Merge branch 'master' of github.com:google/grpc into node_server_metadata

14 files changed, 1914 insertions, 71 deletions

diff --git a/src/core/iomgr/fd_posix.c b/src/core/iomgr/fd_posix.c
index 9f70a26c64..b67c6cde70 100644
--- a/src/core/iomgr/fd_posix.c
+++ b/src/core/iomgr/fd_posix.c
@@ -47,12 +47,63 @@
 
 enum descriptor_state { NOT_READY, READY, WAITING };
 
+/* We need to keep a freelist not because of any concerns of malloc performance
+ * but instead so that implementations with multiple threads in (for example)
+ * epoll_wait deal with the race between pollset removal and incoming poll
+ * notifications.
+ *
+ * The problem is that the poller ultimately holds a reference to this
+ * object, so it is very difficult to know when is safe to free it, at least
+ * without some expensive synchronization.
+ *
+ * If we keep the object freelisted, in the worst case losing this race just
+ * becomes a spurious read notification on a reused fd.
+ */
+/* TODO(klempner): We could use some form of polling generation count to know
+ * when these are safe to free. */
+/* TODO(klempner): Consider disabling freelisting if we don't have multiple
+ * threads in poll on the same fd */
+/* TODO(klempner): Batch these allocations to reduce fragmentation */
+static grpc_fd *fd_freelist = NULL;
+static gpr_mu fd_freelist_mu;
+
+static void freelist_fd(grpc_fd *fd) {
+  gpr_free(fd->watchers);
+  gpr_mu_lock(&fd_freelist_mu);
+  fd->freelist_next = fd_freelist;
+  fd_freelist = fd;
+  gpr_mu_unlock(&fd_freelist_mu);
+}
+
+static grpc_fd *alloc_fd(int fd) {
+  grpc_fd *r = NULL;
+  gpr_mu_lock(&fd_freelist_mu);
+  if (fd_freelist != NULL) {
+    r = fd_freelist;
+    fd_freelist = fd_freelist->freelist_next;
+  }
+  gpr_mu_unlock(&fd_freelist_mu);
+  if (r == NULL) {
+    r = gpr_malloc(sizeof(grpc_fd));
+    gpr_mu_init(&r->set_state_mu);
+    gpr_mu_init(&r->watcher_mu);
+  }
+  gpr_atm_rel_store(&r->refst, 1);
+  gpr_atm_rel_store(&r->readst.state, NOT_READY);
+  gpr_atm_rel_store(&r->writest.state, NOT_READY);
+  gpr_atm_rel_store(&r->shutdown, 0);
+  r->fd = fd;
+  r->watchers = NULL;
+  r->watcher_count = 0;
+  r->watcher_capacity = 0;
+  r->freelist_next = NULL;
+  return r;
+}
+
 static void destroy(grpc_fd *fd) {
-  grpc_iomgr_add_callback(fd->on_done, fd->on_done_user_data);
   gpr_mu_destroy(&fd->set_state_mu);
-  gpr_free(fd->watchers);
+  gpr_mu_destroy(&fd->watcher_mu);
   gpr_free(fd);
-  grpc_iomgr_unref();
 }
 
 static void ref_by(grpc_fd *fd, int n) {
@@ -61,25 +112,30 @@ static void ref_by(grpc_fd *fd, int n) {
 
 static void unref_by(grpc_fd *fd, int n) {
   if (gpr_atm_full_fetch_add(&fd->refst, -n) == n) {
+    grpc_iomgr_add_callback(fd->on_done, fd->on_done_user_data);
+    freelist_fd(fd);
+    grpc_iomgr_unref();
+  }
+}
+
+void grpc_fd_global_init(void) {
+  gpr_mu_init(&fd_freelist_mu);
+}
+
+void grpc_fd_global_shutdown(void) {
+  while (fd_freelist != NULL) {
+    grpc_fd *fd = fd_freelist;
+    fd_freelist = fd_freelist->freelist_next;
     destroy(fd);
   }
+  gpr_mu_destroy(&fd_freelist_mu);
 }
 
 static void do_nothing(void *ignored, int success) {}
 
 grpc_fd *grpc_fd_create(int fd) {
-  grpc_fd *r = gpr_malloc(sizeof(grpc_fd));
+  grpc_fd *r = alloc_fd(fd);
   grpc_iomgr_ref();
-  gpr_atm_rel_store(&r->refst, 1);
-  gpr_atm_rel_store(&r->readst.state, NOT_READY);
-  gpr_atm_rel_store(&r->writest.state, NOT_READY);
-  gpr_mu_init(&r->set_state_mu);
-  gpr_mu_init(&r->watcher_mu);
-  gpr_atm_rel_store(&r->shutdown, 0);
-  r->fd = fd;
-  r->watchers = NULL;
-  r->watcher_count = 0;
-  r->watcher_capacity = 0;
   grpc_pollset_add_fd(grpc_backup_pollset(), r);
   return r;
 }
diff --git a/src/core/iomgr/fd_posix.h b/src/core/iomgr/fd_posix.h
index 232de0c3e0..f42ae19579 100644
--- a/src/core/iomgr/fd_posix.h
+++ b/src/core/iomgr/fd_posix.h
@@ -69,6 +69,7 @@ typedef struct grpc_fd {
 
   grpc_iomgr_cb_func on_done;
   void *on_done_user_data;
+  struct grpc_fd *freelist_next;
 } grpc_fd;
 
 /* Create a wrapped file descriptor.
@@ -135,4 +136,7 @@ void grpc_fd_become_writable(grpc_fd *fd, int allow_synchronous_callback);
 void grpc_fd_ref(grpc_fd *fd);
 void grpc_fd_unref(grpc_fd *fd);
 
+void grpc_fd_global_init(void);
+void grpc_fd_global_shutdown(void);
+
 #endif /* __GRPC_INTERNAL_IOMGR_FD_POSIX_H_ */
diff --git a/src/core/iomgr/iomgr.c b/src/core/iomgr/iomgr.c
index 7f266ab235..8989b491d5 100644
--- a/src/core/iomgr/iomgr.c
+++ b/src/core/iomgr/iomgr.c
@@ -98,7 +98,6 @@ void grpc_iomgr_shutdown(void) {
   gpr_timespec shutdown_deadline =
       gpr_time_add(gpr_now(), gpr_time_from_seconds(10));
 
-  grpc_iomgr_platform_shutdown();
 
   gpr_mu_lock(&g_mu);
   g_shutdown = 1;
@@ -129,6 +128,7 @@ void grpc_iomgr_shutdown(void) {
 
   gpr_event_wait(&g_background_callback_executor_done, gpr_inf_future);
 
+  grpc_iomgr_platform_shutdown();
   grpc_alarm_list_shutdown();
   gpr_mu_destroy(&g_mu);
   gpr_cv_destroy(&g_cv);
diff --git a/src/core/iomgr/iomgr_posix.c b/src/core/iomgr/iomgr_posix.c
index 61fec6bc53..9297f08e99 100644
--- a/src/core/iomgr/iomgr_posix.c
+++ b/src/core/iomgr/iomgr_posix.c
@@ -32,7 +32,14 @@
  */
 
 #include "src/core/iomgr/iomgr_posix.h"
+#include "src/core/iomgr/fd_posix.h"
 
-void grpc_iomgr_platform_init(void) { grpc_pollset_global_init(); }
+void grpc_iomgr_platform_init(void) {
+  grpc_fd_global_init();
+  grpc_pollset_global_init();
+}
 
