diff --git a/base/file.cpp b/base/file.cpp
index a2f2887..2f697a1 100644
--- a/base/file.cpp
+++ b/base/file.cpp
@@ -153,6 +153,37 @@
   return true;
 }
 
+#if defined(_WIN32)
+// Windows implementation of pread. Note that this DOES move the file descriptors read position,
+// but it does so atomically.
+static ssize_t pread(int fd, void* data, size_t byte_count, off64_t offset) {
+  DWORD bytes_read;
+  OVERLAPPED overlapped;
+  memset(&overlapped, 0, sizeof(OVERLAPPED));
+  overlapped.Offset = static_cast<DWORD>(offset);
+  overlapped.OffsetHigh = static_cast<DWORD>(offset >> 32);
+  if (!ReadFile(reinterpret_cast<HANDLE>(_get_osfhandle(fd)), data, static_cast<DWORD>(byte_count),
+                &bytes_read, &overlapped)) {
+    // In case someone tries to read errno (since this is masquerading as a POSIX call)
+    errno = EIO;
+    return -1;
+  }
+  return static_cast<ssize_t>(bytes_read);
+}
+#endif
+
+bool ReadFullyAtOffset(int fd, void* data, size_t byte_count, off64_t offset) {
+  uint8_t* p = reinterpret_cast<uint8_t*>(data);
+  while (byte_count > 0) {
+    ssize_t n = TEMP_FAILURE_RETRY(pread(fd, p, byte_count, offset));
+    if (n <= 0) return false;
+    p += n;
+    byte_count -= n;
+    offset += n;
+  }
+  return true;
+}
+
 bool WriteFully(int fd, const void* data, size_t byte_count) {
   const uint8_t* p = reinterpret_cast<const uint8_t*>(data);
   size_t remaining = byte_count;
diff --git a/base/include/android-base/file.h b/base/include/android-base/file.h
index 651f529..af14892 100644
--- a/base/include/android-base/file.h
+++ b/base/include/android-base/file.h
@@ -42,6 +42,17 @@
 #endif
 
 bool ReadFully(int fd, void* data, size_t byte_count);
+
+// Reads `byte_count` bytes from the file descriptor at the specified offset.
+// Returns false if there was an IO error or EOF was reached before reading `byte_count` bytes.
+//
+// NOTE: On Linux/Mac, this function wraps pread, which provides atomic read support without
+// modifying the read pointer of the file descriptor. On Windows, however, the read pointer does
+// get modified. This means that ReadFullyAtOffset can be used concurrently with other calls to the
+// same function, but concurrently seeking or reading incrementally can lead to unexpected
+// behavior.
+bool ReadFullyAtOffset(int fd, void* data, size_t byte_count, off64_t offset);
+
 bool WriteFully(int fd, const void* data, size_t byte_count);
 
 bool RemoveFileIfExists(const std::string& path, std::string* err = nullptr);
diff --git a/libziparchive/include/ziparchive/zip_archive_stream_entry.h b/libziparchive/include/ziparchive/zip_archive_stream_entry.h
index a40b799..b4766f8 100644
--- a/libziparchive/include/ziparchive/zip_archive_stream_entry.h
+++ b/libziparchive/include/ziparchive/zip_archive_stream_entry.h
@@ -40,7 +40,8 @@
 
   ZipArchiveHandle handle_;
 
-  uint32_t crc32_;
+  off64_t offset_ = 0;
+  uint32_t crc32_ = 0u;
 };
 
 #endif  // LIBZIPARCHIVE_ZIPARCHIVESTREAMENTRY_H_
diff --git a/libziparchive/zip_archive.cc b/libziparchive/zip_archive.cc
index 17c268b..ad40d42 100644
--- a/libziparchive/zip_archive.cc
+++ b/libziparchive/zip_archive.cc
@@ -435,13 +435,20 @@
 
 static int32_t ValidateDataDescriptor(MappedZipFile& mapped_zip, ZipEntry* entry) {
   uint8_t ddBuf[sizeof(DataDescriptor) + sizeof(DataDescriptor::kOptSignature)];
-  if (!mapped_zip.ReadData(ddBuf, sizeof(ddBuf))) {
+  off64_t offset = entry->offset;
+  if (entry->method != kCompressStored) {
+    offset += entry->compressed_length;
+  } else {
+    offset += entry->uncompressed_length;
+  }
+
+  if (!mapped_zip.ReadAtOffset(ddBuf, sizeof(ddBuf), offset)) {
     return kIoError;
   }
 
   const uint32_t ddSignature = *(reinterpret_cast<const uint32_t*>(ddBuf));
-  const uint16_t offset = (ddSignature == DataDescriptor::kOptSignature) ? 4 : 0;
-  const DataDescriptor* descriptor = reinterpret_cast<const DataDescriptor*>(ddBuf + offset);
+  const uint16_t ddOffset = (ddSignature == DataDescriptor::kOptSignature) ? 4 : 0;
+  const DataDescriptor* descriptor = reinterpret_cast<const DataDescriptor*>(ddBuf + ddOffset);
 
