From FEDORA_PATCHES Mon Sep 17 00:00:00 2001

From: Fedora GDB patches <invalid@email.com>

Date: Fri, 27 Oct 2017 21:07:50 +0200

Subject: gdb-python-gil.patch

;; Fix Python GIL with gdb.execute("continue") (Phil Muldoon, BZ 1116957).

;;=push

diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi

--- a/gdb/doc/python.texi

+++ b/gdb/doc/python.texi

@@ -232,6 +232,14 @@ returned as a string.  The default is @code{False}, in which case the

 return value is @code{None}.  If @var{to_string} is @code{True}, the

 @value{GDBN} virtual terminal will be temporarily set to unlimited width

 and height, and its pagination will be disabled; @pxref{Screen Size}.

+

+The @var{release_gil} flag specifies whether @value{GDBN} ought to

+release the Python GIL before executing the command.  This is useful

+in multi-threaded Python programs where by default the Python

+interpreter will acquire the GIL and lock other threads from

+executing.  After the command has completed executing in @value{GDBN}

+the Python GIL is reacquired. This flag must be a boolean value.  If

+omitted, it defaults to @code{False}.

 @end defun

 @findex gdb.breakpoints

diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h

--- a/gdb/python/python-internal.h

+++ b/gdb/python/python-internal.h

@@ -148,6 +148,8 @@ typedef int Py_ssize_t;

 #define PyGILState_Release(ARG) ((void)(ARG))

 #define PyEval_InitThreads()

 #define PyThreadState_Swap(ARG) ((void)(ARG))

+#define PyEval_SaveThread() ((void)(ARG))

+#define PyEval_RestoreThread(ARG) ((void)(ARG))

 #define PyEval_ReleaseLock()

 #endif

diff --git a/gdb/python/python.c b/gdb/python/python.c

--- a/gdb/python/python.c

+++ b/gdb/python/python.c

@@ -556,12 +556,16 @@ execute_gdb_command (PyObject *self, PyObject *args, PyObject *kw)

 {

   const char *arg;

   PyObject *from_tty_obj = NULL, *to_string_obj = NULL;

-  int from_tty, to_string;

-  static const char *keywords[] = { "command", "from_tty", "to_string", NULL };

+  int from_tty, to_string, release_gil;

+  static const char *keywords[] = {"command", "from_tty", "to_string", "release_gil", NULL };

+  PyObject *release_gil_obj = NULL;

+  /* Initialize it just to avoid a GCC false warning.  */

+  PyThreadState *state = NULL;

-  if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "s|O!O!", keywords, &arg,

+  if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "s|O!O!O!", keywords, &arg,

 					&PyBool_Type, &from_tty_obj,

-					&PyBool_Type, &to_string_obj))

+					&PyBool_Type, &to_string_obj,

+					&PyBool_Type, &release_gil_obj))

     return NULL;

   from_tty = 0;

@@ -582,6 +586,15 @@ execute_gdb_command (PyObject *self, PyObject *args, PyObject *kw)

       to_string = cmp;

     }

+  release_gil = 0;

+  if (release_gil_obj)

+    {

+      int cmp = PyObject_IsTrue (release_gil_obj);

+      if (cmp < 0)

+	return NULL;

+      release_gil = cmp;

+    }

+

   std::string to_string_res;

   TRY

@@ -602,6 +615,13 @@ execute_gdb_command (PyObject *self, PyObject *args, PyObject *kw)

       counted_command_line lines = read_command_lines_1 (reader, 1, nullptr);

+      /* In the case of long running GDB commands, allow the user to

+	 release the Python GIL acquired by Python.  Restore the GIL

+	 after the command has completed before handing back to

+	 Python.  */

+      if (release_gil)

+	state = PyEval_SaveThread();

+

       scoped_restore save_async = make_scoped_restore (&current_ui->async, 0);

       scoped_restore save_uiout = make_scoped_restore (&current_uiout);

@@ -617,10 +637,22 @@ execute_gdb_command (PyObject *self, PyObject *args, PyObject *kw)

 							    from_tty);

       else

 	execute_control_commands (lines.get (), from_tty);

+

+      /* Reacquire the GIL if it was released earlier.  */

+      if (release_gil)

