diff --git a/include/backtrace/Backtrace.h b/include/backtrace/Backtrace.h
index df40b87..f0fb0cd 100644
--- a/include/backtrace/Backtrace.h
+++ b/include/backtrace/Backtrace.h
@@ -17,10 +17,25 @@
 #ifndef _BACKTRACE_BACKTRACE_H
 #define _BACKTRACE_BACKTRACE_H
 
-#include <backtrace/backtrace.h>
+#include <stdint.h>
 
 #include <string>
+#include <vector>
 
+#include <backtrace/backtrace_constants.h>
+#include <backtrace/BacktraceMap.h>
+
+struct backtrace_frame_data_t {
+  size_t num;             // The current fame number.
+  uintptr_t pc;           // The absolute pc.
+  uintptr_t sp;           // The top of the stack.
+  size_t stack_size;      // The size of the stack, zero indicate an unknown stack size.
+  const backtrace_map_t* map;   // The map associated with the given pc.
+  std::string func_name;  // The function name associated with this pc, NULL if not found.
+  uintptr_t func_offset;  // pc relative to the start of the function, only valid if func_name is not NULL.
+};
+
+// Forward declarations.
 class BacktraceImpl;
 
 class Backtrace {
@@ -33,9 +48,9 @@
   // If pid >= 0 and tid < 0, then the Backtrace object corresponds to a
   // different process.
   // Tracing a thread in a different process is not supported.
-  // If map_info is NULL, then create the map and manage it internally.
-  // If map_info is not NULL, the map is still owned by the caller.
-  static Backtrace* Create(pid_t pid, pid_t tid, backtrace_map_info_t* map_info = NULL);
+  // If map is NULL, then create the map and manage it internally.
+  // If map is not NULL, the map is still owned by the caller.
+  static Backtrace* Create(pid_t pid, pid_t tid, BacktraceMap* map = NULL);
 
   virtual ~Backtrace();
 
@@ -46,13 +61,12 @@
   // If the string is empty, then no valid function name was found.
   virtual std::string GetFunctionName(uintptr_t pc, uintptr_t* offset);
 
-  // Get the name of the map associated with the given pc. If NULL is returned,
-  // then map_start is not set. Otherwise, map_start is the beginning of this
-  // map.
-  virtual const char* GetMapName(uintptr_t pc, uintptr_t* map_start);
+  // Find the map associated with the given pc.
+  virtual const backtrace_map_t* FindMap(uintptr_t pc);
 
-  // Finds the memory map associated with the given ptr.
-  virtual const backtrace_map_info_t* FindMapInfo(uintptr_t ptr);
+  // Take ownership of the BacktraceMap object associated with the backtrace.
+  // If this is called, the caller must handle deleting the object themselves.
+  virtual BacktraceMap* TakeMapOwnership();
 
   // Read the data at a specific address.
   virtual bool ReadWord(uintptr_t ptr, uint32_t* out_value) = 0;
@@ -62,36 +76,44 @@
   virtual std::string FormatFrameData(size_t frame_num);
   virtual std::string FormatFrameData(const backtrace_frame_data_t* frame);
 
-  pid_t Pid() { return backtrace_.pid; }
-  pid_t Tid() { return backtrace_.tid; }
-  size_t NumFrames() { return backtrace_.num_frames; }
-
-  const backtrace_t* GetBacktrace() { return &backtrace_; }
+  pid_t Pid() { return pid_; }
+  pid_t Tid() { return tid_; }
+  size_t NumFrames() { return frames_.size(); }
 
   const backtrace_frame_data_t* GetFrame(size_t frame_num) {
-    if (frame_num > NumFrames()) {
+    if (frame_num >= frames_.size()) {
       return NULL;
     }
-    return &backtrace_.frames[frame_num];
+    return &frames_[frame_num];
   }
 
-  const backtrace_map_info_t* GetMapList() {
-    return map_info_;
-  }
+  typedef std::vector<backtrace_frame_data_t>::iterator iterator;
+  iterator begin() { return frames_.begin(); }
+  iterator end() { return frames_.end(); }
+
+  typedef std::vector<backtrace_frame_data_t>::const_iterator const_iterator;
+  const_iterator begin() const { return frames_.begin(); }
+  const_iterator end() const { return frames_.end(); }
+
+  BacktraceMap* GetMap() { return map_; }
 
 protected:
-  Backtrace(BacktraceImpl* impl, pid_t pid, backtrace_map_info_t* map_info);
+  Backtrace(BacktraceImpl* impl, pid_t pid, BacktraceMap* map);
 
   virtual bool VerifyReadWordArgs(uintptr_t ptr, uint32_t* out_value);
 
