X-Git-Url: http://wien.tomnetworks.com/gitweb/?a=blobdiff_plain;f=mono%2Fmetadata%2Fmonitor.c;h=d3b51abfc80247f536fdb2410f28edf528411200;hb=abcca89bd4e256a74f55e46f4c45c25ad9c3cdf2;hp=b9a305121641975286467b84392ceba8856a4111;hpb=68be3904cf770be9f98a6ce0e8d71899cb94f189;p=mono.git diff --git a/mono/metadata/monitor.c b/mono/metadata/monitor.c index b9a30512164..d3b51abfc80 100644 --- a/mono/metadata/monitor.c +++ b/mono/metadata/monitor.c @@ -1,5 +1,6 @@ -/* - * monitor.c: Monitor locking functions +/** + * \file + * Monitor locking functions * * Author: * Dick Porter (dick@ximian.com) @@ -18,7 +19,6 @@ #include #include #include -#include #include #include #include @@ -26,10 +26,13 @@ #include #include #include +#include #include #include #include #include +#include +#include /* * Pull the list of opcodes @@ -306,10 +309,9 @@ monitor_is_on_freelist (MonoThreadsSync *mon) /** * mono_locks_dump: - * @include_untaken: - * + * \param include_untaken Whether to list unheld inflated locks. * Print a report on stdout of the managed locks currently held by - * threads. If @include_untaken is specified, list also inflated locks + * threads. If \p include_untaken is specified, list also inflated locks * which are unheld. * This is supposed to be used in debuggers like gdb. */ @@ -357,7 +359,8 @@ mon_finalize (MonoThreadsSync *mon) LOCK_DEBUG (g_message ("%s: Finalizing sync %p", __func__, mon)); if (mon->entry_sem != NULL) { - CloseHandle (mon->entry_sem); + mono_coop_sem_destroy (mon->entry_sem); + g_free (mon->entry_sem); mon->entry_sem = NULL; } /* If this isn't empty then something is seriously broken - it @@ -371,7 +374,7 @@ mon_finalize (MonoThreadsSync *mon) mon->data = monitor_freelist; monitor_freelist = mon; #ifndef DISABLE_PERFCOUNTERS - mono_perfcounters->gc_sync_blocks--; + InterlockedDecrement (&mono_perfcounters->gc_sync_blocks); #endif } @@ -394,7 +397,7 @@ mon_new (gsize id) /* Orphaned events left by aborted threads */ while (new_->wait_list) { LOCK_DEBUG (g_message (G_GNUC_PRETTY_FUNCTION ": (%d): Closing orphaned event %d", mono_thread_info_get_small_id (), new_->wait_list->data)); - CloseHandle (new_->wait_list->data); + mono_w32event_close (new_->wait_list->data); new_->wait_list = g_slist_remove (new_->wait_list, new_->wait_list->data); } } @@ -443,7 +446,7 @@ mon_new (gsize id) new_->data = NULL; #ifndef DISABLE_PERFCOUNTERS - mono_perfcounters->gc_sync_blocks++; + InterlockedIncrement (&mono_perfcounters->gc_sync_blocks); #endif return new_; } @@ -629,18 +632,19 @@ mono_object_hash (MonoObject* obj) #endif } -static void +static gboolean mono_monitor_ensure_owned (LockWord lw, guint32 id) { if (lock_word_is_flat (lw)) { if (lock_word_get_owner (lw) == id) - return; + return TRUE; } else if (lock_word_is_inflated (lw)) { if (mon_status_get_owner (lock_word_get_inflated_lock (lw)->status) == id) - return; + return TRUE; } mono_set_pending_exception (mono_get_exception_synchronization_lock ("Object synchronization method was called from an unsynchronized block of code.")); + return FALSE; } /* @@ -679,7 +683,7 @@ mono_monitor_exit_inflated (MonoObject *obj) tmp_status = InterlockedCompareExchange ((gint32*)&mon->status, new_status, old_status); if (tmp_status == old_status) { if (have_waiters) - ReleaseSemaphore (mon->entry_sem, 1, NULL); + mono_coop_sem_post (mon->entry_sem); break; } old_status = tmp_status; @@ -745,8 +749,8 @@ mono_monitor_try_enter_inflated (MonoObject *obj, guint32 ms, gboolean allow_int HANDLE sem; gint64 then = 0, now, delta; guint32 waitms; - guint32 ret; guint32 new_status, old_status, tmp_status; + MonoSemTimedwaitRet wait_ret; MonoInternalThread *thread; gboolean interrupted = FALSE; @@ -789,7 +793,7 @@ retry: /* The object must be locked by someone else... */ #ifndef DISABLE_PERFCOUNTERS - mono_perfcounters->thread_contentions++; + InterlockedIncrement (&mono_perfcounters->thread_contentions); #endif /* If ms is 0 we don't block, but just fail straight away */ @@ -798,7 +802,7 @@ retry: return 0; } - mono_profiler_monitor_event (obj, MONO_PROFILER_MONITOR_CONTENTION); + MONO_PROFILER_RAISE (monitor_contention, (obj)); /* The slow path begins here. */ retry_contended: @@ -821,7 +825,7 @@ retry_contended: if (G_LIKELY (tmp_status == old_status)) { /* Success */ g_assert (mon->nest == 1); - mono_profiler_monitor_event (obj, MONO_PROFILER_MONITOR_DONE); + MONO_PROFILER_RAISE (monitor_acquired, (obj)); return 1; } } @@ -829,7 +833,7 @@ retry_contended: /* If the object is currently locked by this thread... */ if (mon_status_get_owner (old_status) == id) { mon->nest++; - mono_profiler_monitor_event (obj, MONO_PROFILER_MONITOR_DONE); + MONO_PROFILER_RAISE (monitor_acquired, (obj)); return 1; } @@ -838,11 +842,12 @@ retry_contended: */ if (mon->entry_sem == NULL) { /* Create the semaphore */ - sem = CreateSemaphore (NULL, 0, 0x7fffffff, NULL); - g_assert (sem != NULL); + sem = g_new0 (MonoCoopSem, 1); + mono_coop_sem_init (sem, 0); if (InterlockedCompareExchangePointer ((gpointer*)&mon->entry_sem, sem, NULL) != NULL) { /* Someone else just put a handle here */ - CloseHandle (sem); + mono_coop_sem_destroy (sem); + g_free (sem); } } @@ -864,41 +869,58 @@ retry_contended: } } - if (ms != INFINITE) { + if (ms != MONO_INFINITE_WAIT) { then = mono_msec_ticks (); } waitms = ms; #ifndef DISABLE_PERFCOUNTERS - mono_perfcounters->thread_queue_len++; - mono_perfcounters->thread_queue_max++; + InterlockedIncrement (&mono_perfcounters->thread_queue_len); + InterlockedIncrement (&mono_perfcounters->thread_queue_max); #endif thread = mono_thread_internal_current (); - mono_thread_set_state (thread, ThreadState_WaitSleepJoin); + /* + * If we allow interruption, we check the test state for an abort request before going into sleep. + * This is a workaround to the fact that Thread.Abort does non-sticky interruption of semaphores. + * + * Semaphores don't support the sticky interruption with mono_thread_info_install_interrupt. + * + * A better fix would be to switch to wait with something that allows sticky interrupts together + * with wrapping it with abort_protected_block_count for the non-alertable cases. + * And somehow make this whole dance atomic and not crazy expensive. Good luck. + * + */ + if (allow_interruption) { + if (!mono_thread_test_and_set_state (thread, ThreadState_AbortRequested, ThreadState_WaitSleepJoin)) { + wait_ret = MONO_SEM_TIMEDWAIT_RET_ALERTED; + goto done_waiting; + } + } else { + mono_thread_set_state (thread, ThreadState_WaitSleepJoin); + } /* - * We pass TRUE instead of allow_interruption since we have to check for