-void grpc_iomgr_platform_shutdown(void) { grpc_pollset_global_shutdown(); }
+void grpc_iomgr_platform_shutdown(void) {
+  grpc_pollset_global_shutdown();
+  grpc_fd_global_shutdown();
+}
diff --git a/src/core/json/json.c b/src/core/json/json.c
new file mode 100644
index 0000000000..1cff4fa195
--- /dev/null
+++ b/src/core/json/json.c
@@ -0,0 +1,64 @@
+/*
+ *
+ * Copyright 2014, 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.
+ *
+ */
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+
+#include "src/core/json/json.h"
+
+grpc_json *grpc_json_create(grpc_json_type type) {
+  grpc_json *json = gpr_malloc(sizeof(grpc_json));
+  memset(json, 0, sizeof(grpc_json));
+  json->type = type;
+
+  return json;
+}
+
+void grpc_json_destroy(grpc_json *json) {
+  while (json->child) {
+    grpc_json_destroy(json->child);
+  }
+
+  if (json->next) {
+    json->next->prev = json->prev;
+  }
+
+  if (json->prev) {
+    json->prev->next = json->next;
+  } else if (json->parent) {
+    json->parent->child = json->next;
+  }
+
+  gpr_free(json);
+}
diff --git a/src/core/json/json.h b/src/core/json/json.h
new file mode 100644
index 0000000000..6676744ff7
--- /dev/null
+++ b/src/core/json/json.h
@@ -0,0 +1,88 @@
+/*
+ *
+ * Copyright 2014, 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.
+ *
+ */
+
+#ifndef __GRPC_SRC_CORE_JSON_JSON_H__
+#define __GRPC_SRC_CORE_JSON_JSON_H__
+
+#include <stdlib.h>
+
+#include "src/core/json/json_common.h"
+
+/* A tree-like structure to hold json values. The key and value pointers
+ * are not owned by it.
+ */
+typedef struct grpc_json {
+  struct grpc_json* next;
+  struct grpc_json* prev;
+  struct grpc_json* child;
+  struct grpc_json* parent;
+
+  grpc_json_type type;
+  const char* key;
+  const char* value;
+} grpc_json;
+
+/* The next two functions are going to parse the input string, and
+ * destroy it in the process, in order to use its space to store
+ * all of the keys and values for the returned object tree.
+ *
+ * They assume UTF-8 input stream, and will output UTF-8 encoded
+ * strings in the tree. The input stream's UTF-8 isn't validated,
+ * as in, what you input is what you get as an output.
+ *
+ * All the keys and values in the grpc_json_t objects will be strings
+ * pointing at your input buffer.
+ *
+ * Delete the allocated tree afterward using grpc_json_destroy().
+ */
+grpc_json* grpc_json_parse_string_with_len(char* input, size_t size);
+grpc_json* grpc_json_parse_string(char* input);
+
+/* This function will create a new string using gpr_realloc, and will
+ * deserialize the grpc_json tree into it. It'll be zero-terminated,
+ * but will be allocated in chunks of 256 bytes.
+ *
+ * The indent parameter controls the way the output is formatted.
+ * If indent is 0, then newlines will be suppressed as well, and the
+ * output will be condensed at its maximum.
+ */
+char* grpc_json_dump_to_string(grpc_json* json, int indent);
+
+/* Use these to create or delete a grpc_json object.
+ * Deletion is recursive. We will not attempt to free any of the strings
+ * in any of the objects of that tree.
+ */
+grpc_json* grpc_json_create(grpc_json_type type);
+void grpc_json_destroy(grpc_json* json);
+
+#endif /* __GRPC_SRC_CORE_JSON_JSON_H__ */
diff --git a/src/core/json/json_common.h b/src/core/json/json_common.h
new file mode 100644
index 0000000000..88a8155a42
--- /dev/null
+++ b/src/core/json/json_common.h
@@ -0,0 +1,49 @@
+/*
+ *
+ * Copyright 2014, 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.
+ *
+ */
+
+#ifndef __GRPC_SRC_CORE_JSON_JSON_COMMON_H__
+#define __GRPC_SRC_CORE_JSON_JSON_COMMON_H__
+
+/* The various json types. */
+typedef enum {
+  GRPC_JSON_OBJECT,
+  GRPC_JSON_ARRAY,
+  GRPC_JSON_STRING,
+  GRPC_JSON_NUMBER,
+  GRPC_JSON_TRUE,
+  GRPC_JSON_FALSE,
+  GRPC_JSON_NULL,
+  GRPC_JSON_TOP_LEVEL
+} grpc_json_type;
+
+#endif /* __GRPC_SRC_CORE_JSON_JSON_COMMON_H__ */
diff --git a/src/core/json/json_reader.c b/src/core/json/json_reader.c
new file mode 100644
index 0000000000..75aa87eb03
--- /dev/null
+++ b/src/core/json/json_reader.c
@@ -0,0 +1,653 @@
+/*
+ *
+ * Copyright 2014, 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.
+ *
+ */
+
+#include <string.h>
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/json/json_reader.h"
+
+static void json_reader_string_clear(grpc_json_reader* reader) {
+  reader->vtable->string_clear(reader->userdata);
+}
+
+static void json_reader_string_add_char(grpc_json_reader* reader,
+                                             gpr_uint32 c) {
+  reader->vtable->string_add_char(reader->userdata, c);
+}
+
+static void json_reader_string_add_utf32(grpc_json_reader* reader,
+                                              gpr_uint32 utf32) {
+  reader->vtable->string_add_utf32(reader->userdata, utf32);
+}
+
+static gpr_uint32
+    grpc_json_reader_read_char(grpc_json_reader* reader) {
+  return reader->vtable->read_char(reader->userdata);
+}
+
+static void json_reader_container_begins(grpc_json_reader* reader,
+                                              grpc_json_type type) {
+  reader->vtable->container_begins(reader->userdata, type);
+}
+
+static grpc_json_type
+    grpc_json_reader_container_ends(grpc_json_reader* reader) {
+  return reader->vtable->container_ends(reader->userdata);
+}
+
+static void json_reader_set_key(grpc_json_reader* reader) {
+  reader->vtable->set_key(reader->userdata);
+}
+
+static void json_reader_set_string(grpc_json_reader* reader) {
+  reader->vtable->set_string(reader->userdata);
+}
+
+static int json_reader_set_number(grpc_json_reader* reader) {
+  return reader->vtable->set_number(reader->userdata);
+}
+
+static void json_reader_set_true(grpc_json_reader* reader) {
+  reader->vtable->set_true(reader->userdata);
+}
+
+static void json_reader_set_false(grpc_json_reader* reader) {
+  reader->vtable->set_false(reader->userdata);
+}
+
+static void json_reader_set_null(grpc_json_reader* reader) {
+  reader->vtable->set_null(reader->userdata);
+}
+
+/* Call this function to initialize the reader structure. */
+void grpc_json_reader_init(grpc_json_reader* reader,
+                           grpc_json_reader_vtable* vtable, void* userdata) {
+  memset(reader, 0, sizeof(grpc_json_reader));
+  reader->vtable = vtable;
+  reader->userdata = userdata;
+  json_reader_string_clear(reader);
+  reader->state = GRPC_JSON_STATE_VALUE_BEGIN;
+}
+
+int grpc_json_reader_is_complete(grpc_json_reader* reader) {
+  return ((reader->depth == 0) && ((reader->state == GRPC_JSON_STATE_END) ||
+          (reader->state == GRPC_JSON_STATE_VALUE_END)));
+}
+
+grpc_json_reader_status grpc_json_reader_run(grpc_json_reader* reader) {
+  gpr_uint32 c, success;
+
+  /* This state-machine is a strict implementation of ECMA-404 */
+  for (;;) {
+    c = grpc_json_reader_read_char(reader);
+    switch (c) {
+      /* Let's process the error cases first. */
+      case GRPC_JSON_READ_CHAR_ERROR:
+        return GRPC_JSON_READ_ERROR;
+
+      case GRPC_JSON_READ_CHAR_EAGAIN:
+        return GRPC_JSON_EAGAIN;
+
+      case GRPC_JSON_READ_CHAR_EOF:
+        if (grpc_json_reader_is_complete(reader)) {
+          return GRPC_JSON_DONE;
+        } else {
+          return GRPC_JSON_PARSE_ERROR;
+        }
+        break;
+
+      /* Processing whitespaces. */
+      case ' ':
+      case '\t':
+      case '\n':
+      case '\r':
+        switch (reader->state) {
+          case GRPC_JSON_STATE_OBJECT_KEY_BEGIN:
+          case GRPC_JSON_STATE_OBJECT_KEY_END:
+          case GRPC_JSON_STATE_VALUE_BEGIN:
+          case GRPC_JSON_STATE_VALUE_END:
+          case GRPC_JSON_STATE_END:
+            break;
+
+          case GRPC_JSON_STATE_OBJECT_KEY_STRING:
+          case GRPC_JSON_STATE_VALUE_STRING:
+            if (c != ' ') return GRPC_JSON_PARSE_ERROR;
+            if (reader->unicode_high_surrogate != 0) return GRPC_JSON_PARSE_ERROR;
+            json_reader_string_add_char(reader, c);
+            break;
+
+          case GRPC_JSON_STATE_VALUE_NUMBER:
+          case GRPC_JSON_STATE_VALUE_NUMBER_WITH_DECIMAL:
+          case GRPC_JSON_STATE_VALUE_NUMBER_ZERO:
+          case GRPC_JSON_STATE_VALUE_NUMBER_EPM:
+            success = json_reader_set_number(reader);
+            if (!success) return GRPC_JSON_PARSE_ERROR;
+            json_reader_string_clear(reader);
+            reader->state = GRPC_JSON_STATE_VALUE_END;
+            break;
+
+          default:
+            return GRPC_JSON_PARSE_ERROR;
+        }
+        break;
+
+      /* Value, object or array terminations. */
+      case ',':
+      case '}':
+      case ']':
+        switch (reader->state) {
+          case GRPC_JSON_STATE_OBJECT_KEY_STRING:
+          case GRPC_JSON_STATE_VALUE_STRING:
+            if (reader->unicode_high_surrogate != 0) return GRPC_JSON_PARSE_ERROR;
+            json_reader_string_add_char(reader, c);
+            break;
+
+          case GRPC_JSON_STATE_VALUE_NUMBER:
+          case GRPC_JSON_STATE_VALUE_NUMBER_WITH_DECIMAL:
+          case GRPC_JSON_STATE_VALUE_NUMBER_ZERO:
+          case GRPC_JSON_STATE_VALUE_NUMBER_EPM:
+            success = json_reader_set_number(reader);
+            if (!success) return GRPC_JSON_PARSE_ERROR;
+            json_reader_string_clear(reader);
+            reader->state = GRPC_JSON_STATE_VALUE_END;
+          /* The missing break here is intentional. */
+
+          case GRPC_JSON_STATE_VALUE_END:
+          case GRPC_JSON_STATE_OBJECT_KEY_BEGIN:
+          case GRPC_JSON_STATE_VALUE_BEGIN:
+            if (c == ',') {
+              if (reader->state != GRPC_JSON_STATE_VALUE_END) {
+                return GRPC_JSON_PARSE_ERROR;
+              }
+              if (reader->in_object) {
+                reader->state = GRPC_JSON_STATE_OBJECT_KEY_BEGIN;
+              } else {
+                reader->state = GRPC_JSON_STATE_VALUE_BEGIN;
+              }
+            } else {
+              if (reader->depth-- == 0) return GRPC_JSON_PARSE_ERROR;
+              if ((c == '}') && !reader->in_object) {
+                return GRPC_JSON_PARSE_ERROR;
+              }
+              if ((c == '}') &&
+                  (reader->state == GRPC_JSON_STATE_OBJECT_KEY_BEGIN) &&
+                  !reader->container_just_begun) {
+                return GRPC_JSON_PARSE_ERROR;
+              }
+              if ((c == ']') && !reader->in_array) return GRPC_JSON_PARSE_ERROR;
+              if ((c == ']') &&
+                  (reader->state == GRPC_JSON_STATE_VALUE_BEGIN) &&
+                  !reader->container_just_begun) {
+                return GRPC_JSON_PARSE_ERROR;
+              }
+              reader->state = GRPC_JSON_STATE_VALUE_END;
+              switch (grpc_json_reader_container_ends(reader)) {
+                case GRPC_JSON_OBJECT:
+                  reader->in_object = 1;
