From ae5b39588734aacef5b6b411cf2053fdcef4764a Mon Sep 17 00:00:00 2001 From: =?utf8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= Date: Tue, 19 Apr 2016 21:30:14 -0400 Subject: [PATCH] basic/terminal-util: cache value for colors_enabled After all it's something that we query over and over. For example, systemctl calls colors_enabled() four times for each failing service. The compiler is unable to optimize those calls away because they (potentially) accesses external and global state through on_tty() and getenv(). --- src/basic/terminal-util.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/src/basic/terminal-util.c b/src/basic/terminal-util.c index 0a9d2bbdef7..9521b79daa1 100644 --- a/src/basic/terminal-util.c +++ b/src/basic/terminal-util.c @@ -1135,14 +1135,19 @@ int open_terminal_in_namespace(pid_t pid, const char *name, int mode) { } bool colors_enabled(void) { - const char *colors; + static int enabled = -1; - colors = getenv("SYSTEMD_COLORS"); - if (!colors) { - if (streq_ptr(getenv("TERM"), "dumb")) - return false; - return on_tty(); + if (_unlikely_(enabled < 0)) { + const char *colors; + + colors = getenv("SYSTEMD_COLORS"); + if (colors) + enabled = parse_boolean(colors) != 0; + else if (streq_ptr(getenv("TERM"), "dumb")) + enabled = false; + else + enabled = on_tty(); } - return parse_boolean(colors) != 0; + return enabled; } -- 2.39.2