compat/fsmonitor/fsm-health-win32: add framework for periodically monitoring

Create framework in Win32 version of the "health" thread to
periodically inspect the system and shutdown if warranted.

This version just include the setup for the timeout in
WaitForMultipleObjects() and calls (currently empty) table
of functions.

A later commit will add functions to the table to actually
inspect the system.

Signed-off-by: Jeff Hostetler <[email protected]>

Author: jeffhostetler

compat/fsmonitor/fsm-health-win32.c

@@ -4,6 +4,40 @@
 #include "fsm-health.h"
 #include "fsmonitor--daemon.h"
 
+/*
+ * Every minute wake up and test our health.
+ */
+#define WAIT_FREQ_MS (60 * 1000)
+
+enum interval_fn_ctx { CTX_INIT = 0, CTX_TERM, CTX_TIMER };
+
+typedef int (interval_fn)(struct fsmonitor_daemon_state *state,
+			  enum interval_fn_ctx ctx);
+
+static interval_fn *table[] = {
+	NULL, /* must be last */
+};
+
+/*
+ * Call all of the functions in the table.
+ * Shortcut and return first error.
+ *
+ * Return 0 if all succeeded.
+ */
+static int call_all(struct fsmonitor_daemon_state *state,
+		    enum interval_fn_ctx ctx)
+{
+	int k;
+
+	for (k = 0; table[k]; k++) {
+		int r = table[k](state, ctx);
+		if (r)
+			return r;
+	}
+
+	return 0;
+}
+
 struct fsm_health_data
 {
 	HANDLE hEventShutdown;
@@ -45,24 +79,42 @@ void fsm_health__dtor(struct fsmonitor_daemon_state *state)
 void fsm_health__loop(struct fsmonitor_daemon_state *state)
 {
 	struct fsm_health_data *data = state->health_data;
+	int r;
+
+	r = call_all(state, CTX_INIT);
+	if (r < 0)
+		goto force_error_stop;
+	if (r > 0)
+		goto force_shutdown;
 
 	for (;;) {
 		DWORD dwWait = WaitForMultipleObjects(data->nr_handles,
 						      data->hHandles,
-						      FALSE, INFINITE);
+						      FALSE, WAIT_FREQ_MS);
 
 		if (dwWait == WAIT_OBJECT_0 + HEALTH_SHUTDOWN)
 			goto clean_shutdown;
 
+		if (dwWait == WAIT_TIMEOUT) {
+			r = call_all(state, CTX_TIMER);
+			if (r < 0)
+				goto force_error_stop;
+			if (r > 0)
+				goto force_shutdown;
+			continue;
+		}
+
 		error(_("health thread wait failed [GLE %ld]"),
 		      GetLastError());
 		goto force_error_stop;
 	}
 
 force_error_stop:
 	state->health_error_code = -1;
+force_shutdown:
 	ipc_server_stop_async(state->ipc_server_data);
 clean_shutdown:
+	call_all(state, CTX_TERM);
 	return;
 }