+                  reader->in_array = 0;
+                  break;
+                case GRPC_JSON_ARRAY:
+                  reader->in_object = 0;
+                  reader->in_array = 1;
+                  break;
+                case GRPC_JSON_TOP_LEVEL:
+                  if (reader->depth != 0) return GRPC_JSON_INTERNAL_ERROR;
+                  reader->in_object = 0;
+                  reader->in_array = 0;
+                  reader->state = GRPC_JSON_STATE_END;
+                  break;
+                default:
+                  return GRPC_JSON_INTERNAL_ERROR;
+              }
+            }
+            break;
+
+          default:
+            return GRPC_JSON_PARSE_ERROR;
+        }
+        break;
+
+      /* In-string escaping. */
+      case '\\':
+        switch (reader->state) {
+          case GRPC_JSON_STATE_OBJECT_KEY_STRING:
+            reader->escaped_string_was_key = 1;
+            reader->state = GRPC_JSON_STATE_STRING_ESCAPE;
+            break;
+
+          case GRPC_JSON_STATE_VALUE_STRING:
+            reader->escaped_string_was_key = 0;
+            reader->state = GRPC_JSON_STATE_STRING_ESCAPE;
+            break;
+
+          /* This is the \\ case. */
+          case GRPC_JSON_STATE_STRING_ESCAPE:
+            if (reader->unicode_high_surrogate != 0) return GRPC_JSON_PARSE_ERROR;
+            json_reader_string_add_char(reader, '\\');
+            if (reader->escaped_string_was_key) {
+              reader->state = GRPC_JSON_STATE_OBJECT_KEY_STRING;
+            } else {
+              reader->state = GRPC_JSON_STATE_VALUE_STRING;
+            }
+            break;
+
+          default:
+            return GRPC_JSON_PARSE_ERROR;
+        }
+        break;
+
+      default:
+        reader->container_just_begun = 0;
+        switch (reader->state) {
+          case GRPC_JSON_STATE_OBJECT_KEY_BEGIN:
+            if (c != '"') return GRPC_JSON_PARSE_ERROR;
+            reader->state = GRPC_JSON_STATE_OBJECT_KEY_STRING;
+            break;
+
+          case GRPC_JSON_STATE_OBJECT_KEY_STRING:
+            if (reader->unicode_high_surrogate != 0) return GRPC_JSON_PARSE_ERROR;
+            if (c == '"') {
+              reader->state = GRPC_JSON_STATE_OBJECT_KEY_END;
+              json_reader_set_key(reader);
+              json_reader_string_clear(reader);
+            } else {
+              if (c <= 0x001f) return GRPC_JSON_PARSE_ERROR;
+              json_reader_string_add_char(reader, c);
+            }
+            break;
+
+          case GRPC_JSON_STATE_VALUE_STRING:
+            if (reader->unicode_high_surrogate != 0) return GRPC_JSON_PARSE_ERROR;
+            if (c == '"') {
+              reader->state = GRPC_JSON_STATE_VALUE_END;
+              json_reader_set_string(reader);
+              json_reader_string_clear(reader);
+            } else {
+              if (c < 32) return GRPC_JSON_PARSE_ERROR;
+              json_reader_string_add_char(reader, c);
+            }
+            break;
+
+          case GRPC_JSON_STATE_OBJECT_KEY_END:
+            if (c != ':') return GRPC_JSON_PARSE_ERROR;
+            reader->state = GRPC_JSON_STATE_VALUE_BEGIN;
+            break;
+
+          case GRPC_JSON_STATE_VALUE_BEGIN:
+            switch (c) {
+              case 't':
+                reader->state = GRPC_JSON_STATE_VALUE_TRUE_R;
+                break;
+
+              case 'f':
+                reader->state = GRPC_JSON_STATE_VALUE_FALSE_A;
+                break;
+
+              case 'n':
+                reader->state = GRPC_JSON_STATE_VALUE_NULL_U;
+                break;
+
+              case '"':
+                reader->state = GRPC_JSON_STATE_VALUE_STRING;
+                break;
+
+              case '0':
+                json_reader_string_add_char(reader, c);
+                reader->state = GRPC_JSON_STATE_VALUE_NUMBER_ZERO;
+                break;
+
+              case '1':
+              case '2':
+              case '3':
+              case '4':
+              case '5':
+              case '6':
+              case '7':
+              case '8':
+              case '9':
+              case '-':
+                json_reader_string_add_char(reader, c);
+                reader->state = GRPC_JSON_STATE_VALUE_NUMBER;
+                break;
+
+              case '{':
+                reader->container_just_begun = 1;
+                json_reader_container_begins(reader, GRPC_JSON_OBJECT);
+                reader->depth++;
+                reader->state = GRPC_JSON_STATE_OBJECT_KEY_BEGIN;
+                reader->in_object = 1;
+                reader->in_array = 0;
+                break;
+
+              case '[':
+                reader->container_just_begun = 1;
+                json_reader_container_begins(reader, GRPC_JSON_ARRAY);
+                reader->depth++;
+                reader->in_object = 0;
+                reader->in_array = 1;
+                break;
+            }
+            break;
+
+          case GRPC_JSON_STATE_STRING_ESCAPE:
+            if (reader->escaped_string_was_key) {
+              reader->state = GRPC_JSON_STATE_OBJECT_KEY_STRING;
+            } else {
+              reader->state = GRPC_JSON_STATE_VALUE_STRING;
+            }
+            if (reader->unicode_high_surrogate && c != 'u')
+              return GRPC_JSON_PARSE_ERROR;
+            switch (c) {
+              case '"':
+              case '/':
+                json_reader_string_add_char(reader, c);
+                break;
+              case 'b':
+                json_reader_string_add_char(reader, '\b');
+                break;
+              case 'f':
+                json_reader_string_add_char(reader, '\f');
+                break;
+              case 'n':
+                json_reader_string_add_char(reader, '\n');
+                break;
+              case 'r':
+                json_reader_string_add_char(reader, '\r');
+                break;
+              case 't':
+                json_reader_string_add_char(reader, '\t');
+                break;
+              case 'u':
+                reader->state = GRPC_JSON_STATE_STRING_ESCAPE_U1;
+                reader->unicode_char = 0;
+                break;
+              default:
+                return GRPC_JSON_PARSE_ERROR;
+            }
+            break;
+
+          case GRPC_JSON_STATE_STRING_ESCAPE_U1:
+          case GRPC_JSON_STATE_STRING_ESCAPE_U2:
+          case GRPC_JSON_STATE_STRING_ESCAPE_U3:
+          case GRPC_JSON_STATE_STRING_ESCAPE_U4:
+            if ((c >= '0') && (c <= '9')) {
+              c -= '0';
+            } else if ((c >= 'A') && (c <= 'F')) {
+              c -= 'A' - 10;
+            } else if ((c >= 'a') && (c <= 'f')) {
+              c -= 'a' - 10;
+            } else {
+              return GRPC_JSON_PARSE_ERROR;
+            }
+            reader->unicode_char <<= 4;
+            reader->unicode_char |= c;
+
+            switch (reader->state) {
+              case GRPC_JSON_STATE_STRING_ESCAPE_U1:
+                reader->state = GRPC_JSON_STATE_STRING_ESCAPE_U2;
+                break;
+              case GRPC_JSON_STATE_STRING_ESCAPE_U2:
+                reader->state = GRPC_JSON_STATE_STRING_ESCAPE_U3;
+                break;
+              case GRPC_JSON_STATE_STRING_ESCAPE_U3:
+                reader->state = GRPC_JSON_STATE_STRING_ESCAPE_U4;
+                break;
+              case GRPC_JSON_STATE_STRING_ESCAPE_U4:
+                /* See grpc_json_writer_escape_string to have a description
+                 * of what's going on here.
+                 */
+                if ((reader->unicode_char & 0xfc00) == 0xd800) {
+                  /* high surrogate utf-16 */
+                  if (reader->unicode_high_surrogate != 0)
+                    return GRPC_JSON_PARSE_ERROR;
+                  reader->unicode_high_surrogate = reader->unicode_char;
+                } else if ((reader->unicode_char & 0xfc00) == 0xdc00) {
+                  /* low surrogate utf-16 */
+                  gpr_uint32 utf32;
+                  if (reader->unicode_high_surrogate == 0)
+                    return GRPC_JSON_PARSE_ERROR;
+                  utf32 = 0x10000;
+                  utf32 += (reader->unicode_high_surrogate - 0xd800) * 0x400;
+                  utf32 += reader->unicode_char - 0xdc00;
+                  json_reader_string_add_utf32(reader, utf32);
+                  reader->unicode_high_surrogate = 0;
+                } else {
+                  /* anything else */
+                  if (reader->unicode_high_surrogate != 0)
+                    return GRPC_JSON_PARSE_ERROR;
+                  json_reader_string_add_utf32(reader, reader->unicode_char);
+                }
+                if (reader->escaped_string_was_key) {
+                  reader->state = GRPC_JSON_STATE_OBJECT_KEY_STRING;
+                } else {
+                  reader->state = GRPC_JSON_STATE_VALUE_STRING;
+                }
+                break;
+              default:
+                return GRPC_JSON_INTERNAL_ERROR;
+            }
+            break;
+
+          case GRPC_JSON_STATE_VALUE_NUMBER:
+            json_reader_string_add_char(reader, c);
+            switch (c) {
+              case '0':
+              case '1':
+              case '2':
+              case '3':
+              case '4':
+              case '5':
+              case '6':
+              case '7':
+              case '8':
+              case '9':
+                break;
+              case 'e':
+              case 'E':
+                reader->state = GRPC_JSON_STATE_VALUE_NUMBER_E;
+                break;
+              case '.':
+                reader->state = GRPC_JSON_STATE_VALUE_NUMBER_DOT;
+                break;
+              default:
+                return GRPC_JSON_PARSE_ERROR;
+            }
+            break;
+
+          case GRPC_JSON_STATE_VALUE_NUMBER_WITH_DECIMAL:
+            json_reader_string_add_char(reader, c);
+            switch (c) {
+              case '0':
+              case '1':
+              case '2':
+              case '3':
+              case '4':
+              case '5':
+              case '6':
+              case '7':
+              case '8':
+              case '9':
+                break;
+              case 'e':
+              case 'E':
+                reader->state = GRPC_JSON_STATE_VALUE_NUMBER_E;
+                break;
+              default:
+                return GRPC_JSON_PARSE_ERROR;
+            }
+            break;
+
+          case GRPC_JSON_STATE_VALUE_NUMBER_ZERO:
+            if (c != '.') return GRPC_JSON_PARSE_ERROR;
+            json_reader_string_add_char(reader, c);
+            reader->state = GRPC_JSON_STATE_VALUE_NUMBER_DOT;
+            break;
+
+          case GRPC_JSON_STATE_VALUE_NUMBER_DOT:
