From b92bea5d2a9481de69bb627a7b442a9f58fca43d Mon Sep 17 00:00:00 2001 From: Zbigniew Jędrzejewski-Szmek Date: Sun, 24 Mar 2013 19:59:00 -0400 Subject: Use initalization instead of explicit zeroing MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Before, we would initialize many fields twice: first by filling the structure with zeros, and then a second time with the real values. We can let the compiler do the job for us, avoiding one copy. A downside of this patch is that text gets slightly bigger. This is because all zero() calls are effectively inlined: $ size build/.libs/systemd text data bss dec hex filename before 897737 107300 2560 1007597 f5fed build/.libs/systemd after 897873 107300 2560 1007733 f6075 build/.libs/systemd … actually less than 1‰. A few asserts that the parameter is not null had to be removed. I don't think this changes much, because first, it is quite unlikely for the assert to fail, and second, an immediate SEGV is almost as good as an assert. --- src/systemctl/systemctl.c | 71 ++++++++++++++++++++--------------------------- 1 file changed, 30 insertions(+), 41 deletions(-) (limited to 'src/systemctl') diff --git a/src/systemctl/systemctl.c b/src/systemctl/systemctl.c index e445b50ab8..fd9f580dc2 100644 --- a/src/systemctl/systemctl.c +++ b/src/systemctl/systemctl.c @@ -1193,14 +1193,11 @@ static int enable_wait_for_jobs(DBusConnection *bus) { static int wait_for_jobs(DBusConnection *bus, Set *s) { int r = 0; - WaitData d; + WaitData d = { .set = s }; assert(bus); assert(s); - zero(d); - d.set = s; - if (!dbus_connection_add_filter(bus, wait_filter, &d, NULL)) return log_oom(); @@ -3021,9 +3018,8 @@ static int print_property(const char *name, DBusMessageIter *iter) { dbus_message_iter_recurse(iter, &sub); while (dbus_message_iter_get_arg_type(&sub) == DBUS_TYPE_STRUCT) { - ExecStatusInfo info; + ExecStatusInfo info = {}; - zero(info); if (exec_status_info_deserialize(&sub, &info) >= 0) { char timestamp1[FORMAT_TIMESTAMP_MAX], timestamp2[FORMAT_TIMESTAMP_MAX]; char _cleanup_free_ *t; @@ -3070,14 +3066,12 @@ static int show_one(const char *verb, DBusConnection *bus, const char *path, boo const char *interface = ""; int r; DBusMessageIter iter, sub, sub2, sub3; - UnitStatusInfo info; + UnitStatusInfo info = {}; ExecStatusInfo *p; assert(path); assert(new_line); - zero(info); - r = bus_method_call_with_reply( bus, "org.freedesktop.systemd1", @@ -3654,7 +3648,7 @@ static int enable_sysv_units(char **args) { #if defined(HAVE_SYSV_COMPAT) && defined(HAVE_CHKCONFIG) const char *verb = args[0]; unsigned f = 1, t = 1; - LookupPaths paths; + LookupPaths paths = {}; if (arg_scope != UNIT_FILE_SYSTEM) return 0; @@ -3667,7 +3661,6 @@ static int enable_sysv_units(char **args) { /* Processes all SysV units, and reshuffles the array so that * afterwards only the native units remain */ - zero(paths); r = lookup_paths_init(&paths, SYSTEMD_SYSTEM, false, NULL, NULL, NULL); if (r < 0) return r; @@ -4716,7 +4709,7 @@ static int parse_time_spec(const char *t, usec_t *_u) { } else { char *e = NULL; long hour, minute; - struct tm tm; + struct tm tm = {}; time_t s; usec_t n; @@ -4732,7 +4725,6 @@ static int parse_time_spec(const char *t, usec_t *_u) { n = now(CLOCK_REALTIME); s = (time_t) (n / USEC_PER_SEC); - zero(tm); assert_se(localtime_r(&s, &tm)); tm.tm_hour = (int) hour; @@ -5134,7 +5126,7 @@ finish: } static int talk_initctl(void) { - struct init_request request = {0}; + struct init_request request = {}; int r; int _cleanup_close_ fd = -1; char rl; @@ -5339,41 +5331,38 @@ static int systemctl_main(DBusConnection *bus, int argc, char *argv[], DBusError static int send_shutdownd(usec_t t, char mode, bool dry_run, bool warn, const char *message) { int _cleanup_close_ fd; - struct msghdr msghdr; - struct iovec iovec[2]; - union sockaddr_union sockaddr; - struct sd_shutdown_command c; + struct sd_shutdown_command c = { + .usec = t, + .mode = mode, + .dry_run = dry_run, + .warn_wall = warn, + }; + union sockaddr_union sockaddr = { + .un.sun_family = AF_UNIX, + .un.sun_path = "/run/systemd/shutdownd", + }; + struct iovec iovec[2] = { + {.iov_base = (char*) &c, + .iov_len = offsetof(struct sd_shutdown_command, wall_message), + } + }; + struct msghdr msghdr = { + .msg_name = &sockaddr, + .msg_namelen = offsetof(struct sockaddr_un, sun_path) + + sizeof("/run/systemd/shutdownd") - 1, + .msg_iov = iovec, + .msg_iovlen = 1, + }; fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0); if (fd < 0) return -errno; - zero(c); - c.usec = t; - c.mode = mode; - c.dry_run = dry_run; - c.warn_wall = warn; - - zero(sockaddr); - sockaddr.sa.sa_family = AF_UNIX; - strncpy(sockaddr.un.sun_path, "/run/systemd/shutdownd", sizeof(sockaddr.un.sun_path)); - - zero(msghdr); - msghdr.msg_name = &sockaddr; - msghdr.msg_namelen = offsetof(struct sockaddr_un, sun_path) + sizeof("/run/systemd/shutdownd") - 1; - - zero(iovec); - iovec[0].iov_base = (char*) &c; - iovec[0].iov_len = offsetof(struct sd_shutdown_command, wall_message); - - if (isempty(message)) - msghdr.msg_iovlen = 1; - else { + if (!isempty(message)) { iovec[1].iov_base = (char*) message; iovec[1].iov_len = strlen(message); - msghdr.msg_iovlen = 2; + msghdr.msg_iovlen++; } - msghdr.msg_iov = iovec; if (sendmsg(fd, &msghdr, MSG_NOSIGNAL) < 0) return -errno; -- cgit v1.2.3-54-g00ecf