
-}
-
-#class(#pointer) BlockContext(Context)
-{
-	#dcl caller ip sp ntmprs nargs source  home origin.
-
-	#method value
-	{
-		<primitive: #blockValue>
-	}
-
-	#method value: a 
-	{
-		<primitive: #blockValue>
-	}
-
-	#method value: a value: b
-	{
-		<primitive: #blockValue>
-	}
-
-	#method value: a value: b value: c
-	{
-		<primitive: #blockValue>
-	}
-
-	#method whileTrue: aBlock
-	{
-## http://stackoverflow.com/questions/2500483/is-there-a-way-in-a-message-only-language-to-define-a-whiletrue-message-without
-
-## ----------------------------------------------------------------------------
-
-##		^(self value) ifTrue: [aBlock value. self whileTrue: aBlock].
-
-## ----------------------------------------------------------------------------
-
-		## less block context before whileTrue: is recursively sent.
-		## whileTrue: is sent in a method context.
-##		(self value) ifFalse: [^nil].
-##		aBlock value. 
-##		self whileTrue: aBlock.
-
-## ----------------------------------------------------------------------------
-
-## ----------------------------------------------------------------------------
-		| pc sp xsp |
-
-		sp := thisContext sp.
-		sp := sp - 1. "decrement sp by 1 becuase thisContext pushed above affects the sp method"
-		pc := thisContext pc.
-		self value ifFalse: [ ^nil "^self" ].
-		aBlock value.
-		##thisContext pc: pc - 3 sp: sp.
-		##thisContext pc: pc + 2 sp: sp.   
-		thisContext pc: pc + 1 sp: sp.   
-		## this +2 or - 3 above is dependent on the byte code instruction size used for 'store'  
-		## +2 to skip STORE_INTO_TEMP(pc) and POP_STACKTOP.
-		## TODO: make it independent of the byte code size 
-
-## ----------------------------------------------------------------------------
-
-##        #<label>:
-##		thisContext pc: #<label> sp: sp.
-##
-##		| pc |
-##		pc := thisContext pc.
-##		^self value ifTrue: [aBlock value. thisContext pc: pc]
-
-## ----------------------------------------------------------------------------
-
-##		self value ifTrue: [ aBlock value. thisContext restart. ].
-	}
-
-	#method pc
-	{
-		^ip
-	}
-
-	#method pc: anInteger
-	{
-		ip := anInteger.
-	}
-	
-	#method sp
-	{
-		^sp
-	}
-
-	#method sp: anInteger
-	{
-		sp := anInteger.
-	}
-
-	#method restart
-	{
-		ip := source pc.
-	}
-
-
-
-	"------ TODO: -------------------------------------"
-	#method on: anError do: anExceptionBlock
-	{
-		"TODO: handle if anError is an ErrorSet .."
-	}
-
-	#method ensure: aBlock
-	{
-	}
-
-	#method ifCurtailed: aBlock
-	{
-	}
-
-	"------ TODO: -------------------------------------"
-}
-
 #class(#pointer) CompiledMethod(Object)
 {
 	#dcl owner preamble preamble_data_1 preamble_data_2 ntmprs nargs code source.
 }
 
-#class(#pointer) Process(Object)
-{
-	#dcl state.
-}
-
+#include 'Context.st'.
+#include 'Process.st'.
 
 #class FFI(Object)
 {
@@ -313,23 +177,23 @@ f isNil ifTrue: [ self error: 'No such function' ].
 
 	#method privateOpen: aString
 	{
-		<primitive: #ffiOpen>
+		<primitive: #_ffi_open>
 		^nil. ## TODO: Error signal: 'can not open'
 	}
 
 	#method privateClose: aHandle
 	{
-		<primitive: #ffiClose>
+		<primitive: #_ffi_close>
 	}
 
 	#method privateCall: aSymbol withSig: aString withArgs: anArray
 	{
-		<primitive: #ffiCall>
+		<primitive: #_ffi_call>
 	}
 
