glibc: if malloc_trim() exists, call it periodically

CMakeLists.txt

@@ -725,6 +725,14 @@ CHECK_C_SOURCE_COMPILES(
 	"#include <strings.h>
 	int main(int argc, char **argv) { char buf[1]; bzero(buf, 1); return 0; }
 	" LWS_HAVE_BZERO)
+CHECK_C_SOURCE_COMPILES(
+	"#include <malloc.h>
+	int main(int argc, char **argv) { return malloc_trim(0); }
+	" LWS_HAVE_MALLOC_TRIM)
+CHECK_C_SOURCE_COMPILES(
+	"#include <malloc.h>
+	int main(int argc, char **argv) { return (int)malloc_usable_size((void *)0); }
+	" LWS_HAVE_MALLOC_USABLE_SIZE)
 
 CHECK_FUNCTION_EXISTS(fork LWS_HAVE_FORK)
 CHECK_FUNCTION_EXISTS(getenv LWS_HAVE_GETENV)

cmake/lws_config.h.in

@@ -30,6 +30,8 @@
 #cmakedefine LWS_HAVE_EVP_aes_128_wrap
 #cmakedefine LWS_HAVE_LIBCAP
 #cmakedefine LWS_HAVE_MALLOC_H
+#cmakedefine LWS_HAVE_MALLOC_TRIM
+#cmakedefine LWS_HAVE_MALLOC_USABLE_SIZE
 #cmakedefine LWS_HAVE_mbedtls_net_init
 #cmakedefine LWS_HAVE_mbedtls_ssl_conf_alpn_protocols
 #cmakedefine LWS_HAVE_mbedtls_ssl_get_alpn_protocol

include/libwebsockets/lws-misc.h

@@ -715,6 +715,23 @@ LWS_VISIBLE LWS_EXTERN int
 lws_dir(const char *dirpath, void *user, lws_dir_callback_function cb);
 #endif
 
+/**
+ * lws_get_allocated_heap() - if the platform supports it, returns amount of
+ *				heap allocated by lws itself
+ *
+ * On glibc currently, this reports the total amount of current logical heap
+ * allocation, found by tracking the amount allocated by lws_malloc() and
+ * friends and accounting for freed allocations via lws_free().
+ *
+ * This is useful for confirming where processwide heap allocations actually
+ * come from... this number represents all lws internal allocations, for
+ * fd tables, wsi allocations, ah, etc combined.  It doesn't include allocations
+ * from user code, since lws_malloc() etc are not exported from the library.
+ *
+ * On other platforms, it always returns 0.
+ */
+size_t lws_get_allocated_heap(void);
+
 /**
  * lws_is_ssl() - Find out if connection is using SSL
  * \param wsi:	websocket connection to check

lib/core-net/server.c

@@ -212,7 +212,8 @@ lws_json_dump_context(const struct lws_context *context, char *buf, int len,
 		close(fd);
 	}
 
-	buf += lws_snprintf(buf, end - buf, "\"contexts\":[\n");
+	buf += lws_snprintf(buf, end - buf, "\"heap\":%lld,\n\"contexts\":[\n",
+				(long long)lws_get_allocated_heap());
 
 	buf += lws_snprintf(buf, end - buf, "{ "
 				"\"context_uptime\":\"%ld\",\n"

lib/core/alloc.c

@@ -1,5 +1,13 @@
 #include "core/private.h"
 
+#if defined(LWS_HAVE_MALLOC_USABLE_SIZE)
+
+#include <malloc.h>
+
+/* the heap is processwide */
+static size_t allocated;
+#endif
+
 #if defined(LWS_PLAT_OPTEE)
 
 #define TEE_USER_MEM_HINT_NO_FILL_ZERO       0x80000000
@@ -72,8 +80,11 @@ void lws_set_allocator(void *(*cb)(void *ptr, size_t size, const char *reason))
 }
 #else
 
