Merge "Avoid pathologically high memory use for DEX files." into sc-dev

1 files changed, 15 insertions, 0 deletions

diff --git a/libunwindstack/DexFile.cpp b/libunwindstack/DexFile.cpp
index c3e53c7..e576354 100644
--- a/libunwindstack/DexFile.cpp
+++ b/libunwindstack/DexFile.cpp
@@ -89,6 +89,21 @@ std::shared_ptr<DexFile> DexFile::Create(uint64_t base_addr, uint64_t file_size,
   if (!has_dex_support || file_size == 0) {
     return nullptr;
   }
+
+  // Do not try to open the DEX file if the file name ends with "(deleted)". It does not exist.
+  // This happens when an app is background-optimized by ART and all of its files are replaced.
+  // Furthermore, do NOT try to fallback to in-memory copy. It would work, but all apps tend to
+  // be background-optimized at the same time, so it would lead to excessive memory use during
+  // system-wide profiling (essentially copying all dex files for all apps: hundreds of MBs).
+  // This will cause missing symbols in the backtrace, however, that outcome is inevitable
+  // anyway, since we can not obtain mini-debug-info for the deleted .oat files.
+  const std::string_view filename(info != nullptr ? info->name() : "");
+  const std::string_view kDeleted("(deleted)");
+  if (filename.size() >= kDeleted.size() &&
+      filename.substr(filename.size() - kDeleted.size()) == kDeleted) {
+    return nullptr;
+  }
+
   std::shared_ptr<DexFile> dex_file = CreateFromDisk(base_addr, file_size, info);
   if (dex_file != nullptr) {
     return dex_file;