 	#method privateGetSymbol: aString in: aHandle
 	{
-		<primitive: #ffiGetSym>
+		<primitive: #_ffi_getsym>
 		^nil.
 	}
 }
diff --git a/stix/kernel/test-005.st b/stix/kernel/test-005.st
index 7b791f2..41e72e7 100644
--- a/stix/kernel/test-005.st
+++ b/stix/kernel/test-005.st
@@ -240,9 +240,11 @@
 		## ffi call: #puts withSig: 'i|s' withArgs: #('hello world').
 		ffi close.
 "
+
 		self abc.
 		self abc.
 		self abc.
+
 "
 		FFI isNil dump.
 		FFI notNil dump.
diff --git a/stix/lib/exec.c b/stix/lib/exec.c
index 7f0c60a..fced1ba 100644
--- a/stix/lib/exec.c
+++ b/stix/lib/exec.c
@@ -334,7 +334,6 @@ static int activate_initial_context (stix_t* stix, const stix_ucs_t* objname, co
 	 *    push Stix
 	 *    send #main
 	 */
-
 	stix_oop_context_t ctx;
 	stix_oop_association_t ass;
 	stix_oop_method_t mth;
@@ -364,7 +363,7 @@ TODO: overcome this problem
 	/* the initial context starts the life of the entire VM
 	 * and is not really worked on except that it is used to call the
 	 * initial method. so it doesn't really require any extra stack space.
-	 * TODO: verify my theory above is true */
+	 * TODO: verify this theory of mine. */
 	stix->ip = 0;
 	stix->sp = -1;
 
@@ -385,7 +384,7 @@ TODO: overcome this problem
 
 
 /* ------------------------------------------------------------------------- */
-static int primitive_dump (stix_t* stix, stix_ooi_t nargs)
+static int prim_dump (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_ooi_t i;
 
@@ -406,7 +405,7 @@ static int primitive_dump (stix_t* stix, stix_ooi_t nargs)
 	return 1; /* success */
 }
 
-static int primitive_identical (stix_t* stix, stix_ooi_t nargs)
+static int prim_identical (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_oop_t rcv, arg, b;
 
@@ -422,7 +421,7 @@ static int primitive_identical (stix_t* stix, stix_ooi_t nargs)
 	return 1;
 }
 
-static int primitive_not_identical (stix_t* stix, stix_ooi_t nargs)
+static int prim_not_identical (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_oop_t rcv, arg, b;
 
@@ -438,7 +437,7 @@ static int primitive_not_identical (stix_t* stix, stix_ooi_t nargs)
 	return 1;
 }
 
-static int primitive_class (stix_t* stix, stix_ooi_t nargs)
+static int prim_class (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_oop_t rcv, c;
 
@@ -449,7 +448,7 @@ static int primitive_class (stix_t* stix, stix_ooi_t nargs)
 	return 1; /* success */
 }
 
-static int primitive_new (stix_t* stix, stix_ooi_t nargs)
+static int prim_basic_new (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_oop_t rcv, obj;
 
@@ -471,7 +470,7 @@ static int primitive_new (stix_t* stix, stix_ooi_t nargs)
 	return 1; /* success */
 }
 
-static int primitive_new_with_size (stix_t* stix, stix_ooi_t nargs)
+static int prim_basic_new_with_size (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_oop_t rcv, szoop, obj;
 	stix_oow_t size;
@@ -515,7 +514,7 @@ static int primitive_new_with_size (stix_t* stix, stix_ooi_t nargs)
 	return 1; /* success */
 }
 
-static int primitive_basic_size (stix_t* stix, stix_ooi_t nargs)
+static int prim_basic_size (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_oop_t rcv;
 	STIX_ASSERT (nargs == 0);
@@ -526,7 +525,7 @@ static int primitive_basic_size (stix_t* stix, stix_ooi_t nargs)
 	return 1;
 }
 
-static int primitive_basic_at (stix_t* stix, stix_ooi_t nargs)
+static int prim_basic_at (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_oop_t rcv, pos, v;
 	stix_ooi_t idx;
@@ -587,7 +586,7 @@ static int primitive_basic_at (stix_t* stix, stix_ooi_t nargs)
 	return 1;
 }
 
