MXS-2008 Remove Worker dependency on internal/poll.h

include/maxscale/worker.hh

@@ -564,8 +564,7 @@ public:
     /**
      * Initialize the worker mechanism.
      *
-     * To be called once at process startup. This will cause as many workers
+     * To be called once at process startup.
-     * to be created as the number of threads defined.
      *
      * @return True if the initialization succeeded, false otherwise.
      */
@@ -574,13 +573,23 @@ public:
     /**
      * Finalize the worker mechanism.
      *
-     * To be called once at process shutdown. This will cause all workers
+     * To be called once at process shutdown.
-     * to be destroyed. When the function is called, no worker should be
-     * running anymore.
      */
     static void finish();
 
-    Worker();
+    enum
+    {
+        MAX_EVENTS = 1000
+    };
+
+    /**
+     * Constructs a worker.
+     *
+     * @param max_events  The maximum number of events that can be returned by
+     *                    one call to epoll_wait.
+     */
+    Worker(int max_events = MAX_EVENTS);
+
     virtual ~Worker();
 
     int load(Load::counter_t counter)
@@ -1189,6 +1198,7 @@ private:
     typedef std::multimap<int64_t, DelayedCall*>            DelayedCallsByTime;
     typedef std::unordered_map<uint32_t, DelayedCall*>      DelayedCallsById;
 
+    uint32_t           m_max_events;           /*< Maximum numer of events in each epoll_wait call. */
     STATISTICS         m_statistics;           /*< Worker statistics. */
     MessageQueue*      m_pQueue;               /*< The message queue of the worker. */
     std::thread        m_thread;               /*< The thread object of the worker. */

server/core/internal/poll.hh

@@ -22,8 +22,6 @@
 
 struct mxs_worker;
 
-#define MAX_EVENTS 1000
-
 enum poll_message
 {
     POLL_MSG_CLEAN_PERSISTENT = 0x01

server/core/worker.cc

@@ -35,7 +35,6 @@
 
 #include "internal/dcb.h"
 #include "internal/modules.h"
-#include "internal/poll.hh"
 #include "internal/service.hh"
 #include "internal/statistics.h"
 
@@ -280,7 +279,9 @@ namespace
 
 int create_epoll_instance()
 {
-    int fd = ::epoll_create(MAX_EVENTS);
+    // Since Linux kernel 2.6.8, the size argument is ignored, but must be positive.
+
+    int fd = ::epoll_create(1);
 
     if (fd == -1)
     {
@@ -297,9 +298,10 @@ int create_epoll_instance()
 //static
 uint32_t Worker::s_next_delayed_call_id = 1;
 
-Worker::Worker()
+Worker::Worker(int max_events)
     : m_epoll_fd(create_epoll_instance())
     , m_state(STOPPED)
+    , m_max_events(max_events)
     , m_pQueue(NULL)
     , m_started(false)
     , m_should_shutdown(false)
@@ -308,6 +310,8 @@ Worker::Worker()
     , m_nTotal_descriptors(0)
     , m_pTimer(new PrivateTimer(this, this, &Worker::tick))
 {
+    ss_dassert(max_events > 0);
+
     if (m_epoll_fd != -1)
     {
         m_pQueue = MessageQueue::create(this);
@@ -733,7 +737,7 @@ void Worker::resolve_poll_error(int fd, int errornum, int op)
  */
 void Worker::poll_waitevents()
 {
-    struct epoll_event events[MAX_EVENTS];
+    struct epoll_event events[m_max_events];
 
     m_state = IDLE;
 
@@ -761,7 +765,7 @@ void Worker::poll_waitevents()
         }
 
         m_load.about_to_wait(now);
-        nfds = epoll_wait(m_epoll_fd, events, MAX_EVENTS, timeout);
+        nfds = epoll_wait(m_epoll_fd, events, m_max_events, timeout);
         m_load.about_to_work();
 
         if (nfds == -1 && errno != EINTR)