Diff: src/vm/thread.h

Revision:

0:14e5e829dffe

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/vm/thread.h	Wed Jul 21 12:50:41 2010 +0000
@@ -0,0 +1,88 @@
+/*
+# This file is Copyright 2007, 2009 Dean Hall.
+#
+# This file is part of the PyMite VM.
+# The PyMite VM is free software: you can redistribute it and/or modify
+# it under the terms of the GNU GENERAL PUBLIC LICENSE Version 2.
+#
+# The PyMite VM 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.
+# A copy of the GNU GENERAL PUBLIC LICENSE Version 2
+# is seen in the file COPYING in this directory.
+*/
+
+
+#ifndef __THREAD_H__
+#define __THREAD_H__
+
+
+/**
+ * \file
+ * \brief VM Thread
+ *
+ * Encapsulating a frame pointer, a root code object and thread state.
+ */
+
+
+#include "interp.h"
+
+
+ /** Frequency in Hz to switch threads */
+#define THREAD_RESCHEDULE_FREQUENCY    10
+
+
+/**
+ * Interpreter return values
+ *
+ * Used to control interpreter loop
+ * and indicate return value.
+ * Negative values indicate erroneous results.
+ * Positive values indicate "continue interpreting",
+ * but first do something special like reschedule threads
+ * or (TBD) sweep the heap.
+ */
+typedef enum PmInterpCtrl_e
+{
+    /* other erroneous exits go here with negative values */
+    INTERP_CTRL_ERR = -1,   /**< Generic error causes exit */
+    INTERP_CTRL_EXIT = 0,   /**< Normal execution exit */
+    INTERP_CTRL_CONT = 1,   /**< Continue interpreting */
+    INTERP_CTRL_RESCHED = 2 /**< Reschedule threads */
+        /* all positive values indicate "continue interpreting" */
+} PmInterpCtrl_t, *pPmInterpCtrl_t;
+
+/**
+ * Thread obj
+ *
+ */
+typedef struct PmThread_s
+{
+    /** object descriptor */
+    PmObjDesc_t od;
+
+    /** current frame pointer */
+    pPmFrame_t pframe;
+
+    /**
+     * Interpreter loop control value
+     *
+     * A positive value means continue interpreting.
+     * A zero value means normal interpreter exit.
+     * A negative value signals an error exit.
+     */
+    PmInterpCtrl_t interpctrl;
+} PmThread_t,
+ *pPmThread_t;
+
+
+/**
+ * Constructs a thread for a root frame.
+ *
+ * @param pframe Frame object as a basis for this thread.
+ * @param r_pobj Return by reference; Ptr to the newly created thread object.
+ * @return Return status
+ */
+PmReturn_t thread_new(pPmObj_t pframe, pPmObj_t *r_pobj);
+
+#endif /* __THREAD_H__ */