block signals when writing db to ensure db isn't corrupted

git-svn-id: https://svn.musicpd.org/mpd/trunk@730 09075e82-0dd4-0310-85a5-a0d7c8717e4f

src/directory.c

@@ -553,6 +553,7 @@ int printDirectoryInfo(FILE * fp, char * name) {
 	return 0;
 }
 
+/* DON'T BLOCK SIGNALS IN THIS FUNCTION, called by writeDirectoryDB() */
 void writeDirectoryInfo(FILE * fp, Directory * directory) {
 	ListNode * node = (directory->subDirectories)->firstNode;
 	Directory * subDirectory;
@@ -684,12 +685,18 @@ int writeDirectoryDB() {
 	while(!(fp=fopen(directorydb,"w")) && errno==EINTR);
 	if(!fp) return -1;
 
+	/* block signals so we ensure the db doesn't get corrupted */
+	/* no functions that writeDirectoryInfoCalls should mess with
+	   signals or signal blocking! */
+	blockSignals();
 	myfprintf(fp,"%s\n",DIRECTORY_INFO_BEGIN);
 	myfprintf(fp,"%s%s\n",DIRECTORY_MPD_VERSION,VERSION);
 	myfprintf(fp,"%s%s\n",DIRECTORY_FS_CHARSET,getFsCharset());
 	myfprintf(fp,"%s\n",DIRECTORY_INFO_END);
 
 	writeDirectoryInfo(fp,mp3rootDirectory);
+	unblockSignals();
+
 	while(fclose(fp) && errno==EINTR);
 
 	return 0;

src/sig_handlers.c

@@ -90,6 +90,8 @@ void blockSignals() {
 	sigaddset(&sset,SIGCHLD);
 	sigaddset(&sset,SIGUSR1);
 	sigaddset(&sset,SIGHUP);
+	sigaddset(&sset,SIGINT);
+	sigaddset(&sset,SIGTERM);
 	while(sigprocmask(SIG_BLOCK,&sset,NULL)<0 && errno==EINTR);
 }
 
@@ -100,5 +102,7 @@ void unblockSignals() {
 	sigaddset(&sset,SIGCHLD);
 	sigaddset(&sset,SIGUSR1);
 	sigaddset(&sset,SIGHUP);
+	sigaddset(&sset,SIGINT);
+	sigaddset(&sset,SIGTERM);
 	while(sigprocmask(SIG_UNBLOCK,&sset,NULL)<0 && errno==EINTR);
 }

src/song.c

@@ -132,6 +132,7 @@ void freeSongList(SongList * list) {
 	freeList(list);
 }
 
+/* DON'T BLOCK SIGNALS IN THIS FUNCTION, called by writeDirectoryDB() */
 int printSongInfo(FILE * fp, Song * song) {
 	myfprintf(fp,"%s%s\n",SONG_FILE,song->utf8file);
 
@@ -151,6 +152,7 @@ int printSongInfoFromList(FILE * fp, SongList * list) {
 	return 0;
 }
 
+/* DON'T BLOCK SIGNALS IN THIS FUNCTION, called by writeDirectoryDB() */
 void writeSongInfoFromList(FILE * fp, SongList * list) {
 	ListNode * tempNode = list->firstNode;
 

src/tag.c

@@ -51,6 +51,7 @@
 #include "mp4ff/mp4ff.h"
 #endif
 
+/* DON'T BLOCK SIGNALS IN THIS FUNCTION, called by writeDirectoryDB() */
 void printMpdTag(FILE * fp, MpdTag * tag) {
 	if(tag->artist) myfprintf(fp,"Artist: %s\n",tag->artist);
 	if(tag->album) myfprintf(fp,"Album: %s\n",tag->album);