ok, fix some bug due to a child process dieing before the parent can

even assign pid, thus we need to block CHLD signal around fork();

git-svn-id: https://svn.musicpd.org/mpd/trunk@694 09075e82-0dd4-0310-85a5-a0d7c8717e4f

src/decode.c

@@ -25,6 +25,7 @@
 #include "audio.h"
 #include "path.h"
 #include "log.h"
+#include "sig_handlers.h"
 
 #ifdef HAVE_MAD
 #include "mp3_decode.h"
@@ -216,10 +217,13 @@ int decoderInit(PlayerControl * pc, Buffer * cb, AudioFormat *af,
 	int pid;
 	int ret; 
 	decode_pid = &(pc->decode_pid);
+
+	blockSignals();
 	pid = fork();
 
 	if(pid==0) {
 		/* CHILD */
+		unblockSignals();
 
 		while(1) {
 			if(dc->start) {
@@ -279,12 +283,15 @@ int decoderInit(PlayerControl * pc, Buffer * cb, AudioFormat *af,
 		/* END OF CHILD */
 	}
 	else if(pid<0) {
+		unblockSignals();
 		strncpy(pc->erroredFile,pc->file,MAXPATHLEN);
 		pc->erroredFile[MAXPATHLEN] = '\0';
 		pc->error = PLAYER_ERROR_SYSTEM;
 		return -1;
 	}
-	else *decode_pid = pid;
+
+	*decode_pid = pid;
+	unblockSignals();
 
 	return 0;
 }

src/directory.c

@@ -117,6 +117,7 @@ void directory_sigChldHandler(int pid, int status) {
 			DEBUG("direcotry_sigChldHandler: "
 					"updated db succesffully\n");
 		}
+		else ERROR("problems updating db\n");
 		directory_updatePid = 0;
 	}
 }
@@ -127,8 +128,12 @@ int updateInit(FILE * fp, List * pathList) {
 		return -1;
 	}
 
+	/* need to block CHLD signal, cause it can exit before we
+		even get a chance to assign directory_updatePID */
+	blockSignals();	
 	directory_updatePid = fork();
        	if(directory_updatePid==0) {
+		unblockSignals();
               	/* child */
                	struct sigaction sa;
                	sa.sa_flags = 0;
@@ -163,8 +168,6 @@ int updateInit(FILE * fp, List * pathList) {
 				}
 				else {
 					if(updateDirectory(directory)<0)  {
-						ERROR("problems updating music "
-							"db\n");
 						exit(EXIT_FAILURE);
 					}
 				}
@@ -175,19 +178,19 @@ int updateInit(FILE * fp, List * pathList) {
 		if(writeDirectoryDB()<0) {
 			ERROR("problems writing music db file, \"%s\"\n",
 					directorydb);
-			myfprintf(fp,"%s problems writing music db\n",
-					COMMAND_RESPOND_ERROR);
 			exit(EXIT_FAILURE);
 		}
 		exit(EXIT_SUCCESS);
 	}
 	else if(directory_updatePid < 0) {
+		unblockSignals();
 		ERROR("updateInit: Problems forking()'ing\n");
 		myfprintf(fp,"%s problems trying to update\n",
 				COMMAND_RESPOND_ERROR);
 		directory_updatePid = 0;
 		return -1;
 	}
+	unblockSignals();
 
 	directory_updateJobId++;
 	if(directory_updateJobId > 1<<15) directory_updateJobId = 1;

src/player.c

@@ -31,6 +31,7 @@
 #include "volume.h"
 #include "playerData.h"
 #include "permission.h"
+#include "sig_handlers.h"
 
 #include <stdio.h>
 #include <sys/types.h>
@@ -88,11 +89,14 @@ void player_sigChldHandler(int pid, int status) {
 }
 
 int playerInit() {
+	blockSignals();
 	player_pid = fork();
-
 	if(player_pid==0) {
 		PlayerControl * pc = &(getPlayerData()->playerControl);
 		struct sigaction sa;
+
+		unblockSignals();
+
 		sa.sa_flags = 0;
 		sigemptyset(&sa.sa_mask);
 
@@ -136,11 +140,13 @@ int playerInit() {
 		exit(EXIT_SUCCESS);
 	}
 	else if(player_pid<0) {
+		unblockSignals();
 		ERROR("player Problems fork()'ing\n");
 		player_pid = 0;
 
 		return -1;
 	}
+	unblockSignals();
 
 	return 0;
 }