-static int primitive_basic_at_put (stix_t* stix, stix_ooi_t nargs)
+static int prim_basic_at_put (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_oop_t rcv, pos, val;
 	stix_ooi_t idx;
@@ -670,7 +669,7 @@ static int primitive_basic_at_put (stix_t* stix, stix_ooi_t nargs)
 	return 1;
 }
 
-static int primitive_block_value (stix_t* stix, stix_ooi_t nargs)
+static int prim_block_value (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_oop_context_t blkctx, org_blkctx;
 	stix_ooi_t local_ntmprs, i;
@@ -772,7 +771,7 @@ printf ("<<ENTERING BLOCK>>\n");
 	return 1;
 }
 
-static int primitive_integer_add (stix_t* stix, stix_ooi_t nargs)
+static int prim_integer_add (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_ooi_t tmp;
 	stix_oop_t rcv, arg;
@@ -796,7 +795,7 @@ static int primitive_integer_add (stix_t* stix, stix_ooi_t nargs)
 	return 0;
 }
 
-static int primitive_integer_sub (stix_t* stix, stix_ooi_t nargs)
+static int prim_integer_sub (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_ooi_t tmp;
 	stix_oop_t rcv, arg;
@@ -820,7 +819,7 @@ static int primitive_integer_sub (stix_t* stix, stix_ooi_t nargs)
 	return 0;
 }
 
-static int primitive_integer_mul (stix_t* stix, stix_ooi_t nargs)
+static int prim_integer_mul (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_ooi_t tmp;
 	stix_oop_t rcv, arg;
@@ -844,7 +843,7 @@ static int primitive_integer_mul (stix_t* stix, stix_ooi_t nargs)
 	return 0;
 }
 
-static int primitive_integer_eq (stix_t* stix, stix_ooi_t nargs)
+static int prim_integer_eq (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_oop_t rcv, arg;
 
@@ -872,7 +871,7 @@ static int primitive_integer_eq (stix_t* stix, stix_ooi_t nargs)
 	return 0;
 }
 
-static int primitive_integer_ne (stix_t* stix, stix_ooi_t nargs)
+static int prim_integer_ne (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_oop_t rcv, arg;
 
@@ -899,7 +898,7 @@ static int primitive_integer_ne (stix_t* stix, stix_ooi_t nargs)
 /* TODO: handle LargeInteger */
 	return 0;
 }
-static int primitive_integer_lt (stix_t* stix, stix_ooi_t nargs)
+static int prim_integer_lt (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_oop_t rcv, arg;
 
@@ -927,7 +926,7 @@ static int primitive_integer_lt (stix_t* stix, stix_ooi_t nargs)
 	return 0;
 }
 
-static int primitive_integer_gt (stix_t* stix, stix_ooi_t nargs)
+static int prim_integer_gt (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_oop_t rcv, arg;
 
@@ -955,7 +954,7 @@ static int primitive_integer_gt (stix_t* stix, stix_ooi_t nargs)
 	return 0;
 }
 
-static int primitive_integer_le (stix_t* stix, stix_ooi_t nargs)
+static int prim_integer_le (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_oop_t rcv, arg;
 
@@ -983,7 +982,7 @@ static int primitive_integer_le (stix_t* stix, stix_ooi_t nargs)
 	return 0;
 }
 
-static int primitive_integer_ge (stix_t* stix, stix_ooi_t nargs)
+static int prim_integer_ge (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_oop_t rcv, arg;
 
@@ -1011,7 +1010,18 @@ static int primitive_integer_ge (stix_t* stix, stix_ooi_t nargs)
 	return 0;
 }
 
-static int primitive_ffi_open (stix_t* stix, stix_ooi_t nargs)
+static int prim_scheduler_add (stix_t* stix, stix_ooi_t nargs)
+{
+	return 0;
+}
+
+static int prim_scheduler_remove (stix_t* stix, stix_ooi_t nargs)
+{
+	return 0;
+}
+
+
+static int prim_ffi_open (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_oop_t rcv, arg;
 	void* handle;
@@ -1049,7 +1059,7 @@ static int primitive_ffi_open (stix_t* stix, stix_ooi_t nargs)
 	return 1;
 }
 
