Adds a wrapper for fork(2) that drops and real-time priority. The function
ast_dropprio_fork() should perhaps be added in another file.

--- asterisk/asterisk.c.ORIG	2004-11-10 20:55:50.000000000 +0100
+++ asterisk/asterisk.c	2004-11-10 21:22:33.000000000 +0100
@@ -187,7 +187,7 @@
 	struct rusage rusage;
 	int status;
 	void (*prev_handler) = signal(SIGCHLD, null_sig_handler);
-	pid = fork();
+	pid = ast_dropprio_fork();
 	if (pid == 0) {
 		/* Close file descriptors and launch system command */
 		for (x=STDERR_FILENO + 1; x<4096;x++) {
@@ -518,6 +518,18 @@
 	return 0;
 }
 
+pid_t ast_dropprio_fork(void)
+{
+	pid_t pid;
+
+	pid = fork();
+	if (pid == 0) {
+		/* This is the child. Drop elevated priority */
+		set_priority(0);
+	}
+	return pid;
+}
+
 static void ast_run_atexits(void)
 {
 	struct ast_atexit *ae;
--- asterisk/include/asterisk/app.h.wf-dropprio-fork	2005-01-22 13:31:14.000000000 +0100
+++ asterisk/include/asterisk/app.h	2005-01-22 13:53:35.000000000 +0100
@@ -53,6 +53,9 @@
 /*! Safely spawn an external program while closingn file descriptors */
 extern int ast_safe_system(const char *s);
 
+/*! Fork and drop elevated priority in the child */
+extern pid_t ast_dropprio_fork(void);
+
 /*! Send DTMF to chan (optionally entertain peer)   */
 int ast_dtmf_stream(struct ast_channel *chan, struct ast_channel *peer, char *digits, int between);
 
--- asterisk/apps/app_festival.c.ORIG	2004-11-10 21:22:56.000000000 +0100
+++ asterisk/apps/app_festival.c	2004-11-10 21:23:39.000000000 +0100
@@ -21,6 +21,7 @@
 #include <asterisk/config.h>
 #include <asterisk/utils.h>
 #include <asterisk/lock.h>
+#include <asterisk/app.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
@@ -111,7 +112,7 @@
 	char c;
 #endif
 
-        res = fork();
+        res = ast_dropprio_fork();
         if (res < 0)
                 ast_log(LOG_WARNING, "Fork failed\n");
         if (res)
--- asterisk/apps/app_ices.c.ORIG	2004-11-10 21:24:11.000000000 +0100
+++ asterisk/apps/app_ices.c	2004-11-10 21:24:59.000000000 +0100
@@ -19,6 +19,7 @@
 #include <asterisk/pbx.h>
 #include <asterisk/module.h>
 #include <asterisk/translate.h>
+#include <asterisk/app.h>
 #include <string.h>
 #include <stdio.h>
 #include <signal.h>
@@ -52,7 +53,7 @@
 {
 	int res;
 	int x;
-	res = fork();
+	res = ast_dropprio_fork();
 	if (res < 0) 
 		ast_log(LOG_WARNING, "Fork failed\n");
 	if (res)
--- asterisk/apps/app_mp3.c.ORIG	2004-11-10 21:25:20.000000000 +0100
+++ asterisk/apps/app_mp3.c	2004-11-10 21:25:36.000000000 +0100
@@ -19,6 +19,7 @@
 #include <asterisk/pbx.h>
 #include <asterisk/module.h>
 #include <asterisk/translate.h>
+#include <asterisk/app.h>
 #include <string.h>
 #include <stdio.h>
 #include <signal.h>
@@ -49,7 +50,7 @@
 {
 	int res;
 	int x;
-	res = fork();
+	res = ast_dropprio_fork();
 	if (res < 0) 
 		ast_log(LOG_WARNING, "Fork failed\n");
 	if (res)
--- asterisk/res/res_musiconhold.c.ORIG	2004-11-10 08:59:32.000000000 +0100
+++ asterisk/res/res_musiconhold.c	2004-11-10 21:27:43.000000000 +0100
@@ -24,6 +24,7 @@
 #include <asterisk/musiconhold.h>
 #include <asterisk/config.h>
 #include <asterisk/utils.h>
+#include <asterisk/app.h>
 #include <stdlib.h>
 #include <errno.h>
 #include <unistd.h>
@@ -211,7 +212,7 @@
 		sleep(respawn_time - (time(NULL) - class->start));
 	}
 	time(&class->start);
-	class->pid = fork();
+	class->pid = ast_dropprio_fork();
 	if (class->pid < 0) {
 		close(fds[0]);
 		close(fds[1]);
--- asterisk/res/res_agi.c.ORIG	2004-11-10 21:26:24.000000000 +0100
+++ asterisk/res/res_agi.c	2004-11-10 21:26:45.000000000 +0100
@@ -24,6 +24,7 @@
 #include <asterisk/module.h>
 #include <asterisk/astdb.h>
 #include <asterisk/callerid.h>
+#include <asterisk/app.h>
 #include <math.h>
 #include <stdlib.h>
 #include <unistd.h>
@@ -242,7 +243,7 @@
 			return -1;
 		}
 	}
-	pid = fork();
+	pid = ast_dropprio_fork();
 	if (pid < 0) {
 		ast_log(LOG_WARNING, "Failed to fork(): %s\n", strerror(errno));
 		return -1;