SERVER-20161: allow capped collection insert notifier to externally notified

2 files changed, 25 insertions, 1 deletions

diff --git a/src/mongo/db/catalog/collection.cpp b/src/mongo/db/catalog/collection.cpp
index fd48011e54f..c754ce46254 100644
--- a/src/mongo/db/catalog/collection.cpp
+++ b/src/mongo/db/catalog/collection.cpp
@@ -125,6 +125,11 @@ void CappedInsertNotifier::notifyOfInsert(int count) {
     _cappedNewDataNotifier.notify_all();
 }
 
+void CappedInsertNotifier::notifyAll() {
+    stdx::lock_guard<stdx::mutex> lk(_cappedNewDataMutex);
+    _cappedNewDataNotifier.notify_all();
+}
+
 uint64_t CappedInsertNotifier::getCount() const {
     stdx::lock_guard<stdx::mutex> lk(_cappedNewDataMutex);
     return _cappedInsertCount;
@@ -139,6 +144,13 @@ void CappedInsertNotifier::waitForInsert(uint64_t referenceCount, Microseconds t
     }
 }
 
+void CappedInsertNotifier::waitForInsert(uint64_t referenceCount) const {
+    stdx::unique_lock<stdx::mutex> lk(_cappedNewDataMutex);
+    while (!_dead && referenceCount == _cappedInsertCount) {
+        _cappedNewDataNotifier.wait(lk);
+    }
+}
+
 void CappedInsertNotifier::kill() {
     stdx::lock_guard<stdx::mutex> lk(_cappedNewDataMutex);
     _dead = true;
diff --git a/src/mongo/db/catalog/collection.h b/src/mongo/db/catalog/collection.h
index 61d32a53aef..6a5e3819fbb 100644
--- a/src/mongo/db/catalog/collection.h
+++ b/src/mongo/db/catalog/collection.h
@@ -114,6 +114,11 @@ public:
     void notifyOfInsert(int count);
 
     /**
+     * Wakes up all threads waiting but doesn't increment the count.
+     */
+    void notifyAll();
+
+    /**
      * Get a counter value which is incremented on every insert into a capped collection.
      * The return value should be used as a reference value to pass into waitForCappedInsert().
      */
@@ -122,11 +127,18 @@ public:
     /**
      * Waits for 'timeout' microseconds, or until notifyAll() is called to indicate that new
      * data is available in the capped collection.
+     *
+     * NOTE: Waiting threads can be signaled by calling kill or notify* methods.
      */
     void waitForInsert(uint64_t referenceCount, Microseconds timeout) const;
 
     /**
-     * Cancels the notifier if the collection is dropped/invalidated.
+     * Same as above but without a timeout.
+     */
+    void waitForInsert(uint64_t referenceCount) const;
+
+    /**
+     * Cancels the notifier if the collection is dropped/invalidated, and wakes all waiting.
      */
     void kill();