   // Validate that the values in the data descriptor match those in the central
   // directory.
@@ -899,7 +906,9 @@
     /* read as much as we can */
     if (zstream.avail_in == 0) {
       const size_t getSize = (compressed_length > kBufSize) ? kBufSize : compressed_length;
-      if (!mapped_zip.ReadData(read_buf.data(), getSize)) {
+      off64_t offset = entry->offset + (entry->compressed_length - compressed_length);
+      // Make sure to read at offset to ensure concurrent access to the fd.
+      if (!mapped_zip.ReadAtOffset(read_buf.data(), getSize, offset)) {
         ALOGW("Zip: inflate read failed, getSize = %zu: %s", getSize, strerror(errno));
         return kIoError;
       }
@@ -962,12 +971,15 @@
   uint64_t crc = 0;
   while (count < length) {
     uint32_t remaining = length - count;
+    off64_t offset = entry->offset + count;
 
-    // Safe conversion because kBufSize is narrow enough for a 32 bit signed
-    // value.
+    // Safe conversion because kBufSize is narrow enough for a 32 bit signed value.
     const size_t block_size = (remaining > kBufSize) ? kBufSize : remaining;
-    if (!mapped_zip.ReadData(buf.data(), block_size)) {
-      ALOGW("CopyFileToFile: copy read failed, block_size = %zu: %s", block_size, strerror(errno));
+
+    // Make sure to read at offset to ensure concurrent access to the fd.
+    if (!mapped_zip.ReadAtOffset(buf.data(), block_size, offset)) {
+      ALOGW("CopyFileToFile: copy read failed, block_size = %zu, offset = %" PRId64 ": %s",
+            block_size, static_cast<int64_t>(offset), strerror(errno));
       return kIoError;
     }
 
@@ -986,12 +998,6 @@
 int32_t ExtractToWriter(ZipArchiveHandle handle, ZipEntry* entry, Writer* writer) {
   ZipArchive* archive = reinterpret_cast<ZipArchive*>(handle);
   const uint16_t method = entry->method;
-  off64_t data_offset = entry->offset;
-
-  if (!archive->mapped_zip.SeekToOffset(data_offset)) {
-    ALOGW("Zip: lseek to data at %" PRId64 " failed", static_cast<int64_t>(data_offset));
-    return kIoError;
-  }
 
   // this should default to kUnknownCompressionMethod.
   int32_t return_value = -1;
@@ -1111,52 +1117,21 @@
   }
 }
 
-bool MappedZipFile::SeekToOffset(off64_t offset) {
-  if (has_fd_) {
-    if (lseek64(fd_, offset, SEEK_SET) != offset) {
-      ALOGE("Zip: lseek to %" PRId64 " failed: %s\n", offset, strerror(errno));
-      return false;
-    }
-    return true;
-  } else {
-    if (offset < 0 || offset > static_cast<off64_t>(data_length_)) {
-      ALOGE("Zip: invalid offset: %" PRId64 ", data length: %" PRId64 "\n", offset, data_length_);
-      return false;
-    }
-
-    read_pos_ = offset;
-    return true;
-  }
-}
-
-bool MappedZipFile::ReadData(uint8_t* buffer, size_t read_amount) {
-  if (has_fd_) {
-    if (!android::base::ReadFully(fd_, buffer, read_amount)) {
-      ALOGE("Zip: read from %d failed\n", fd_);
-      return false;
-    }
-  } else {
-    memcpy(buffer, static_cast<uint8_t*>(base_ptr_) + read_pos_, read_amount);
-    read_pos_ += read_amount;
-  }
-  return true;
-}
-
 // Attempts to read |len| bytes into |buf| at offset |off|.
 bool MappedZipFile::ReadAtOffset(uint8_t* buf, size_t len, off64_t off) {
-#if !defined(_WIN32)
   if (has_fd_) {
-    if (static_cast<size_t>(TEMP_FAILURE_RETRY(pread64(fd_, buf, len, off))) != len) {
+    if (!android::base::ReadFullyAtOffset(fd_, buf, len, off)) {
       ALOGE("Zip: failed to read at offset %" PRId64 "\n", off);
       return false;
     }
-    return true;
+  } else {
+    if (off < 0 || off > static_cast<off64_t>(data_length_)) {
+      ALOGE("Zip: invalid offset: %" PRId64 ", data length: %" PRId64 "\n", off, data_length_);
+      return false;
+    }
+    memcpy(buf, static_cast<uint8_t*>(base_ptr_) + off, len);
   }
-#endif
-  if (!SeekToOffset(off)) {
-    return false;
-  }
-  return ReadData(buf, len);
+  return true;
 }
 
