Use signalfd to handle SIGCHLDsubmit/tizen/20150817.084057accepted/tizen/wearable/20150817.134811accepted/tizen/tv/20150817.134530accepted/tizen/mobile/20150817.134136

Change-Id: I5b70a40908d2c6b7c68ccc7424a624b5f391b45b
Signed-off-by: Sangyoon Jang <s89.jang@samsung.com>

2 files changed, 74 insertions, 93 deletions

diff --git a/am_session_agent/agent.c b/am_session_agent/agent.c
index 42cd475e..65c96488 100644
--- a/am_session_agent/agent.c
+++ b/am_session_agent/agent.c
@@ -53,11 +53,15 @@
 #include <rua.h>
 
 #define _static_ static inline
-#define POLLFD_MAX 1
 #define SQLITE_FLUSH_MAX       (1048576)       /* (1024*1024) */
 #define AUL_POLL_CNT		15
 #define AUL_PR_NAME			16
 
+enum {
+	MAIN_FD = 0,
+	SIGCHLD_FD,
+	POLLFD_MAX
+};
 
 static char *agent_cmdline;
 static int initialized = 0;
@@ -81,9 +85,8 @@ _static_ int __term_app(int pid);
 _static_ int __resume_app(int pid);
 _static_ int __real_send(int clifd, int ret);
 _static_ void __send_result_to_caller(int clifd, int ret);
-_static_ void __agent_main_loop(int main_fd);
+_static_ void __agent_main_loop(struct pollfd pfds[]);
 _static_ int __agent_pre_init(int argc, char **argv);
-_static_ int __agent_post_init();
 
 
 
@@ -589,8 +592,10 @@ static void __add_history(const char *pkg_name, const char *app_path, unsigned c
 		_E("rua add history error");
 }
 
-_static_ void __agent_main_loop(int main_fd)
+_static_ void __agent_main_loop(struct pollfd pfds[])
 {
+	int main_fd = pfds[MAIN_FD].fd;
+	int sigchld_fd = pfds[SIGCHLD_FD].fd;
 	bundle *kb = NULL;
 	app_pkt_t *pkt = NULL;
 	app_info_from_db *menu_info = NULL;
@@ -659,8 +664,7 @@ _static_ void __agent_main_loop(int main_fd)
 	_D("start %s: type=%s caller_uid=%d path=%s",appId,menu_info->pkg_type,uid,app_path);
 
 	PERF("get package information & modify bundle done");
-	if( !strcmp(menu_info->pkg_type, "wgt") || !strcmp(menu_info->pkg_type, "rpm") || !strcmp(menu_info->pkg_type, "tpk"))
-	{
+	if (!strcmp(menu_info->pkg_type, "wgt") || !strcmp(menu_info->pkg_type, "rpm") || !strcmp(menu_info->pkg_type, "tpk")) {
 		pid = fork();
 		if (pid == 0) {
 			PERF("fork done");
@@ -668,7 +672,8 @@ _static_ void __agent_main_loop(int main_fd)
 
 			close(clifd);
 			close(main_fd);
-			__signal_unset_sigchld();
+			close(sigchld_fd);
+			__signal_unblock_sigchld();
 			__signal_fini();
 
 			snprintf(sock_path, UNIX_PATH_MAX, "%s/%d", AUL_SOCK_PREFIX, getpid());
@@ -700,9 +705,7 @@ _static_ void __agent_main_loop(int main_fd)
 	if (pid > 0) {
 		if (is_real_launch) {
 			/*TODO: retry*/
-			__signal_block_sigchld();
 			__send_app_launch_signal_dbus(pid);
-			__signal_unblock_sigchld();
 
 			__add_history(appId, app_path, pkt->data);
 		}
@@ -760,25 +763,6 @@ _static_ int __agent_pre_init(int argc, char **argv)
 	return fd;
 }
 
-_static_ int __agent_post_init()
-{
-	/* Setting this as a global variable to keep track
-	of agent poll cnt */
-	/* static int initialized = 0;*/
-
-	if (initialized) {
-		initialized++;
-		return 0;
-	}
-
-	if (__signal_set_sigchld() < 0)
-		return -1;
-
-	initialized++;
-
-	return 0;
-}
-
 static void __send_dead_siganl_to_amd(void)
 {
 	bundle *kb;
@@ -791,6 +775,7 @@ static void __send_dead_siganl_to_amd(void)
 int main(int argc, char **argv)
 {
 	int main_fd;
+	int sigchld_fd;
 	struct pollfd pfds[POLLFD_MAX];
 	int i;
 
@@ -803,24 +788,35 @@ int main(int argc, char **argv)
 		exit(-1);
 	}
 
-	pfds[0].fd = main_fd;
-	pfds[0].events = POLLIN;
-	pfds[0].revents = 0;
+	pfds[MAIN_FD].fd = main_fd;
+	pfds[MAIN_FD].events = POLLIN;
+	pfds[MAIN_FD].revents = 0;
+
+	sigchld_fd = __signal_get_sigchld_fd();
+	if (sigchld_fd < 0) {
+		_E("get sigchld fd failed");
+		exit(-1);
+	}
+
+	pfds[SIGCHLD_FD].fd = sigchld_fd;
+	pfds[SIGCHLD_FD].events = POLLIN;
+	pfds[SIGCHLD_FD].revents = 0;
 
 	while (loop_flag == TRUE) {
 		if (poll(pfds, POLLFD_MAX, -1) < 0)
 			continue;
 