the + * We pass ALERTABLE instead of allow_interruption since we have to check for the * StopRequested case below. */ - MONO_ENTER_GC_SAFE; - ret = WaitForSingleObjectEx (mon->entry_sem, waitms, TRUE); - MONO_EXIT_GC_SAFE; + wait_ret = mono_coop_sem_timedwait (mon->entry_sem, waitms, MONO_SEM_FLAGS_ALERTABLE); mono_thread_clr_state (thread, ThreadState_WaitSleepJoin); - + +done_waiting: #ifndef DISABLE_PERFCOUNTERS - mono_perfcounters->thread_queue_len--; + InterlockedDecrement (&mono_perfcounters->thread_queue_len); #endif - if (ret == WAIT_IO_COMPLETION && !allow_interruption) { + if (wait_ret == MONO_SEM_TIMEDWAIT_RET_ALERTED && !allow_interruption) { interrupted = TRUE; /* * We have to obey a stop/suspend request even if * allow_interruption is FALSE to avoid hangs at shutdown. */ - if (!mono_thread_test_state (mono_thread_internal_current (), (MonoThreadState)(ThreadState_StopRequested | ThreadState_SuspendRequested | ThreadState_AbortRequested))) { - if (ms != INFINITE) { + if (!mono_thread_test_state (mono_thread_internal_current (), ThreadState_SuspendRequested | ThreadState_AbortRequested)) { + if (ms != MONO_INFINITE_WAIT) { now = mono_msec_ticks (); /* it should not overflow before ~30k years */ @@ -914,23 +936,23 @@ retry_contended: /* retry from the top */ goto retry_contended; } - } else if (ret == WAIT_OBJECT_0) { + } else if (wait_ret == MONO_SEM_TIMEDWAIT_RET_SUCCESS) { interrupted = FALSE; /* retry from the top */ goto retry_contended; - } else if (ret == WAIT_TIMEOUT) { + } else if (wait_ret == MONO_SEM_TIMEDWAIT_RET_TIMEDOUT) { /* we're done */ } /* Timed out or interrupted */ mon_decrement_entry_count (mon); - mono_profiler_monitor_event (obj, MONO_PROFILER_MONITOR_FAIL); + MONO_PROFILER_RAISE (monitor_failed, (obj)); - if (ret == WAIT_IO_COMPLETION) { + if (wait_ret == MONO_SEM_TIMEDWAIT_RET_ALERTED) { LOCK_DEBUG (g_message ("%s: (%d) interrupted waiting, returning -1", __func__, id)); return -1; - } else if (ret == WAIT_TIMEOUT) { + } else if (wait_ret == MONO_SEM_TIMEDWAIT_RET_TIMEDOUT) { LOCK_DEBUG (g_message ("%s: (%d) timed out waiting, returning FALSE", __func__, id)); return 0; } else { @@ -951,11 +973,6 @@ mono_monitor_try_enter_internal (MonoObject *obj, guint32 ms, gboolean allow_int LOCK_DEBUG (g_message("%s: (%d) Trying to lock object %p (%d ms)", __func__, id, obj, ms)); - if (G_UNLIKELY (!obj)) { - mono_set_pending_exception (mono_get_exception_argument_null ("obj")); - return FALSE; - } - lw.sync = obj->synchronisation; if (G_LIKELY (lock_word_is_free (lw))) { @@ -998,24 +1015,78 @@ mono_monitor_try_enter_internal (MonoObject *obj, guint32 ms, gboolean allow_int return -1; } -gboolean +/* This is an icall */ +MonoBoolean +mono_monitor_enter_internal (MonoObject *obj) +{ + gint32 res; + gboolean allow_interruption = TRUE; + if (G_UNLIKELY (!obj)) { + mono_set_pending_exception (mono_get_exception_argument_null ("obj")); + return FALSE; + } + + /* + * An inquisitive mind could ask what's the deal with this loop. + * It exists to deal with interrupting a monitor enter that happened within an abort-protected block, like a .cctor. + * + * The thread will be set with a pending abort and the wait might even be interrupted. Either way, once we call mono_thread_interruption_checkpoint, + * it will return NULL meaning we can't be aborted right now. Once that happens we switch to non-alertable. + */ + do { + res = mono_monitor_try_enter_internal (obj, MONO_INFINITE_WAIT, allow_interruption); + /*This means we got interrupted during the wait and didn't got the monitor.