+	PyEval_RestoreThread (state);

     }

   CATCH (except, RETURN_MASK_ALL)

     {

-      GDB_PY_HANDLE_EXCEPTION (except);

+      if (except.reason < 0)

+	{

+	  /* Reacquire the GIL if it was released earlier.  */

+	  if (release_gil)

+	    PyEval_RestoreThread (state);

+

+	  gdbpy_convert_exception (except);

+	  return NULL;

+	}

     }

   END_CATCH

diff --git a/gdb/testsuite/gdb.python/py-gil-mthread.c b/gdb/testsuite/gdb.python/py-gil-mthread.c

new file mode 100644

--- /dev/null

+++ b/gdb/testsuite/gdb.python/py-gil-mthread.c

@@ -0,0 +1,13 @@

+#include <stdio.h>

+#include <unistd.h>

+

+int

+main (void)

+{

+  int i;

+  for (i = 0; i < 10; i++)

+    {

+      sleep (1); /* break-here */

+      printf ("Sleeping %d\n", i);

+    }

+}

diff --git a/gdb/testsuite/gdb.python/py-gil-mthread.exp b/gdb/testsuite/gdb.python/py-gil-mthread.exp

new file mode 100644

--- /dev/null

+++ b/gdb/testsuite/gdb.python/py-gil-mthread.exp

@@ -0,0 +1,69 @@

+# Copyright (C) 2014 Free Software Foundation, Inc.

+

+# This program is free software; you can redistribute it and/or modify

+# it under the terms of the GNU General Public License as published by

+# the Free Software Foundation; either version 3 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, see <http://www.gnu.org/licenses/>.

+

+standard_testfile .c .py

+set executable $testfile

+

+if { [prepare_for_testing $testfile.exp $executable $srcfile] } {

+    return -1

+}

+

+# Skip all tests if Python scripting is not enabled.

+if { [skip_python_tests] } { continue }

+

+if ![runto_main] {

+    return -1

+}

+

+gdb_breakpoint $srcfile:[gdb_get_line_number "break-here"] temporary

+gdb_continue_to_breakpoint "break-here" ".* break-here .*"

+

+set test "response"

+set timeout 60

+set sleeping_last -1

+set hello_last 0

+set minimal 5

+gdb_test_multiple "python exec (open ('$srcdir/$subdir/$srcfile2').read ())" $test {

+    -re "Error: unable to start thread\r\n" {

+	fail $test

+	# Not $gdb_prompt-synced!

+    }

+    -re "Sleeping (\[0-9\]+)\r\n" {

+	set n $expect_out(1,string)

+	if { $sleeping_last + 1 != $n } {

+	    fail $test

+	} else {

+	    set sleeping_last $n

+	    if { $sleeping_last >= $minimal && $hello_last >= $minimal } {

+		pass $test

+	    } else {

+		exp_continue

+	    }

+	}

+    }

+    -re "Hello \\( (\[0-9\]+) \\)\r\n" {

+	set n $expect_out(1,string)

+	if { $hello_last + 1 != $n } {

+	    fail $test

+	} else {

+	    set hello_last $n

+	    if { $sleeping_last >= $minimal && $hello_last >= $minimal } {

+		pass $test

+	    } else {

+		exp_continue

+	    }

+	}

+    }

+}

diff --git a/gdb/testsuite/gdb.python/py-gil-mthread.py b/gdb/testsuite/gdb.python/py-gil-mthread.py

new file mode 100644

--- /dev/null

+++ b/gdb/testsuite/gdb.python/py-gil-mthread.py

@@ -0,0 +1,28 @@

+try:

+   import thread

+except:

+   import _thread

+import time

+import gdb

+

+# Define a function for the thread

+def print_thread_hello():

+   count = 0

+   while count < 10:

+      time.sleep(1)

+      count += 1

+      print ("Hello ( %d )" % count)

+

+# Create a threads a continue

+try:

+   thread.start_new_thread (print_thread_hello, ())

+   gdb.execute ("continue", release_gil=True)

+except:

+   try:

+      _thread.start_new_thread (print_thread_hello, ())

+      gdb.execute ("continue", release_gil=True)

+   except:

+      print ("Error: unable to start thread")

+

+while 1:

+   pass