document my understanding of why the pipe_of_death_mutex is a Good Thing

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@88967 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/server/mpm/threaded/threaded.c b/server/mpm/threaded/threaded.c
index 6a4bd53a6976ed0a12dc39f9c21dc022d0d2a711..463780efcf9ae333135ff13a353fe38b4d34754a 100644 (file)
--- a/server/mpm/threaded/threaded.c
+++ b/server/mpm/threaded/threaded.c
@@ -129,7 +129,8 @@ char ap_coredump_dir[MAX_STRING_LEN];
 
 static apr_file_t *pipe_of_death_in = NULL;
 static apr_file_t *pipe_of_death_out = NULL;
-static apr_lock_t *pipe_of_death_mutex;
+static apr_lock_t *pipe_of_death_mutex;   /* insures that a child process only
+                                             consumes one character */
 
 /* *Non*-shared http_main globals... */