+  bool BuildMap();
+
+  pid_t pid_;
+  pid_t tid_;
+
+  BacktraceMap* map_;
+  bool map_shared_;
+
+  std::vector<backtrace_frame_data_t> frames_;
+
   BacktraceImpl* impl_;
 
-  backtrace_map_info_t* map_info_;
-
-  bool map_info_requires_delete_;
-
-  backtrace_t backtrace_;
-
   friend class BacktraceImpl;
 };
 
diff --git a/include/backtrace/BacktraceMap.h b/include/backtrace/BacktraceMap.h
new file mode 100644
index 0000000..e5389c1
--- /dev/null
+++ b/include/backtrace/BacktraceMap.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _BACKTRACE_BACKTRACE_MAP_H
+#define _BACKTRACE_BACKTRACE_MAP_H
+
+#include <stdint.h>
+#include <sys/mman.h>
+
+#include <string>
+#include <vector>
+
+struct backtrace_map_t {
+  uintptr_t start;
+  uintptr_t end;
+  int flags;
+  std::string name;
+};
+
+class BacktraceMap {
+public:
+  BacktraceMap(pid_t pid);
+  virtual ~BacktraceMap();
+
+  // Get the map data structure for the given address.
+  const backtrace_map_t* Find(uintptr_t addr);
+
+  // The flags returned are the same flags as used by the mmap call.
+  // The values are PROT_*.
+  int GetFlags(uintptr_t pc) {
+    const backtrace_map_t* map = Find(pc);
+    if (map) {
+      return map->flags;
+    }
+    return PROT_NONE;
+  }
+
+  bool IsReadable(uintptr_t pc) { return GetFlags(pc) & PROT_READ; }
+  bool IsWritable(uintptr_t pc) { return GetFlags(pc) & PROT_WRITE; }
+  bool IsExecutable(uintptr_t pc) { return GetFlags(pc) & PROT_EXEC; }
+
+  typedef std::vector<backtrace_map_t>::iterator iterator;
+  iterator begin() { return maps_.begin(); }
+  iterator end() { return maps_.end(); }
+
+  typedef std::vector<backtrace_map_t>::const_iterator const_iterator;
+  const_iterator begin() const { return maps_.begin(); }
+  const_iterator end() const { return maps_.end(); }
+
+  virtual bool Build();
+
+protected:
+  virtual bool ParseLine(const char* line, backtrace_map_t* map);
+
+  std::vector<backtrace_map_t> maps_;
+  pid_t pid_;
+};
+
+#endif // _BACKTRACE_BACKTRACE_MAP_H
diff --git a/include/backtrace/backtrace.h b/include/backtrace/backtrace.h
deleted file mode 100644
index cfcbf0f..0000000
--- a/include/backtrace/backtrace.h
+++ /dev/null
@@ -1,131 +0,0 @@
-/*
- * Copyright (C) 2013 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef _BACKTRACE_H
-#define _BACKTRACE_H
-
-#include <stdint.h>
-#include <stdbool.h>
-#include <sys/types.h>
-
-__BEGIN_DECLS
-
-// When the pid to be traced is set to this value, then trace the current
-// process. If the tid value is not BACKTRACE_NO_TID, then the specified
-// thread from the current process will be traced.
-#define BACKTRACE_CURRENT_PROCESS -1
-// When the tid to be traced is set to this value, then trace the specified
-// current thread of the specified pid.
-#define BACKTRACE_CURRENT_THREAD -1
-
-#define MAX_BACKTRACE_FRAMES 64
-
-typedef struct backtrace_map_info {
-  struct backtrace_map_info* next;
-  uintptr_t start;
-  uintptr_t end;
-  bool is_readable;
-  bool is_writable;
-  bool is_executable;
-  char name[];
-} backtrace_map_info_t;
-
-typedef struct {
-  size_t num;             /* The current fame number. */
-  uintptr_t pc;           /* The absolute pc. */
-  uintptr_t sp;           /* The top of the stack. */
-  size_t stack_size;      /* The size of the stack, zero indicate an unknown stack size. */
-  const char* map_name;   /* The name of the map to which this pc belongs, NULL indicates the pc doesn't belong to a known map. */
-  uintptr_t map_offset;   /* pc relative to the start of the map, only valid if map_name is not NULL. */
-  char* func_name;        /* The function name associated with this pc, NULL if not found. */
-  uintptr_t func_offset;  /* pc relative to the start of the function, only valid if func_name is not NULL. */
-} backtrace_frame_data_t;
-
-typedef struct {
-  backtrace_frame_data_t frames[MAX_BACKTRACE_FRAMES];