+            json_reader_string_add_char(reader, c);
+            switch (c) {
+              case '0':
+              case '1':
+              case '2':
+              case '3':
+              case '4':
+              case '5':
+              case '6':
+              case '7':
+              case '8':
+              case '9':
+                reader->state = GRPC_JSON_STATE_VALUE_NUMBER_WITH_DECIMAL;
+                break;
+              default:
+                return GRPC_JSON_PARSE_ERROR;
+            }
+            break;
+
+          case GRPC_JSON_STATE_VALUE_NUMBER_E:
+            json_reader_string_add_char(reader, c);
+            switch (c) {
+              case '0':
+              case '1':
+              case '2':
+              case '3':
+              case '4':
+              case '5':
+              case '6':
+              case '7':
+              case '8':
+              case '9':
+              case '+':
+              case '-':
+                reader->state = GRPC_JSON_STATE_VALUE_NUMBER_EPM;
+                break;
+              default:
+                return GRPC_JSON_PARSE_ERROR;
+            }
+            break;
+
+          case GRPC_JSON_STATE_VALUE_NUMBER_EPM:
+            json_reader_string_add_char(reader, c);
+            switch (c) {
+              case '0':
+              case '1':
+              case '2':
+              case '3':
+              case '4':
+              case '5':
+              case '6':
+              case '7':
+              case '8':
+              case '9':
+                break;
+              default:
+                return GRPC_JSON_PARSE_ERROR;
+            }
+            break;
+
+          case GRPC_JSON_STATE_VALUE_TRUE_R:
+            if (c != 'r') return GRPC_JSON_PARSE_ERROR;
+            reader->state = GRPC_JSON_STATE_VALUE_TRUE_U;
+            break;
+
+          case GRPC_JSON_STATE_VALUE_TRUE_U:
+            if (c != 'u') return GRPC_JSON_PARSE_ERROR;
+            reader->state = GRPC_JSON_STATE_VALUE_TRUE_E;
+            break;
+
+          case GRPC_JSON_STATE_VALUE_TRUE_E:
+            if (c != 'e') return GRPC_JSON_PARSE_ERROR;
+            json_reader_set_true(reader);
+            reader->state = GRPC_JSON_STATE_VALUE_END;
+            break;
+
+          case GRPC_JSON_STATE_VALUE_FALSE_A:
+            if (c != 'a') return GRPC_JSON_PARSE_ERROR;
+            reader->state = GRPC_JSON_STATE_VALUE_FALSE_L;
+            break;
+
+          case GRPC_JSON_STATE_VALUE_FALSE_L:
+            if (c != 'l') return GRPC_JSON_PARSE_ERROR;
+            reader->state = GRPC_JSON_STATE_VALUE_FALSE_S;
+            break;
+
+          case GRPC_JSON_STATE_VALUE_FALSE_S:
+            if (c != 's') return GRPC_JSON_PARSE_ERROR;
+            reader->state = GRPC_JSON_STATE_VALUE_FALSE_E;
+            break;
+
+          case GRPC_JSON_STATE_VALUE_FALSE_E:
+            if (c != 'e') return GRPC_JSON_PARSE_ERROR;
+            json_reader_set_false(reader);
+            reader->state = GRPC_JSON_STATE_VALUE_END;
+            break;
+
+          case GRPC_JSON_STATE_VALUE_NULL_U:
+            if (c != 'u') return GRPC_JSON_PARSE_ERROR;
+            reader->state = GRPC_JSON_STATE_VALUE_NULL_L1;
+            break;
+
+          case GRPC_JSON_STATE_VALUE_NULL_L1:
+            if (c != 'l') return GRPC_JSON_PARSE_ERROR;
+            reader->state = GRPC_JSON_STATE_VALUE_NULL_L2;
+            break;
+
+          case GRPC_JSON_STATE_VALUE_NULL_L2:
+            if (c != 'l') return GRPC_JSON_PARSE_ERROR;
+            json_reader_set_null(reader);
+            reader->state = GRPC_JSON_STATE_VALUE_END;
+            break;
+
+          /* All of the VALUE_END cases are handled in the specialized case
+           * above. */
+          case GRPC_JSON_STATE_VALUE_END:
+            switch (c) {
+              case ',':
+              case '}':
+              case ']':
+                return GRPC_JSON_INTERNAL_ERROR;
+                break;
+
+              default:
+                return GRPC_JSON_PARSE_ERROR;
+            }
+            break;
+
+          case GRPC_JSON_STATE_END:
+            return GRPC_JSON_PARSE_ERROR;
+        }
+    }
+  }
+
+  return GRPC_JSON_INTERNAL_ERROR;
+}
diff --git a/src/core/json/json_reader.h b/src/core/json/json_reader.h
new file mode 100644
index 0000000000..388ee3633f
--- /dev/null
+++ b/src/core/json/json_reader.h
@@ -0,0 +1,160 @@
+/*
+ *
+ * Copyright 2014, 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.
+ *
+ */
+
+#ifndef __GRPC_SRC_CORE_JSON_JSON_READER_H__
+#define __GRPC_SRC_CORE_JSON_JSON_READER_H__
+
+#include <grpc/support/port_platform.h>
+#include "src/core/json/json_common.h"
+
+typedef enum {
+  GRPC_JSON_STATE_OBJECT_KEY_BEGIN,
+  GRPC_JSON_STATE_OBJECT_KEY_STRING,
+  GRPC_JSON_STATE_OBJECT_KEY_END,
+  GRPC_JSON_STATE_VALUE_BEGIN,
+  GRPC_JSON_STATE_VALUE_STRING,
+  GRPC_JSON_STATE_STRING_ESCAPE,
+  GRPC_JSON_STATE_STRING_ESCAPE_U1,
+  GRPC_JSON_STATE_STRING_ESCAPE_U2,
+  GRPC_JSON_STATE_STRING_ESCAPE_U3,
+  GRPC_JSON_STATE_STRING_ESCAPE_U4,
+  GRPC_JSON_STATE_VALUE_NUMBER,
+  GRPC_JSON_STATE_VALUE_NUMBER_WITH_DECIMAL,
+  GRPC_JSON_STATE_VALUE_NUMBER_ZERO,
+  GRPC_JSON_STATE_VALUE_NUMBER_DOT,
+  GRPC_JSON_STATE_VALUE_NUMBER_E,
+  GRPC_JSON_STATE_VALUE_NUMBER_EPM,
+  GRPC_JSON_STATE_VALUE_TRUE_R,
+  GRPC_JSON_STATE_VALUE_TRUE_U,
+  GRPC_JSON_STATE_VALUE_TRUE_E,
+  GRPC_JSON_STATE_VALUE_FALSE_A,
+  GRPC_JSON_STATE_VALUE_FALSE_L,
+  GRPC_JSON_STATE_VALUE_FALSE_S,
+  GRPC_JSON_STATE_VALUE_FALSE_E,
+  GRPC_JSON_STATE_VALUE_NULL_U,
+  GRPC_JSON_STATE_VALUE_NULL_L1,
+  GRPC_JSON_STATE_VALUE_NULL_L2,
+  GRPC_JSON_STATE_VALUE_END,
+  GRPC_JSON_STATE_END
+} grpc_json_reader_state;
+
+enum {
+  /* The first non-unicode value is 0x110000. But let's pick
+   * a value high enough to start our error codes from. These
+   * values are safe to return from the read_char function.
+   */
+  GRPC_JSON_READ_CHAR_EOF = 0x7ffffff0,
+  GRPC_JSON_READ_CHAR_EAGAIN,
+  GRPC_JSON_READ_CHAR_ERROR
+};
+
+struct grpc_json_reader;
+
+typedef struct grpc_json_reader_vtable {
+  /* Clears your internal string scratchpad. */
+  void (*string_clear)(void* userdata);
+  /* Adds a char to the string scratchpad. */
+  void (*string_add_char)(void* userdata, gpr_uint32 c);
+  /* Adds a utf32 char to the string scratchpad. */
+  void (*string_add_utf32)(void* userdata, gpr_uint32 c);
+  /* Reads a character from your input. May be utf-8, 16 or 32. */
+  gpr_uint32 (*read_char)(void* userdata);
+  /* Starts a container of type GRPC_JSON_ARRAY or GRPC_JSON_OBJECT. */
+  void (*container_begins)(void* userdata, grpc_json_type type);
+  /* Ends the current container. Must return the type of its parent. */
+  grpc_json_type (*container_ends)(void* userdata);
+  /* Your internal string scratchpad is an object's key. */
+  void (*set_key)(void* userdata);
+  /* Your internal string scratchpad is a string value. */
+  void (*set_string)(void* userdata);
+  /* Your internal string scratchpad is a numerical value. Return 1 if valid. */
+  int (*set_number)(void* userdata);
+  /* Sets the values true, false or null. */
+  void (*set_true)(void* userdata);
+  void (*set_false)(void* userdata);
+  void (*set_null)(void* userdata);
+} grpc_json_reader_vtable;
+
+typedef struct grpc_json_reader {
+  /* That structure is fully private, and initialized by grpc_json_reader_init.
+   * The definition is public so you can put it on your stack.
+   */
+
+  void* userdata;
+  grpc_json_reader_vtable* vtable;
+  int depth;
+  int in_object;
+  int in_array;
+  int escaped_string_was_key;
+  int container_just_begun;
+  gpr_uint16 unicode_char, unicode_high_surrogate;
+  grpc_json_reader_state state;
+} grpc_json_reader;
+
+/* The return type of the parser. */
+typedef enum {
+  GRPC_JSON_DONE,          /* The parser finished successfully. */
+  GRPC_JSON_EAGAIN,        /* The parser yields to get more data. */
+  GRPC_JSON_READ_ERROR,    /* The parser passes through a read error. */
+  GRPC_JSON_PARSE_ERROR,   /* The parser found an error in the json stream. */
+  GRPC_JSON_INTERNAL_ERROR /* The parser got an internal error. */
+} grpc_json_reader_status;
+
+/* Call this function to start parsing the input. It will return the following:
+ *    . GRPC_JSON_DONE if the input got eof, and the parsing finished
+ *      successfully.
+ *    . GRPC_JSON_EAGAIN if the read_char function returned again. Call the
+ *      parser again as needed. It is okay to call the parser in polling mode,
+ *      although a bit dull.
+ *    . GRPC_JSON_READ_ERROR if the read_char function returned an error. The
+ *      state isn't broken however, and the function can be called again if the
+ *      error has been corrected. But please use the EAGAIN feature instead for
+ *      consistency.
+ *    . GRPC_JSON_PARSE_ERROR if the input was somehow invalid.
+ *    . GRPC_JSON_INTERNAL_ERROR if the parser somehow ended into an invalid
+ *      internal state.
+ */
+grpc_json_reader_status grpc_json_reader_run(grpc_json_reader* reader);
+
+/* Call this function to initialize the reader structure. */
+void grpc_json_reader_init(grpc_json_reader* reader,
+                           grpc_json_reader_vtable* vtable, void* userdata);
+
+/* You may call this from the read_char callback if you don't know where is the
+ * end of your input stream, and you'd like the json reader to hint you that it
+ * has completed reading its input, so you can return an EOF to it. Note that
+ * there might still be trailing whitespaces after that point.
+ */
+int grpc_json_reader_is_complete(grpc_json_reader* reader);
+
+#endif /* __GRPC_SRC_CORE_JSON_JSON_READER_H__ */
diff --git a/src/core/json/json_string.c b/src/core/json/json_string.c
new file mode 100644
index 0000000000..d29e9e30e8
--- /dev/null
+++ b/src/core/json/json_string.c
@@ -0,0 +1,391 @@
+/*
+ *
+ * Copyright 2014, 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.
+ *
+ */
+
+#include <string.h>
+#include <stdlib.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+
+#include "src/core/json/json.h"
+#include "src/core/json/json_reader.h"
+#include "src/core/json/json_writer.h"
+
+/* The json reader will construct a bunch of grpc_json objects and
+ * link them all up together in a tree-like structure that will represent
+ * the json data in memory.
+ *
+ * It also uses its own input as a scratchpad to store all of the decoded,
+ * unescaped strings. So we need to keep track of all these pointers in
+ * that opaque structure the reader will carry for us.
+ *
+ * Note that this works because the act of parsing json always reduces its
+ * input size, and never expands it.
+ */
+typedef struct {
+  grpc_json* top;
+  grpc_json* current_container;
+  grpc_json* current_value;
+  gpr_uint8* input;
+  gpr_uint8* key;
+  gpr_uint8* string;