-static int primitive_ffi_close (stix_t* stix, stix_ooi_t nargs)
+static int prim_ffi_close (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_oop_t rcv, arg;
 	void* handle;
@@ -1074,7 +1084,7 @@ static int primitive_ffi_close (stix_t* stix, stix_ooi_t nargs)
 	return 1;
 }
 
-static int primitive_ffi_call (stix_t* stix, stix_ooi_t nargs)
+static int prim_ffi_call (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_oop_t rcv, fun, sig, args;
 
@@ -1243,7 +1253,7 @@ printf ("CALL ERROR %d %d\n", dcGetError (dc), DC_ERROR_UNSUPPORTED_MODE);
 	return 1;
 }
 
-static int primitive_ffi_getsym (stix_t* stix, stix_ooi_t nargs)
+static int prim_ffi_getsym (stix_t* stix, stix_ooi_t nargs)
 {
 	stix_oop_t rcv, hnd, fun;
 	void* sym;
@@ -1286,43 +1296,47 @@ printf ("wrong function name...\n");
 
 
 
-struct primitive_t
+struct prim_t
 {
-	stix_ooi_t          nargs; /* expected number of arguments */
+	stix_ooi_t          nargs;   /* expected number of arguments */
 	stix_prim_impl_t    handler;
-	const char*         name; /* the name is supposed to be 7-bit ascii only */
+	const char*         name;    /* the name is supposed to be 7-bit ascii only */
 };
-typedef struct primitive_t primitive_t;
+typedef struct prim_t prim_t;
 
-static primitive_t primitives[] =
+static prim_t primitives[] =
 {
-	{  -1,   primitive_dump,                 "dump"          },
-	{   1,   primitive_identical,            "identical"     },
-	{   1,   primitive_not_identical,        "notIdentical"  },
-	{   0,   primitive_class,                "class"         },
+	{  -1,   prim_dump,                 "_dump"                },
+	{   1,   prim_identical,            "_identical"           },
+	{   1,   prim_not_identical,        "_not_identical"       },
+	{   0,   prim_class,                "_class"               },
 
-	{   0,   primitive_new,                  "new"           },
-	{   1,   primitive_new_with_size,        "newWithSize"   },
-	{   0,   primitive_basic_size,           "basicSize"     },
+	{   0,   prim_basic_new,            "_basic_new"           },
+	{   1,   prim_basic_new_with_size,  "_basic_new_with_size" },
+	{   0,   prim_basic_size,           "_basic_size"          },
 
-	{   1,   primitive_basic_at,             "basicAt"       },
-	{   2,   primitive_basic_at_put,         "basicAtPut"    },
+	{   1,   prim_basic_at,             "_basic_at"            },
+	{   2,   prim_basic_at_put,         "_basic_at_put"        },
 
-	{  -1,   primitive_block_value,          "blockValue"    },
-	{   1,   primitive_integer_add,          "integerAdd"    },
-	{   1,   primitive_integer_sub,          "integerSub"    },
-	{   1,   primitive_integer_mul,          "integerMul"    },
-	{   1,   primitive_integer_eq,           "integerEQ"     },
-	{   1,   primitive_integer_ne,           "integerNE"     },
-	{   1,   primitive_integer_lt,           "integerLT"     },
-	{   1,   primitive_integer_gt,           "integerGT"     },
-	{   1,   primitive_integer_le,           "integerLE"     },
-	{   1,   primitive_integer_ge,           "integerGE"     },
+	{  -1,   prim_block_value,          "_block_value"         },
 
