s3-prefork: Add parent->client messaging

Signed-off-by: Andreas Schneider <asn@samba.org>
Signed-off-by: Simo Sorce <idra@samba.org>

3 files changed, 39 insertions, 0 deletions

diff --git a/source3/lib/server_prefork.c b/source3/lib/server_prefork.c
index 82645504f8..bcb5e0f19e 100644
--- a/source3/lib/server_prefork.c
+++ b/source3/lib/server_prefork.c
@@ -19,6 +19,8 @@
 */
 
 #include "includes.h"
+#include "serverid.h"
+#include "messages.h"
 #include "system/time.h"
 #include "system/shmem.h"
 #include "system/filesys.h"
@@ -423,6 +425,23 @@ void prefork_send_signal_to_all(struct prefork_pool *pfp, int signal_num)
 	}
 }
 
+void prefork_warn_active_children(struct messaging_context *msg_ctx,
+				  struct prefork_pool *pfp)
+{
+	const DATA_BLOB ping = data_blob_null;
+	int i;
+
+	for (i = 0; i < pfp->pool_size; i++) {
+		if (pfp->pool[i].status == PF_WORKER_NONE) {
+			continue;
+		}
+
+		messaging_send(msg_ctx,
+				pid_to_procid(pfp->pool[i].pid),
+				MSG_PREFORK_PARENT_EVENT, &ping);
+	}
+}
+
 static void prefork_sigchld_handler(struct tevent_context *ev_ctx,
 				    struct tevent_signal *se,
 				    int signum, int count,
diff --git a/source3/lib/server_prefork.h b/source3/lib/server_prefork.h
index d240641a39..17491536ff 100644
--- a/source3/lib/server_prefork.h
+++ b/source3/lib/server_prefork.h
@@ -226,6 +226,16 @@ void prefork_reset_allowed_clients(struct prefork_pool *pfp);
 void prefork_send_signal_to_all(struct prefork_pool *pfp, int signal_num);
 
 /**
+* @brief Send a message to all children that the server changed something
+*	 in the pool and they may want to take action.
+*
+* @param msg_ctx	The messaging context.
+* @param pfp		The pool.
+*/
+void prefork_warn_active_children(struct messaging_context *msg_ctx,
+				  struct prefork_pool *pfp);
+
+/**
 * @brief Sets the SIGCHLD callback
 *
 * @param pfp		The pool handler.
diff --git a/source3/lib/server_prefork_util.c b/source3/lib/server_prefork_util.c
index 638ce66f09..01c7994f60 100644
--- a/source3/lib/server_prefork_util.c
+++ b/source3/lib/server_prefork_util.c
@@ -67,6 +67,7 @@ void pfh_manage_pool(struct tevent_context *ev_ctx,
 	time_t now = time(NULL);
 	int total, avail;
 	int ret, n;
+	bool msg = false;
 
 	if ((cfg->prefork_status & PFH_NEW_MAX) &&
 	    !(cfg->prefork_status & PFH_ENOSPC)) {
@@ -119,6 +120,7 @@ void pfh_manage_pool(struct tevent_context *ev_ctx,
 			if (n == avail) break;
 			n = avail;
 		}
+		msg = true;
 	} else if (avail > total + cfg->spawn_rate) {
 		n = avail;
 		while (avail > total + cfg->spawn_rate) {
@@ -130,6 +132,14 @@ void pfh_manage_pool(struct tevent_context *ev_ctx,
 		}
 	}
 
+	/* send message to all children when we change maximum allowed
+	 * connections, so that they can decide to start again to listen to
+	 * sockets if they were already topping the number of allowed
+	 * clients. Useful only when we increase allowed clients */
+	if (msg) {
+		prefork_warn_active_children(msg_ctx, pool);
+	}
+
 	DEBUG(10, ("Stats: children: %d, allowed connections: %d\n",
 		  prefork_count_children(pool, NULL),
 		  prefork_count_allowed_connections(pool)));