+  gpr_uint8* string_ptr;
+  size_t remaining_input;
+} json_reader_userdata;
+
+/* This json writer will put everything in a big string.
+ * The point is that we allocate that string in chunks of 256 bytes.
+ */
+typedef struct {
+  char* output;
+  size_t free_space;
+  size_t string_len;
+  size_t allocated;
+} json_writer_userdata;
+
+
+/* This function checks if there's enough space left in the output buffer,
+ * and will enlarge it if necessary. We're only allocating chunks of 256
+ * bytes at a time (or multiples thereof).
+ */
+static void json_writer_output_check(void* userdata, size_t needed) {
+  json_writer_userdata* state = userdata;
+  if (state->free_space >= needed) return;
+  needed -= state->free_space;
+  /* Round up by 256 bytes. */
+  needed = (needed + 0xff) & ~0xff;
+  state->output = gpr_realloc(state->output, state->allocated + needed);
+  state->free_space += needed;
+  state->allocated += needed;
+}
+
+/* These are needed by the writer's implementation. */
+static void json_writer_output_char(void* userdata, char c) {
+  json_writer_userdata* state = userdata;
+  json_writer_output_check(userdata, 1);
+  state->output[state->string_len++] = c;
+  state->free_space--;
+}
+
+static void json_writer_output_string_with_len(void* userdata,
+                                               const char* str, size_t len) {
+  json_writer_userdata* state = userdata;
+  json_writer_output_check(userdata, len);
+  memcpy(state->output + state->string_len, str, len);
+  state->string_len += len;
+  state->free_space -= len;
+}
+
+static void json_writer_output_string(void* userdata,
+                                           const char* str) {
+  size_t len = strlen(str);
+  json_writer_output_string_with_len(userdata, str, len);
+}
+
+/* The reader asks us to clear our scratchpad. In our case, we'll simply mark
+ * the end of the current string, and advance our output pointer.
+ */
+static void json_reader_string_clear(void* userdata) {
+  json_reader_userdata* state = userdata;
+  if (state->string) {
+    GPR_ASSERT(state->string_ptr < state->input);
+    *state->string_ptr++ = 0;
+  }
+  state->string = state->string_ptr;
+}
+
+static void json_reader_string_add_char(void* userdata, gpr_uint32 c) {
+  json_reader_userdata* state = userdata;
+  GPR_ASSERT(state->string_ptr < state->input);
+  GPR_ASSERT(c <= 0xff);
+  *state->string_ptr++ = (char)c;
+}
+
+/* We are converting a UTF-32 character into UTF-8 here,
+ * as described by RFC3629.
+ */
+static void json_reader_string_add_utf32(void* userdata, gpr_uint32 c) {
+  if (c <= 0x7f) {
+    json_reader_string_add_char(userdata, c);
+  } else if (c <= 0x7ff) {
+    int b1 = 0xc0 | ((c >> 6) & 0x1f);
+    int b2 = 0x80 | (c & 0x3f);
+    json_reader_string_add_char(userdata, b1);
+    json_reader_string_add_char(userdata, b2);
+  } else if (c <= 0xffff) {
+    int b1 = 0xe0 | ((c >> 12) & 0x0f);
+    int b2 = 0x80 | ((c >> 6) & 0x3f);
+    int b3 = 0x80 | (c & 0x3f);
+    json_reader_string_add_char(userdata, b1);
+    json_reader_string_add_char(userdata, b2);
+    json_reader_string_add_char(userdata, b3);
+  } else if (c <= 0x1fffff) {
+    int b1 = 0xf0 | ((c >> 18) & 0x07);
+    int b2 = 0x80 | ((c >> 12) & 0x3f);
+    int b3 = 0x80 | ((c >> 6) & 0x3f);
+    int b4 = 0x80 | (c & 0x3f);
+    json_reader_string_add_char(userdata, b1);
+    json_reader_string_add_char(userdata, b2);
+    json_reader_string_add_char(userdata, b3);
+    json_reader_string_add_char(userdata, b4);
+  }
+}
+
+/* We consider that the input may be a zero-terminated string. So we
+ * can end up hitting eof before the end of the alleged string length.
+ */
+static gpr_uint32 json_reader_read_char(void* userdata) {
+  gpr_uint32 r;
+  json_reader_userdata* state = userdata;
+
+  if (state->remaining_input == 0) return GRPC_JSON_READ_CHAR_EOF;
+
+  r = *state->input++;
+  state->remaining_input--;
+
+  if (r == 0) {
+    state->remaining_input = 0;
+    return GRPC_JSON_READ_CHAR_EOF;
+  }
+
+  return r;
+}
+
+/* Helper function to create a new grpc_json object and link it into
+ * our tree-in-progress inside our opaque structure.
+ */
+static grpc_json* json_create_and_link(void* userdata,
+                                       grpc_json_type type) {
+  json_reader_userdata* state = userdata;
+  grpc_json* json = grpc_json_create(type);
+
+  json->parent = state->current_container;
+  json->prev = state->current_value;
+  state->current_value = json;
+
+  if (json->prev) {
+    json->prev->next = json;
+  }
+  if (json->parent) {
+    if (!json->parent->child) {
+      json->parent->child = json;
+    }
+    if (json->parent->type == GRPC_JSON_OBJECT) {
+      json->key = (char*) state->key;
+    }
+  }
+  if (!state->top) {
+    state->top = json;
+  }
+
+  return json;
+}
+
+static void json_reader_container_begins(void* userdata, grpc_json_type type) {
+  json_reader_userdata* state = userdata;
+  grpc_json* container;
+
+  GPR_ASSERT(type == GRPC_JSON_ARRAY || type == GRPC_JSON_OBJECT);
+
+  container = json_create_and_link(userdata, type);
+  state->current_container = container;
+  state->current_value = NULL;
+}
+
+/* It's important to remember that the reader is mostly stateless, so it
+ * isn't trying to remember what the container was prior the one that just
+ * ends. Since we're keeping track of these for our own purpose, we are
+ * able to return that information back, which is useful for it to validate
+ * the input json stream.
+ *
+ * Also note that if we're at the top of the tree, and the last container
+ * ends, we have to return GRPC_JSON_TOP_LEVEL.
+ */
+static grpc_json_type json_reader_container_ends(void* userdata) {
+  grpc_json_type container_type = GRPC_JSON_TOP_LEVEL;
+  json_reader_userdata* state = userdata;
+
+  GPR_ASSERT(state->current_container);
+
+  state->current_value = state->current_container;
+  state->current_container = state->current_container->parent;
+
+  if (state->current_container) {
+    container_type = state->current_container->type;
+  }
+
+  return container_type;
+}
+
+/* The next 3 functions basically are the reader asking us to use our string
+ * scratchpad for one of these 3 purposes.
+ *
+ * Note that in the set_number case, we're not going to try interpreting it.
+ * We'll keep it as a string, and leave it to the caller to evaluate it.
+ */
+static void json_reader_set_key(void* userdata) {
+  json_reader_userdata* state = userdata;
+  state->key = state->string;
+}
+
+static void json_reader_set_string(void* userdata) {
+  json_reader_userdata* state = userdata;
+  grpc_json* json = json_create_and_link(userdata, GRPC_JSON_STRING);
+  json->value = (char*) state->string;
+}
+
+static int json_reader_set_number(void* userdata) {
+  json_reader_userdata* state = userdata;
+  grpc_json* json = json_create_and_link(userdata, GRPC_JSON_NUMBER);
+  json->value = (char*) state->string;
+  return 1;
+}
+
+/* The object types true, false and null are self-sufficient, and don't need
+ * any more information beside their type.
+ */
+static void json_reader_set_true(void* userdata) {
+  json_create_and_link(userdata, GRPC_JSON_TRUE);
+}
+
+static void json_reader_set_false(void* userdata) {
+  json_create_and_link(userdata, GRPC_JSON_FALSE);
+}
+
+static void json_reader_set_null(void* userdata) {
+  json_create_and_link(userdata, GRPC_JSON_NULL);
+}
+
+static grpc_json_reader_vtable reader_vtable = {
+  json_reader_string_clear,
+  json_reader_string_add_char,
+  json_reader_string_add_utf32,
+  json_reader_read_char,
+  json_reader_container_begins,
+  json_reader_container_ends,
+  json_reader_set_key,
+  json_reader_set_string,
+  json_reader_set_number,
+  json_reader_set_true,
+  json_reader_set_false,
+  json_reader_set_null
+};
+
+/* And finally, let's define our public API. */
+grpc_json* grpc_json_parse_string_with_len(char* input, size_t size) {
+  grpc_json_reader reader;
+  json_reader_userdata state;
+  grpc_json *json = NULL;
+  grpc_json_reader_status status;
+
+  if (!input) return NULL;
+
+  state.top = state.current_container = state.current_value = NULL;
+  state.string = state.key = NULL;
+  state.string_ptr = state.input = (gpr_uint8*) input;
+  state.remaining_input = size;
+  grpc_json_reader_init(&reader, &reader_vtable, &state);
+
+  status = grpc_json_reader_run(&reader);
+  json = state.top;
+
+  if ((status != GRPC_JSON_DONE) && json) {
+    grpc_json_destroy(json);
+    json = NULL;
+  }
+
+  return json;
+}
+
+#define UNBOUND_JSON_STRING_LENGTH 0x7fffffff
+
+grpc_json* grpc_json_parse_string(char* input) {
+  return grpc_json_parse_string_with_len(input, UNBOUND_JSON_STRING_LENGTH);
+}
+
+static void json_dump_recursive(grpc_json_writer* writer,
+                                grpc_json* json, int in_object) {
+  while (json) {
+    if (in_object) grpc_json_writer_object_key(writer, json->key);
+
+    switch (json->type) {
+      case GRPC_JSON_OBJECT:
+      case GRPC_JSON_ARRAY:
+        grpc_json_writer_container_begins(writer, json->type);
+        if (json->child)
+          json_dump_recursive(writer, json->child,
+                              json->type == GRPC_JSON_OBJECT);
+        grpc_json_writer_container_ends(writer, json->type);
+        break;
+      case GRPC_JSON_STRING:
+        grpc_json_writer_value_string(writer, json->value);
+        break;
+      case GRPC_JSON_NUMBER:
+        grpc_json_writer_value_raw(writer, json->value);
+        break;
+      case GRPC_JSON_TRUE:
+        grpc_json_writer_value_raw_with_len(writer, "true", 4);
+        break;
+      case GRPC_JSON_FALSE:
+        grpc_json_writer_value_raw_with_len(writer, "false", 5);
+        break;
+      case GRPC_JSON_NULL:
+        grpc_json_writer_value_raw_with_len(writer, "null", 4);
+        break;
+      default:
+        abort();
+    }
+    json = json->next;
+  }
+}
+
+static grpc_json_writer_vtable writer_vtable = {
+  json_writer_output_char,
+  json_writer_output_string,
+  json_writer_output_string_with_len
+};
+
+char* grpc_json_dump_to_string(grpc_json* json, int indent) {
+  grpc_json_writer writer;
+  json_writer_userdata state;
+
+  state.output = NULL;
+  state.free_space = state.string_len = state.allocated = 0;
+  grpc_json_writer_init(&writer, indent, &writer_vtable, &state);
+
+  json_dump_recursive(&writer, json, 0);
+
+  json_writer_output_char(&state, 0);
+
+  return state.output;
+}
diff --git a/src/core/json/json_writer.c b/src/core/json/json_writer.c
new file mode 100644
index 0000000000..63c86ac008
--- /dev/null
+++ b/src/core/json/json_writer.c
@@ -0,0 +1,252 @@
+/*
+ *
+ * Copyright 2014, 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.
+ *
+ */
+
+#include <string.h>
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/json/json_writer.h"
+
