From 6832a7a4e04c84192f0bafc6ac990fc79cd13882 Mon Sep 17 00:00:00 2001
From: Narayan Kamath <narayan@google.com>
Date: Mon, 23 Feb 2015 15:43:35 +0000
Subject: [PATCH] Remove useless refCounting from FileMap.

Nobody ever called acquire() so release() was always
equivalent to delete. Just use delete instead so that
people can use unique_ptr directly (or shared_ptr if
they really want refcounts).

Change-Id: I9e3ad5e0f6a4fcc4e02e5a2ff7ef9514fe234415
---
 include/utils/FileMap.h      | 18 ++----------------
 libutils/FileMap.cpp         |  8 +-------
 libutils/Tokenizer.cpp       |  6 ++----
 libziparchive/zip_archive.cc |  8 +++-----
 4 files changed, 8 insertions(+), 32 deletions(-)

diff --git a/include/utils/FileMap.h b/include/utils/FileMap.h
index 6c0aa52742f6..f70fc927e4ca 100644
--- a/include/utils/FileMap.h
+++ b/include/utils/FileMap.h
@@ -63,6 +63,8 @@ class FileMap {
     bool create(const char* origFileName, int fd,
                 off64_t offset, size_t length, bool readOnly);
 
+    ~FileMap(void);
+
     /*
      * Return the name of the file this map came from, if known.
      */
@@ -83,19 +85,6 @@ class FileMap {
      */
     off64_t getDataOffset(void) const { return mDataOffset; }
 
-    /*
-     * Get a "copy" of the object.
-     */
-    FileMap* acquire(void) { mRefCount++; return this; }
-
-    /*
-     * Call this when mapping is no longer needed.
-     */
-    void release(void) {
-        if (--mRefCount <= 0)
-            delete this;
-    }
-
     /*
      * This maps directly to madvise() values, but allows us to avoid
      * including <sys/mman.h> everywhere.
@@ -112,15 +101,12 @@ class FileMap {
     int advise(MapAdvice advice);
 
 protected:
-    // don't delete objects; call release()
-    ~FileMap(void);
 
 private:
     // these are not implemented
     FileMap(const FileMap& src);
     const FileMap& operator=(const FileMap& src);
 
-    int         mRefCount;      // reference count
     char*       mFileName;      // original file name, if known
     void*       mBasePtr;       // base of mmap area; page aligned
     size_t      mBaseLength;    // length, measured from "mBasePtr"
diff --git a/libutils/FileMap.cpp b/libutils/FileMap.cpp
index 0af066f8bc6e..91e45d873256 100644
--- a/libutils/FileMap.cpp
+++ b/libutils/FileMap.cpp
@@ -48,7 +48,7 @@ using namespace android;
 
 // Constructor.  Create an empty object.
 FileMap::FileMap(void)
-    : mRefCount(1), mFileName(NULL), mBasePtr(NULL), mBaseLength(0),
+    : mFileName(NULL), mBasePtr(NULL), mBaseLength(0),
       mDataPtr(NULL), mDataLength(0)
 {
 }
@@ -56,11 +56,6 @@ FileMap::FileMap(void)
 // Destructor.
 FileMap::~FileMap(void)
 {
-    assert(mRefCount == 0);
-
-    //printf("+++ removing FileMap %p %zu\n", mDataPtr, mDataLength);
-
-    mRefCount = -100;       // help catch double-free
     if (mFileName != NULL) {
         free(mFileName);
     }
@@ -134,7 +129,6 @@ bool FileMap::create(const char* origFileName, int fd, off64_t offset, size_t le
 
     void* ptr;
 
-    assert(mRefCount == 1);
     assert(fd >= 0);
     assert(offset >= 0);
     assert(length > 0);
diff --git a/libutils/Tokenizer.cpp b/libutils/Tokenizer.cpp
index 7067533b10b7..610002fe3df7 100644
--- a/libutils/Tokenizer.cpp
+++ b/libutils/Tokenizer.cpp
@@ -43,9 +43,7 @@ Tokenizer::Tokenizer(const String8& filename, FileMap* fileMap, char* buffer,
 }
 
 Tokenizer::~Tokenizer() {
-    if (mFileMap) {
-        mFileMap->release();
-    }
+    delete mFileMap;
     if (mOwnBuffer) {
         delete[] mBuffer;
     }
@@ -74,7 +72,7 @@ status_t Tokenizer::open(const String8& filename, Tokenizer** outTokenizer) {
                 fileMap->advise(FileMap::SEQUENTIAL);
                 buffer = static_cast<char*>(fileMap->getDataPtr());
             } else {
-                fileMap->release();
+                delete fileMap;
                 fileMap = NULL;
 
                 // Fall back to reading into a buffer since we can't mmap files in sysfs.
diff --git a/libziparchive/zip_archive.cc b/libziparchive/zip_archive.cc
index afc122dc47b8..ebbab9f21cbc 100644
--- a/libziparchive/zip_archive.cc
+++ b/libziparchive/zip_archive.cc
@@ -321,9 +321,7 @@ struct ZipArchive {
       close(fd);
     }
 
-    if (directory_map != NULL) {
-      directory_map->release();
-    }
+    delete directory_map;
     free(hash_table);
   }
 };
@@ -335,7 +333,7 @@ static android::FileMap* MapFileSegment(const int fd, const off64_t start,
   android::FileMap* file_map = new android::FileMap;
   const bool success = file_map->create(debug_file_name, fd, start, length, read_only);
   if (!success) {
-    file_map->release();
+    delete file_map;
     return NULL;
   }
 
@@ -1170,7 +1168,7 @@ int32_t ExtractEntryToFile(ZipArchiveHandle handle,
   const int32_t error = ExtractToMemory(handle, entry,
                                         reinterpret_cast<uint8_t*>(map->getDataPtr()),
                                         map->getDataLength());
-  map->release();
+  delete map;
   return error;
 }