Added cancel button to the LoadingDialog

GUI/LoadingDialog.py

@@ -2,7 +2,7 @@
 
 # Form implementation generated from reading ui file 'LoadingDialog.ui'
 #
-# Created: Wed Dec  7 19:30:07 2016
+# Created: Tue Feb 21 22:38:30 2017
 #      by: PyQt5 UI code generator 5.2.1
 #
 # WARNING! All changes made in this file will be lost!
@@ -12,9 +12,9 @@
 class Ui_Dialog(object):
     def setupUi(self, Dialog):
         Dialog.setObjectName("Dialog")
-        Dialog.resize(195, 40)
-        self.gridLayout = QtWidgets.QGridLayout(Dialog)
-        self.gridLayout.setObjectName("gridLayout")
+        Dialog.resize(208, 89)
+        self.gridLayout_2 = QtWidgets.QGridLayout(Dialog)
+        self.gridLayout_2.setObjectName("gridLayout_2")
         self.horizontalLayout = QtWidgets.QHBoxLayout()
         self.horizontalLayout.setObjectName("horizontalLayout")
         spacerItem = QtWidgets.QSpacerItem(40, 20, QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Minimum)
@@ -34,7 +34,20 @@ def setupUi(self, Dialog):
         self.horizontalLayout.addWidget(self.label_StatusText)
         spacerItem1 = QtWidgets.QSpacerItem(40, 20, QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Minimum)
         self.horizontalLayout.addItem(spacerItem1)
-        self.gridLayout.addLayout(self.horizontalLayout, 0, 0, 1, 1)
+        self.gridLayout_2.addLayout(self.horizontalLayout, 0, 0, 1, 1)
+        self.widget_Cancel = QtWidgets.QWidget(Dialog)
+        self.widget_Cancel.setObjectName("widget_Cancel")
+        self.gridLayout = QtWidgets.QGridLayout(self.widget_Cancel)
+        self.gridLayout.setContentsMargins(0, 0, 0, 0)
+        self.gridLayout.setObjectName("gridLayout")
+        spacerItem2 = QtWidgets.QSpacerItem(40, 20, QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Minimum)
+        self.gridLayout.addItem(spacerItem2, 0, 0, 1, 1)
+        self.pushButton_Cancel = QtWidgets.QPushButton(self.widget_Cancel)
+        self.pushButton_Cancel.setObjectName("pushButton_Cancel")
+        self.gridLayout.addWidget(self.pushButton_Cancel, 0, 1, 1, 1)
+        spacerItem3 = QtWidgets.QSpacerItem(40, 20, QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Minimum)
+        self.gridLayout.addItem(spacerItem3, 0, 2, 1, 1)
+        self.gridLayout_2.addWidget(self.widget_Cancel, 1, 0, 1, 1)
 
         self.retranslateUi(Dialog)
         QtCore.QMetaObject.connectSlotsByName(Dialog)
@@ -43,4 +56,5 @@ def retranslateUi(self, Dialog):
         _translate = QtCore.QCoreApplication.translate
         Dialog.setWindowTitle(_translate("Dialog", "Dialog"))
         self.label_StatusText.setText(_translate("Dialog", "Processing"))
+        self.pushButton_Cancel.setText(_translate("Dialog", "Cancel"))
 

GUI/LoadingDialog.ui

@@ -6,14 +6,14 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>195</width>
-    <height>40</height>
+    <width>208</width>
+    <height>89</height>
    </rect>
   </property>
   <property name="windowTitle">
    <string>Dialog</string>
   </property>
-  <layout class="QGridLayout" name="gridLayout">
+  <layout class="QGridLayout" name="gridLayout_2">
    <item row="0" column="0">
     <layout class="QHBoxLayout" name="horizontalLayout">
      <item>
@@ -67,6 +67,45 @@
      </item>
     </layout>
    </item>
+   <item row="1" column="0">
+    <widget class="QWidget" name="widget_Cancel" native="true">
+     <layout class="QGridLayout" name="gridLayout">
+      <item row="0" column="0">
+       <spacer name="horizontalSpacer_3">
+        <property name="orientation">
+         <enum>Qt::Horizontal</enum>
+        </property>
+        <property name="sizeHint" stdset="0">
+         <size>
+          <width>40</width>
+          <height>20</height>
+         </size>
+        </property>
+       </spacer>
+      </item>
+      <item row="0" column="1">
+       <widget class="QPushButton" name="pushButton_Cancel">
+        <property name="text">
+         <string>Cancel</string>
+        </property>
+       </widget>
+      </item>
+      <item row="0" column="2">
+       <spacer name="horizontalSpacer_4">
+        <property name="orientation">
+         <enum>Qt::Horizontal</enum>
+        </property>
+        <property name="sizeHint" stdset="0">
+         <size>
+          <width>40</width>
+          <height>20</height>
+         </size>
+        </property>
+       </spacer>
+      </item>
+     </layout>
+    </widget>
+   </item>
   </layout>
  </widget>
  <resources/>

