diff options
author | Mark H Weaver <mhw@netris.org> | 2013-11-17 03:19:32 -0500 |
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committer | Mark H Weaver <mhw@netris.org> | 2013-11-23 14:48:00 -0500 |
commit | 8571dbde639e0ee9885bad49c9e180474bd23646 (patch) | |
tree | 4f83be3a956a7302b52ed71b8d393a654d790583 /libguile/procprop.c | |
parent | e676a4c34211efc8a7558afb0f8572b88a89c683 (diff) | |
download | guile-8571dbde639e0ee9885bad49c9e180474bd23646.tar.gz |
Block system asyncs while 'overrides_lock' is held.
* libguile/procprop.c (scm_set_procedure_property_x): Block system
asyncs while overrides_lock is held. Use dynwind block in case
an exception is thrown.
Diffstat (limited to 'libguile/procprop.c')
-rw-r--r-- | libguile/procprop.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/libguile/procprop.c b/libguile/procprop.c index 36228d3f3..be57b6bac 100644 --- a/libguile/procprop.c +++ b/libguile/procprop.c @@ -229,7 +229,13 @@ SCM_DEFINE (scm_set_procedure_property_x, "set-procedure-property!", 3, 0, 0, SCM_MISC_ERROR ("arity is a deprecated read-only property", SCM_EOL); #endif - scm_i_pthread_mutex_lock (&overrides_lock); + scm_dynwind_begin (0); + /* Here we must block asyncs while overrides_lock is held, to avoid + deadlocks which can happen as follows: scm_i_program_properties + calls out to the VM, which will run asyncs. Asyncs are permitted + to run VM code, which sometimes checks procedure properties, which + locks overrides_lock. */ + scm_i_dynwind_pthread_mutex_lock_block_asyncs (&overrides_lock); props = scm_hashq_ref (overrides, proc, SCM_BOOL_F); if (scm_is_false (props)) { @@ -239,7 +245,7 @@ SCM_DEFINE (scm_set_procedure_property_x, "set-procedure-property!", 3, 0, 0, props = SCM_EOL; } scm_hashq_set_x (overrides, proc, scm_assq_set_x (props, key, val)); - scm_i_pthread_mutex_unlock (&overrides_lock); + scm_dynwind_end (); return SCM_UNSPECIFIED; } |