+static void json_writer_output_char(grpc_json_writer* writer, char c) {
+  writer->vtable->output_char(writer->userdata, c);
+}
+
+static void json_writer_output_string(grpc_json_writer* writer, const char* str) {
+  writer->vtable->output_string(writer->userdata, str);
+}
+
+static void json_writer_output_string_with_len(grpc_json_writer* writer, const char* str, size_t len) {
+  writer->vtable->output_string_with_len(writer->userdata, str, len);
+}
+
+void grpc_json_writer_init(grpc_json_writer* writer, int indent,
+                           grpc_json_writer_vtable* vtable, void* userdata) {
+  memset(writer, 0, sizeof(grpc_json_writer));
+  writer->container_empty = 1;
+  writer->indent = indent;
+  writer->vtable = vtable;
+  writer->userdata = userdata;
+}
+
+static void json_writer_output_indent(
+    grpc_json_writer* writer) {
+  static const char spacesstr[] =
+      "                "
+      "                "
+      "                "
+      "                ";
+
+  int spaces = writer->depth * writer->indent;
+
+  if (writer->indent == 0) return;
+
+  if (writer->got_key) {
+    json_writer_output_char(writer, ' ');
+    return;
+  }
+
+  while (spaces >= (sizeof(spacesstr) - 1)) {
+    json_writer_output_string_with_len(writer, spacesstr,
+                                            sizeof(spacesstr) - 1);
+    spaces -= (sizeof(spacesstr) - 1);
+  }
+
+  if (spaces == 0) return;
+
+  json_writer_output_string_with_len(
+      writer, spacesstr + sizeof(spacesstr) - 1 - spaces, spaces);
+}
+
+static void json_writer_value_end(grpc_json_writer* writer) {
+  if (writer->container_empty) {
+    writer->container_empty = 0;
+    if ((writer->indent == 0) || (writer->depth == 0)) return;
+    json_writer_output_char(writer, '\n');
+  } else {
+    json_writer_output_char(writer, ',');
+    if (writer->indent == 0) return;
+    json_writer_output_char(writer, '\n');
+  }
+}
+
+static void json_writer_escape_utf16(grpc_json_writer* writer, gpr_uint16 utf16) {
+  static const char hex[] = "0123456789abcdef";
+
+  json_writer_output_string_with_len(writer, "\\u", 2);
+  json_writer_output_char(writer, hex[(utf16 >> 12) & 0x0f]);
+  json_writer_output_char(writer, hex[(utf16 >> 8) & 0x0f]);
+  json_writer_output_char(writer, hex[(utf16 >> 4) & 0x0f]);
+  json_writer_output_char(writer, hex[(utf16) & 0x0f]);
+}
+
+static void json_writer_escape_string(grpc_json_writer* writer,
+                                      const char* string) {
+  json_writer_output_char(writer, '"');
+
+  for (;;) {
+    gpr_uint8 c = (gpr_uint8)*string++;
+    if (c == 0) {
+      break;
+    } else if ((c >= 32) && (c <= 127)) {
+      if ((c == '\\') || (c == '"')) json_writer_output_char(writer, '\\');
+      json_writer_output_char(writer, c);
+    } else if (c < 32) {
+      switch (c) {
+        case '\b':
+          json_writer_output_string_with_len(writer, "\\b", 2);
+          break;
+        case '\f':
+          json_writer_output_string_with_len(writer, "\\f", 2);
+          break;
+        case '\n':
+          json_writer_output_string_with_len(writer, "\\n", 2);
+          break;
+        case '\r':
+          json_writer_output_string_with_len(writer, "\\r", 2);
+          break;
+        case '\t':
+          json_writer_output_string_with_len(writer, "\\t", 2);
+          break;
+        default:
+          json_writer_escape_utf16(writer, c);
+          break;
+      }
+    } else {
+      gpr_uint32 utf32 = 0;
+      int extra = 0;
+      int i;
+      int valid = 1;
+      if ((c & 0xe0) == 0xc0) {
+        utf32 = c & 0x1f;
+        extra = 1;
+      } else if ((c & 0xf0) == 0xe0) {
+        utf32 = c & 0x0f;
+        extra = 2;
+      } else if ((c & 0xf8) == 0xf0) {
+        utf32 = c & 0x07;
+        extra = 3;
+      } else {
+        break;
+      }
+      for (i = 0; i < extra; i++) {
+        utf32 <<= 6;
+        c = *string++;
+        if ((c & 0xc0) != 0x80) {
+          valid = 0;
+          break;
+        }
+        utf32 |= c & 0x3f;
+      }
+      if (!valid) break;
+      /* The range 0xd800 - 0xdfff is reserved by the surrogates ad vitam.
+       * Any other range is technically reserved for future usage, so if we
+       * don't want the software to break in the future, we have to allow
+       * anything else. The first non-unicode character is 0x110000. */
+      if (((utf32 >= 0xd800) && (utf32 <= 0xdfff)) ||
+          (utf32 >= 0x110000)) break;
+      if (utf32 >= 0x10000) {
+        /* If utf32 contains a character that is above 0xffff, it needs to be
+         * broken down into a utf-16 surrogate pair. A surrogate pair is first
+         * a high surrogate, followed by a low surrogate. Each surrogate holds
+         * 10 bits of usable data, thus allowing a total of 20 bits of data.
+         * The high surrogate marker is 0xd800, while the low surrogate marker
+         * is 0xdc00. The low 10 bits of each will be the usable data.
+         *
+         * After re-combining the 20 bits of data, one has to add 0x10000 to
+         * the resulting value, in order to obtain the original character.
+         * This is obviously because the range 0x0000 - 0xffff can be written
+         * without any special trick.
+         *
+         * Since 0x10ffff is the highest allowed character, we're working in
+         * the range 0x00000 - 0xfffff after we decrement it by 0x10000.
+         * That range is exactly 20 bits.
+         */
+        utf32 -= 0x10000;
+        json_writer_escape_utf16(writer, 0xd800 | (utf32 >> 10));
+        json_writer_escape_utf16(writer, 0xdc00 | (utf32 & 0x3ff));
+      } else {
+        json_writer_escape_utf16(writer, utf32);
+      }
+    }
+  }
+
+  json_writer_output_char(writer, '"');
+}
+
+void grpc_json_writer_container_begins(grpc_json_writer* writer, grpc_json_type type) {
+  if (!writer->got_key) json_writer_value_end(writer);
+  json_writer_output_indent(writer);
+  json_writer_output_char(writer, type == GRPC_JSON_OBJECT ? '{' : '[');
+  writer->container_empty = 1;
+  writer->got_key = 0;
+  writer->depth++;
+}
+
+void grpc_json_writer_container_ends(grpc_json_writer* writer, grpc_json_type type) {
+  if (writer->indent && !writer->container_empty)
+    json_writer_output_char(writer, '\n');
+  writer->depth--;
+  if (!writer->container_empty) json_writer_output_indent(writer);
+  json_writer_output_char(writer, type == GRPC_JSON_OBJECT ? '}' : ']');
+  writer->container_empty = 0;
+  writer->got_key = 0;
+}
+
+void grpc_json_writer_object_key(grpc_json_writer* writer, const char* string) {
+  json_writer_value_end(writer);
+  json_writer_output_indent(writer);
+  json_writer_escape_string(writer, string);
+  json_writer_output_char(writer, ':');
+  writer->got_key = 1;
+}
+
+void grpc_json_writer_value_raw(grpc_json_writer* writer, const char* string) {
+  if (!writer->got_key) json_writer_value_end(writer);
+  json_writer_output_indent(writer);
+  json_writer_output_string(writer, string);
+  writer->got_key = 0;
+}
+
+void grpc_json_writer_value_raw_with_len(grpc_json_writer* writer, const char* string, size_t len) {
+  if (!writer->got_key) json_writer_value_end(writer);
+  json_writer_output_indent(writer);
+  json_writer_output_string_with_len(writer, string, len);
+  writer->got_key = 0;
+}
+
+void grpc_json_writer_value_string(grpc_json_writer* writer, const char* string) {
+  if (!writer->got_key) json_writer_value_end(writer);
+  json_writer_output_indent(writer);
+  json_writer_escape_string(writer, string);
+  writer->got_key = 0;
+}
diff --git a/src/core/json/json_writer.h b/src/core/json/json_writer.h
new file mode 100644
index 0000000000..0568401590
--- /dev/null
+++ b/src/core/json/json_writer.h
@@ -0,0 +1,93 @@
+/*
+ *
+ * Copyright 2014, 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.
+ *
+ */
+
+/* The idea of the writer is basically symmetrical of the reader. While the
+ * reader emits various calls to your code, the writer takes basically the
+ * same calls and emit json out of it. It doesn't try to make any check on
+ * the order of the calls you do on it. Meaning you can theorically force
+ * it to generate invalid json.
+ *
+ * Also, unlike the reader, the writer expects UTF-8 encoded input strings.
+ * These strings will be UTF-8 validated, and any invalid character will
+ * cut the conversion short, before any invalid UTF-8 sequence, thus forming
+ * a valid UTF-8 string overall.
+ */
+
+#ifndef __GRPC_SRC_CORE_JSON_JSON_WRITER_H__
+#define __GRPC_SRC_CORE_JSON_JSON_WRITER_H__
+
+#include <stdlib.h>
+
+#include "src/core/json/json_common.h"
+
+typedef struct grpc_json_writer_vtable {
+  /* Adds a character to the output stream. */
+  void (*output_char)(void* userdata, char);
+  /* Adds a zero-terminated string to the output stream. */
+  void (*output_string)(void* userdata, const char* str);
+  /* Adds a fixed-length string to the output stream. */
+  void (*output_string_with_len)(void* userdata, const char* str, size_t len);
+
+} grpc_json_writer_vtable;
+
+typedef struct grpc_json_writer {
+  void* userdata;
+  grpc_json_writer_vtable* vtable;
+  int indent;
+  int depth;
+  int container_empty;
+  int got_key;
+} grpc_json_writer;
+
+/* Call this to initialize your writer structure. The indent parameter is
+ * specifying the number of spaces to use for indenting the output. If you
+ * use indent=0, then the output will not have any newlines either, thus
+ * emitting a condensed json output.
+ */
+void grpc_json_writer_init(grpc_json_writer* writer, int indent,
+                           grpc_json_writer_vtable* vtable, void* userdata);
+
+/* Signals the beginning of a container. */
+void grpc_json_writer_container_begins(grpc_json_writer* writer, grpc_json_type type);
+/* Signals the end of a container. */
+void grpc_json_writer_container_ends(grpc_json_writer* writer, grpc_json_type type);
+/* Writes down an object key for the next value. */
+void grpc_json_writer_object_key(grpc_json_writer* writer, const char* string);
+/* Sets a raw value. Useful for numbers. */
+void grpc_json_writer_value_raw(grpc_json_writer* writer, const char* string);
+/* Sets a raw value with its length. Useful for values like true or false. */
+void grpc_json_writer_value_raw_with_len(grpc_json_writer* writer, const char* string, size_t len);
+/* Sets a string value. It'll be escaped, and utf-8 validated. */
+void grpc_json_writer_value_string(grpc_json_writer* writer, const char* string);
+
+#endif /* __GRPC_SRC_CORE_JSON_JSON_WRITER_H__ */
diff --git a/src/core/security/credentials.c b/src/core/security/credentials.c
index 2f75556e7b..5d06f14215 100644
--- a/src/core/security/credentials.c
+++ b/src/core/security/credentials.c
@@ -42,7 +42,7 @@
 #include <grpc/support/sync.h>
 #include <grpc/support/time.h>
 
