[RFC][patch 9/9] export threads to Python

[Thiago Jung Bauermann <bauerman at br dot ibm dot com>]

2008-04-29  Tom Tromey <tromey@redhat.com>

	* Makefile.in (python.o): Depend on inferior.h and gdbthread.h.
	* gdbthread.h (prune_threads): Declare.
	* python/python.c: Include inferior.h, gdbthread.h.
	(demand_python): Register new functions.
	(count_callback): New function.
	(struct set_thread_info): New struct.
	(update_tuple_callback): New function.
	(gdbpy_get_threads): Likewise.
	(gdbpy_get_current_thread): Likewise.
	(gdbpy_switch_to_thread): Likewise.
	* thread.c (prune_threads): No longer 'static'.  Rewrote.

Index: python-tromey.git/gdb/Makefile.in
===================================================================
--- python-tromey.git.orig/gdb/Makefile.in	2008-04-29 11:49:51.000000000 -0300
+++ python-tromey.git/gdb/Makefile.in	2008-04-29 11:55:27.000000000 -0300
@@ -3426,7 +3426,7 @@ PYTHON_CFLAGS=-fno-strict-aliasing
 python.o: $(srcdir)/python/python.c $(defs_h) $(python_h) \
 	$(command_h) $(libiberty_h) $(cli_decode_h) $(charset_h) $(top_h) \
 	$(exceptions_h) $(python_internal_h) $(version_h) $(solib_h) \
-	$(linespec_h) $(symtab_h) $(source_h)
+	$(linespec_h) $(symtab_h) $(source_h) $(inferior_h) $(gdbthread_h)
 	$(CC) -c $(INTERNAL_CFLAGS) $(PYTHON_CFLAGS) $(srcdir)/python/python.c
 python-block.o: $(srcdir)/python/block.c $(defs_h) $(block_h) $(dictionary_h) \
 	$(symtab_h) $(python_h) $(python_internal_h)
Index: python-tromey.git/gdb/gdbthread.h
===================================================================
--- python-tromey.git.orig/gdb/gdbthread.h	2008-04-29 11:47:48.000000000 -0300
+++ python-tromey.git/gdb/gdbthread.h	2008-04-29 11:54:06.000000000 -0300
@@ -110,6 +110,9 @@ extern int valid_thread_id (int thread);
 /* Search function to lookup a thread by 'pid'.  */
 extern struct thread_info *find_thread_pid (ptid_t ptid);
 
+/* Prune dead threads from the list of threads.  */
+extern void prune_threads (void);
+
 /* Iterator function to call a user-provided callback function
    once for each known thread.  */
 typedef int (*thread_callback_func) (struct thread_info *, void *);
Index: python-tromey.git/gdb/python/python.c
===================================================================
--- python-tromey.git.orig/gdb/python/python.c	2008-04-29 11:47:56.000000000 -0300
+++ python-tromey.git/gdb/python/python.c	2008-04-29 11:54:06.000000000 -0300
@@ -31,6 +31,8 @@
 #include "symtab.h"
 #include "source.h"
 #include "version.h"
+#include "inferior.h"
+#include "gdbthread.h"
 
 #include <ctype.h>
 
@@ -41,6 +43,9 @@ static PyObject *execute_gdb_command (Py
 static PyObject *gdbpy_solib_address (PyObject *, PyObject *);
 static PyObject *gdbpy_decode_line (PyObject *, PyObject *);
 static PyObject *gdbpy_find_pc_function (PyObject *, PyObject *);
+static PyObject *gdbpy_get_threads (PyObject *, PyObject *);
+static PyObject *gdbpy_get_current_thread (PyObject *, PyObject *);
+static PyObject *gdbpy_switch_to_thread (PyObject *, PyObject *);
 
 
 void
@@ -85,6 +90,13 @@ demand_python ()
 Return a tuple holding the file name (or None) and line number (or None).\n\
 Note: may later change to return an object." },
 
