Changeset 23611

Timestamp:

2008-04-30 13:31:20 (6 months ago)

Author:

zarzycki@…

Message:

<rdar://problem/5737942> WindowServer is hammering my console with "Please fix the framework to cache the Mach port" messages

Files:

• trunk/launchd/src/libbootstrap.c (modified) (1 diff)

trunk/launchd/src/libbootstrap.c

@@ -170 +170 @@
 bootstrap_look_up2(mach_port_t bp, name_t service_name, mach_port_t *sp, pid_t target_pid, uint64_t flags)
 {
-        kern_return_t kr;
+        static pthread_mutex_t bslu2_lock = PTHREAD_MUTEX_INITIALIZER;
+        static mach_port_t prev_bp;
+        static mach_port_t prev_sp;
+        static name_t prev_name;
+        kern_return_t kr = 0;
         mach_port_t puc;
 
+        pthread_mutex_lock(&bslu2_lock);
+
+        if (prev_sp) {
+                if ((bp == prev_bp) && (strncmp(prev_name, service_name, sizeof(name_t)) == 0)
+                                && (mach_port_mod_refs(mach_task_self(), prev_sp, MACH_PORT_RIGHT_SEND, 1) == 0)) {
+                        *sp = prev_sp;
+                        goto out;
+                } else {
+                        mach_port_deallocate(mach_task_self(), prev_sp);
+                        prev_sp = 0;
+                }
+        }
+
         if ((kr = vproc_mig_look_up2(bp, service_name, sp, target_pid, flags)) != VPROC_ERR_TRY_PER_USER) {
-                return kr;
+                goto out;
         }
 
         if ((kr = vproc_mig_lookup_per_user_context(bp, 0, &puc)) != 0) {
-                return kr;
+                goto out;
         }
 
         kr = vproc_mig_look_up2(puc, service_name, sp, target_pid, flags);
         mach_port_deallocate(mach_task_self(), puc);
+
+out:
+        if (kr == 0 && prev_sp == 0 && mach_port_mod_refs(mach_task_self(), *sp, MACH_PORT_RIGHT_SEND, 1) == 0) {
+                /* We're going to hold on to a send right as a MRU cache */
+                prev_bp = bp;
+                prev_sp = *sp;
+                strlcpy(prev_name, service_name, sizeof(name_t));
+        }
+
+        pthread_mutex_unlock(&bslu2_lock);
 
         return kr;