-  size_t num_frames;
-
-  pid_t pid;
-  pid_t tid;
-  backtrace_map_info_t* map_info_list;
-} backtrace_t;
-
-typedef struct {
-  void* data;
-  const backtrace_t* backtrace;
-} backtrace_context_t;
-
-/* Create a context for the backtrace data and gather the backtrace.
- * If pid < 0, then gather the backtrace for the current process.
- */
-bool backtrace_create_context(
-    backtrace_context_t* context, pid_t pid, pid_t tid, size_t num_ignore_frames);
-
-/* The same as backtrace_create_context, except that it is assumed that
- * the pid map has already been acquired and the caller will handle freeing
- * the map data.
- */
-bool backtrace_create_context_with_map(
-    backtrace_context_t* context, pid_t pid, pid_t tid, size_t num_ignore_frames,
-    backtrace_map_info_t* map_info);
-
-/* Gather the backtrace data for a pthread instead of a process. */
-bool backtrace_create_thread_context(
-    backtrace_context_t* context, pid_t tid, size_t num_ignore_frames);
-
-/* Free any memory allocated during the context create. */
-void backtrace_destroy_context(backtrace_context_t* context);
-
-/* Read data at a specific address for a process. */
-bool backtrace_read_word(
-    const backtrace_context_t* context, uintptr_t ptr, uint32_t* value);
-
-/* Get information about the map name associated with a pc. If NULL is
- * returned, then map_start is not set.
- */
-const char* backtrace_get_map_name(
-    const backtrace_context_t* context, uintptr_t pc, uintptr_t* map_start);
-
-/* Get the function name and offset given the pc. If NULL is returned,
- * then func_offset is not set. The returned string is allocated using
- * malloc and must be freed by the caller.
- */
-char* backtrace_get_func_name(
-    const backtrace_context_t* context, uintptr_t pc, uintptr_t* func_offset);
-
-/* Loads memory map from /proc/<pid>/maps. If pid < 0, then load the memory
- * map for the current process.
- */
-backtrace_map_info_t* backtrace_create_map_info_list(pid_t pid);
-
-/* Frees memory associated with the map list. */
-void backtrace_destroy_map_info_list(backtrace_map_info_t* map_info_list);
-
-/* Finds the memory map that contains the specified pc. */
-const backtrace_map_info_t* backtrace_find_map_info(
-    const backtrace_map_info_t* map_info_list, uintptr_t pc);
-
-/* Create a formatted line of backtrace information for a single frame. */
-void backtrace_format_frame_data(
-    const backtrace_context_t* context, size_t frame_num, char* buf,
-    size_t buf_size);
-
-/* Get the backtrace data structure associated with the context. */
-const backtrace_t* backtrace_get_data(backtrace_context_t* context);
-
-__END_DECLS
-
-#endif /* _BACKTRACE_H */
diff --git a/include/backtrace/backtrace_constants.h b/include/backtrace/backtrace_constants.h
new file mode 100644
index 0000000..f8c1575
--- /dev/null
+++ b/include/backtrace/backtrace_constants.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _BACKTRACE_BACKTRACE_CONSTANTS_H
+#define _BACKTRACE_BACKTRACE_CONSTANTS_H
+
+// When the pid to be traced is set to this value, then trace the current
+// process. If the tid value is not BACKTRACE_NO_TID, then the specified
+// thread from the current process will be traced.
+#define BACKTRACE_CURRENT_PROCESS -1
+// When the tid to be traced is set to this value, then trace the specified
+// current thread of the specified pid.
+#define BACKTRACE_CURRENT_THREAD -1
+
+#define MAX_BACKTRACE_FRAMES 64
+
+#endif // _BACKTRACE_BACKTRACE_CONSTANTS_H
diff --git a/include/utils/CallStack.h b/include/utils/CallStack.h
index bfe2ddb..27e89f4 100644
--- a/include/utils/CallStack.h
+++ b/include/utils/CallStack.h
@@ -18,7 +18,7 @@
 #define ANDROID_CALLSTACK_H
 
 #include <android/log.h>
-#include <backtrace/backtrace.h>
+#include <backtrace/backtrace_constants.h>
 #include <utils/String8.h>
 #include <utils/Vector.h>