Fix the segdefault bug in CompressedSecondaryCache and its tests (#10507)

Summary:
This fix is to replace `AllocateBlock()` with `new`. Once I figure out why `AllocateBlock()` might cause the segfault, I will update the implementation.

Fix the bug that causes ./compressed_secondary_cache_test output following test failures:

```
Note: Google Test filter = CompressedSecondaryCacheTest.MergeChunksIntoValueTest
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from CompressedSecondaryCacheTest
[ RUN      ] CompressedSecondaryCacheTest.MergeChunksIntoValueTest
[       OK ] CompressedSecondaryCacheTest.MergeChunksIntoValueTest (1 ms)
[----------] 1 test from CompressedSecondaryCacheTest (1 ms total)

[----------] Global test environment tear-down
[==========] 1 test from 1 test case ran. (9 ms total)
[  PASSED  ] 1 test.
t/run-compressed_secondary_cache_test-CompressedSecondaryCacheTest.MergeChunksIntoValueTest: line 4: 1091086 Segmentation fault      (core dumped) TEST_TMPDIR=$d ./compressed_secondary_cache_test --gtest_filter=CompressedSecondaryCacheTest.MergeChunksIntoValueTest
Note: Google Test filter = CompressedSecondaryCacheTest.BasicTestWithMemoryAllocatorAndCompression
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from CompressedSecondaryCacheTest
[ RUN      ] CompressedSecondaryCacheTest.BasicTestWithMemoryAllocatorAndCompression
[       OK ] CompressedSecondaryCacheTest.BasicTestWithMemoryAllocatorAndCompression (1 ms)
[----------] 1 test from CompressedSecondaryCacheTest (1 ms total)

[----------] Global test environment tear-down
[==========] 1 test from 1 test case ran. (2 ms total)
[  PASSED  ] 1 test.
t/run-compressed_secondary_cache_test-CompressedSecondaryCacheTest.BasicTestWithMemoryAllocatorAndCompression: line 4: 1090883 Segmentation fault      (core dumped) TEST_TMPDIR=$d ./compressed_secondary_cache_test --gtest_filter=CompressedSecondaryCacheTest.BasicTestWithMemoryAllocatorAndCompression

```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10507

Test Plan:
Test 1:
```
$make -j 24
$./compressed_secondary_cache_test
```
Test 2:
```
$COMPILE_WITH_ASAN=1  make -j 24
$./compressed_secondary_cache_test
```
Test 3:
```
$COMPILE_WITH_TSAN=1 make -j 24
$./compressed_secondary_cache_test
```

Reviewed By: anand1976

Differential Revision: D38529885

Pulled By: gitbw95

fbshipit-source-id: d903fa3fadbd4d29f9528728c63a4f61c4396890

HISTORY.md

@@ -23,6 +23,7 @@
 * Fixed a bug where blobs read during compaction would pollute the cache.
 * Fixed a data race in LRUCache when used with a secondary_cache.
 * Fixed a bug where blobs read by iterators would be inserted into the cache even with the `fill_cache` read option set to false.
+* Fixed the segfault caused by `AllocateData()` in `CompressedSecondaryCache::SplitValueIntoChunks()` and `MergeChunksIntoValueTest`.
 
 ### Behavior Change
 * Added checksum handshake during the copying of decompressed WAL fragment. This together with #9875, #10037, #10212, #10114 and #10319 provides end-to-end integrity protection for write batch during recovery.

cache/compressed_secondary_cache.cc

@@ -149,7 +149,6 @@ CompressedSecondaryCache::SplitValueIntoChunks(
 
   CacheValueChunk dummy_head = CacheValueChunk();
   CacheValueChunk* current_chunk = &dummy_head;
-  CacheAllocationPtr ptr;
   // Do not split when value size is large or there is no compression.
   size_t predicted_chunk_size{0};
   size_t actual_chunk_size{0};
@@ -170,8 +169,9 @@ CompressedSecondaryCache::SplitValueIntoChunks(
       tmp_size = *(--upper);
     }
 
