make "update" command background/non-blocking

git-svn-id: https://svn.musicpd.org/mpd/trunk@665 09075e82-0dd4-0310-85a5-a0d7c8717e4f

src/command.c

@@ -317,8 +317,7 @@ int handleSearch(FILE * fp, unsigned int * permission, int argArrayLength,
 int handleUpdate(FILE * fp, unsigned int * permission, int argArrayLength, 
 		char ** argArray) 
 {
-	incrPlaylistVersion(); 
-        return updateMp3Directory(fp);
+        return updateInit(fp);
 }
 
 int handleNext(FILE * fp, unsigned int * permission, int argArrayLength, 

src/directory.c

@@ -26,14 +26,21 @@
 #include "conf.h"
 #include "stats.h"
 #include "playlist.h"
+#include "listen.h"
+#include "interface.h"
+#include "volume.h"
 
 #include <string.h>
 #include <sys/types.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <sys/wait.h>
 #include <sys/stat.h>
 #include <dirent.h>
 #include <unistd.h>
 #include <stdio.h>
 #include <errno.h>
+#include <signal.h>
 
 #define DIRECTORY_DIR		"directory: "
 #define DIRECTORY_MTIME		"mtime: "
@@ -63,6 +70,8 @@ Directory * mp3rootDirectory = NULL;
 
 char directorydb[MAXPATHLEN+1];
 
+int directory_updatePid = 0;
+
 DirectoryList * newDirectoryList();
 
 int addToDirectory(Directory * directory, char * shortname, char * name);
@@ -79,6 +88,61 @@ void deleteEmptyDirectoriesInDirectory(Directory * directory);
 
 int addSubDirectoryToDirectory(Directory * directory, char * shortname, char * name);
 
+void directory_sigChldHandler(int pid, int status) {
+	if(directory_updatePid==pid) {
+		if(WIFSIGNALED(status) && WTERMSIG(status)!=SIGTERM) {
+                        ERROR("update process died from a "
+                                        "non-TERM signal: %i\n",
+                                        WTERMSIG(status));
+                }
+		else if(WEXITSTATUS(status)==EXIT_SUCCESS) {
+			readDirectoryDB();
+			incrPlaylistVersion();
+			DEBUG("direcotry_sigChldHandler: "
+					"updated db succesffully\n");
+		}
+		directory_updatePid = 0;
+	}
+}
+
+int updateInit(FILE * fp) {
+	if(directory_updatePid > 0) {
+		myfprintf(fp,"%s already updating\n",COMMAND_RESPOND_ERROR);
+		return -1;
+	}
+
+	directory_updatePid = fork();
+       	if(directory_updatePid==0) {
+              	/* child */
+               	struct sigaction sa;
+               	sa.sa_flags = 0;
+               	sigemptyset(&sa.sa_mask);
+
+               	sa.sa_handler = SIG_IGN;
+               	sigaction(SIGPIPE,&sa,NULL);
+               	sigaction(SIGCHLD,&sa,NULL);
+
+               	close(listenSocket);
+               	freeAllInterfaces();
+               	finishPlaylist();
+		finishVolume();
+
+		if(updateMp3Directory(stderr)) exit(EXIT_FAILURE);
+		exit(EXIT_SUCCESS);
+	}
+	else if(directory_updatePid < 0) {
+		ERROR("updateInit: Problems forking()'ing\n");
+		myfprintf(fp,"%s problems trying to update\n",
+				COMMAND_RESPOND_ERROR);
+		directory_updatePid = 0;
+		return -1;
+	}
+
+	DEBUG("updateInit: fork()'d update child\n");
+
+	return 0;
+}
+
 Directory * newDirectory(Directory * parentDirectory, char * dirname, time_t mtime) {
 	Directory * directory;
 

src/directory.h

@@ -28,6 +28,10 @@
 
 extern char directorydb[MAXPATHLEN+1];
 
+void directory_sigChldHandler(int pid, int status);
+
+int updateInit(FILE * fp);
+
 void initMp3Directory();
 
 void closeMp3Directory();

src/player.c

@@ -66,10 +66,7 @@ void resetPlayer() {
 	getPlayerData()->playerControl.decode_pid = 0;
 }
 
