diff --git a/third_party/gperftools/src/base/sysinfo.cc b/third_party/gperftools/src/base/sysinfo.cc
index cad751b..8183494 100644
--- a/third_party/gperftools/src/base/sysinfo.cc
+++ b/third_party/gperftools/src/base/sysinfo.cc
@@ -160,7 +160,7 @@
   const char* p = envbuf;
   while (*p != '\0') {    // will happen at the \0\0 that terminates the buffer
     // proc file has the format NAME=value\0NAME=value\0NAME=value\0...
-    const char* endp = (char*)memchr(p, '\0', sizeof(envbuf) - (p - envbuf));
+    const char* endp = (const char*)memchr(p, '\0', sizeof(envbuf) - (p - envbuf));
     if (endp == NULL)            // this entry isn't NUL terminated
       return NULL;
     else if (!memcmp(p, name, namelen) && p[namelen] == '=')    // it's a match
diff --git a/third_party/gperftools/src/base/thread_lister.c b/third_party/gperftools/src/base/thread_lister.c
index ca1b2de..e837c3e 100644
--- a/third_party/gperftools/src/base/thread_lister.c
+++ b/third_party/gperftools/src/base/thread_lister.c
@@ -36,6 +36,9 @@
 #ifdef HAVE_SYS_PRCTL
 # include <sys/prctl.h>
 #endif
+#ifdef HAVE_UNISTD_H
+# include <unistd.h>
+#endif
 #include "base/thread_lister.h"
 #include "base/linuxthreads.h"
 /* Include other thread listers here that define THREADS macro
diff --git a/third_party/gperftools/src/gperftools/tcmalloc.h b/third_party/gperftools/src/gperftools/tcmalloc.h
new file mode 100644
index 0000000..8fc5554
--- /dev/null
+++ b/third_party/gperftools/src/gperftools/tcmalloc.h
@@ -0,0 +1,135 @@
+// -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*-
+/* Copyright (c) 2003, Google Inc.
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * 
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * ---
+ * Author: Sanjay Ghemawat <opensource@google.com>
+ *         .h file by Craig Silverstein <opensource@google.com>
+ */
+
+#ifndef TCMALLOC_TCMALLOC_H_
+#define TCMALLOC_TCMALLOC_H_
+
+#include <stddef.h>                     // for size_t
+#ifdef HAVE_SYS_CDEFS_H
+#include <sys/cdefs.h>   // where glibc defines __THROW
+#endif
+
+// __THROW is defined in glibc systems.  It means, counter-intuitively,
+// "This function will never throw an exception."  It's an optional
+// optimization tool, but we may need to use it to match glibc prototypes.
+#ifndef __THROW    /* I guess we're not on a glibc system */
+# define __THROW   /* __THROW is just an optimization, so ok to make it "" */
+#endif
+
+// Define the version number so folks can check against it
+#define TC_VERSION_MAJOR  2
+#define TC_VERSION_MINOR  4
+#define TC_VERSION_PATCH  ""
+#define TC_VERSION_STRING "gperftools 2.4"
+
+// For struct mallinfo, if it's defined.
+#ifdef HAVE_STRUCT_MALLINFO
+// Malloc can be in several places on older versions of OS X.
+# if defined(HAVE_MALLOC_H)
+# include <malloc.h>
+# elif defined(HAVE_SYS_MALLOC_H)
+# include <sys/malloc.h>
+# elif defined(HAVE_MALLOC_MALLOC_H)
+# include <malloc/malloc.h>
+# endif
+#endif
+
+// Annoying stuff for windows -- makes sure clients can import these functions
+#ifndef PERFTOOLS_DLL_DECL
+# ifdef _WIN32
+#   define PERFTOOLS_DLL_DECL  __declspec(dllimport)
+# else
+#   define PERFTOOLS_DLL_DECL
+# endif
+#endif
+
+#ifdef __cplusplus
+namespace std {
+struct nothrow_t;
+}
+
+extern "C" {
+#endif
+  // Returns a human-readable version string.  If major, minor,
+  // and/or patch are not NULL, they are set to the major version,
+  // minor version, and patch-code (a string, usually "").
+  PERFTOOLS_DLL_DECL const char* tc_version(int* major, int* minor,
+                                            const char** patch) __THROW;
+
+  PERFTOOLS_DLL_DECL void* tc_malloc(size_t size) __THROW;
+  PERFTOOLS_DLL_DECL void* tc_malloc_skip_new_handler(size_t size) __THROW;
+  PERFTOOLS_DLL_DECL void tc_free(void* ptr) __THROW;
+  PERFTOOLS_DLL_DECL void* tc_realloc(void* ptr, size_t size) __THROW;
+  PERFTOOLS_DLL_DECL void* tc_calloc(size_t nmemb, size_t size) __THROW;
+  PERFTOOLS_DLL_DECL void tc_cfree(void* ptr) __THROW;
+
+  PERFTOOLS_DLL_DECL void* tc_memalign(size_t __alignment,
+                                       size_t __size) __THROW;
+  PERFTOOLS_DLL_DECL int tc_posix_memalign(void** ptr,
+                                           size_t align, size_t size) __THROW;
+  PERFTOOLS_DLL_DECL void* tc_valloc(size_t __size) __THROW;
+  PERFTOOLS_DLL_DECL void* tc_pvalloc(size_t __size) __THROW;
+
+  PERFTOOLS_DLL_DECL void tc_malloc_stats(void) __THROW;
+  PERFTOOLS_DLL_DECL int tc_mallopt(int cmd, int value) __THROW;
+#if 1
+  PERFTOOLS_DLL_DECL struct mallinfo tc_mallinfo(void) __THROW;
+#endif
+
+  // This is an alias for MallocExtension::instance()->GetAllocatedSize().
+  // It is equivalent to
+  //    OS X: malloc_size()
+  //    glibc: malloc_usable_size()
+  //    Windows: _msize()
+  PERFTOOLS_DLL_DECL size_t tc_malloc_size(void* ptr) __THROW;
+
+#ifdef __cplusplus
+  PERFTOOLS_DLL_DECL int tc_set_new_mode(int flag) __THROW;
+  PERFTOOLS_DLL_DECL void* tc_new(size_t size);
+  PERFTOOLS_DLL_DECL void* tc_new_nothrow(size_t size,
+                                          const std::nothrow_t&) __THROW;
+  PERFTOOLS_DLL_DECL void tc_delete(void* p) __THROW;
+  PERFTOOLS_DLL_DECL void tc_delete_nothrow(void* p,
+                                            const std::nothrow_t&) __THROW;
+  PERFTOOLS_DLL_DECL void* tc_newarray(size_t size);
+  PERFTOOLS_DLL_DECL void* tc_newarray_nothrow(size_t size,
+                                               const std::nothrow_t&) __THROW;
+  PERFTOOLS_DLL_DECL void tc_deletearray(void* p) __THROW;
+  PERFTOOLS_DLL_DECL void tc_deletearray_nothrow(void* p,
+                                                 const std::nothrow_t&) __THROW;
+}
+#endif
+
+#endif  // #ifndef TCMALLOC_TCMALLOC_H_