-		/* init with concerning X & EFL (because of booting
-		sequence problem)*/
-		if (__agent_post_init() < 0) {
-			_E("agent post init failed");
-			exit(-1);
-		}
-
 		for (i = 0; i < POLLFD_MAX; i++) {
-			if ((pfds[i].revents & POLLIN) != 0) {
-				__agent_main_loop(pfds[i].fd);
+			if ((pfds[i].revents & POLLIN) == 0)
+				continue;
+
+			switch (i) {
+			case MAIN_FD:
+				__agent_main_loop(pfds);
+				break;
+			case SIGCHLD_FD:
+				__agent_sig_child(pfds[i].fd);
+				break;
 			}
 		}
 	}
diff --git a/am_session_agent/sigchild.h b/am_session_agent/sigchild.h
index b557e736..654d1386 100644
--- a/am_session_agent/sigchild.h
+++ b/am_session_agent/sigchild.h
@@ -19,11 +19,11 @@
  *
  */
 
+#include <sys/signalfd.h>
 #include "launch.h"
 #include "aul_util.h"
 #include "app_signal.h"
 
-static struct sigaction old_sigchild;
 static DBusConnection *bus = NULL;
 sigset_t oldmask;
 
@@ -166,14 +166,22 @@ static int __sigchild_action(void *data)
 	return 0;
 }
 
-static void __agent_sig_child(int signo, siginfo_t *info, void *data)
+static void __agent_sig_child(int sigchld_fd)
 {
+	struct signalfd_siginfo info;
+	ssize_t s;
 	int status;
 	pid_t child_pid;
 	pid_t child_pgid;
 
-	child_pgid = getpgid(info->si_pid);
-	_D("dead_pid = %d pgid = %d", info->si_pid, child_pgid);
+	s = read(sigchld_fd, &info, sizeof(struct signalfd_siginfo));
+	if (s != sizeof(struct signalfd_siginfo)) {
+		_E("error reading sigchld info");
+		return;
+	}
+
+	child_pgid = getpgid(info.ssi_pid);
+	_D("dead_pid = %d pgid = %d", info.ssi_pid, child_pgid);
 
 	while ((child_pid = waitpid(-1, &status, WNOHANG)) > 0) {
 		if (child_pid == child_pgid)
@@ -187,6 +195,17 @@ static void __agent_sig_child(int signo, siginfo_t *info, void *data)
 static inline int __signal_init(void)
 {
 	int i;
+	DBusError error;
+
+	dbus_error_init(&error);
+	dbus_threads_init_default();
+	bus = dbus_bus_get_private(DBUS_BUS_SESSION, &error);
+	if (!bus) {
+		_E("Failed to connect to the D-BUS daemon: %s", error.message);
+		dbus_error_free(&error);
+		return -1;
+	}
+
 	for (i = 0; i < _NSIG; i++) {
 		switch (i) {
 			/* controlled by sys-assert package*/
@@ -210,66 +229,29 @@ static inline int __signal_init(void)
 	return 0;
 }
 
-static inline int __signal_set_sigchld(void)
+static inline int __signal_get_sigchld_fd(void)
 {
-	struct sigaction act;
-	DBusError error;
+	sigset_t mask;
+	int sfd;
 
-	dbus_error_init(&error);
-	dbus_threads_init_default();
-	bus = dbus_bus_get_private(DBUS_BUS_SESSION, &error);
-	if (!bus) {
-		_E("Failed to connect to the D-BUS daemon: %s", error.message);
-		dbus_error_free(&error);
-		return -1;
-	}
-	/* TODO: if process stop mechanism is included,
-	should be modified (SA_NOCLDSTOP)*/
-	act.sa_handler = NULL;
-	act.sa_sigaction = __agent_sig_child;
-	sigemptyset(&act.sa_mask);
-	act.sa_flags = SA_NOCLDSTOP | SA_SIGINFO;
-
-	if (sigaction(SIGCHLD, &act, &old_sigchild) < 0)
-		return -1;
-
-	return 0;
-}
-
-static inline int __signal_unset_sigchld(void)
-{
-	struct sigaction dummy;
-
-	if (bus == NULL)
-		return 0;
+	sigemptyset(&mask);
+	sigaddset(&mask, SIGCHLD);
 
-	dbus_connection_close(bus);
-	if (sigaction(SIGCHLD, &old_sigchild, &dummy) < 0)
-		return -1;
-
-	return 0;
-}
-
-static inline int __signal_block_sigchld(void)
-{
-	sigset_t newmask;
-
-	sigemptyset(&newmask);
-	sigaddset(&newmask, SIGCHLD);
+	if (sigprocmask(SIG_BLOCK, &mask, &oldmask) == -1)
+		_E("failed to sigprocmask");
 
-	if (sigprocmask(SIG_BLOCK, &newmask, &oldmask) < 0) {
-		_E("SIG_BLOCK error");
+	sfd = signalfd(-1, &mask, SFD_NONBLOCK | SFD_CLOEXEC);
+	if (sfd == -1) {
+		_E("failed to create signal for SIGCHLD");
 		return -1;
 	}
 
-	_D("SIGCHLD blocked");
-
-	return 0;
+	return sfd;
 }
 
 static inline int __signal_unblock_sigchld(void)
 {
-	if(sigprocmask(SIG_SETMASK, &oldmask, NULL) < 0) {
+	if (sigprocmask(SIG_SETMASK, &oldmask, NULL) < 0) {
 		_E("SIG_SETMASK error");
 		return -1;
 	}
@@ -280,6 +262,9 @@ static inline int __signal_unblock_sigchld(void)
 
 static inline int __signal_fini(void)
 {
+	if (bus)
+		dbus_connection_close(bus);
+
 #ifndef PRELOAD_ACTIVATE
 	int i;
 	for (i = 0; i < _NSIG; i++)