-	{   1,   primitive_ffi_open,             "ffiOpen"       },
-	{   1,   primitive_ffi_close,            "ffiClose"      },
-	{   2,   primitive_ffi_getsym,           "ffiGetSym"     },
-	{   3,   primitive_ffi_call,             "ffiCall"       }
+	{   1,   prim_integer_add,          "_integer_add"         },
+	{   1,   prim_integer_sub,          "_integer_sub"         },
+	{   1,   prim_integer_mul,          "_integer_mul"         },
+	{   1,   prim_integer_eq,           "_integer_eq"          },
+	{   1,   prim_integer_ne,           "_integer_ne"          },
+	{   1,   prim_integer_lt,           "_integer_lt"          },
+	{   1,   prim_integer_gt,           "_integer_gt"          },
+	{   1,   prim_integer_le,           "_integer_le"          },
+	{   1,   prim_integer_ge,           "_integer_ge"          },
+
+	{   1,   prim_scheduler_add,        "_scheduler_add"       },
+	{   1,   prim_scheduler_remove,     "_scheduler_remove"    },
+
+	{   1,   prim_ffi_open,             "_ffi_open"            },
+	{   1,   prim_ffi_close,            "_ffi_close"           },
+	{   2,   prim_ffi_getsym,           "_ffi_getsym"          },
+	{   3,   prim_ffi_call,             "_ffi_call"            }
 	
 };
 
@@ -1342,14 +1356,7 @@ int stix_getprimno (stix_t* stix, const stix_ucs_t* name)
 	return -1;
 }
 
-struct stix_prim_mod_data_t 
-{
-	void* handle;
-	stix_prim_mod_t mod;
-};
-typedef struct stix_prim_mod_data_t stix_prim_mod_data_t;
-
-static stix_prim_impl_t query_primitive_module (stix_t* stix, const stix_uch_t* name, stix_oow_t len)
+static stix_prim_impl_t query_prim_module (stix_t* stix, const stix_uch_t* name, stix_oow_t len)
 {
 	stix_rbt_pair_t* pair;
 	stix_prim_mod_data_t* mdp;
@@ -1396,6 +1403,8 @@ static stix_prim_impl_t query_primitive_module (stix_t* stix, const stix_uch_t*
 #if defined(STIX_ENABLE_STATIC_MODULE)
 		/* attempt to find a statically linked module */
 
+/*TODO: CHANGE THIS PART */
+
 		/* TODO: binary search ... */
 		for (n = 0; n < STIX_COUNTOF(static_modtab); n++)
 		{
@@ -1474,18 +1483,14 @@ static stix_prim_impl_t query_primitive_module (stix_t* stix, const stix_uch_t*
 		mdp = (stix_prim_mod_data_t*)STIX_RBT_VPTR(pair);
 		if (load (stix, &mdp->mod) <= -1)
 		{
-			/* stix->errnum = STIX_ENOENT; TODO: proper error code and handling */
+			stix->errnum = STIX_ENOENT; /* TODO: proper error code and handling */
 			stix_rbt_delete (&stix->pmtable, name, mod_name_len);
 			stix->vmprim.mod_close (stix, mdp->handle);
 			return STIX_NULL;
 		}
 
-		if (!mdp->mod.query)
-		{
-			/* the module must be at fault */
-			stix->errnum = STIX_EINVAL; /* TODO: proper error code and handling */
-			return STIX_NULL;
-		}
+		/* the module loader must ensure to set a proper query handler */
+		STIX_ASSERT (mdp->mod.query != STIX_NULL);
 	}
 
 done:
@@ -2133,7 +2138,7 @@ printf ("]\n");
 						/* merge two SmallIntegers to get a full pointer */
 						handler = (stix_oow_t)STIX_OOP_TO_SMINT(newmth->preamble_data[0]) << (STIX_OOW_BITS / 2) | 
 						          (stix_oow_t)STIX_OOP_TO_SMINT(newmth->preamble_data[1]);
-						if (!handler) handler = query_primitive_module (stix, ((stix_oop_char_t)name)->slot, STIX_OBJ_GET_SIZE(name));
+						if (!handler) handler = query_prim_module (stix, ((stix_oop_char_t)name)->slot, STIX_OBJ_GET_SIZE(name));
 
 						if (handler)
 						{
@@ -2344,7 +2349,7 @@ printf ("<<<RETURNIGN TO THE INITIAL CONTEXT>>>\n");
 
