[Fuchsia] Give VMOs names

runtime/vm/virtual_memory_fuchsia.cc

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(HOST_OS_FUCHSIA)
 
 #include "vm/virtual_memory.h"
 
 #include <magenta/process.h>
@@ skipping 183 matching lines @@
   mx_status_t status =
       mx_vmar_unmap(vmar, reinterpret_cast<uintptr_t>(address), size);
   if (status != NO_ERROR) {
     LOG_ERR("mx_vmar_unmap failed: %s\n", mx_status_get_string(status));
     return false;
   }
   return true;
 }
 
 
-bool VirtualMemory::Commit(uword addr, intptr_t size, bool executable) {
+bool VirtualMemory::Commit(uword addr,
+                           intptr_t size,
+                           bool executable,
+                           const char* name) {
   ASSERT(Contains(addr));
   ASSERT(Contains(addr + size) || (addr + size == end()));
   mx_handle_t vmo = MX_HANDLE_INVALID;
   mx_status_t status = mx_vmo_create(size, 0u, &vmo);
   if (status != NO_ERROR) {
     LOG_ERR("mx_vmo_create(%ld) failed: %s\n", size,
             mx_status_get_string(status));
     return false;
   }
 
+  if (name != NULL) {
+    status = mx_object_set_property(vmo, MX_PROP_NAME, name, strlen(name));
+    if (status != NO_ERROR) {

[abarth, 2017/06/09 19:46:40]

The pattern we've been using is to ignore errors on setting the name.

[zra, 2017/06/09 20:10:22]

Done.

+      mx_handle_close(vmo);
+      LOG_ERR("mx_object_set_property on vmo failed: %s\n",
+          mx_status_get_string(status));
+    }
+  }
+
   mx_handle_t vmar = static_cast<mx_handle_t>(handle());
   const size_t offset = addr - start();
   const uint32_t flags = MX_VM_FLAG_SPECIFIC | MX_VM_FLAG_PERM_READ |
                          MX_VM_FLAG_PERM_WRITE |
                          (executable ? MX_VM_FLAG_PERM_EXECUTE : 0);
   uintptr_t mapped_addr;
   status = mx_vmar_map(vmar, offset, vmo, 0, size, flags, &mapped_addr);
   if (status != NO_ERROR) {
     mx_handle_close(vmo);
     LOG_ERR("mx_vmar_map(%ld, %ld, %u) failed: %s\n", offset, size, flags,
@@ skipping 49 matching lines @@
     return false;
   }
   LOG_INFO("mx_vmar_protect(%lx, %lx, %x) success\n", page_address,
            end_address - page_address, prot);
   return true;
 }
 
 }  // namespace dart
 
 #endif  // defined(HOST_OS_FUCHSIA)