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authorDaniel Jacobowitz <drow@false.org>2008-07-27 21:12:40 +0000
committerDaniel Jacobowitz <drow@false.org>2008-07-27 21:12:40 +0000
commit57380f4e0bbdfa396ed068db6bd867b4fafd9925 (patch)
treec55eb8d7d1ab1052274749c38291df076a980cb2
parente09490f18a66aa4d02a2f5b7a75d2530caf09d5b (diff)
downloadgdb-57380f4e0bbdfa396ed068db6bd867b4fafd9925.zip
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* linux-nat.c (resume_callback): Add more debugging output.
(linux_nat_has_pending_sigint): New function, based on linux_nat_has_pending. (set_ignore_sigint, maybe_clear_ignore_sigint): New functions. (stop_wait_callback): Remove flush_mask handling. Honor ignore_sigint. Call maybe_clear_ignore_sigint. Pass NULL to recursive calls. (linux_nat_has_pending, flush_callback): Remove. (linux_nat_filter_event): Check for ignore_sigint. (linux_nat_wait): Remove flush_mask support and call to flush_callback. Use set_ignore_sigint and maybe_clear_ignore_sigint. * linux-nat.h (struct lwp_info): Add ignore_sigint field. * gdb.threads/manythreads.exp: Use remote_expect instead of after. Add a test for duplicated SIGINTs.
-rw-r--r--gdb/ChangeLog15
-rw-r--r--gdb/linux-nat.c224
-rw-r--r--gdb/linux-nat.h3
-rw-r--r--gdb/testsuite/ChangeLog5
-rw-r--r--gdb/testsuite/gdb.threads/manythreads.exp34
5 files changed, 165 insertions, 116 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 7cc48ef..3dce7a7 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,20 @@
2008-07-27 Daniel Jacobowitz <dan@codesourcery.com>
+ * linux-nat.c (resume_callback): Add more debugging output.
+ (linux_nat_has_pending_sigint): New function, based on
+ linux_nat_has_pending.
+ (set_ignore_sigint, maybe_clear_ignore_sigint): New functions.
+ (stop_wait_callback): Remove flush_mask handling. Honor
+ ignore_sigint. Call maybe_clear_ignore_sigint. Pass NULL
+ to recursive calls.
+ (linux_nat_has_pending, flush_callback): Remove.
+ (linux_nat_filter_event): Check for ignore_sigint.
+ (linux_nat_wait): Remove flush_mask support and call to
+ flush_callback. Use set_ignore_sigint and maybe_clear_ignore_sigint.
+ * linux-nat.h (struct lwp_info): Add ignore_sigint field.
+
+2008-07-27 Daniel Jacobowitz <dan@codesourcery.com>
+
* linux-nat.c (count_events_callback, select_event_lwp_callback): Only
report events from resumed threads.
diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c
index 5ccff50..b59a35c 100644
--- a/gdb/linux-nat.c
+++ b/gdb/linux-nat.c
@@ -1603,6 +1603,12 @@ resume_callback (struct lwp_info *lp, void *data)
lp->step = 0;
memset (&lp->siginfo, 0, sizeof (lp->siginfo));
}
+ else if (lp->stopped && debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog, "RC: Not resuming sibling %s (has pending)\n",
+ target_pid_to_str (lp->ptid));
+ else if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog, "RC: Not resuming sibling %s (not stopped)\n",
+ target_pid_to_str (lp->ptid));
return 0;
}
@@ -2036,14 +2042,66 @@ stop_callback (struct lwp_info *lp, void *data)
return 0;
}
-/* Wait until LP is stopped. If DATA is non-null it is interpreted as
- a pointer to a set of signals to be flushed immediately. */
+/* Return non-zero if LWP PID has a pending SIGINT. */
static int
-stop_wait_callback (struct lwp_info *lp, void *data)
