Add SelectableEvent class

common/Makefile.am

@@ -16,6 +16,7 @@ libswsscommon_la_SOURCES = \
     json.cpp                  \
     producertable.cpp         \
     select.cpp                \
+    selectableevent.cpp       \
     consumertable.cpp         \
     ipaddress.cpp             \
     ipprefix.cpp              \

common/selectableevent.cpp

@@ -0,0 +1,75 @@
+#include <stdio.h>
+#include <string.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <iostream>
+#include <system_error>
+
+#include "common/logger.h"
+#include "common/selectableevent.h"
+
+namespace swss {
+
+SelectableEvent::SelectableEvent() :
+    m_efd(0)
+{
+    m_efd = eventfd(0, 0);
+
+    if (m_efd == -1)
+    {
+        SWSS_LOG_ERROR("failed to create eventfd, errno: %s", strerror(errno));
+
+        throw std::runtime_error("failed to create eventfd");
+    }
+}
+
+SelectableEvent::~SelectableEvent()
+{
+    close(m_efd);
+}
+
+void SelectableEvent::addFd(fd_set *fd)
+{
+    FD_SET(m_efd, fd);
+}
+
+int SelectableEvent::readCache()
+{
+    return Selectable::NODATA;
+}
+
+void SelectableEvent::readMe()
+{
+    uint64_t r;
+    ssize_t s = read(m_efd, &r, sizeof(uint64_t));
+
+    if (s != sizeof(uint64_t))
+    {
+        SWSS_LOG_ERROR("read failed, errno: %s", strerror(errno));
+
+        throw std::runtime_error("read failed");
+    }
+}
+
+bool SelectableEvent::isMe(fd_set *fd)
+{
+    return FD_ISSET(m_efd, fd);
+}
+
+void SelectableEvent::notify()
+{
+    SWSS_LOG_ENTER();
+
+    uint64_t value = 1;
+    ssize_t s = write(m_efd, &value, sizeof(uint64_t));
+
+    if (s != sizeof(uint64_t))
+    {
+        SWSS_LOG_ERROR("write failed, errno: %s", strerror(errno));
+
+        throw std::runtime_error("write failed");
+    }
+}
+
+}

common/selectableevent.h

@@ -0,0 +1,31 @@
+#ifndef __SELECTABLEEVENT__
+#define __SELECTABLEEVENT__
+
+#include <string>
+#include <vector>
+#include <limits>
+#include <sys/eventfd.h>
+#include "selectable.h"
+
+namespace swss {
+
+class SelectableEvent : public Selectable
+{
+public:
+    SelectableEvent();
+    virtual ~SelectableEvent();
+
+    void notify();
+
+    virtual void addFd(fd_set *fd);
+    virtual bool isMe(fd_set *fd);
+    virtual int readCache();
+    virtual void readMe();
+
+private:
+    int m_efd;
+};
+
+}
+
+#endif // __SELECTABLEEVENT__

tests/Makefile.am

@@ -16,6 +16,6 @@ tests_SOURCES = redis_ut.cpp
 
 tests_CFLAGS = $(DBGFLAGS) $(AM_CFLAGS) $(CFLAGS_COMMON) $(CFLAGS_GTEST)
 tests_CPPFLAGS = $(DBGFLAGS) $(AM_CFLAGS) $(CFLAGS_COMMON) $(CFLAGS_GTEST)
-tests_LDADD = -lnl-genl-3 -lhiredis -lhiredis -lpthread \
-	-L$(top_srcdir)/common -lswsscommon $(LDADD_GTEST)
+tests_LDADD = $(LDADD_GTEST) -lnl-genl-3 -lhiredis -lhiredis -lpthread \
+	-L$(top_srcdir)/common -lswsscommon
 

tests/redis_ut.cpp

@@ -2,6 +2,7 @@
 #include "common/producertable.h"
 #include "common/consumertable.h"
 #include "common/select.h"
+#include "common/selectableevent.h"
 #include <iostream>
 #include <memory>
 #include <thread>
@@ -221,3 +222,45 @@ TEST(DBConnector, multitable)
     cout << endl << "Done." << endl;
 }
 
+void selectableEventThread(swss::Selectable *ev, int *value)
+{
+    swss::Select s;
+
+    s.addSelectable(ev);
+
+    swss::Selectable *sel;
+
+    int fd;
+
+    std::cout << "listening ... " << std::endl;
+
+    int result = s.select(&sel, &fd, 2000);
+
+    if (result == swss::Select::OBJECT)
+    {
+        if (sel == ev)
+        {
+            std::cout << "Got notification: "<<std::endl;
+            *value = 2;
+        }
+    }
+}
+
+TEST(DBConnector, selectableevent)
+{
+    int value = 1;
+
+    swss::SelectableEvent ev;
+
+    std::thread t(selectableEventThread, &ev, &value);
+
+    sleep(1);
+
+    EXPECT_EQ(value, 1);
+
+    ev.notify();
+
+    t.join();
+
+    EXPECT_EQ(value, 2);
+}