Initial checkin of gRPC to third_party/

third_party/grpc/src/core/transport/connectivity_state.c

Index: third_party/grpc/src/core/transport/connectivity_state.c
diff --git a/third_party/grpc/src/core/transport/connectivity_state.c b/third_party/grpc/src/core/transport/connectivity_state.c
new file mode 100644
index 0000000000000000000000000000000000000000..87765b9799d6c6e782ba220e2b8a04ee86919ce1
--- /dev/null
+++ b/third_party/grpc/src/core/transport/connectivity_state.c
@@ -0,0 +1,164 @@
+/*
+ *
+ * Copyright 2015-2016, 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 "src/core/transport/connectivity_state.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+
+int grpc_connectivity_state_trace = 0;
+
+const char *grpc_connectivity_state_name(grpc_connectivity_state state) {
+  switch (state) {
+    case GRPC_CHANNEL_IDLE:
+      return "IDLE";
+    case GRPC_CHANNEL_CONNECTING:
+      return "CONNECTING";
+    case GRPC_CHANNEL_READY:
+      return "READY";
+    case GRPC_CHANNEL_TRANSIENT_FAILURE:
+      return "TRANSIENT_FAILURE";
+    case GRPC_CHANNEL_FATAL_FAILURE:
+      return "FATAL_FAILURE";
+  }
+  GPR_UNREACHABLE_CODE(return "UNKNOWN");
+}
+
+void grpc_connectivity_state_init(grpc_connectivity_state_tracker *tracker,
+                                  grpc_connectivity_state init_state,
+                                  const char *name) {
+  tracker->current_state = init_state;
+  tracker->watchers = NULL;
+  tracker->name = gpr_strdup(name);
+}
+
+void grpc_connectivity_state_destroy(grpc_exec_ctx *exec_ctx,
+                                     grpc_connectivity_state_tracker *tracker) {
+  int success;
+  grpc_connectivity_state_watcher *w;
+  while ((w = tracker->watchers)) {
+    tracker->watchers = w->next;
+
+    if (GRPC_CHANNEL_FATAL_FAILURE != *w->current) {
+      *w->current = GRPC_CHANNEL_FATAL_FAILURE;
+      success = 1;
+    } else {
+      success = 0;
+    }
+    grpc_exec_ctx_enqueue(exec_ctx, w->notify, success, NULL);
+    gpr_free(w);
+  }
+  gpr_free(tracker->name);
+}
+
+grpc_connectivity_state grpc_connectivity_state_check(
+    grpc_connectivity_state_tracker *tracker) {
+  if (grpc_connectivity_state_trace) {
+    gpr_log(GPR_DEBUG, "CONWATCH: %p %s: get %s", tracker, tracker->name,
+            grpc_connectivity_state_name(tracker->current_state));
+  }
+  return tracker->current_state;
+}
+
+int grpc_connectivity_state_notify_on_state_change(
+    grpc_exec_ctx *exec_ctx, grpc_connectivity_state_tracker *tracker,
+    grpc_connectivity_state *current, grpc_closure *notify) {
+  if (grpc_connectivity_state_trace) {
+    if (current == NULL) {
+      gpr_log(GPR_DEBUG, "CONWATCH: %p %s: unsubscribe notify=%p", tracker,
+              tracker->name, notify);
+    } else {
+      gpr_log(GPR_DEBUG, "CONWATCH: %p %s: from %s [cur=%s] notify=%p", tracker,
+              tracker->name, grpc_connectivity_state_name(*current),
+              grpc_connectivity_state_name(tracker->current_state), notify);
+    }
+  }
+  if (current == NULL) {
+    grpc_connectivity_state_watcher *w = tracker->watchers;
+    if (w != NULL && w->notify == notify) {
+      grpc_exec_ctx_enqueue(exec_ctx, notify, false, NULL);
+      tracker->watchers = w->next;
+      gpr_free(w);
+      return 0;
+    }
+    while (w != NULL) {
+      grpc_connectivity_state_watcher *rm_candidate = w->next;
+      if (rm_candidate != NULL && rm_candidate->notify == notify) {
+        grpc_exec_ctx_enqueue(exec_ctx, notify, false, NULL);
+        w->next = w->next->next;
+        gpr_free(rm_candidate);
+        return 0;
+      }
+      w = w->next;
+    }
+    return 0;
+  } else {
+    if (tracker->current_state != *current) {
+      *current = tracker->current_state;
+      grpc_exec_ctx_enqueue(exec_ctx, notify, true, NULL);
+    } else {
+      grpc_connectivity_state_watcher *w = gpr_malloc(sizeof(*w));
+      w->current = current;
+      w->notify = notify;
+      w->next = tracker->watchers;
+      tracker->watchers = w;
+    }
+    return tracker->current_state == GRPC_CHANNEL_IDLE;
+  }
+}
+
+void grpc_connectivity_state_set(grpc_exec_ctx *exec_ctx,
+                                 grpc_connectivity_state_tracker *tracker,
+                                 grpc_connectivity_state state,
+                                 const char *reason) {
+  grpc_connectivity_state_watcher *w;
+  if (grpc_connectivity_state_trace) {
+    gpr_log(GPR_DEBUG, "SET: %p %s: %s --> %s [%s]", tracker, tracker->name,
+            grpc_connectivity_state_name(tracker->current_state),
+            grpc_connectivity_state_name(state), reason);
+  }
+  if (tracker->current_state == state) {
+    return;
+  }
+  GPR_ASSERT(tracker->current_state != GRPC_CHANNEL_FATAL_FAILURE);
+  tracker->current_state = state;
+  while ((w = tracker->watchers) != NULL) {
+    *w->current = tracker->current_state;
+    tracker->watchers = w->next;
+    grpc_exec_ctx_enqueue(exec_ctx, w->notify, true, NULL);
+    gpr_free(w);
+  }
+}