-#include "third_party/cJSON/cJSON.h"
+#include "src/core/json/json.h"
 
 #include <string.h>
 #include <stdio.h>
@@ -336,7 +336,7 @@ grpc_oauth2_token_fetcher_credentials_parse_server_response(
   char *null_terminated_body = NULL;
   char *new_access_token = NULL;
   grpc_credentials_status status = GRPC_CREDENTIALS_OK;
-  cJSON *json = NULL;
+  grpc_json *json = NULL;
 
   if (response->body_length > 0) {
     null_terminated_body = gpr_malloc(response->body_length + 1);
@@ -351,41 +351,48 @@ grpc_oauth2_token_fetcher_credentials_parse_server_response(
     status = GRPC_CREDENTIALS_ERROR;
     goto end;
   } else {
-    cJSON *access_token = NULL;
-    cJSON *token_type = NULL;
-    cJSON *expires_in = NULL;
-    json = cJSON_Parse(null_terminated_body);
+    grpc_json *access_token = NULL;
+    grpc_json *token_type = NULL;
+    grpc_json *expires_in = NULL;
+    grpc_json *ptr;
+    json = grpc_json_parse_string(null_terminated_body);
     if (json == NULL) {
       gpr_log(GPR_ERROR, "Could not parse JSON from %s", null_terminated_body);
       status = GRPC_CREDENTIALS_ERROR;
       goto end;
     }
-    if (json->type != cJSON_Object) {
+    if (json->type != GRPC_JSON_OBJECT) {
       gpr_log(GPR_ERROR, "Response should be a JSON object");
       status = GRPC_CREDENTIALS_ERROR;
       goto end;
     }
-    access_token = cJSON_GetObjectItem(json, "access_token");
-    if (access_token == NULL || access_token->type != cJSON_String) {
+    for (ptr = json->child; ptr; ptr = ptr->next) {
+      if (strcmp(ptr->key, "access_token") == 0) {
+        access_token = ptr;
+      } else if (strcmp(ptr->key, "token_type") == 0) {
+        token_type = ptr;
+      } else if (strcmp(ptr->key, "expires_in") == 0) {
+        expires_in = ptr;
+      }
+    }
+    if (access_token == NULL || access_token->type != GRPC_JSON_STRING) {
       gpr_log(GPR_ERROR, "Missing or invalid access_token in JSON.");
       status = GRPC_CREDENTIALS_ERROR;
       goto end;
     }
-    token_type = cJSON_GetObjectItem(json, "token_type");
-    if (token_type == NULL || token_type->type != cJSON_String) {
+    if (token_type == NULL || token_type->type != GRPC_JSON_STRING) {
       gpr_log(GPR_ERROR, "Missing or invalid token_type in JSON.");
       status = GRPC_CREDENTIALS_ERROR;
       goto end;
     }
-    expires_in = cJSON_GetObjectItem(json, "expires_in");
-    if (expires_in == NULL || expires_in->type != cJSON_Number) {
+    if (expires_in == NULL || expires_in->type != GRPC_JSON_NUMBER) {
       gpr_log(GPR_ERROR, "Missing or invalid expires_in in JSON.");
       status = GRPC_CREDENTIALS_ERROR;
       goto end;
     }
-    gpr_asprintf(&new_access_token, "%s %s", token_type->valuestring,
-                 access_token->valuestring);
-    token_lifetime->tv_sec = expires_in->valueint;
+    gpr_asprintf(&new_access_token, "%s %s", token_type->value,
+                 access_token->value);
+    token_lifetime->tv_sec = strtol(expires_in->value, NULL, 10);
     token_lifetime->tv_nsec = 0;
     if (*token_elem != NULL) grpc_mdelem_unref(*token_elem);
     *token_elem = grpc_mdelem_from_strings(ctx, GRPC_AUTHORIZATION_METADATA_KEY,
@@ -400,7 +407,7 @@ end:
   }
   if (null_terminated_body != NULL) gpr_free(null_terminated_body);
   if (new_access_token != NULL) gpr_free(new_access_token);
-  if (json != NULL) cJSON_Delete(json);
+  if (json != NULL) grpc_json_destroy(json);
   return status;
 }
 