+linux_nat_has_pending_sigint (int pid)
+{
+ sigset_t pending, blocked, ignored;
+ int i;
+
+ linux_proc_pending_signals (pid, &pending, &blocked, &ignored);
+
+ if (sigismember (&pending, SIGINT)
+ && !sigismember (&ignored, SIGINT))
+ return 1;
+
+ return 0;
+}
+
+/* Set a flag in LP indicating that we should ignore its next SIGINT. */
+
+static int
+set_ignore_sigint (struct lwp_info *lp, void *data)
{
- sigset_t *flush_mask = data;
+ /* If a thread has a pending SIGINT, consume it; otherwise, set a
+ flag to consume the next one. */
+ if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status)
+ && WSTOPSIG (lp->status) == SIGINT)
+ lp->status = 0;
+ else
+ lp->ignore_sigint = 1;
+
+ return 0;
+}
+
+/* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
+ This function is called after we know the LWP has stopped; if the LWP
+ stopped before the expected SIGINT was delivered, then it will never have
+ arrived. Also, if the signal was delivered to a shared queue and consumed
+ by a different thread, it will never be delivered to this LWP. */
+static void
+maybe_clear_ignore_sigint (struct lwp_info *lp)
+{
+ if (!lp->ignore_sigint)
+ return;
+
+ if (!linux_nat_has_pending_sigint (GET_LWP (lp->ptid)))
+ {
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "MCIS: Clearing bogus flag for %s\n",
+ target_pid_to_str (lp->ptid));
+ lp->ignore_sigint = 0;
+ }
+}
+
+/* Wait until LP is stopped. */
+
+static int
+stop_wait_callback (struct lwp_info *lp, void *data)
+{
if (!lp->stopped)
{
int status;
@@ -2052,26 +2110,24 @@ stop_wait_callback (struct lwp_info *lp, void *data)
if (status == 0)
return 0;
- /* Ignore any signals in FLUSH_MASK. */
- if (flush_mask && sigismember (flush_mask, WSTOPSIG (status)))
+ if (lp->ignore_sigint && WIFSTOPPED (status)
+ && WSTOPSIG (status) == SIGINT)
{
- if (!lp->signalled)
- {
- lp->stopped = 1;
- return 0;
- }
+ lp->ignore_sigint = 0;
errno = 0;
ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog,
- "PTRACE_CONT %s, 0, 0 (%s)\n",
+ "PTRACE_CONT %s, 0, 0 (%s) (discarding SIGINT)\n",
target_pid_to_str (lp->ptid),
errno ? safe_strerror (errno) : "OK");
- return stop_wait_callback (lp, flush_mask);
+ return stop_wait_callback (lp, NULL);
}
+ maybe_clear_ignore_sigint (lp);
+
if (WSTOPSIG (status) != SIGSTOP)
{
if (WSTOPSIG (status) == SIGTRAP)
@@ -2108,7 +2164,7 @@ stop_wait_callback (struct lwp_info *lp, void *data)
}
/* Hold this event/waitstatus while we check to see if
there are any more (we still want to get that SIGSTOP). */
- stop_wait_callback (lp, data);
+ stop_wait_callback (lp, NULL);
if (target_can_async_p ())
{
@@ -2169,7 +2225,7 @@ stop_wait_callback (struct lwp_info *lp, void *data)
/* Hold this event/waitstatus while we check to see if
there are any more (we still want to get that SIGSTOP). */
- stop_wait_callback (lp, data);
+ stop_wait_callback (lp, NULL);
/* If the lp->status field is still empty, use it to
hold this event. If not, then this event must be
@@ -2202,96 +2258,6 @@ stop_wait_callback (struct lwp_info *lp, void *data)
return 0;
}
-/* Check whether PID has any pending signals in FLUSH_MASK. If so set
- the appropriate bits in PENDING, and return 1 - otherwise return 0. */
-
-static int
-linux_nat_has_pending (int pid, sigset_t *pending, sigset_t *flush_mask)
-{
- sigset_t blocked, ignored;
- int i;
-