*/ + if (res == -1) { + MonoException *exc = mono_thread_interruption_checkpoint (); + if (exc) { + mono_set_pending_exception (exc); + return FALSE; + } else { + //we detected a pending interruption but it turned out to be a false positive, we ignore it from now on (this feels like a hack, right?, threads.c should give us less confusing directions) + allow_interruption = FALSE; + } + } + } while (res == -1); + return TRUE; +} + +/** + * mono_monitor_enter: + */ +gboolean mono_monitor_enter (MonoObject *obj) { - return mono_monitor_try_enter_internal (obj, INFINITE, FALSE) == 1; + return mono_monitor_enter_internal (obj); } -gboolean +/* Called from JITted code so we return guint32 instead of gboolean */ +guint32 mono_monitor_enter_fast (MonoObject *obj) { + if (G_UNLIKELY (!obj)) { + /* don't set pending exn on the fast path, just return + * FALSE and let the slow path take care of it. */ + return FALSE; + } return mono_monitor_try_enter_internal (obj, 0, FALSE) == 1; } +/** + * mono_monitor_try_enter: + */ gboolean mono_monitor_try_enter (MonoObject *obj, guint32 ms) { + if (G_UNLIKELY (!obj)) { + mono_set_pending_exception (mono_get_exception_argument_null ("obj")); + return FALSE; + } return mono_monitor_try_enter_internal (obj, ms, FALSE) == 1; } +/** + * mono_monitor_exit: + */ void mono_monitor_exit (MonoObject *obj) { @@ -1030,7 +1101,8 @@ mono_monitor_exit (MonoObject *obj) lw.sync = obj->synchronisation; - mono_monitor_ensure_owned (lw, mono_thread_info_get_small_id ()); + if (!mono_monitor_ensure_owned (lw, mono_thread_info_get_small_id ())) + return; if (G_UNLIKELY (lock_word_is_inflated (lw))) mono_monitor_exit_inflated (obj); @@ -1072,17 +1144,25 @@ mono_monitor_threads_sync_members_offset (int *status_offset, int *nest_offset) } void -ves_icall_System_Threading_Monitor_Monitor_try_enter_with_atomic_var (MonoObject *obj, guint32 ms, char *lockTaken) +ves_icall_System_Threading_Monitor_Monitor_try_enter_with_atomic_var (MonoObject *obj, guint32 ms, MonoBoolean *lockTaken) { gint32 res; + gboolean allow_interruption = TRUE; + if (G_UNLIKELY (!obj)) { + mono_set_pending_exception (mono_get_exception_argument_null ("obj")); + return; + } do { - res = mono_monitor_try_enter_internal (obj, ms, TRUE); + res = mono_monitor_try_enter_internal (obj, ms, allow_interruption); /*This means we got interrupted during the wait and didn't got the monitor.*/ if (res == -1) { MonoException *exc = mono_thread_interruption_checkpoint (); if (exc) { mono_set_pending_exception (exc); return; + } else { + //we detected a pending interruption but it turned out to be a false positive, we ignore it from now on (this feels like a hack, right?, threads.c should give us less confusing directions) + allow_interruption = FALSE; } } } while (res == -1); @@ -1090,6 +1170,9 @@ ves_icall_System_Threading_Monitor_Monitor_try_enter_with_atomic_var (MonoObject *lockTaken = res == 1; } +/** + * mono_monitor_enter_v4: + */ void mono_monitor_enter_v4 (MonoObject *obj, char *lock_taken) { @@ -1098,7 +1181,22 @@ mono_monitor_enter_v4 (MonoObject *obj, char *lock_taken) return; } - ves_icall_System_Threading_Monitor_Monitor_try_enter_with_atomic_var (obj, INFINITE, lock_taken); + MonoBoolean taken; + + ves_icall_System_Threading_Monitor_Monitor_try_enter_with_atomic_var (obj, MONO_INFINITE_WAIT, &taken); + *lock_taken = taken; +} + +/* Called from JITted code */ +void +mono_monitor_enter_v4_internal (MonoObject *obj, MonoBoolean *lock_taken) +{ + if (*lock_taken == 1) { + mono_set_pending_exception (mono_get_exception_argument ("lockTaken", "lockTaken is already true")); + return; + } + + ves_icall_System_Threading_Monitor_Monitor_try_enter_with_atomic_var (obj, MONO_INFINITE_WAIT, lock_taken); } /* @@ -1107,9 +1205,10 @@ mono_monitor_enter_v4 (MonoObject *obj, char *lock_taken) * Same as mono_monitor_enter_v4, but return immediately if the * monitor cannot be acquired. * Returns TRUE if the lock was acquired, FALSE otherwise. + * Called from JITted code so we return guint32 instead of gboolean. */ -gboolean -mono_monitor_enter_v4_fast (MonoObject *obj, char *lock_taken) +guint32 +mono_monitor_enter_v4_fast (MonoObject *obj, MonoBoolean *lock_taken) { if (*lock_taken == 1) return FALSE; @@ -1120,7 +1219,7 @@ mono_monitor_enter_v4_fast (MonoObject *obj, char *lock_taken) return res == 1; } -gboolean +MonoBoolean ves_icall_System_Threading_Monitor_Monitor_test_owner (MonoObject *obj) { LockWord lw; @@ -1138,7 +1237,7 @@ ves_icall_System_Threading_Monitor_Monitor_test_owner (MonoObject *obj) return(FALSE); } -gboolean +MonoBoolean ves_icall_System_Threading_Monitor_Monitor_test_synchronised (MonoObject *obj) { LockWord lw; @@ -1173,7 +1272,8 @@ ves_icall_System_Threading_Monitor_Monitor_pulse (MonoObject *obj) id = mono_thread_info_get_small_id (); lw.sync = obj->synchronisation; - mono_monitor_ensure_owned (lw, id); + if (!mono_monitor_ensure_owned (lw, id)) + return; if (!lock_word_is_inflated (lw)) { /* No threads waiting. A wait would have inflated the lock */ @@ -1187,7 +1287,7 @@ ves_icall_System_Threading_Monitor_Monitor_pulse (MonoObject *obj) if (mon->wait_list != NULL) { LOCK_DEBUG (g_message ("%s: (%d) signalling and dequeuing handle %p", __func__, mono_thread_info_get_small_id (), mon->wait_list->data)); - SetEvent (mon->wait_list->data); + mono_w32event_set (mon->wait_list->data); mon->wait_list = g_slist_remove (mon->wait_list, mon->wait_list->data); } } @@ -1204,7 +1304,8 @@ ves_icall_System_Threading_Monitor_Monitor_pulse_all (MonoObject *obj) id = mono_thread_info_get_small_id (); lw.sync = obj->synchronisation; - mono_monitor_ensure_owned (lw, id); + if (!mono_monitor_ensure_owned (lw, id)) + return; if (!lock_word_is_inflated (lw)) { /* No threads waiting. A wait would have inflated the lock */ @@ -1218,19 +1319,19 @@ ves_icall_System_Threading_Monitor_Monitor_pulse_all (MonoObject *obj) while (mon->wait_list != NULL) { LOCK_DEBUG (g_message ("%s: (%d) signalling and dequeuing handle %p", __func__, mono_thread_info_get_small_id (), mon->wait_list->data)); - SetEvent (mon->wait_list->data); + mono_w32event_set (mon->wait_list->data); mon->wait_list = g_slist_remove (mon->wait_list, mon->wait_list->data); } } -gboolean +MonoBoolean ves_icall_System_Threading_Monitor_Monitor_wait (MonoObject *obj, guint32 ms) { LockWord