MEDIUM: pool: refactor malloc_trim/glibc and jemalloc api addition detections.

Attempt to detect jemalloc at runtime before hand whether linked or via
symbols overrides, and fall back to malloc_trim/glibc for Linux otherwise.

diff --git a/src/pool.c b/src/pool.c
index af46b4469048e49de6f7d2e3b4df2d4cef92f8da..514a53e12ff5fb73bac0f1db4e5d29336e69a0ec 100644 (file)
--- a/src/pool.c
+++ b/src/pool.c
@@ -42,66 +42,68 @@ int mem_poison_byte = -1;
 static int mem_fail_rate = 0;
 #endif
 
-#if defined(HA_HAVE_MALLOC_TRIM)
-static int using_libc_allocator = 0;
+static int using_default_allocator = 1;
+static int(*my_mallctl)(const char *, void *, size_t *, void *, size_t) = NULL;
 
 /* ask the allocator to trim memory pools */
 static void trim_all_pools(void)
 {
-       if (using_libc_allocator)
+#if defined(HA_HAVE_MALLOC_TRIM)
+       if (using_default_allocator)
                malloc_trim(0);
+#endif
 }
 
 /* check if we're using the same allocator as the one that provides
  * malloc_trim() and mallinfo(). The principle is that on glibc, both
  * malloc_trim() and mallinfo() are provided, and using mallinfo() we
  * can check if malloc() is performed through glibc or any other one
- * the executable was linked against (e.g. jemalloc).
+ * the executable was linked against (e.g. jemalloc). Prior to this we
+ * have to check whether we're running on jemalloc by verifying if the
+ * mallctl() function is provided. Its pointer will be used later.
  */
 static void detect_allocator(void)
 {
+       extern int mallctl(const char *, void *, size_t *, void *, size_t) __attribute__((weak));
+
+       my_mallctl = mallctl;
+
+       if (!my_mallctl) {
+               my_mallctl = get_sym_curr_addr("mallctl");
+               using_default_allocator = (my_mallctl == NULL);
+       }
+
+       if (!my_mallctl) {
+#if defined(HA_HAVE_MALLOC_TRIM)
 #ifdef HA_HAVE_MALLINFO2
-       struct mallinfo2 mi1, mi2;
+               struct mallinfo2 mi1, mi2;
 #else
-       struct mallinfo mi1, mi2;
+               struct mallinfo mi1, mi2;
 #endif
-       void *ptr;
+               void *ptr;
 
 #ifdef HA_HAVE_MALLINFO2
-       mi1 = mallinfo2();
+               mi1 = mallinfo2();
 #else
-       mi1 = mallinfo();
+               mi1 = mallinfo();
 #endif
-       ptr = DISGUISE(malloc(1));
+               ptr = DISGUISE(malloc(1));
 #ifdef HA_HAVE_MALLINFO2
-       mi2 = mallinfo2();
+               mi2 = mallinfo2();
 #else
-       mi2 = mallinfo();
+               mi2 = mallinfo();
 #endif
-       free(DISGUISE(ptr));
-
-       using_libc_allocator = !!memcmp(&mi1, &mi2, sizeof(mi1));
-}
+               free(DISGUISE(ptr));
 
-static int is_trim_enabled(void)
-{
-       return using_libc_allocator;
-}
-#else
-
-static void trim_all_pools(void)
-{
-}
-
-static void detect_allocator(void)
-{
+               using_default_allocator = !!memcmp(&mi1, &mi2, sizeof(mi1));
+#endif
+       }
 }
 
 static int is_trim_enabled(void)
 {
-       return 0;
+       return using_default_allocator;
 }
-#endif
 
 /* Try to find an existing shared pool with the same characteristics and
  * returns it, otherwise creates this one. NULL is returned if no memory