+	{ "get_threads", gdbpy_get_threads, METH_NOARGS,
+	  "Return a tuple holding all the valid thread IDs." },
+	{ "get_current_thread", gdbpy_get_current_thread, METH_NOARGS,
+	  "Return the thread ID of the current thread." },
+	{ "switch_to_thread", gdbpy_switch_to_thread, METH_VARARGS,
+	  "Switch to a thread, given the thread ID." },
+
 	{NULL, NULL, 0, NULL}
       };
 
@@ -474,6 +486,75 @@ gdbpy_decode_line (PyObject *self, PyObj
 
 
 
+/* Threads.  */
+
+static int
+count_callback (struct thread_info *info, void *user_data)
+{
+  int *count = (int *) user_data;
+  ++*count;
+  return 0;
+}
+
+struct set_thread_info
+{
+  PyObject *tuple;
+  int index;
+};
+
+static int
+update_tuple_callback (struct thread_info *info, void *user_data)
+{
+  struct set_thread_info *tinfo = (struct set_thread_info *) user_data;
+  PyTuple_SetItem (tinfo->tuple, tinfo->index, PyInt_FromLong (info->num));
+  ++tinfo->index;
+  return 0;
+}
+
+static PyObject *
+gdbpy_get_threads (PyObject *unused1, PyObject *unused2)
+{
+  int thread_count = 0;
+  struct set_thread_info info;
+  PyObject *result;
+
+  prune_threads ();
+  target_find_new_threads ();
+
+  iterate_over_threads (count_callback, &thread_count);
+
+  if (!thread_count)
+    Py_RETURN_NONE;
+
+  result = PyTuple_New (thread_count);
+  info.tuple = result;
+  info.index = 0;
+  iterate_over_threads (update_tuple_callback, &info);
+  return result;
+}
+
+static PyObject *
+gdbpy_get_current_thread (PyObject *unused1, PyObject *unused2)
+{
+  if (PIDGET (inferior_ptid) == 0)
+    Py_RETURN_NONE;
+  return PyInt_FromLong (pid_to_thread_id (inferior_ptid));
+}
+
+static PyObject *
+gdbpy_switch_to_thread (PyObject *self, PyObject *args)
+{
+  int id;
+  if (! PyArg_ParseTuple (args, "i", &id))
+    return NULL;
+  if (! valid_thread_id (id))
+    return PyErr_Format (PyExc_RuntimeError, "invalid thread id");
+  switch_to_thread (thread_id_to_pid (id));
+  Py_RETURN_NONE;
+}
+
+
+
 void
 _initialize_python (void)
 {
Index: python-tromey.git/gdb/thread.c
===================================================================
--- python-tromey.git.orig/gdb/thread.c	2008-04-29 11:47:48.000000000 -0300
+++ python-tromey.git/gdb/thread.c	2008-04-29 11:54:06.000000000 -0300
@@ -60,7 +60,6 @@ static int thread_alive (struct thread_i
 static void info_threads_command (char *, int);
 static void thread_apply_command (char *, int);
 static void restore_current_thread (ptid_t);
-static void prune_threads (void);
 
 void
 delete_step_resume_breakpoint (void *arg)
@@ -400,16 +399,23 @@ thread_alive (struct thread_info *tp)
   return 1;
 }
 
-static void
+void
 prune_threads (void)
 {
-  struct thread_info *tp, *next;
+  struct thread_info *tp;
+  struct thread_info **prevp = &thread_list;
 
-  for (tp = thread_list; tp; tp = next)
+  for (tp = *prevp; tp; tp = *prevp)
     {
-      next = tp->next;
+      /* If the thread has died, free it and unlink it from the list.
+	 Otherwise, advance to the next thread.  */
       if (!thread_alive (tp))
-	delete_thread (tp->ptid);
+	{
+	  (*prevp)->next = tp->next;
+	  free_thread (tp);
+	}
+      else
+	prevp = &tp->next;
     }
 }
 

-- 
-- 
[]'s
Thiago Jung Bauermann
Software Engineer
IBM Linux Technology Center