lw; MonoThreadsSync *mon; HANDLE event; guint32 nest; - guint32 ret; + MonoW32HandleWaitRet ret; gboolean success = FALSE; gint32 regain; MonoInternalThread *thread = mono_thread_internal_current (); @@ -1240,7 +1341,8 @@ ves_icall_System_Threading_Monitor_Monitor_wait (MonoObject *obj, guint32 ms) lw.sync = obj->synchronisation; - mono_monitor_ensure_owned (lw, id); + if (!mono_monitor_ensure_owned (lw, id)) + return FALSE; if (!lock_word_is_inflated (lw)) { mono_monitor_inflate_owned (obj, id); @@ -1253,7 +1355,7 @@ ves_icall_System_Threading_Monitor_Monitor_wait (MonoObject *obj, guint32 ms) if (mono_thread_current_check_pending_interrupt ()) return FALSE; - event = CreateEvent (NULL, FALSE, FALSE, NULL); + event = mono_w32event_create (FALSE, FALSE); if (event == NULL) { mono_set_pending_exception (mono_get_exception_synchronization_lock ("Failed to set up wait event")); return FALSE; @@ -1263,7 +1365,7 @@ ves_icall_System_Threading_Monitor_Monitor_wait (MonoObject *obj, guint32 ms) /* This looks superfluous */ if (mono_thread_current_check_pending_interrupt ()) { - CloseHandle (event); + mono_w32event_close (event); return FALSE; } @@ -1285,7 +1387,11 @@ ves_icall_System_Threading_Monitor_Monitor_wait (MonoObject *obj, guint32 ms) * signalled before we wait, we still succeed. */ MONO_ENTER_GC_SAFE; - ret = WaitForSingleObjectEx (event, ms, TRUE); +#ifdef HOST_WIN32 + ret = mono_w32handle_convert_wait_ret (mono_win32_wait_for_single_object_ex (event, ms, TRUE), 1); +#else + ret = mono_w32handle_wait_one (event, ms, TRUE); +#endif /* HOST_WIN32 */ MONO_EXIT_GC_SAFE; /* Reset the thread state fairly early, so we don't have to worry @@ -1295,7 +1401,7 @@ ves_icall_System_Threading_Monitor_Monitor_wait (MonoObject *obj, guint32 ms) /* Regain the lock with the previous nest count */ do { - regain = mono_monitor_try_enter_inflated (obj, INFINITE, TRUE, id); + regain = mono_monitor_try_enter_inflated (obj, MONO_INFINITE_WAIT, TRUE, id); /* We must regain the lock before handling interruption requests */ } while (regain == -1); @@ -1305,12 +1411,16 @@ ves_icall_System_Threading_Monitor_Monitor_wait (MonoObject *obj, guint32 ms) LOCK_DEBUG (g_message ("%s: (%d) Regained %p lock %p", __func__, mono_thread_info_get_small_id (), obj, mon)); - if (ret == WAIT_TIMEOUT) { + if (ret == MONO_W32HANDLE_WAIT_RET_TIMEOUT) { /* Poll the event again, just in case it was signalled * while we were trying to regain the monitor lock */ MONO_ENTER_GC_SAFE; - ret = WaitForSingleObjectEx (event, 0, FALSE); +#ifdef HOST_WIN32 + ret = mono_w32handle_convert_wait_ret (mono_win32_wait_for_single_object_ex (event, 0, FALSE), 1); +#else + ret = mono_w32handle_wait_one (event, 0, FALSE); +#endif /* HOST_WIN32 */ MONO_EXIT_GC_SAFE; } @@ -1324,7 +1434,7 @@ ves_icall_System_Threading_Monitor_Monitor_wait (MonoObject *obj, guint32 ms) * thread. */ - if (ret == WAIT_OBJECT_0) { + if (ret == MONO_W32HANDLE_WAIT_RET_SUCCESS_0) { LOCK_DEBUG (g_message ("%s: (%d) Success", __func__, mono_thread_info_get_small_id ())); success = TRUE; } else { @@ -1334,7 +1444,7 @@ ves_icall_System_Threading_Monitor_Monitor_wait (MonoObject *obj, guint32 ms) */ mon->wait_list = g_slist_remove (mon->wait_list, event); } - CloseHandle (event); + mono_w32event_close (event); return success; }