make sure signals are only handled by the main thread. Fix bus error on rclmon exit (double delete)

src/common/rclinit.cpp

@@ -1,5 +1,5 @@
 #ifndef lint
-static char rcsid[] = "@(#$Id: rclinit.cpp,v 1.8 2006-11-08 15:34:20 dockes Exp $ (C) 2004 J.F.Dockes";
+static char rcsid[] = "@(#$Id: rclinit.cpp,v 1.9 2007-05-21 13:30:21 dockes Exp $ (C) 2004 J.F.Dockes";
 #endif
 /*
  *   This program is free software; you can redistribute it and/or modify
@@ -21,6 +21,7 @@ static char rcsid[] = "@(#$Id: rclinit.cpp,v 1.8 2006-11-08 15:34:20 dockes Exp
 #include <stdio.h>
 #include <signal.h>
 #include <locale.h>
+#include <pthread.h>
 
 #include "debuglog.h"
 #include "rclconfig.h"
@@ -36,6 +37,16 @@ RclConfig *recollinit(RclInitFlags flags,
     if (cleanup)
 	atexit(cleanup);
 
+    // We ignore SIGPIPE always. All pieces of code which can write to a pipe
+    // must check write() return values.
+    signal(SIGPIPE, SIG_IGN);
+    
+    // We block SIGCLD globally. We intend to properly wait for our children
+    sigset_t sset;
+    sigemptyset(&sset);
+    sigaddset(&sset, SIGCHLD);
+    pthread_sigmask(SIG_BLOCK, &sset, 0);
+
     if (sigcleanup) {
 	for (unsigned int i = 0; i < sizeof(catchedSigs) / sizeof(int); i++)
 	    if (signal(catchedSigs[i], SIG_IGN) != SIG_IGN)
@@ -86,3 +97,15 @@ RclConfig *recollinit(RclInitFlags flags,
 
     return config;
 }
+
+// Signals are handled by the main thread. All others should call this routine
+// to block possible signals
+void recoll_threadinit()
+{
+    sigset_t sset;
+    sigemptyset(&sset);
+
+    for (unsigned int i = 0; i < sizeof(catchedSigs) / sizeof(int); i++)
+	sigaddset(&sset, catchedSigs[i]);
+    pthread_sigmask(SIG_BLOCK, &sset, 0);
+}

src/common/rclinit.h

@@ -16,7 +16,7 @@
  */
 #ifndef _RCLINIT_H_INCLUDED_
 #define _RCLINIT_H_INCLUDED_
-/* @(#$Id: rclinit.h,v 1.5 2006-11-08 07:22:14 dockes Exp $  (C) 2004 J.F.Dockes */
+/* @(#$Id: rclinit.h,v 1.6 2007-05-21 13:30:21 dockes Exp $  (C) 2004 J.F.Dockes */
 
 #include <string>
 #ifndef NO_NAMESPACES
@@ -26,6 +26,10 @@ using std::string;
 class RclConfig;
 /**
  * Initialize by reading configuration, opening log file, etc.
+ * 
+ * This must be called from the main thread before starting any others. It sets
+ * up the global signal handling. other threads must call recoll_threadinit()
+ * when starting.
  *
  * @param flags   misc modifiers
  * @param cleanup function to call before exiting (atexit)
@@ -46,5 +50,7 @@ inline RclConfig *recollinit(void (*cleanup)(void), void (*sigcleanup)(int),
 			     string &reason, const string *argcnf = 0) {
     return recollinit(RCLINIT_NONE, cleanup, sigcleanup, reason, argcnf);
 }
+// Threads need to call this. The main thread handles all signals.
+extern void recoll_threadinit();
 
 #endif /* _RCLINIT_H_INCLUDED_ */