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authorNeil Jerram <neil@ossau.uklinux.net>2009-03-04 23:45:11 +0000
committerNeil Jerram <neil@ossau.uklinux.net>2009-03-05 19:48:41 +0000
commit2bfcaf2605f8366d8c708c148bde5313b88497e0 (patch)
tree2f935a03b143ea7a0b0dab5be4fc2f28da54ece1
parent58bef38c0ae2be6e729bf98f80b4b770d4b47037 (diff)
downloadguile-2bfcaf2605f8366d8c708c148bde5313b88497e0.tar.gz
Lock ordering: don't allocate when in critical section (scm_sigaction_for_thread)
This fixes the following helgrind report. Thread #1: lock order "0x4114748 before 0x4331084" violated at 0x40234F7: pthread_mutex_lock (hg_intercepts.c:408) by 0x407A55F: deval (eval.c:4077) by 0x407A071: scm_dapply (eval.c:5012) by 0x407888A: scm_apply (eval.c:4811) by 0x407E20C: scm_call_0 (eval.c:4666) by 0x406BDF7: scm_dynamic_wind (dynwind.c:111) by 0x407620C: ceval (eval.c:4571) by 0x407E8D9: scm_primitive_eval_x (eval.c:5921) by 0x407E934: scm_eval_x (eval.c:5956) by 0x40B9140: scm_shell (script.c:737) by 0x4095AC5: invoke_main_func (init.c:367) by 0x4065A81: c_body (continuations.c:349) Required order was established by acquisition of lock at 0x4114748 at 0x40234F7: pthread_mutex_lock (hg_intercepts.c:408) by 0x40B7BE1: scm_sigaction_for_thread (scmsigs.c:339) by 0x40911DE: scm_gsubr_apply (gsubr.c:223) by 0x4079E36: scm_dapply (eval.c:4930) by 0x407AB68: deval (eval.c:4378) by 0x407A071: scm_dapply (eval.c:5012) by 0x407888A: scm_apply (eval.c:4811) by 0x407E1D0: scm_call_1 (eval.c:4672) by 0x407FEEE: scm_map (eval.c:5489) by 0x407BDCC: deval (eval.c:4367) by 0x407D197: deval (eval.c:3698) by 0x407A071: scm_dapply (eval.c:5012) followed by a later acquisition of lock at 0x4331084 at 0x40234F7: pthread_mutex_lock (hg_intercepts.c:408) by 0x40DC397: scm_enter_guile (threads.c:377) by 0x40DC8F4: scm_pthread_mutex_lock (threads.c:1485) by 0x4083FAA: scm_gc_for_newcell (gc.c:484) by 0x40A9781: scm_cons (inline.h:115) by 0x4079867: scm_dapply (eval.c:4850) by 0x407888A: scm_apply (eval.c:4811) by 0x40796D6: scm_call_3 (eval.c:4684) by 0x409A7C2: module_variable (modules.c:302) by 0x409A7EE: module_variable (modules.c:312) by 0x409A962: scm_sym2var (modules.c:466) by 0x40738F4: scm_lookupcar1 (eval.c:2874) * libguile/scmsigs.c (close_1): Renamed `handler_to_async'; also handle #f case and wrapping the async in a cons, if necessary. (install_handler): Pass in async instead of constructing it; combine two branches into one. (scm_sigaction_for_thread): Allocate async upfront instead of inside the critical section, and pass it to install_handler calls. Leave critical section before signaling out-of-range error.
