[patch] perchild.c (Re: setjmp/longjmp vs try/throw/catch)

[Tsuyoshi SASAMOTO]

>Switching to setjmp/longjmp does appear to work well with apache and gcc.
>But that leaves me wondering if I need to worry about thread-safety.
>Is using setjmp/longjmp with Worker or Windoze MPM asking for trouble?
>And if so, is there an alternative approach I could try?

Please refer to this discussion about thread safety of setjmp/longjmp:
    http://groups.google.com/[EMAIL PROTECTED]


And... in perchild.c, I found setjmp/longjmp is used unsafely
(one jmpbuffer is shared by all threads).


Tsuyoshi SASAMOTO
[EMAIL PROTECTED]

--- httpd-2.0/server/mpm/experimental/perchild/perchild.c       Tue Mar 16 08:08:41 
2004
+++ httpd-2.0/server/mpm/experimental/perchild/perchild.c       Wed Jul 21 04:26:15 
2004
@@ -137,7 +137,7 @@
 static int requests_this_child;
 static int num_listensocks = 0;
 static ap_pod_t *pod;
-static jmp_buf jmpbuffer;
+static jmp_buf *jmpbuffers;
 
 struct child_info_t {
     uid_t uid;
@@ -617,7 +617,7 @@
     bodylen = strlen(body);
 
     headers = iov.iov_base;
-    headerslen = body - headers;
+    headerslen = body - 1 - headers;
 
     bucket = apr_bucket_heap_create(body, bodylen, NULL, alloc);
     APR_BRIGADE_INSERT_HEAD(bb, bucket);
@@ -758,7 +758,7 @@
                 }
             }
             apr_thread_mutex_unlock(idle_thread_count_mutex);
-            if (setjmp(jmpbuffer) != 1) {
+            if (setjmp(jmpbuffers[thread_num]) != 1) {
                 process_socket(ptrans, csd, conn_id, bucket_alloc);
             }
             else {
@@ -1668,6 +1668,8 @@
     }
     ap_child_table = (ap_ctable *)apr_pcalloc(p, server_limit * sizeof(ap_ctable));
 
+    jmpbuffers = (jmp_buf *)apr_palloc(p, thread_limit * sizeof(jmp_buf));
+
     return OK;
 }
 
@@ -1704,7 +1706,7 @@
                              ap_server_conf, "Could not pass request to proper "
                              "child, request will not be honored.");
             }
-            longjmp(jmpbuffer, 1); 
+            longjmp(jmpbuffers[thread_num], 1); 
         }
         return OK;
     }