 				/* the block context object created here is used
 				 * as a base object for block context activation.
-				 * primitive_block_value() clones a block 
+				 * prim_block_value() clones a block 
 				 * context and activates the cloned context.
 				 * this base block context is created with no 
 				 * stack for this reason. */
@@ -2397,7 +2402,7 @@ printf ("<<<RETURNIGN TO THE INITIAL CONTEXT>>>\n");
 
 				/* the block context object created here is used
 				 * as a base object for block context activation.
-				 * primitive_block_value() clones a block 
+				 * prim_block_value() clones a block 
 				 * context and activates the cloned context.
 				 * this base block context is created with no 
 				 * stack for this reason. */
@@ -2412,7 +2417,7 @@ printf ("<<<RETURNIGN TO THE INITIAL CONTEXT>>>\n");
 				/* [NOTE]
 				 *  blkctx->caller is left to nil. it is set to the 
 				 *  active context before it gets activated. see
-				 *  primitive_block_value().
+				 *  prim_block_value().
 				 *
 				 *  blkctx->home is set here to the active context.
 				 *  it's redundant to have them pushed to the stack
@@ -2496,6 +2501,8 @@ oops:
 
 int stix_invoke (stix_t* stix, const stix_ucs_t* objname, const stix_ucs_t* mthname)
 {
+	/*stix_oop_process_t proc;*/
+
 	if (activate_initial_context (stix, objname, mthname) <= -1) return -1;
 	return stix_execute (stix);
 }
diff --git a/stix/lib/gc.c b/stix/lib/gc.c
index a35663e..099caa8 100644
--- a/stix/lib/gc.c
+++ b/stix/lib/gc.c
@@ -285,12 +285,14 @@ void stix_gc (stix_t* stix)
 	stix->_method_context    = stix_moveoop (stix, stix->_method_context);
 	stix->_block_context     = stix_moveoop (stix, stix->_block_context);
 	stix->_process           = stix_moveoop (stix, stix->_process);
+	stix->_process_scheduler = stix_moveoop (stix, stix->_process_scheduler);
 	stix->_true_class        = stix_moveoop (stix, stix->_true_class);
 	stix->_false_class       = stix_moveoop (stix, stix->_false_class);
 	stix->_character         = stix_moveoop (stix, stix->_character);
 	stix->_small_integer     = stix_moveoop (stix, stix->_small_integer);
 
 	stix->sysdic = (stix_oop_set_t) stix_moveoop (stix, (stix_oop_t)stix->sysdic);
+	stix->scheduler = (stix_oop_process_scheduler_t) stix_moveoop (stix, (stix_oop_t)stix->scheduler);
 
 	for (i = 0; i < stix->tmp_count; i++)
 	{
diff --git a/stix/lib/ignite.c b/stix/lib/ignite.c
index 844498e..f1253eb 100644
--- a/stix/lib/ignite.c
+++ b/stix/lib/ignite.c
@@ -135,6 +135,7 @@ static int ignite_1 (stix_t* stix)
 	stix->_method_context    = alloc_kernel_class (stix, 0, STIX_CLASS_SPEC_MAKE(STIX_CONTEXT_NAMED_INSTVARS, 1, STIX_OBJ_TYPE_OOP));
 	stix->_block_context     = alloc_kernel_class (stix, 0, STIX_CLASS_SPEC_MAKE(STIX_CONTEXT_NAMED_INSTVARS, 1, STIX_OBJ_TYPE_OOP));
 	stix->_process           = alloc_kernel_class (stix, 0, STIX_CLASS_SPEC_MAKE(STIX_PROCESS_NAMED_INSTVARS, 1, STIX_OBJ_TYPE_OOP));
+	stix->_process_scheduler = alloc_kernel_class (stix, 0, STIX_CLASS_SPEC_MAKE(STIX_PROCESS_SCHEDULER_NAMED_INSTVARS, 0, STIX_OBJ_TYPE_OOP));
 	stix->_true_class        = alloc_kernel_class (stix, 0, STIX_CLASS_SPEC_MAKE(0, 0, STIX_OBJ_TYPE_OOP));
 	stix->_false_class       = alloc_kernel_class (stix, 0, STIX_CLASS_SPEC_MAKE(0, 0, STIX_OBJ_TYPE_OOP));
 	/* TOOD: what is a proper spec for Character and SmallInteger?
@@ -152,7 +153,9 @@ static int ignite_1 (stix_t* stix)
 	    !stix->_namespace         || !stix->_pool_dictionary   ||
 	    !stix->_method_dictionary || !stix->_method            || !stix->_association ||
 