PINCE.py

@@ -845,6 +845,7 @@ def __init__(self, parent=None):
         # Check refresh_table method of FunctionsInfoWidgetForm for exemplary usage
         self.background_thread = self.BackgroundThread()
         self.background_thread.output_ready.connect(self.accept)
+        self.pushButton_Cancel.clicked.connect(self.cancel_thread)
         pince_directory = SysUtils.get_current_script_directory()
         self.movie = QMovie(pince_directory + "/media/LoadingDialog/ajax-loader.gif", QByteArray())
         self.label_Animated.setMovie(self.movie)
@@ -853,6 +854,11 @@ def __init__(self, parent=None):
         self.movie.setSpeed(100)
         self.movie.start()
 
+    # This function only cancels the last command sent
+    # Override this if you want to do dangerous stuff like, God forbid, background_thread.terminate()
+    def cancel_thread(self):
+        GDB_Engine.cancel_last_command()
+
     def exec_(self):
         self.background_thread.start()
         super(LoadingDialogForm, self).exec_()

libPINCE/GDB_Engine.py

@@ -111,9 +111,21 @@
 # See gdb_async_condition's docstrings
 gdb_async_output = ""
 
+#:doc:cancel_send_command
+# A boolean value. Used to cancel the last gdb command sent
+# Use the function cancel_last_command to make use of this variable
+# Return value of the current send_command call will be an empty string
+cancel_send_command = False
+
 
 # The comments next to the regular expressions shows the expected gdb output, hope it helps to the future developers
 
+def cancel_last_command():
+    """Cancels the last gdb command sent"""
+    global cancel_send_command
+    cancel_send_command = True
+
+
 def send_command(command, control=False, cli_output=False, send_with_file=False, file_contents_send=None,
                  recv_with_file=False):
     """Issues the command sent, raises an exception if the inferior is running or no inferior has been selected
@@ -147,6 +159,7 @@ def send_command(command, control=False, cli_output=False, send_with_file=False,
     """
     global child
     global gdb_output
+    global cancel_send_command
     with lock_send_command:
         time0 = time()
         if not gdb_initialized:
@@ -178,11 +191,17 @@ def send_command(command, control=False, cli_output=False, send_with_file=False,
         if not control:
             while gdb_output is "":
                 sleep(type_defs.CONST_TIME.GDB_INPUT_SLEEP)
-        if not control:
-            if recv_with_file or cli_output:
-                output = pickle.load(open(recv_file, "rb"))
+                if cancel_send_command:
+                    break
+            if not cancel_send_command:
+                if recv_with_file or cli_output:
+                    output = pickle.load(open(recv_file, "rb"))
+                else:
+                    output = gdb_output
             else:
-                output = gdb_output
+                output = ""
+                child.sendcontrol("c")
+                cancel_send_command = False
         else:
             output = ""
         if type(output) == str:
@@ -302,7 +321,7 @@ def wait_for_stop(timeout=1):
 
 
 def interrupt_inferior(interrupt_reason=type_defs.STOP_REASON.DEBUG):
-    """Interrupt the inferior, can be also used to cancel the current gdb command
+    """Interrupt the inferior
 
     Args:
         interrupt_reason (int): Just changes the global variable stop_reason. Can be a member of type_defs.STOP_REASON
@@ -348,6 +367,7 @@ def init_gdb(gdb_path=type_defs.PATHS.GDB_PATH):
     global referenced_jumps_dict
     global referenced_calls_dict
     global gdb_output
+    global cancel_send_command
     detach()
 
     # Temporary IPC_PATH, this little hack is needed because send_command requires a valid IPC_PATH
@@ -360,6 +380,7 @@ def init_gdb(gdb_path=type_defs.PATHS.GDB_PATH):
     referenced_jumps_dict.clear()
     referenced_calls_dict.clear()
     gdb_output = ""
+    cancel_send_command = False
 
     libpince_dir = SysUtils.get_libpince_directory()
     child = pexpect.spawn('sudo LC_NUMERIC=C ' + gdb_path + ' --interpreter=mi', cwd=libpince_dir,