Merge pull request #249 from pcc/xgetinputfocus

[mono.git] / mono / metadata / sgen-os-posix.c

diff --git a/mono/metadata/sgen-os-posix.c b/mono/metadata/sgen-os-posix.c
index 0a0c4f1414ce2caf848f0ab30e702d0f3aa70f75..fc05f4e624bd1fd4938f36119bec60e883162da2 100644 (file)
--- a/mono/metadata/sgen-os-posix.c
+++ b/mono/metadata/sgen-os-posix.c
@@ -51,6 +51,7 @@ static MonoSemType suspend_ack_semaphore;
 static MonoSemType *suspend_ack_semaphore_ptr;
 
 static sigset_t suspend_signal_mask;
+static sigset_t suspend_ack_signal_mask;
 
 static void
 suspend_thread (SgenThreadInfo *info, void *context)
@@ -104,6 +105,14 @@ suspend_thread (SgenThreadInfo *info, void *context)
                mono_gc_get_gc_callbacks ()->thread_suspend_func (info->runtime_data, context);
 
        DEBUG (4, fprintf (gc_debug_file, "Posting suspend_ack_semaphore for suspend from %p %p\n", info, (gpointer)mono_native_thread_id_get ()));
+
+       /*
+       Block the restart signal. 
+       We need to block the restart signal while posting to the suspend_ack semaphore or we race to sigsuspend,
+       which might miss the signal and get stuck.
+       */
+       pthread_sigmask (SIG_BLOCK, &suspend_ack_signal_mask, NULL);
+
        /* notify the waiting thread */
        MONO_SEM_POST (suspend_ack_semaphore_ptr);
        info->stop_count = stop_count;
@@ -114,6 +123,9 @@ suspend_thread (SgenThreadInfo *info, void *context)
                sigsuspend (&suspend_signal_mask);
        } while (info->signal != restart_signal_num && info->doing_handshake);
 
+       /* Unblock the restart signal. */
+       pthread_sigmask (SIG_UNBLOCK, &suspend_ack_signal_mask, NULL);
+
        DEBUG (4, fprintf (gc_debug_file, "Posting suspend_ack_semaphore for resume from %p %p\n", info, (gpointer)mono_native_thread_id_get ()));
        /* notify the waiting thread */
        MONO_SEM_POST (suspend_ack_semaphore_ptr);
@@ -132,7 +144,7 @@ suspend_handler (int sig, siginfo_t *siginfo, void *context)
                suspend_thread (info, context);
        } else {
                /* This can happen while a thread is dying */
-               g_print ("no thread info in suspend\n");
+               //g_print ("no thread info in suspend\n");
        }
 
        errno = old_errno;
@@ -145,6 +157,15 @@ restart_handler (int sig)
        int old_errno = errno;
 
        info = mono_thread_info_current ();
+       /*
+       If the thread info is null is means we're currently in the process of cleaning up,
+       the pthread destructor has already kicked in and it has explicitly invoked the suspend handler.
+       
+       This means this thread has been suspended, TLS is dead, so the only option we have is to
+       rely on pthread_self () and seatch over the thread list.
+       */
+       if (!info)
+               info = mono_thread_info_lookup (pthread_self ());
 
        /*
         * If a thread is dying there might be no thread info.  In
@@ -154,7 +175,6 @@ restart_handler (int sig)
                info->signal = restart_signal_num;
                DEBUG (4, fprintf (gc_debug_file, "Restart handler in %p %p\n", info, (gpointer)mono_native_thread_id_get ()));
        }
-
        errno = old_errno;
 }
 
@@ -208,6 +228,8 @@ mono_sgen_thread_handshake (BOOL suspend)
                if (mono_native_thread_id_equals (mono_thread_info_get_tid (info), me)) {
                        continue;
                }
+               if (info->gc_disabled)
+                       continue;
                /*if (signum == suspend_signal_num && info->stop_count == global_stop_count)
                        continue;*/
                if (suspend) {
@@ -252,6 +274,10 @@ mono_sgen_os_init (void)
 
        sigfillset (&suspend_signal_mask);
        sigdelset (&suspend_signal_mask, restart_signal_num);
+
+       sigemptyset (&suspend_ack_signal_mask);
+       sigaddset (&suspend_ack_signal_mask, restart_signal_num);
+       
 }
 
 int