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Re: [PATCH] GDB checkpoint can't/shouldn't be possible with multiple threads on Linux
On Tue, Apr 12, 2011 at 9:41 AM, Pedro Alves <pedro@codesourcery.com> wrote:
> Small nit I should have caught before:
>
> On Tuesday 12 April 2011 14:27:49, Kevin Pouget wrote:
>> +static int
>> +inf_has_multiple_thread_cb (struct thread_info *tp, void *data)
>> +{
>> + ?int *has_multiple_threads = (int *) data;
>
> can you rename this local as well, in line with the other
> local in the other function? ?To "count", or "count_p", or something
> like that. ?Thanks. ?(pre-approved)
fixed with count_p, thanks
Kevin
--
2011-04-12 Kevin Pouget <kevin.pouget@st.com>
PR threads/12628
* linux-fork.c (checkpoint_command): Disallow checkpointing of
processes with multiple threads.
(inf_has_multiple_thread_cb): New function.
(inf_has_multiple_threads): New function.
--
diff --git a/gdb/linux-fork.c b/gdb/linux-fork.c
index 7f654af..de512c3 100644
--- a/gdb/linux-fork.c
+++ b/gdb/linux-fork.c
@@ -616,6 +616,33 @@ linux_fork_checkpointing_p (int pid)
return (checkpointing_pid == pid);
}
+/* Callback for iterate over threads. Used to check whether
+ the current inferior is multi-threaded. Returns true as soon
+ as it sees the second thread of the current inferior. */
+
+static int
+inf_has_multiple_thread_cb (struct thread_info *tp, void *data)
+{
+ int *count_p = (int *) data;
+
+ if (current_inferior ()->pid == ptid_get_pid (tp->ptid))
+ (*count_p)++;
+
+ /* Stop the iteration if multiple threads have been detected. */
+ return *count_p > 1;
+}
+
+/* Return true if the current inferior is multi-threaded. */
+
+static int
+inf_has_multiple_threads (void)
+{
+ int count = 0;
+
+ iterate_over_threads (inf_has_multiple_thread_cb, &count);
+ return (count > 1);
+}
+
static void
checkpoint_command (char *args, int from_tty)
{
@@ -628,6 +655,14 @@ checkpoint_command (char *args, int from_tty)
pid_t retpid;
struct cleanup *old_chain;
+ if (!target_has_execution)
+ error (_("The program is not being run."));
+
+ /* Ensure that the inferior is not multithreaded. */
+ update_thread_list ();
+ if (inf_has_multiple_threads ())
+ error (_("checkpoint: can't checkpoint multiple threads."));
+
/* Make the inferior fork, record its (and gdb's) state. */
if (lookup_minimal_symbol ("fork", NULL, NULL) != NULL)