fiss-minit

commit 3e74ca153eaba689ad8fd1bf6eee3982e35f2265
parent 7eb38b0b211c82edffe5b66d9fbf963fac420941
Author: leitner <leitner>
Date:   Wed, 17 Mar 2004 12:19:11 +0000

add history mode (msvc -H)

Diffstat:
M
CHANGES
 | 
2
++
M
minit.c
 | 
31
+++++++++++++++++++++++++++++++
M
msvc.8
 | 
6
++++++
M
msvc.c
 | 
42
+++++++++++++++++++++++++++++++++++++++++-

4 files changed, 80 insertions(+), 1 deletion(-)
diff --git a/CHANGES b/CHANGES
@@ -13,6 +13,8 @@
   Don't assume MINITROOT is 10 bytes long (Erich Schubert)
   add man pages!! (Erich Schubert)
   add a way to ask minit for dependencies
+  msvc -H will now dump the ten least recently spawned processes.
+    This is useful to see which process is looping.
 
 0.9.1:
   fix embarassing typo in msvc (Gelu G. Lupas)
diff --git a/minit.c b/minit.c
@@ -38,6 +38,11 @@ extern char **split(char *buf,int c,int *len,int plus,int ofs);
 
 extern char **environ;
 
+#define HISTORY 10
+#ifdef HISTORY
+int history[HISTORY];
+#endif
+
 /* return index of service in process data structure or -1 if not found */
 int findservice(char *service) {
   int i;
@@ -262,6 +267,12 @@ int startservice(int service,int pause,int father) {
 	 service,root[service].name,father,father>=0?root[father].name:"[msvc]");
 #endif
   root[service].father=father;
+#ifdef HISTORY
+  {
+    memmove(history+1,history,sizeof(int)*((HISTORY)-1));
+    history[0]=service;
+  }
+#endif
   if (root[service].logservice>=0)
     startservice(root[service].logservice,pause,service);
   if (chdir(MINITROOT) || chdir(root[service].name)) return -1;
@@ -350,6 +361,11 @@ int main(int argc, char *argv[]) {
   time_t last=time(0);
   int nfds=1;
 
+#ifdef HISTORY
+  for (i=0; i<HISTORY; ++i)
+    history[i]=-1;
+#endif
+
   infd=open(MINITROOT "/in",O_RDWR);
   outfd=open(MINITROOT "/out",O_RDWR|O_NONBLOCK);
 
@@ -546,6 +562,21 @@ ok:
 	    break;
 	  }
 	}
+      } else {
+	if (buf[0]=='h') {
+#ifdef HISTORY
+	  write(outfd,"1:",2);
+	  {
+	    int i;
+	    for (i=0; i<HISTORY; ++i)
+	      if (history[i]!=-1)
+		write(outfd,root[history[i]].name,str_len(root[history[i]].name)+1);
+	    write(outfd,"\0",2);
+	  }
+#else
+	  write(outfd,"0",1);
+#endif
+	}
       }
       break;
     default:
diff --git a/msvc.8 b/msvc.8
@@ -81,6 +81,12 @@ because this services depended on them.  Please note that this is not
 done recursively (i.e. if default depends on qmail and qmail depends on
 log, this will print qmail, not qmail/log.  But msvc -D qmail will print
 qmail/log).
+.TP
+.B \-H
+Print history.
+This will print the names of the ten least recently spawned processes.
+This is useful if you see a process looping (initialization fails and
+minit is restarting it all the time).
 .SH "RETURN CODES"
 Generally, msvc return zero if everything is OK or 1 on error (could not
 open /etc/minit/in or /etc/minit/out or there is no process with the
diff --git a/msvc.c b/msvc.c
@@ -87,6 +87,42 @@ unsigned long uptime(char *service) {
   return atoi(buf);
 }
 
+void dumphistory() {
+  char tmp[16384];
+  int i,j;
+  char first,last;
+  first=1; last='x';
+  write(infd,"h",1);
+  for (;;) {
+    int prev,done;
+    j=read(outfd,tmp,sizeof(tmp));
+    if (j<1) break;
+    done=i=0;
+    if (first) {
+      if (tmp[0]=='0') {
+	buffer_putsflush(buffer_2,"msvc: minit compiled without history support.\n");
+	return;
+      }
+      i+=2;
+    } else {
+      if (!tmp[0] && last=='\n') break;
+    }
+    prev=i;
+    for (; i<j; ++i)
+      if (!tmp[i]) {
+	tmp[i]=done?0:'\n';
+	if (i<j && !tmp[i+1]) { done=1; --j; }
+      }
+    if (first)
+      write(1,tmp+2,j-2);
+    else
+      write(1,tmp,j);
+    if (done) break;
+    last=tmp[j-1];
+    first=0;
+  }
+}
+
 void dumpdependencies(char* service) {
   char tmp[16384];
   int i,j;
@@ -145,6 +181,7 @@ int main(int argc,char *argv[]) {
 	" -g\tget; output just the PID\n"
 	" -Ppid\tset PID of service (for pidfilehack)\n"
 	" -D service\tprint services started as dependency\n"
+	" -H\tprint last n respawned services\n"
 	" -C\tClear; remove service form active list\n\n");
     return 0;
   }
@@ -155,7 +192,7 @@ int main(int argc,char *argv[]) {
       buffer_putsflush(buffer_2,"could not acquire lock!\n");
       sleep(1);
     }
-    if (argc==2) {
+    if (argc==2 && argv[1][1]!='H') {
       pid_t pid=__readpid(argv[1]);
       if (buf[0]!='0') {
 	unsigned long len;
@@ -254,6 +291,9 @@ int main(int argc,char *argv[]) {
 	      ret=1;
 	    }
 	  break;
+	case 'H':
+	  dumphistory();
+	  break;
 	case 'D':
 	  dumpdependencies(argv[2]);
 	  break;