-void player_sigHandler(int signal) {
-	if(signal==SIGCHLD) {
-		int status;
-		int pid = wait3(&status,WNOHANG,NULL);
+void player_sigChldHandler(int pid, int status) {
 	if(player_pid==pid) {
 		if(WIFSIGNALED(status) && WTERMSIG(status)!=SIGTERM) {
 			ERROR("player process died from a "
@@ -78,8 +75,7 @@ void player_sigHandler(int signal) {
 		}
 		resetPlayer();
 	}
-		else if(pid==getPlayerData()->playerControl.decode_pid &&
-				player_pid<=0) 
+	else if(pid==getPlayerData()->playerControl.decode_pid && player_pid<=0)
 	{
 		if(WIFSIGNALED(status) && WTERMSIG(status)!=SIGTERM) {
 			ERROR("(caught by master parent) "
@@ -89,7 +85,6 @@ void player_sigHandler(int signal) {
 		}
 		getPlayerData()->playerControl.decode_pid = 0;
 	}
-	}
 }
 
 int playerInit() {

src/player.h

@@ -79,7 +79,7 @@ typedef struct _PlayerControl {
 	int decode_pid;
 } PlayerControl;
 
-void player_sigHandler(int signal);
+void player_sigChldHandler(int pid, int status);
 
 int playerPlay(FILE * fp, char * utf8file);
 

src/playlist.c

@@ -144,7 +144,9 @@ void finishPlaylist() {
 	stopPlaylist(stderr);
 	clearPlaylist(stderr);
 	free(playlist.songs);
+	playlist.songs = NULL;
 	free(playlist.order);
+	playlist.order = NULL;
 }
 
 int clearPlaylist(FILE * fp) {
@@ -627,6 +629,8 @@ int deleteFromPlaylist(FILE * fp, int song) {
 void deleteASongFromPlaylist(Song * song) {
 	int i;
 
+	if(NULL==playlist.songs) return;
+	
 	for(i=0;i<playlist.length;i++) {
 		if(song==playlist.songs[i]) {
 			deleteFromPlaylist(stderr,i);

src/sig_handlers.c

@@ -22,6 +22,10 @@
 #include "directory.h"
 
 #include <signal.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <sys/wait.h>
 
 struct sigaction original_termSa;
 struct sigaction original_hupSa;
@@ -41,6 +45,15 @@ void hupSigHandler(int signal) {
 	readDirectoryDB();
 }
 
+void chldSigHandler(int signal) {
+	int status;
+	int pid = wait3(&status,WNOHANG,NULL);
+	if(pid>0) {
+		player_sigChldHandler(pid,status);
+		directory_sigChldHandler(pid,status);
+	}
+}
+
 void initSigHandlers() {
 	struct sigaction sa;
 
@@ -50,12 +63,14 @@ void initSigHandlers() {
 	sigaction(SIGPIPE,&sa,NULL);
 	sa.sa_handler = usr1SigHandler;
 	sigaction(SIGUSR1,&sa,NULL);
-	sa.sa_handler = player_sigHandler;
+	sigaddset(&sa.sa_mask,SIGTERM);
+	sigaddset(&sa.sa_mask,SIGHUP);
+	sigaddset(&sa.sa_mask,SIGCHLD);
+	sa.sa_handler = chldSigHandler;
 	sigaction(SIGCHLD,&sa,NULL);
 	sa.sa_handler = hupSigHandler;
 	sigaction(SIGHUP,&sa,&original_hupSa);
 	sa.sa_handler = termSigHandler;
-	/*sigaddset(&sa.sa_mask,SIGTERM);*/
 	sigaction(SIGTERM,&sa,&original_termSa);
 }
 
@@ -70,6 +85,7 @@ void blockSignals() {
 	sigemptyset(&sset);
 	sigaddset(&sset,SIGCHLD);
 	sigaddset(&sset,SIGUSR1);
+	sigaddset(&sset,SIGHUP);
 	sigprocmask(SIG_BLOCK,&sset,NULL);
 }
 
@@ -79,6 +95,7 @@ void unblockSignals() {
 	sigemptyset(&sset);
 	sigaddset(&sset,SIGCHLD);
 	sigaddset(&sset,SIGUSR1);
+	sigaddset(&sset,SIGHUP);
 	sigprocmask(SIG_UNBLOCK,&sset,NULL);
 }
 
@@ -87,6 +104,7 @@ void blockTermSignal() {
 
 	sigemptyset(&sset);
 	sigaddset(&sset,SIGTERM);
+	sigaddset(&sset,SIGHUP);
 	sigprocmask(SIG_BLOCK,&sset,NULL);
 }
 
@@ -95,5 +113,6 @@ void unblockTermSignal() {
 
 	sigemptyset(&sset);
 	sigaddset(&sset,SIGTERM);
+	sigaddset(&sset,SIGHUP);
 	sigprocmask(SIG_UNBLOCK,&sset,NULL);
 }