Add some basic backoff when restarting programs

1 files changed, 31 insertions, 5 deletions

diff --git a/piper.c b/piper.c
index be3d677..62f1b9c 100644
--- a/piper.c
+++ b/piper.c
@@ -5,12 +5,12 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/time.h>
 #include <sys/types.h>
 #include <sys/wait.h>
+#include <time.h>
 #include <unistd.h>
 
-//#define NUM_PROCS 2
-
 struct proc {
 	pid_t pid;
 	char *cmd;
@@ -18,6 +18,9 @@ struct proc {
 	int  _stdin;
 	int  _stdout;
 	int  _stderr;
+	time_t last_started;
+	time_t next_start;
+	int num_starts;
 } *procs;
 
 int num_procs = 0;
@@ -126,6 +129,13 @@ run_cmd(struct proc *proc)
 {
 	pid_t cpid;
 
+	// XXX: This REALLY needs to be done better
+	time_t t = time(NULL);
+	if (t < procs->next_start)
+		sleep(procs->next_start - t);
+
+	procs->last_started = time(NULL);
+
 	cpid = fork();
 	if (cpid == 0) {
 		if (proc->_stdin != -1) {
@@ -260,6 +270,12 @@ print_argv()
 }
 
 int
+have_nonstarted()
+{
+	return 0;
+}
+
+int
 main(int argc, char **argv)
 {
 	int i;
@@ -283,6 +299,9 @@ main(int argc, char **argv)
 		procs[i]._stdin = -1;
 		procs[i]._stdout = -1;
 		procs[i]._stderr = -1;
+		procs[i].last_started = 0;
+		procs[i].next_start = 0;
+		procs[i].num_starts = 0;
 		gen_argv(&procs[i]);
 	}
 
@@ -308,11 +327,11 @@ main(int argc, char **argv)
 		if (sendsignal != 0)
 			signal_procs();
 
-		pid = wait(NULL);
+		pid = waitpid(0, NULL, 0);
 		if (pid == -1) {
-			if (errno == EINTR)
+			if (errno == EINTR) {
 				continue;
-			else
+			} else
 				fail(1, "wait");
 		}
 
@@ -320,6 +339,13 @@ main(int argc, char **argv)
 		if (p == NULL)
 			continue; // XXX: Log something here?
 		p->pid = -1;
+
+		time_t t = time(NULL);
+		if (p->last_started >= t - (p->num_starts + 1)) {
+			p->next_start = t + p->num_starts;
+			p->num_starts++;
+		} else
+			p->num_starts = 0;
 	}
 
 	return 0;