[Lldb-commits] [lldb] a37c381 - Increase memory buffer for scanning objc classes on darwin systems

[Jason Molenda via lldb-commits]

Author: Jason Molenda
Date: 2022-02-04T23:53:27-08:00
New Revision: a37c38176a5a1f797e6bc2b8771be017394e8e32

URL: https://github.com/llvm/llvm-project/commit/a37c38176a5a1f797e6bc2b8771be017394e8e32
DIFF: https://github.com/llvm/llvm-project/commit/a37c38176a5a1f797e6bc2b8771be017394e8e32.diff

LOG: Increase memory buffer for scanning objc classes on darwin systems

iOS systems are getting near this limit; double itfrom a 150kb
buffer to a 300kb buffer, which is freed after processing the
list of classes.

rdar://88454594
Differential Revision: https://reviews.llvm.org/D118972

Added: 
    

Modified: 
    lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp

Removed: 
    


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diff  --git a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
index cfba6db54997a..64a1bd6233f97 100644
--- a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
+++ b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
@@ -2008,7 +2008,8 @@ AppleObjCRuntimeV2::SharedCacheClassInfoExtractor::UpdateISAToDescriptorMap() {
       shared_cache_base_addr == LLDB_INVALID_ADDRESS)
     return DescriptorMapUpdateResult::Fail();
 
-  const uint32_t num_classes = 128 * 1024;
+  // The number of entries to pre-allocate room for.
+  const uint32_t max_num_classes = 256 * 1024;
 
   UtilityFunction *get_class_info_code = GetClassInfoUtilityFunction(exe_ctx);
   if (!get_class_info_code) {
@@ -2030,7 +2031,7 @@ AppleObjCRuntimeV2::SharedCacheClassInfoExtractor::UpdateISAToDescriptorMap() {
   DiagnosticManager diagnostics;
 
   const uint32_t class_info_byte_size = addr_size + 4;
-  const uint32_t class_infos_byte_size = num_classes * class_info_byte_size;
+  const uint32_t class_infos_byte_size = max_num_classes * class_info_byte_size;
   lldb::addr_t class_infos_addr = process->AllocateMemory(
       class_infos_byte_size, ePermissionsReadable | ePermissionsWritable, err);
   const uint32_t relative_selector_offset_addr_size = 64;
@@ -2096,10 +2097,12 @@ AppleObjCRuntimeV2::SharedCacheClassInfoExtractor::UpdateISAToDescriptorMap() {
       num_class_infos = return_value.GetScalar().ULong();
       LLDB_LOG(log, "Discovered {0} Objective-C classes in the shared cache",
                num_class_infos);
-      assert(num_class_infos <= num_classes);
+      // Assert if there were more classes than we pre-allocated
+      // room for.
+      assert(num_class_infos <= max_num_classes);
       if (num_class_infos > 0) {
-        if (num_class_infos > num_classes) {
-          num_class_infos = num_classes;
+        if (num_class_infos > max_num_classes) {
+          num_class_infos = max_num_classes;
 
           success = false;
         } else {