Mercurial > octave

diff liboctave/util/quit.cc @ 31633:d9970470108a stable

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Remove several race conditions with signal handler (bug #61370). This patch removes several race conditions between the interpreter and the Ctrl-C signal handler, as described in more detail in bug #61370. * libinterp/corefcn/sighandlers.h: Make can_interrupt atomic. * libinterp/corefcn/sighandlers.cc: Make can_interrupt, signals_caught atomic, use atomic value read for signals_caught, octave_interrupt_state, change 1 to true. * liboctave/util/quit.h: Move octave_interrupt_state and octave_signal_caught to C++ only code, rewrite octave_quit() function, rewrite OCTAVE_QUIT macro to use octave_quit_c() function. * liboctave/util/quit.cc: Make octave_interrupt_state and octave_signal_caught atomic, add new wrapper function octave_quit_c(). * libinterp/corefcn/interpreter.h: Make octave_initialized atomic. * libinterp/corefcn/interpreter.cc: Make octave_initialized atomic, change 0 to false. * liboctave/util/action-container.h: New namespace "util", make m_val atomic. * liboctave/util/oct-atomic.c: Reorder preprocessor if-elif-else ladder. * liboctave/util/cmd-edit.cc: Change 0 to false.
author Reinhard Resch <r_resch@a1.net>
date Sat, 03 Dec 2022 10:36:59 -0500
parents aac27ad79be6
children 7d3467f8d713
line wrap: on
line diff
--- a/liboctave/util/quit.cc	Sat Dec 03 13:55:14 2022 +0100
+++ b/liboctave/util/quit.cc	Sat Dec 03 10:36:59 2022 -0500
@@ -27,6 +27,7 @@
 #  include "config.h"
 #endif
 
+#include <atomic>
 #include <cstring>
 
 #include <ostream>
@@ -35,9 +36,9 @@
 
 #include "quit.h"
 
-sig_atomic_t octave_interrupt_state = 0;
+std::atomic<sig_atomic_t> octave_interrupt_state{0};
 
-volatile sig_atomic_t octave_signal_caught = 0;
+volatile std::atomic<bool> octave_signal_caught{false};
 
 void (*octave_signal_hook) (void) = nullptr;
 void (*octave_interrupt_hook) (void) = nullptr;
@@ -95,6 +96,11 @@
     }
 }
 
+void octave_quit_c (void)
+{
+  octave_quit ();
+}
+
 OCTAVE_END_NAMESPACE(octave)
 
 void
@@ -103,10 +109,12 @@
   if (octave_signal_hook)
     octave_signal_hook ();
 
-  if (octave_interrupt_state > 0)
-    {
-      octave_interrupt_state = -1;
+  sig_atomic_t curr_interrupt_state = octave_interrupt_state.load ();
 
-      throw octave::interrupt_exception ();
-    }
+  while (curr_interrupt_state > 0 &&
+    ! octave_interrupt_state.compare_exchange_weak (curr_interrupt_state, -1))
+    ;
+
+  if (curr_interrupt_state > 0)
+    throw octave::interrupt_exception ();
 }