-    ptr = AllocateBlock(tmp_size, cache_options_.memory_allocator.get());
-    current_chunk->next = reinterpret_cast<CacheValueChunk*>(ptr.release());
+    CacheValueChunk* new_chunk =
+        reinterpret_cast<CacheValueChunk*>(new char[tmp_size]);
+    current_chunk->next = new_chunk;
     current_chunk = current_chunk->next;
     actual_chunk_size = tmp_size - sizeof(CacheValueChunk) + 1;
     memcpy(current_chunk->data, src_ptr, actual_chunk_size);

cache/compressed_secondary_cache_test.cc

@@ -570,42 +570,28 @@ class CompressedSecondaryCacheTest : public testing::Test {
   }
 
   void MergeChunksIntoValueTest() {
-    JemallocAllocatorOptions jopts;
-    std::shared_ptr<MemoryAllocator> allocator;
-    std::string msg;
-    if (JemallocNodumpAllocator::IsSupported(&msg)) {
-      Status s = NewJemallocNodumpAllocator(jopts, &allocator);
-      if (!s.ok()) {
-        ROCKSDB_GTEST_BYPASS("JEMALLOC not supported");
-      }
-    } else {
-      ROCKSDB_GTEST_BYPASS("JEMALLOC not supported");
-    }
-
     using CacheValueChunk = CompressedSecondaryCache::CacheValueChunk;
     Random rnd(301);
     size_t size1{2048};
     std::string str1 = rnd.RandomString(static_cast<int>(size1));
-    CacheAllocationPtr ptr =
-        AllocateBlock(sizeof(CacheValueChunk) - 1 + size1, allocator.get());
-    CacheValueChunk* current_chunk =
-        reinterpret_cast<CacheValueChunk*>(ptr.release());
+    CacheValueChunk* current_chunk = reinterpret_cast<CacheValueChunk*>(
+        new char[sizeof(CacheValueChunk) - 1 + size1]);
     CacheValueChunk* chunks_head = current_chunk;
     memcpy(current_chunk->data, str1.data(), size1);
     current_chunk->size = size1;
 
     size_t size2{256};
     std::string str2 = rnd.RandomString(static_cast<int>(size2));
-    ptr = AllocateBlock(sizeof(CacheValueChunk) - 1 + size2, allocator.get());
-    current_chunk->next = reinterpret_cast<CacheValueChunk*>(ptr.release());
+    current_chunk->next = reinterpret_cast<CacheValueChunk*>(
+        new char[sizeof(CacheValueChunk) - 1 + size2]);
     current_chunk = current_chunk->next;
     memcpy(current_chunk->data, str2.data(), size2);
     current_chunk->size = size2;
 
     size_t size3{31};
     std::string str3 = rnd.RandomString(static_cast<int>(size3));
-    ptr = AllocateBlock(sizeof(CacheValueChunk) - 1 + size3, allocator.get());
-    current_chunk->next = reinterpret_cast<CacheValueChunk*>(ptr.release());
+    current_chunk->next = reinterpret_cast<CacheValueChunk*>(
+        new char[sizeof(CacheValueChunk) - 1 + size3]);
     current_chunk = current_chunk->next;
     memcpy(current_chunk->data, str3.data(), size3);
     current_chunk->size = size3;
@@ -614,8 +600,7 @@ class CompressedSecondaryCacheTest : public testing::Test {
     std::string str = str1 + str2 + str3;
 
     std::unique_ptr<CompressedSecondaryCache> sec_cache =
-        std::make_unique<CompressedSecondaryCache>(1000, 0, true, 0.5,
-                                                   allocator);
+        std::make_unique<CompressedSecondaryCache>(1000, 0, true, 0.5);
     size_t charge{0};
     CacheAllocationPtr value =
         sec_cache->MergeChunksIntoValue(chunks_head, charge);