- linux_proc_pending_signals (pid, pending, &blocked, &ignored);
-
- if (!flush_mask)
- return 0;
-
- for (i = 1; i < NSIG; i++)
- if (sigismember (pending, i))
- if (!sigismember (flush_mask, i)
- || sigismember (&blocked, i)
- || sigismember (&ignored, i))
- sigdelset (pending, i);
-
- if (sigisemptyset (pending))
- return 0;
-
- return 1;
-}
-
-/* DATA is interpreted as a mask of signals to flush. If LP has
- signals pending, and they are all in the flush mask, then arrange
- to flush them. LP should be stopped, as should all other threads
- it might share a signal queue with. */
-
-static int
-flush_callback (struct lwp_info *lp, void *data)
-{
- sigset_t *flush_mask = data;
- sigset_t pending, intersection, blocked, ignored;
- int pid, status;
-
- /* Normally, when an LWP exits, it is removed from the LWP list. The
- last LWP isn't removed till later, however. So if there is only
- one LWP on the list, make sure it's alive. */
- if (lwp_list == lp && lp->next == NULL)
- if (!linux_nat_thread_alive (lp->ptid))
- return 0;
-
- /* Just because the LWP is stopped doesn't mean that new signals
- can't arrive from outside, so this function must be careful of
- race conditions. However, because all threads are stopped, we
- can assume that the pending mask will not shrink unless we resume
- the LWP, and that it will then get another signal. We can't
- control which one, however. */
-
- if (lp->status)
- {
- if (debug_linux_nat)
- printf_unfiltered (_("FC: LP has pending status %06x\n"), lp->status);
- if (WIFSTOPPED (lp->status) && sigismember (flush_mask, WSTOPSIG (lp->status)))
- lp->status = 0;
- }
-
- /* While there is a pending signal we would like to flush, continue
- the inferior and collect another signal. But if there's already
- a saved status that we don't want to flush, we can't resume the
- inferior - if it stopped for some other reason we wouldn't have
- anywhere to save the new status. In that case, we must leave the
- signal unflushed (and possibly generate an extra SIGINT stop).
- That's much less bad than losing a signal. */
- while (lp->status == 0
- && linux_nat_has_pending (GET_LWP (lp->ptid), &pending, flush_mask))
- {
- int ret;
-
- errno = 0;
- ret = ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
- if (debug_linux_nat)
- fprintf_unfiltered (gdb_stderr,
- "FC: Sent PTRACE_CONT, ret %d %d\n", ret, errno);
-
- lp->stopped = 0;
- stop_wait_callback (lp, flush_mask);
- if (debug_linux_nat)
- fprintf_unfiltered (gdb_stderr,
- "FC: Wait finished; saved status is %d\n",
- lp->status);
- }
-
- return 0;
-}
-
/* Return non-zero if LP has a wait status pending. */
static int
@@ -2657,6 +2623,36 @@ linux_nat_filter_event (int lwpid, int status, int options)
return NULL;
}
+ /* Make sure we don't report a SIGINT that we have already displayed
+ for another thread. */
+ if (lp->ignore_sigint
+ && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT)
+ {
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "LLW: Delayed SIGINT caught for %s.\n",
+ target_pid_to_str (lp->ptid));
+
+ /* This is a delayed SIGINT. */
+ lp->ignore_sigint = 0;
+
+ registers_changed ();
+ linux_ops->to_resume (pid_to_ptid (GET_LWP (lp->ptid)),
+ lp->step, TARGET_SIGNAL_0);
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "LLW: %s %s, 0, 0 (discard SIGINT)\n",
+ lp->step ?