-rw-r--r--libguile/scmsigs.c48
1 files changed, 25 insertions, 23 deletions
diff --git a/libguile/scmsigs.c b/libguile/scmsigs.c
index 943327303..c4060070b 100644
--- a/libguile/scmsigs.c
+++ b/libguile/scmsigs.c
@@ -108,10 +108,20 @@ static SIGRETTYPE (*orig_handlers[NSIG])(int);
#endif
static SCM
-close_1 (SCM proc, SCM arg)
+handler_to_async (SCM handler, int signum)
{
- return scm_primitive_eval_x (scm_list_3 (scm_sym_lambda, SCM_EOL,
- scm_list_2 (proc, arg)));
+ if (scm_is_false (handler))
+ return SCM_BOOL_F;
+ else
+ {
+ SCM async = scm_primitive_eval_x (scm_list_3 (scm_sym_lambda, SCM_EOL,
+ scm_list_2 (handler,
+ scm_from_int (signum))));
+#if !SCM_USE_PTHREAD_THREADS
+ async = scm_cons (async, SCM_BOOL_F);
+#endif
+ return async;
+ }
}
#if SCM_USE_PTHREAD_THREADS
@@ -239,23 +249,10 @@ ensure_signal_delivery_thread ()
#endif /* !SCM_USE_PTHREAD_THREADS */
static void
-install_handler (int signum, SCM thread, SCM handler)
+install_handler (int signum, SCM thread, SCM handler, SCM async)
{
- if (scm_is_false (handler))
- {
- SCM_SIMPLE_VECTOR_SET (*signal_handlers, signum, SCM_BOOL_F);
- SCM_SIMPLE_VECTOR_SET (signal_handler_asyncs, signum, SCM_BOOL_F);
- }
- else
- {
- SCM async = close_1 (handler, scm_from_int (signum));
-#if !SCM_USE_PTHREAD_THREADS
- async = scm_cons (async, SCM_BOOL_F);
-#endif
- SCM_SIMPLE_VECTOR_SET (*signal_handlers, signum, handler);
- SCM_SIMPLE_VECTOR_SET (signal_handler_asyncs, signum, async);
- }
-
+ SCM_SIMPLE_VECTOR_SET (*signal_handlers, signum, handler);
+ SCM_SIMPLE_VECTOR_SET (signal_handler_asyncs, signum, async);
SCM_SIMPLE_VECTOR_SET (signal_handler_threads, signum, thread);
}
@@ -308,6 +305,7 @@ SCM_DEFINE (scm_sigaction_for_thread, "sigaction", 1, 3, 0,
int save_handler = 0;
SCM old_handler;
+ SCM async;
csig = scm_to_signed_integer (signum, 0, NSIG-1);
@@ -334,6 +332,10 @@ SCM_DEFINE (scm_sigaction_for_thread, "sigaction", 1, 3, 0,
SCM_MISC_ERROR ("thread has already exited", SCM_EOL);
}
+ /* Allocate upfront, as we can't do it inside the critical
+ section. */
+ async = handler_to_async (handler, csig);
+
ensure_signal_delivery_thread ();
SCM_CRITICAL_SECTION_START;
@@ -351,7 +353,7 @@ SCM_DEFINE (scm_sigaction_for_thread, "sigaction", 1, 3, 0,
#else
chandler = (SIGRETTYPE (*) (int)) handler_int;
#endif
- install_handler (csig, SCM_BOOL_F, SCM_BOOL_F);
+ install_handler (csig, SCM_BOOL_F, SCM_BOOL_F, async);
}
else
SCM_OUT_OF_RANGE (2, handler);
@@ -366,7 +368,7 @@ SCM_DEFINE (scm_sigaction_for_thread, "sigaction", 1, 3, 0,
{
action = orig_handlers[csig];
orig_handlers[csig].sa_handler = SIG_ERR;
- install_handler (csig, SCM_BOOL_F, SCM_BOOL_F);
+ install_handler (csig, SCM_BOOL_F, SCM_BOOL_F, async);
}
#else
if (orig_handlers[csig] == SIG_ERR)
@@ -375,7 +377,7 @@ SCM_DEFINE (scm_sigaction_for_thread, "sigaction", 1, 3, 0,
{
chandler = orig_handlers[csig];
orig_handlers[csig] = SIG_ERR;
- install_handler (csig, SCM_BOOL_F, SCM_BOOL_F);
+ install_handler (csig, SCM_BOOL_F, SCM_BOOL_F, async);
}
#endif
}
@@ -391,7 +393,7 @@ SCM_DEFINE (scm_sigaction_for_thread, "sigaction", 1, 3, 0,
if (orig_handlers[csig] == SIG_ERR)
save_handler = 1;
#endif
- install_handler (csig, thread, handler);
+ install_handler (csig, thread, handler, async);
}
/* XXX - Silently ignore setting handlers for `program error signals'