diff --git a/src/core/security/json_token.c b/src/core/security/json_token.c
index 82bd9b505a..b1548f02a7 100644
--- a/src/core/security/json_token.c
+++ b/src/core/security/json_token.c
@@ -44,7 +44,8 @@
 #include <openssl/bio.h>
 #include <openssl/evp.h>
 #include <openssl/pem.h>
-#include "third_party/cJSON/cJSON.h"
+
+#include "src/core/json/json.h"
 
 /* --- Constants. --- */
 
@@ -64,18 +65,20 @@ static grpc_jwt_encode_and_sign_override g_jwt_encode_and_sign_override = NULL;
 
 /* --- grpc_auth_json_key. --- */
 
-static const char *json_get_string_property(cJSON *json,
+static const char *json_get_string_property(grpc_json *json,
                                             const char *prop_name) {
-  cJSON *child = NULL;
-  child = cJSON_GetObjectItem(json, prop_name);
-  if (child == NULL || child->type != cJSON_String) {
+  grpc_json *child;
+  for (child = json->child; child != NULL; child = child->next) {
+    if (strcmp(child->key, prop_name) == 0) break;
+  }
+  if (child == NULL || child->type != GRPC_JSON_STRING) {
     gpr_log(GPR_ERROR, "Invalid or missing %s property.", prop_name);
     return NULL;
   }
-  return child->valuestring;
+  return child->value;
 }
 
-static int set_json_key_string_property(cJSON *json, const char *prop_name,
+static int set_json_key_string_property(grpc_json *json, const char *prop_name,
                                         char **json_key_field) {
   const char *prop_value = json_get_string_property(json, prop_name);
   if (prop_value == NULL) return 0;
@@ -91,7 +94,8 @@ int grpc_auth_json_key_is_valid(const grpc_auth_json_key *json_key) {
 grpc_auth_json_key grpc_auth_json_key_create_from_string(
     const char *json_string) {
   grpc_auth_json_key result;
-  cJSON *json = cJSON_Parse(json_string);
+  char *scratchpad = gpr_strdup(json_string);
+  grpc_json *json = grpc_json_parse_string(scratchpad);
   BIO *bio = NULL;
   const char *prop_value;
   int success = 0;
@@ -100,7 +104,7 @@ grpc_auth_json_key grpc_auth_json_key_create_from_string(
   result.type = GRPC_AUTH_JSON_KEY_TYPE_INVALID;
   if (json == NULL) {
     gpr_log(GPR_ERROR, "Invalid json string %s", json_string);
-    return result;
+    goto end;
   }
 
   prop_value = json_get_string_property(json, "type");
@@ -136,8 +140,9 @@ grpc_auth_json_key grpc_auth_json_key_create_from_string(
 
 end:
   if (bio != NULL) BIO_free(bio);
-  if (json != NULL) cJSON_Delete(json);
+  if (json != NULL) grpc_json_destroy(json);
   if (!success) grpc_auth_json_key_destruct(&result);
+  gpr_free(scratchpad);
   return result;
 }
 
@@ -164,49 +169,63 @@ void grpc_auth_json_key_destruct(grpc_auth_json_key *json_key) {
 
 /* --- jwt encoding and signature. --- */
 
+static grpc_json *create_child(grpc_json *brother, grpc_json *parent,
+                         const char *key, const char *value,
+                         grpc_json_type type) {
+  grpc_json *child = grpc_json_create(type);
+  if (brother) brother->next = child;
+  if (!parent->child) parent->child = child;
+  child->parent = parent;
+  child->value = value;
+  child->key = key;
+  return child;
+}
+
 static char *encoded_jwt_header(const char *algorithm) {
-  cJSON *json = cJSON_CreateObject();
-  cJSON *child = cJSON_CreateString(algorithm);
+  grpc_json *json = grpc_json_create(GRPC_JSON_OBJECT);
+  grpc_json *child = NULL;
   char *json_str = NULL;
   char *result = NULL;
-  cJSON_AddItemToObject(json, "alg", child);
-  child = cJSON_CreateString(GRPC_JWT_TYPE);
-  cJSON_AddItemToObject(json, "typ", child);
-  json_str = cJSON_PrintUnformatted(json);
+
+  child = create_child(NULL, json, "alg", algorithm, GRPC_JSON_STRING);
+  create_child(child, json, "typ", GRPC_JWT_TYPE, GRPC_JSON_STRING);
+
+  json_str = grpc_json_dump_to_string(json, 0);
   result = grpc_base64_encode(json_str, strlen(json_str), 1, 0);
-  free(json_str);
-  cJSON_Delete(json);
+  gpr_free(json_str);
+  grpc_json_destroy(json);
   return result;
 }
 
 static char *encoded_jwt_claim(const grpc_auth_json_key *json_key,
                                const char *scope, gpr_timespec token_lifetime) {
-  cJSON *json = cJSON_CreateObject();
-  cJSON *child = NULL;
+  grpc_json *json = grpc_json_create(GRPC_JSON_OBJECT);
+  grpc_json *child = NULL;
   char *json_str = NULL;
   char *result = NULL;
   gpr_timespec now = gpr_now();
   gpr_timespec expiration = gpr_time_add(now, token_lifetime);
+  /* log10(2^64) ~= 20 */
+  char now_str[24];
+  char expiration_str[24];
   if (gpr_time_cmp(token_lifetime, grpc_max_auth_token_lifetime) > 0) {
     gpr_log(GPR_INFO, "Cropping token lifetime to maximum allowed value.");
     expiration = gpr_time_add(now, grpc_max_auth_token_lifetime);
   }
-  child = cJSON_CreateString(json_key->client_email);
-  cJSON_AddItemToObject(json, "iss", child);
-  child = cJSON_CreateString(scope);
-  cJSON_AddItemToObject(json, "scope", child);
-  child = cJSON_CreateString(GRPC_JWT_AUDIENCE);
-  cJSON_AddItemToObject(json, "aud", child);
-  child = cJSON_CreateNumber(now.tv_sec);
-  cJSON_SetIntValue(child, now.tv_sec);
-  cJSON_AddItemToObject(json, "iat", child);
-  child = cJSON_CreateNumber(expiration.tv_sec);
-  cJSON_SetIntValue(child, expiration.tv_sec);
-  cJSON_AddItemToObject(json, "exp", child);
-  json_str = cJSON_PrintUnformatted(json);
+  sprintf(now_str, "%ld", now.tv_sec);
+  sprintf(expiration_str, "%ld", expiration.tv_sec);
+
+  child = create_child(NULL, json, "iss", json_key->client_email,
+                       GRPC_JSON_STRING);
+  child = create_child(child, json, "scope", scope, GRPC_JSON_STRING);
+  child = create_child(child, json, "aud", GRPC_JWT_AUDIENCE, GRPC_JSON_STRING);
+  child = create_child(child, json, "iat", now_str, GRPC_JSON_NUMBER);
+  create_child(child, json, "exp", expiration_str, GRPC_JSON_NUMBER);
+
+  json_str = grpc_json_dump_to_string(json, 0);
   result = grpc_base64_encode(json_str, strlen(json_str), 1, 0);
-  free(json_str);
-  cJSON_Delete(json);
+  gpr_free(json_str);
+  grpc_json_destroy(json);
   return result;
 }
 
@@ -216,10 +235,10 @@ static char *dot_concat_and_free_strings(char *str1, char *str2) {
   size_t result_len = str1_len + 1 /* dot */ + str2_len;
   char *result = gpr_malloc(result_len + 1 /* NULL terminated */);
   char *current = result;
-  strncpy(current, str1, str1_len);
+  memcpy(current, str1, str1_len);
   current += str1_len;
   *(current++) = '.';
-  strncpy(current, str2, str2_len);
+  memcpy(current, str2, str2_len);
   current += str2_len;
   GPR_ASSERT((current - result) == result_len);
   *current = '\0';