From 738c899e4c1ab9d25cfbcd1010f34e0cce400bca Mon Sep 17 00:00:00 2001 From: Andy Wingo Date: Thu, 1 Dec 2011 12:57:49 +0100 Subject: [PATCH] fix deadlock in before-gc-hook on certain 7.2alpha gc versions * libguile/gc.c (scm_init_gc): Only adjust gc frequency in the gc start hook if we know that it won't take a lock. --- libguile/gc.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/libguile/gc.c b/libguile/gc.c index c03c23982..ff1ebe6b1 100644 --- a/libguile/gc.c +++ b/libguile/gc.c @@ -1024,11 +1024,20 @@ scm_init_gc () after_gc_async_thunk), SCM_BOOL_F); - scm_c_hook_add (&scm_before_gc_c_hook, adjust_gc_frequency, NULL, 0); scm_c_hook_add (&scm_before_gc_c_hook, queue_after_gc_hook, NULL, 0); scm_c_hook_add (&scm_before_gc_c_hook, start_gc_timer, NULL, 0); scm_c_hook_add (&scm_after_gc_c_hook, accumulate_gc_timer, NULL, 0); +#if HAVE_GC_GET_HEAP_USAGE_SAFE + /* GC_get_heap_usage does not take a lock, and so can run in the GC + start hook. */ + scm_c_hook_add (&scm_before_gc_c_hook, adjust_gc_frequency, NULL, 0); +#else + /* GC_get_heap_usage might take a lock (and did from 7.2alpha1 to + 7.2alpha7), so call it in the after_gc_hook. */ + scm_c_hook_add (&scm_after_gc_c_hook, adjust_gc_frequency, NULL, 0); +#endif + #ifdef HAVE_GC_SET_START_CALLBACK GC_set_start_callback (run_before_gc_c_hook); #endif