-	    !stix->_method_context    || !stix->_block_context     || !stix->_process ||
+	    !stix->_method_context    || !stix->_block_context     || 
+	    !stix->_process           || !stix->_process_scheduler ||
+
 	    !stix->_true_class        || !stix->_false_class       || 
 	    !stix->_character         || !stix->_small_integer) return -1;
 
@@ -189,6 +192,10 @@ static int ignite_2 (stix_t* stix)
 	if (!tmp) return -1;
 	stix->sysdic = (stix_oop_set_t)tmp;
 
+	tmp = (stix_oop_t)stix_instantiate (stix, stix->_process_scheduler, STIX_NULL, 0);
+	if (!tmp) return -1;
+	stix->scheduler = (stix_oop_process_scheduler_t)tmp;
+
 	/* Export the system dictionary via the first class variable of the Stix class */
 	((stix_oop_class_t)stix->_apex)->slot[0] = (stix_oop_t)stix->sysdic;
 
@@ -225,6 +232,7 @@ static int ignite_3 (stix_t* stix)
 		{ 13, { 'M','e','t','h','o','d','C','o','n','t','e','x','t'              } },
 		{ 12, { 'B','l','o','c','k','C','o','n','t','e','x','t'                  } },
 		{  7, { 'P','r','o','c','e','s','s'                                      } },
+		{ 16, { 'P','r','o','c','e','s','s','S','c','h','e','d','u','l','e','r'  } },
 		{  4, { 'T','r','u','e'                                                  } },
 		{  5, { 'F','a','l','s','e'                                              } },
 		{  9, { 'C','h','a','r','a','c','t','e','r'                              } },
@@ -232,6 +240,7 @@ static int ignite_3 (stix_t* stix)
 	};
 
 	static stix_uch_t str_stix[] = { 'S','t','i','x' };
+	static stix_uch_t str_scheduler[] = { 'S', 'c', 'h', 'e', 'd', 'u', 'l', 'e', 'r' };
 
 	stix_oow_t i;
 	stix_oop_t sym;
@@ -251,10 +260,16 @@ static int ignite_3 (stix_t* stix)
 		stix_ptr++;
 	}
 
+	/* Make the system dictionary available as the global name 'Stix' */
 	sym = stix_makesymbol (stix, str_stix, 4);
 	if (!sym) return -1;
 	if (!stix_putatsysdic(stix, sym, (stix_oop_t)stix->sysdic)) return -1;
 
+	/* Make the process scheduler avaialble as the global name 'Scheduler' */
+	sym = stix_makesymbol (stix, str_scheduler, 4);
+	if (!sym) return -1;
+	if (!stix_putatsysdic(stix, sym, (stix_oop_t)stix->scheduler)) return -1;
+
 	return 0;
 }
 
diff --git a/stix/lib/proc.c b/stix/lib/proc.c
index 752fc5b..63126b7 100644
--- a/stix/lib/proc.c
+++ b/stix/lib/proc.c
@@ -27,8 +27,7 @@
 
 #include "stix-prv.h"
 
-
-stix_oop_process_t stix_makeproc (stix_t* stix)
+stix_oop_process_t stix_addnewproc (stix_t* stix)
 {
 	stix_oop_process_t proc;
 
@@ -36,6 +35,18 @@ stix_oop_process_t stix_makeproc (stix_t* stix)
 	if (!proc) return STIX_NULL;
 
 	proc->state = STIX_OOP_FROM_SMINT(0);
+	
 	STIX_ASSERT (STIX_OBJ_GET_SIZE(proc) == STIX_PROCESS_NAMED_INSTVARS + stix->option.dfl_procstk_size);
 	return proc;
 }
+
+void stix_schedproc (stix_t* stix, stix_oop_process_t proc)
+{
+	/* TODO: if scheduled, don't add */
+	/*proc->next = stix->_active_process;
+	proc->_active_process = proc;*/
+}
+
+void stix_unschedproc (stix_t* stix, stix_oop_process_t proc)
+{
+}
diff --git a/stix/lib/stix.c b/stix/lib/stix.c
index 7d881d4..9501f63 100644
--- a/stix/lib/stix.c
+++ b/stix/lib/stix.c
@@ -80,6 +80,18 @@ oops:
 	return -1;
 }
 
