Support auto-heartbeat on Windows, callback

In addition to already existing support on POSIX, callback.

Author: vveljko

.pubnub.yml

@@ -1,8 +1,13 @@
 name: c-core
 schema: 1
-version: 2.12.0
+version: 2.12.1
 scm: github.com/pubnub/c-core
 changelog:
+  - version: v2.12.1
+    date: Nov 22, 2019
+    changes:
+      - type: enhancement
+        text: Add support for automatic sending of heartbeat messages on Windows, callback.
   - version: v2.12.0
     date: Nov 15, 2019
     changes:

core/pb_sleep_ms.h

@@ -0,0 +1,6 @@
+/* -*- c-file-style:"stroustrup"; indent-tabs-mode: nil -*- */
+#if defined _WIN32
+void pb_sleep_ms(DWORD dwMilliseconds);
+#else
+void pb_sleep_ms(long milliseconds);
+#endif

core/pbauto_heartbeat.h

@@ -0,0 +1,106 @@
+/* -*- c-file-style:"stroustrup"; indent-tabs-mode: nil -*- */
+#if !defined INC_PBAUTO_HEARTBEAT
+#define INC_PBAUTO_HEARTBEAT
+
+#if PUBNUB_USE_AUTO_HEARTBEAT
+#if defined      _WIN32
+typedef DWORD    pubnub_thread_t;
+typedef FILETIME pubnub_timespec_t;
+typedef void     pubnub_watcher_t;
+#define thread_handle_field() HANDLE thread_handle;
+#define UNIT_IN_MILLI 1000
+#else
+typedef pthread_t       pubnub_thread_t;
+typedef struct timespec pubnub_timespec_t;
+typedef void*           pubnub_watcher_t;
+#define thread_handle_field()
+#endif
+
+
+/** Maximum number of auto heartbeat thumpers that can be used at one time */
+#define PUBNUB_MAX_HEARTBEAT_THUMPERS 16
+#define UNASSIGNED PUBNUB_MAX_HEARTBEAT_THUMPERS
+
+struct pubnub_heartbeat_data {
+    pubnub_t* pb;
+    pubnub_t* heartbeat_pb;
+    size_t    period_sec;
+};
+
+struct HeartbeatWatcherData {
+    struct pubnub_heartbeat_data heartbeat_data[PUBNUB_MAX_HEARTBEAT_THUMPERS] pubnub_guarded_by(mutw);
+    unsigned thumpers_in_use pubnub_guarded_by(mutw);
+    /** Times left for each of the thumper timers in progress */
+    size_t heartbeat_timers[PUBNUB_MAX_HEARTBEAT_THUMPERS] pubnub_guarded_by(timerlock);
+    /** Array of thumper indexes whos auto heartbeat timers are active and running */
+    unsigned timer_index_array[PUBNUB_MAX_HEARTBEAT_THUMPERS] pubnub_guarded_by(timerlock);
+    /** Number of active thumper timers */
+    unsigned active_timers pubnub_guarded_by(timerlock);
+    bool stop_heartbeat_watcher_thread pubnub_guarded_by(stoplock);
+    pubnub_mutex_t                     mutw;
+    pubnub_mutex_t                     timerlock;
+    pubnub_mutex_t                     stoplock;
+    pubnub_thread_t                    thread_id;
+    thread_handle_field()
+};
+
+/** Pubnub context fields for saving subscribed channels and channel groups
+  */
+#define M_channelInfo()                                       \
+    struct {                                                  \
+        char* channel;                                        \
+        char* channel_group;                                  \
+    } channelInfo;
+
+/** Pubnub context fields for heartbeat info used by the module for keeping presence.
+ */
+#define M_heartbeatInfo() unsigned thumperIndex;
+
+/** Reads channel and channel groups saved(subscribed on)
+  */
+void pbauto_heartbeat_read_channelInfo(pubnub_t const* pb,
+                                       char const** channel,
+                                       char const** channel_group);
+
+/** Manipulates thumpers in use */
+pubnub_watcher_t pbauto_heartbeat_watcher_thread(void* arg);
+
+/** Initializes and starts auto heartbeat watcher thread. Different on different platforms */
+int pbauto_heartbeat_init(struct HeartbeatWatcherData* m_watcher);
+
+/** Gives notice to auto heartbeat module that subscribe, or heartbeat transaction has begun */
+void pbauto_heartbeat_transaction_ongoing(pubnub_t const* pb);
+
+/** Starts auto heartbeat timer, if auto heartbeat is enabled, when subscribe transaction
+    is finished.
+  */
+void pbauto_heartbeat_start_timer(pubnub_t const* pb);
+
+/** Releases allocated strings for subscribed channels and channel groups
+  */
+void pbauto_heartbeat_free_channelInfo(pubnub_t* pb);
+
+/** Preparess channels and channel groups, to be used in request url.
+  */
+enum pubnub_res pbauto_heartbeat_prepare_channels_and_ch_groups(pubnub_t* pb,
+                                                                char const** channel,
+                                                                char const** channel_group);
+
+/** Stops auto heartbeat thread */
+void pbauto_heartbeat_stop(void);
+
+#else
+#define M_channelInfo()
+#define M_heartbeatInfo()
+#define pbauto_heartbeat_read_channelInfo(pb, channel, channel_group)
+#define pbauto_heartbeat_watcher_thread(arg)
+#define pbauto_heartbeat_init(m_watcher)
+#define pbauto_heartbeat_transaction_ongoing(pb)
+#define pbauto_heartbeat_start_timer(pb)
+#define pbauto_heartbeat_free_channelInfo(pb)
+#define pbauto_heartbeat_prepare_channels_and_ch_groups(pb, addr_channel, addr_channel_group) PNR_OK
+#define pbauto_heartbeat_stop()
+#endif /* PUBNUB_USE_AUTO_HEARTBEAT */
+
+#endif /* !defined INC_PBAUTO_HEARTBEAT */
+