Initial commit

1 files changed, 121 insertions, 0 deletions

diff --git a/src/com_start.c b/src/com_start.c
new file mode 100644
index 0000000..73bb2ec
--- /dev/null
+++ b/src/com_start.c
@@ -0,0 +1,121 @@
+#include "genrc.h"
+
+void
+report_exec_error(int rc, char const *program)
+{
+	if (WIFEXITED(rc)) {
+		if (WEXITSTATUS(rc)) {
+			genrc_error("%s exited with status %d",
+				    program, WEXITSTATUS(rc));
+		}
+	} else if (WIFSIGNALED(rc)) {
+		char const *coremsg = "";
+#ifdef WCOREDUMP
+		if (WCOREDUMP(rc))
+			coremsg = " (core dumped)";
+#endif
+		genrc_error("%s terminated on signal %d%s",
+			    program, WTERMSIG(rc), coremsg);
+	} else if (WIFSTOPPED(rc)) {
+		genrc_error("%s stopped on signal %d",
+			    program, WSTOPSIG(rc));
+	} else {
+		genrc_error("%s terminated with unrecognized status: %d",
+			    program, rc);
+	}
+}
+
+typedef void (*SIGHANDLER)(int);
+
+void
+sigchld(int sig)
+{
+}
+
+int
+timedwaitpid(pid_t pid, int *status)
+{
+	struct timeval now, stoptime, ttw;
+	int rc = -1;
+	SIGHANDLER oldsig;
+	
+	oldsig = signal(SIGCHLD, sigchld);
+	gettimeofday(&stoptime, NULL);
+	stoptime.tv_sec += genrc_timeout;
+	while (1) {
+		pid_t p;
+		
+		p = waitpid(pid, status, WNOHANG);
+		if (p == pid) {
+			rc = 0;
+			break;
+		}
+		if (p < 0 && errno != EINTR) {
+			system_error(errno, "waitpid");
+			break;
+		}
+
+		gettimeofday(&now, NULL);
+		if (timercmp(&now, &stoptime, >=))
+			break;
+		timersub(&stoptime, &now, &ttw);
+		if (select(0, NULL, NULL, NULL, &ttw) < 0) {
+			if (errno != EINTR) {
+				system_error(errno, "select");
+				break;
+			}
+		}
+
+	}
+	signal(SIGCHLD, oldsig);
+	if (rc) {
+		kill(pid, SIGKILL);
+	}
+	return rc;
+}
+
+int
+com_start(void)
+{
+	pid_t pid;
+	int status;
+	PIDLIST pids;
+	char *p;
+	
+	pidlist_init(&pids);
+	if (get_pid_list(genrc_pid_closure, &pids) == 0) {
+		int running = pids.pidc > 0;
+		pidlist_free(&pids);
+		if (running) {
+			genrc_error("%s is already running", genrc_program);
+			return 1;
+		}
+	}
+
+	if ((p = getenv("GENRC_SENTINEL")) && *p == '1')
+		return sentinel();
+	
+	pid = fork();
+	if (pid == -1) {
+		system_error(errno, "fork");
+		return 1;
+	}
+	if (pid == 0) {
+		char *argv[] = { SHELL, "-c", NULL, NULL };
+		argv[2] = genrc_command;
+		execvp(SHELL, argv);
+		system_error(errno, "failed to exec %s", genrc_program);
+		exit(127);
+	}
+
+	if (timedwaitpid(pid, &status)) {
+		genrc_error("timed out waiting for %s to return",
+			    genrc_program);
+		return 1;
+	}
+	if (!(WIFEXITED(status) && WEXITSTATUS(status) == 0)) {
+		report_exec_error(status, genrc_program);
+		return 1;
+	}
+	return 0;
+}