8354969: Add strdup function for ResourceArea

Reviewed-by: dholmes, iklam

Author: toxaart

src/hotspot/os/windows/perfMemory_windows.cpp

@@ -1606,10 +1606,8 @@ static void open_file_mapping(int vmid, char** addrp, size_t* sizep, TRAPS) {
   // using resource arrays for these names prevents the leaks
   // that would otherwise occur.
   //
-  char* rfilename = NEW_RESOURCE_ARRAY(char, strlen(filename) + 1);
-  char* robjectname = NEW_RESOURCE_ARRAY(char, strlen(objectname) + 1);
-  strcpy(rfilename, filename);
-  strcpy(robjectname, objectname);
+  char* rfilename = ResourceArea::strdup(THREAD, filename);
+  char* robjectname = ResourceArea::strdup(THREAD, objectname);
 
   // free the c heap resources that are no longer needed
   FREE_C_HEAP_ARRAY(char, luser);

src/hotspot/share/classfile/classLoader.cpp

@@ -1507,8 +1507,7 @@ char* ClassLoader::get_canonical_path(const char* orig, Thread* thread) {
   char* canonical_path = NEW_RESOURCE_ARRAY_IN_THREAD(thread, char, JVM_MAXPATHLEN);
   ResourceMark rm(thread);
   // os::native_path writes into orig_copy
-  char* orig_copy = NEW_RESOURCE_ARRAY_IN_THREAD(thread, char, strlen(orig)+1);
-  strcpy(orig_copy, orig);
+  char* orig_copy = ResourceArea::strdup(thread, orig);
   if ((CanonicalizeEntry)(os::native_path(orig_copy), canonical_path, JVM_MAXPATHLEN) < 0) {
     return nullptr;
   }

src/hotspot/share/classfile/modules.cpp

@@ -641,8 +641,7 @@ const char* Modules::ArchivedProperty::get_numbered_property_as_sorted_string()
     if (prop_value == nullptr) {
       break;
     }
-    char* p = resource_allocate_bytes(strlen(prop_value) + 1);
-    strcpy(p, prop_value);
+    char* p = ResourceArea::strdup(prop_value);
     while (*p == ',') p++; // skip leading commas
     while (*p) {
       char* next = strchr(p, ',');

src/hotspot/share/memory/arena.hpp

@@ -216,6 +216,13 @@ class Arena : public CHeapObjBase {
   MemTag get_mem_tag() const { return _mem_tag; }
   Tag get_tag() const { return _tag; }
 
+  char* strdup(const char* s) {
+    const size_t sz = strlen(s) + 1;
+    char* ptr = (char*)Amalloc(sz);
+    memcpy(ptr, s, sz);
+    return ptr;
+  }
+
 private:
   // Reset this Arena to empty, access will trigger grow if necessary
   void reset(void) {

src/hotspot/share/memory/resourceArea.hpp

@@ -143,6 +143,14 @@ class ResourceArea: public Arena {
       assert(_max == state._max,     "Sanity check: idempotence");
     }
   }
+
+  static char* strdup(const char* src) {
+    return static_cast<Arena*>(Thread::current()->resource_area())->strdup(src);
+  }
+
+  static char* strdup(Thread* thread, const char* src) {
+    return static_cast<Arena*>(thread->resource_area())->strdup(src);
+  }
 };
 
 

src/hotspot/share/prims/jvmtiEnvBase.cpp

@@ -468,8 +468,7 @@ JvmtiEnvBase::get_all_native_method_prefixes(int* count_ptr) {
       // retrieve a prefix and so that it is safe against asynchronous changes
       // copy it into the resource area
       char* prefix = prefixes[j];
-      char* prefix_copy = NEW_RESOURCE_ARRAY(char, strlen(prefix)+1);
-      strcpy(prefix_copy, prefix);
+      char* prefix_copy = ResourceArea::strdup(prefix);
       prefix_array->at_put_grow(total_count++, prefix_copy);
     }
   }

src/hotspot/share/services/heapDumper.cpp

@@ -2709,8 +2709,7 @@ HeapDumper::~HeapDumper() {
 // returns the error string (resource allocated), or null
 char* HeapDumper::error_as_C_string() const {
   if (error() != nullptr) {
-    char* str = NEW_RESOURCE_ARRAY(char, strlen(error())+1);
-    strcpy(str, error());
+    char* str = ResourceArea::strdup(error());
     return str;
   } else {
     return nullptr;

test/hotspot/gtest/memory/test_arena.cpp

@@ -381,3 +381,13 @@ TEST_VM(Arena, different_chunk_sizes) {
     Arena ar7(mtTest, Arena::Tag::tag_other, random_arena_chunk_size());
   }
 }
+
+TEST_VM(Arena, string_duplicate)
+{
+  char testString[] = "this is a test string";
+  Arena ar(mtTest);
+  auto copy = ar.strdup(&testString[0]);
+  int result = strcmp(testString, copy);
+  ASSERT_TRUE(0 == result);
+  ASSERT_NE(copy, &testString[0]);
+}