+static stix_rbt_walk_t unload_primitive_module (stix_rbt_t* rbt, stix_rbt_pair_t* pair, void* ctx)
+{
+	stix_t* stix = (stix_t*)ctx;
+	stix_prim_mod_data_t* md;
+
+	md = STIX_RBT_VPTR(pair);
+	if (md->mod.unload) md->mod.unload (stix, &md->mod);
+	if (md->handle) stix->vmprim.mod_close (stix, md->handle);
+
+	return STIX_RBT_WALK_FORWARD;
+}
+
 void stix_fini (stix_t* stix)
 {
 	stix_cb_t* cb;
@@ -89,6 +101,7 @@ void stix_fini (stix_t* stix)
 		if (cb->fini) cb->fini (stix);
 	}
 
+	stix_rbt_walk (&stix->pmtable, unload_primitive_module, stix);
 	stix_rbt_fini (&stix->pmtable);
 
 	stix_killheap (stix, stix->newheap);
diff --git a/stix/lib/stix.h b/stix/lib/stix.h
index 1138bb3..ce5103a 100644
--- a/stix/lib/stix.h
+++ b/stix/lib/stix.h
@@ -467,14 +467,28 @@ struct stix_context_t
 	stix_oop_t         slot[1]; /* stack */
 };
 
+#define STIX_PROCESS_SCHEDULER_NAMED_INSTVARS 4
+typedef struct stix_process_scheduler_t stix_process_scheduler_t;
+typedef struct stix_process_scheduler_t* stix_oop_process_scheduler_t;
+struct stix_process_scheduler_t
+{
+	STIX_OBJ_HEADER;
+	stix_oop_t tally;
+	stix_oop_t head;
+	stix_oop_t tail;
+	stix_oop_t active;
+};
 
-#define STIX_PROCESS_NAMED_INSTVARS 1
+#define STIX_PROCESS_NAMED_INSTVARS 4
 typedef struct stix_process_t stix_process_t;
 typedef struct stix_process_t* stix_oop_process_t;
 struct stix_process_t
 {
 	STIX_OBJ_HEADER;
+	stix_oop_t  sp;
 	stix_oop_t  state;
+	stix_oop_t  prev;
+	stix_oop_t  next;
 
 	/* == variable indexed part == */
 	stix_oop_t slot[1]; /* process stack */
@@ -586,6 +600,13 @@ struct stix_prim_mod_t
 	void*                  ctx;
 };
 
+struct stix_prim_mod_data_t 
+{
+	void* handle;
+	stix_prim_mod_t mod;
+};
+typedef struct stix_prim_mod_data_t stix_prim_mod_data_t;
+
 /* =========================================================================
  * STIX VM
  * ========================================================================= */
@@ -644,6 +665,7 @@ struct stix_t
 	stix_oop_t _method_context; /* MethodContext */
 	stix_oop_t _block_context; /* BlockContext */
 	stix_oop_t _process; /* Process */
+	stix_oop_t _process_scheduler; /* ProcessScheduler */
 	stix_oop_t _true_class; /* True */
 	stix_oop_t _false_class; /* False */
 	stix_oop_t _character; /* Character */
@@ -653,6 +675,7 @@ struct stix_t
 
 	stix_oop_set_t symtab; /* system-wide symbol table. instance of SymbolSet */
 	stix_oop_set_t sysdic; /* system dictionary. instance of SystemDictionary */
+	stix_oop_process_scheduler_t scheduler; /* instance of ProcessScheduler */
 
 	stix_oop_t* tmp_stack[256]; /* stack for temporaries */
 	stix_oow_t tmp_count;