-static void *_realloc(void *ptr, size_t size, const char *reason)
+static void *
+_realloc(void *ptr, size_t size, const char *reason)
 {
+	void *v;
+
 	if (size) {
 #if defined(LWS_WITH_ESP32)
 		lwsl_notice("%s: size %lu: %s (free heap %d)\n", __func__,
@@ -82,14 +93,28 @@ static void *_realloc(void *ptr, size_t size, const char *reason)
 		lwsl_debug("%s: size %lu: %s\n", __func__,
 			   (unsigned long)size, reason);
 #endif
-#if defined(LWS_PLAT_OPTEE)
-		return (void *)TEE_Realloc(ptr, size);
-#else
-		return (void *)realloc(ptr, size);
+
+#if defined(LWS_HAVE_MALLOC_USABLE_SIZE)
+		if (ptr)
+			allocated -= malloc_usable_size(ptr);
 #endif
+
+#if defined(LWS_PLAT_OPTEE)
+		v = (void *)TEE_Realloc(ptr, size);
+#else
+		v = (void *)realloc(ptr, size);
+#endif
+#if defined(LWS_HAVE_MALLOC_USABLE_SIZE)
+		allocated += malloc_usable_size(v);
+#endif
+		return v;
 	}
-	if (ptr)
+	if (ptr) {
+#if defined(LWS_HAVE_MALLOC_USABLE_SIZE)
+		allocated -= malloc_usable_size(ptr);
+#endif
 		free(ptr);
+	}
 
 	return NULL;
 }
@@ -104,8 +129,10 @@ void *lws_realloc(void *ptr, size_t size, const char *reason)
 void *lws_zalloc(size_t size, const char *reason)
 {
 	void *ptr = _lws_realloc(NULL, size, reason);
+
 	if (ptr)
 		memset(ptr, 0, size);
+
 	return ptr;
 }
 
@@ -113,4 +140,13 @@ void lws_set_allocator(void *(*cb)(void *ptr, size_t size, const char *reason))
 {
 	_lws_realloc = cb;
 }
+
+size_t lws_get_allocated_heap(void)
+{
+#if defined(LWS_HAVE_MALLOC_USABLE_SIZE)
+	return allocated;
+#else
+	return 0;
+#endif
+}
 #endif

lib/misc/dir.c

@@ -94,6 +94,12 @@ lws_dir(const char *dirpath, void *user, lws_dir_callback_function cb)
 		if (strchr(namelist[i]->d_name, '~'))
 			goto skip;
 		lde.name = namelist[i]->d_name;
+
+		/*
+		 * some filesystems don't report this (ZFS) and tell that
+		 * files are LDOT_UNKNOWN
+		 */
+
 		switch (namelist[i]->d_type) {
 		case DT_BLK:
 			lde.type = LDOT_BLOCK;

lib/plat/unix/unix-service.c

@@ -22,6 +22,10 @@
 #define _GNU_SOURCE
 #include "core/private.h"
 
+#if defined(LWS_HAVE_MALLOC_TRIM)
+#include <malloc.h>
+#endif
+
 int
 lws_poll_listen_fd(struct lws_pollfd *fd)
 {
@@ -209,4 +213,7 @@ lws_plat_service_periodic(struct lws_context *context)
 	    kill(context->started_with_parent, 0) < 0)
 		kill(getpid(), SIGTERM);
 #endif
+#if defined(LWS_HAVE_MALLOC_TRIM)
+	malloc_trim(4 * 1024);
+#endif
 }

lib/roles/http/server/lejp-conf.c

@@ -907,7 +907,7 @@ lwsws_get_config_d_cb(const char *dirpath, void *user,
 	struct lws_dir_args *da = (struct lws_dir_args *)user;
 	char path[256];
 
-	if (lde->type != LDOT_FILE)
+	if (lde->type != LDOT_FILE && lde->type != LDOT_UNKNOWN /* ZFS */)
 		return 0;
 
 	lws_snprintf(path, sizeof(path) - 1, "%s/%s", dirpath, lde->name);

plugins/server-status.js

@@ -105,6 +105,9 @@ function ws_open_server_status()
 				s += ", <span class=\"sn\">Virt stack + heap Usage:</span> <span class=\"v\">" +
 					humanize(parseInt(sm[0], 10) * 4096) + "B</span>";
 			}
+			s += ", <span class=\"sn\">lws heap usage:</span> <span class=\"v\">" +
+			humanize(jso.i.heap) + "B</span>";
+
 				
 			for (n = 0; n < jso.files.length; n++) {
 				s += "<br><span class=n>" + san(jso.files[n].path) + ":</span><br>    " + san(jso.files[n].val);