CDRIVER-3535 add mongoc_interrupt_t

build/generate-future-functions.py

@@ -56,6 +56,7 @@
     typedef("size_t", None),
     typedef("ssize_t", None),
     typedef("uint32_t", None),
+    typedef("void_ptr",  "void *"),
 
     # Const fundamental.
     typedef("const_char_ptr", "const char *"),

src/libmongoc/CMakeLists.txt

@@ -514,6 +514,7 @@ set (SOURCES ${SOURCES}
    ${PROJECT_SOURCE_DIR}/src/mongoc/mongoc-host-list.c
    ${PROJECT_SOURCE_DIR}/src/mongoc/mongoc-index.c
    ${PROJECT_SOURCE_DIR}/src/mongoc/mongoc-init.c
+   ${PROJECT_SOURCE_DIR}/src/mongoc/mongoc-interrupt.c
    ${PROJECT_SOURCE_DIR}/src/mongoc/mongoc-list.c
    ${PROJECT_SOURCE_DIR}/src/mongoc/mongoc-linux-distro-scanner.c
    ${PROJECT_SOURCE_DIR}/src/mongoc/mongoc-log.c
@@ -896,6 +897,7 @@ set (test-libmongoc-sources
    ${PROJECT_SOURCE_DIR}/tests/test-mongoc-gridfs.c
    ${PROJECT_SOURCE_DIR}/tests/test-mongoc-handshake.c
    ${PROJECT_SOURCE_DIR}/tests/test-mongoc-hedged-reads.c
+   ${PROJECT_SOURCE_DIR}/tests/test-mongoc-interrupt.c
    ${PROJECT_SOURCE_DIR}/tests/test-mongoc-linux-distro-scanner.c
    ${PROJECT_SOURCE_DIR}/tests/test-mongoc-list.c
    ${PROJECT_SOURCE_DIR}/tests/test-mongoc-log.c

src/libmongoc/src/mongoc/CMakeLists.txt

@@ -115,6 +115,7 @@ set (src_libmongoc_src_mongoc_DIST_noinst_hs
    mongoc-handshake-os-private.h
    mongoc-handshake-private.h
    mongoc-host-list-private.h
+   mongoc-interrupt-private.h
    mongoc-libressl-private.h
    mongoc-linux-distro-scanner-private.h
    mongoc-list-private.h
@@ -197,6 +198,7 @@ set (src_libmongoc_src_mongoc_DIST_cs
    mongoc-find-and-modify.c
    mongoc-host-list.c
    mongoc-init.c
+   mongoc-interrupt.c
    mongoc-gridfs.c
    mongoc-gridfs-bucket.c
    mongoc-gridfs-bucket-file.c

src/libmongoc/src/mongoc/mongoc-interrupt-private.h

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2020-present MongoDB, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "mongoc/mongoc-prelude.h"
+
+#ifndef MONGOC_STREAM_INTERRUPTIBLE_PRIVATE_H
+#define MONGOC_STREAM_INTERRUPTIBLE_PRIVATE_H
+
+#include "mongoc/mongoc-stream.h"
+
+/* Creates a stream to use to interrupt calls to mongoc_stream_poll.
+ *
+ * The expected use is to cancel in-progress ismaster commands (especially for
+ * awaitable ismaster). An ismaster command may not respond for a long time, so
+ * reading the reply may block on mongoc_stream_poll until data is readable. To
+ * interrupt mongoc_stream_poll, a stream retrieved by
+ * _mongoc_interrupt_get_stream can be added to the call of poll. Any other
+ * thread can call _mongoc_interrupt_interrupt to write to that stream.
+ */
+typedef struct _mongoc_interrupt_t mongoc_interrupt_t;
+
+mongoc_interrupt_t *
+_mongoc_interrupt_new (uint32_t timeout_ms);
+
+/* Interrupt the stream. An in progress poll for POLLIN should return. */
+bool
+_mongoc_interrupt_interrupt (mongoc_interrupt_t *interrupt);
+
+/* Returns a socket stream, that can be polled alongside other
+ * socket streams. */
+mongoc_stream_t *
+_mongoc_interrupt_get_stream (mongoc_interrupt_t *interrupt);
+
+/* Flushes queued data on an interrupt.
+ *
+ * This is not guaranteed to flush all data, but it does not block.
+ */
+bool
+_mongoc_interrupt_flush (mongoc_interrupt_t *interrupt);
+
+void
+_mongoc_interrupt_destroy (mongoc_interrupt_t *interrupt);
+
+#endif /* MONGOC_STREAM_INTERRUPTIBLE_PRIVATE_H */