From a4d6fe73cf07b3be3af6b7811cfc5950320bb37f Mon Sep 17 00:00:00 2001
From: Qi Wang <interwq@gwu.edu>
Date: Wed, 14 Jun 2017 12:12:23 -0700
Subject: [PATCH] Only abort on dlsym when necessary.

If neither background_thread nor lazy_lock is in use, do not abort on dlsym
errors.
---
 .../jemalloc/internal/background_thread_externs.h  |  1 +
 src/background_thread.c                            | 14 +++++++++++---
 src/ctl.c                                          |  7 +++++++
 3 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/include/jemalloc/internal/background_thread_externs.h b/include/jemalloc/internal/background_thread_externs.h
index 7c883697..8b4b8471 100644
--- a/include/jemalloc/internal/background_thread_externs.h
+++ b/include/jemalloc/internal/background_thread_externs.h
@@ -6,6 +6,7 @@ extern malloc_mutex_t background_thread_lock;
 extern atomic_b_t background_thread_enabled_state;
 extern size_t n_background_threads;
 extern background_thread_info_t *background_thread_info;
+extern bool can_enable_background_thread;
 
 bool background_thread_create(tsd_t *tsd, unsigned arena_ind);
 bool background_threads_enable(tsd_t *tsd);
diff --git a/src/background_thread.c b/src/background_thread.c
index a7403b85..1ff59447 100644
--- a/src/background_thread.c
+++ b/src/background_thread.c
@@ -20,6 +20,9 @@ size_t n_background_threads;
 /* Thread info per-index. */
 background_thread_info_t *background_thread_info;
 
+/* False if no necessary runtime support. */
+bool can_enable_background_thread;
+
 /******************************************************************************/
 
 #ifdef JEMALLOC_PTHREAD_CREATE_WRAPPER
@@ -785,9 +788,14 @@ background_thread_boot0(void) {
 #ifdef JEMALLOC_PTHREAD_CREATE_WRAPPER
 	pthread_create_fptr = dlsym(RTLD_NEXT, "pthread_create");
 	if (pthread_create_fptr == NULL) {
-		malloc_write("<jemalloc>: Error in dlsym(RTLD_NEXT, "
-		    "\"pthread_create\")\n");
-		abort();
+		can_enable_background_thread = false;
+		if (config_lazy_lock || opt_background_thread) {
+			malloc_write("<jemalloc>: Error in dlsym(RTLD_NEXT, "
+			    "\"pthread_create\")\n");
+			abort();
+		}
+	} else {
+		can_enable_background_thread = true;
 	}
 #endif
 	return false;
diff --git a/src/ctl.c b/src/ctl.c
index b3ae4aab..f1310cdf 100644
--- a/src/ctl.c
+++ b/src/ctl.c
@@ -1522,6 +1522,13 @@ background_thread_ctl(tsd_t *tsd, const size_t *mib, size_t miblen,
 
 		background_thread_enabled_set(tsd_tsdn(tsd), newval);
 		if (newval) {
+			if (!can_enable_background_thread) {
+				malloc_printf("<jemalloc>: Error in dlsym("
+			            "RTLD_NEXT, \"pthread_create\"). Cannot "
+				    "enable background_thread\n");
+				ret = EFAULT;
+				goto label_return;
+			}
 			if (background_threads_enable(tsd)) {
 				ret = EFAULT;
 				goto label_return;