+ "PTRACE_SINGLESTEP" : "PTRACE_CONT",
+ target_pid_to_str (lp->ptid));
+
+ lp->stopped = 0;
+ gdb_assert (lp->resumed);
+
+ /* Discard the event. */
+ return NULL;
+ }
+
/* An interesting event. */
gdb_assert (lp);
return lp;
@@ -2715,7 +2711,6 @@ linux_nat_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
int options = 0;
int status = 0;
pid_t pid = PIDGET (ptid);
- sigset_t flush_mask;
if (debug_linux_nat_async)
fprintf_unfiltered (gdb_stdlog, "LLW: enter\n");
@@ -2737,8 +2732,6 @@ linux_nat_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
set_executing (lp->ptid, 1);
}
- sigemptyset (&flush_mask);
-
/* Block events while we're here. */
linux_nat_async_events (sigchld_sync);
@@ -2948,11 +2941,15 @@ retry:
if (signo == TARGET_SIGNAL_INT && signal_pass_state (signo) == 0)
{
/* If ^C/BREAK is typed at the tty/console, SIGINT gets
- forwarded to the entire process group, that is, all LWP's
- will receive it. Since we only want to report it once,
- we try to flush it from all LWPs except this one. */
- sigaddset (&flush_mask, SIGINT);
+ forwarded to the entire process group, that is, all LWPs
+ will receive it - unless they're using CLONE_THREAD to
+ share signals. Since we only want to report it once, we
+ mark it as ignored for all LWPs except this one. */
+ iterate_over_lwps (set_ignore_sigint, NULL);
+ lp->ignore_sigint = 0;
}
+ else
+ maybe_clear_ignore_sigint (lp);
}
/* This LWP is stopped now. */
@@ -2969,8 +2966,7 @@ retry:
/* ... and wait until all of them have reported back that
they're no longer running. */
- iterate_over_lwps (stop_wait_callback, &flush_mask);
- iterate_over_lwps (flush_callback, &flush_mask);
+ iterate_over_lwps (stop_wait_callback, NULL);
/* If we're not waiting for a specific LWP, choose an event LWP
from among those that have had events. Giving equal priority
diff --git a/gdb/linux-nat.h b/gdb/linux-nat.h
index f3386f7..a25719b 100644
--- a/gdb/linux-nat.h
+++ b/gdb/linux-nat.h
@@ -62,6 +62,9 @@ struct lwp_info
be the address of a hardware watchpoint. */
struct siginfo siginfo;
+ /* Non-zero if we expect a duplicated SIGINT. */
+ int ignore_sigint;
+
/* If WAITSTATUS->KIND != TARGET_WAITKIND_SPURIOUS, the waitstatus
for this LWP's last event. This may correspond to STATUS above,
or to a local variable in lin_lwp_wait. */
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index ae66c01..fce30d8 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,5 +1,10 @@
2008-07-27 Daniel Jacobowitz <dan@codesourcery.com>
+ * gdb.threads/manythreads.exp: Use remote_expect instead of after.
+ Add a test for duplicated SIGINTs.
+
+2008-07-27 Daniel Jacobowitz <dan@codesourcery.com>
+
* gdb.threads/schedlock.exp (get_args): Update to work for any
value of NUM.
(Top level): Report the number of threads that did not resume.
diff --git a/gdb/testsuite/gdb.threads/manythreads.exp b/gdb/testsuite/gdb.threads/manythreads.exp
index a92d049..2bdedf0 100644
--- a/gdb/testsuite/gdb.threads/manythreads.exp
+++ b/gdb/testsuite/gdb.threads/manythreads.exp
@@ -58,8 +58,11 @@ gdb_test_multiple "continue" "first continue" {
}
}
+# Wait one second. This is better than the TCL "after" command, because
+# we don't lose GDB's output while we do it.
+remote_expect host 1 { timeout { } }
+
# Send a Ctrl-C and verify that we can do info threads and continue
-after 1000
send_gdb "\003"
set message "stop threads 1"
gdb_test_multiple "" "stop threads 1" {
@@ -110,8 +113,35 @@ gdb_test_multiple "continue" "second continue" {
}
}
+# Wait another second. If the program stops on its own, GDB has failed
+# to handle duplicate SIGINTs sent to multiple threads.
+set failed 0
+remote_expect host 1 {
+ -re "\\\[New \[^\]\]*\\\]\r\n" {
+ exp_continue -continue_timer
+ }
+ -re "\\\[\[^\]\]* exited\\\]\r\n" {
+ exp_continue -continue_timer
+ }
+ -re "Thread \[^\n\]* executing\r\n" {
+ exp_continue -continue_timer
+ }
+ -re "Program received signal SIGINT.*$gdb_prompt $" {
+ if { $failed == 0 } {
+ fail "check for duplicate SIGINT"
+ }
+ send_gdb "continue\n"
+ set failed 1
+ exp_continue
+ }
+ timeout {
+ if { $failed == 0 } {
+ pass "check for duplicate SIGINT"
+ }
+ }
+}
+
# Send another Ctrl-C and verify that we can do info threads and quit
-after 1000
send_gdb "\003"
set message "stop threads 2"
gdb_test_multiple "" "stop threads 2" {