 void CentralDirectory::Initialize(void* map_base_ptr, off64_t cd_start_offset, size_t cd_size) {
diff --git a/libziparchive/zip_archive_private.h b/libziparchive/zip_archive_private.h
index 840f1af..174aa3f 100644
--- a/libziparchive/zip_archive_private.h
+++ b/libziparchive/zip_archive_private.h
@@ -93,14 +93,10 @@
 class MappedZipFile {
  public:
   explicit MappedZipFile(const int fd)
-      : has_fd_(true), fd_(fd), base_ptr_(nullptr), data_length_(0), read_pos_(0) {}
+      : has_fd_(true), fd_(fd), base_ptr_(nullptr), data_length_(0) {}
 
   explicit MappedZipFile(void* address, size_t length)
-      : has_fd_(false),
-        fd_(-1),
-        base_ptr_(address),
-        data_length_(static_cast<off64_t>(length)),
-        read_pos_(0) {}
+      : has_fd_(false), fd_(-1), base_ptr_(address), data_length_(static_cast<off64_t>(length)) {}
 
   bool HasFd() const { return has_fd_; }
 
@@ -110,10 +106,6 @@
 
   off64_t GetFileLength() const;
 
-  bool SeekToOffset(off64_t offset);
-
-  bool ReadData(uint8_t* buffer, size_t read_amount);
-
   bool ReadAtOffset(uint8_t* buf, size_t len, off64_t off);
 
  private:
@@ -127,8 +119,6 @@
 
   void* const base_ptr_;
   const off64_t data_length_;
-  // read_pos_ is the offset to the base_ptr_ where we read data from.
-  size_t read_pos_;
 };
 
 class CentralDirectory {
diff --git a/libziparchive/zip_archive_stream_entry.cc b/libziparchive/zip_archive_stream_entry.cc
index 50352ef..9ec89b1 100644
--- a/libziparchive/zip_archive_stream_entry.cc
+++ b/libziparchive/zip_archive_stream_entry.cc
@@ -38,13 +38,8 @@
 static constexpr size_t kBufSize = 65535;
 
 bool ZipArchiveStreamEntry::Init(const ZipEntry& entry) {
-  ZipArchive* archive = reinterpret_cast<ZipArchive*>(handle_);
-  off64_t data_offset = entry.offset;
-  if (!archive->mapped_zip.SeekToOffset(data_offset)) {
-    ALOGW("lseek to data at %" PRId64 " failed: %s", data_offset, strerror(errno));
-    return false;
-  }
   crc32_ = entry.crc32;
+  offset_ = entry.offset;
   return true;
 }
 
@@ -61,11 +56,11 @@
  protected:
   bool Init(const ZipEntry& entry) override;
 
-  uint32_t length_;
+  uint32_t length_ = 0u;
 
  private:
   std::vector<uint8_t> data_;
-  uint32_t computed_crc32_;
+  uint32_t computed_crc32_ = 0u;
 };
 
 bool ZipArchiveStreamEntryUncompressed::Init(const ZipEntry& entry) {
@@ -89,7 +84,7 @@
   size_t bytes = (length_ > data_.size()) ? data_.size() : length_;
   ZipArchive* archive = reinterpret_cast<ZipArchive*>(handle_);
   errno = 0;
-  if (!archive->mapped_zip.ReadData(data_.data(), bytes)) {
+  if (!archive->mapped_zip.ReadAtOffset(data_.data(), bytes, offset_)) {
     if (errno != 0) {
       ALOGE("Error reading from archive fd: %s", strerror(errno));
     } else {
@@ -104,6 +99,7 @@
   }
   computed_crc32_ = crc32(computed_crc32_, data_.data(), data_.size());
   length_ -= bytes;
+  offset_ += bytes;
   return &data_;
 }
 
@@ -129,9 +125,9 @@
   z_stream z_stream_;
   std::vector<uint8_t> in_;
   std::vector<uint8_t> out_;
-  uint32_t uncompressed_length_;
-  uint32_t compressed_length_;
-  uint32_t computed_crc32_;
+  uint32_t uncompressed_length_ = 0u;
+  uint32_t compressed_length_ = 0u;
+  uint32_t computed_crc32_ = 0u;
 };
 
 // This method is using libz macros with old-style-casts
@@ -210,7 +206,7 @@
       size_t bytes = (compressed_length_ > in_.size()) ? in_.size() : compressed_length_;
       ZipArchive* archive = reinterpret_cast<ZipArchive*>(handle_);
       errno = 0;
-      if (!archive->mapped_zip.ReadData(in_.data(), bytes)) {
+      if (!archive->mapped_zip.ReadAtOffset(in_.data(), bytes, offset_)) {
         if (errno != 0) {
           ALOGE("Error reading from archive fd: %s", strerror(errno));
         } else {
@@ -220,6 +216,7 @@
       }
 
       compressed_length_ -= bytes;
+      offset_ += bytes;
       z_stream_.next_in = in_.data();
       z_stream_.avail_in = bytes;
     }