[dpdk-dev] [RFC v2 6/6] ipc: remove main IPC thread

[Anatoly Burakov]

Previously, to handle requests from peer(s), or replies for a
request (sync or async) by itself, a dedicated IPC thread was set
up.

Now that every other piece of the puzzle is in place, we can get rid
of the IPC thread, and move waiting for IPC messages entirely into the
interrupt thread.

Signed-off-by: Jianfeng Tan <jianfeng....@intel.com>
Signed-off-by: Anatoly Burakov <anatoly.bura...@intel.com>
Suggested-by: Thomas Monjalon <tho...@monjalon.net>
---

Notes:
    RFC->RFCv2:
    - Fixed resource leaks
    - Improved readability

 lib/librte_eal/common/eal_common_proc.c | 46 ++++++++++++++-----------
 1 file changed, 25 insertions(+), 21 deletions(-)

diff --git a/lib/librte_eal/common/eal_common_proc.c 
b/lib/librte_eal/common/eal_common_proc.c
index 6f3366403..162d67ca5 100644
--- a/lib/librte_eal/common/eal_common_proc.c
+++ b/lib/librte_eal/common/eal_common_proc.c
@@ -25,6 +25,7 @@
 #include <rte_cycles.h>
 #include <rte_eal.h>
 #include <rte_errno.h>
+#include <rte_interrupts.h>
 #include <rte_lcore.h>
 #include <rte_log.h>
 #include <rte_tailq.h>
@@ -101,6 +102,8 @@ static struct {
        /**< used in async requests only */
 };
 
+static struct rte_intr_handle ipc_intr_handle;
+
 /* forward declarations */
 static int
 mp_send(struct rte_mp_msg *msg, const char *peer, int type);
@@ -350,18 +353,17 @@ process_msg(struct mp_msg_internal *m, struct sockaddr_un 
*s)
        }
 }
 
-static void *
+static void
 mp_handle(void *arg __rte_unused)
 {
        struct mp_msg_internal msg;
        struct sockaddr_un sa;
 
        while (1) {
-               if (read_msg(&msg, &sa) == 0)
-                       process_msg(&msg, &sa);
+               if (read_msg(&msg, &sa) < 0)
+                       break;
+               process_msg(&msg, &sa);
        }
-
-       return NULL;
 }
 
 static int
@@ -570,7 +572,6 @@ rte_mp_channel_init(void)
 {
        char path[PATH_MAX];
        int dir_fd;
-       pthread_t mp_handle_tid;
 
        /* create filter path */
        create_socket_path("*", path, sizeof(path));
@@ -585,36 +586,32 @@ rte_mp_channel_init(void)
        if (dir_fd < 0) {
                RTE_LOG(ERR, EAL, "failed to open %s: %s\n",
                        mp_dir_path, strerror(errno));
-               return -1;
+               goto fail;
        }
 
        if (flock(dir_fd, LOCK_EX)) {
                RTE_LOG(ERR, EAL, "failed to lock %s: %s\n",
                        mp_dir_path, strerror(errno));
-               close(dir_fd);
-               return -1;
+               goto fail;
        }
 
        if (rte_eal_process_type() == RTE_PROC_PRIMARY &&
                        unlink_sockets(mp_filter)) {
                RTE_LOG(ERR, EAL, "failed to unlink mp sockets\n");
-               close(dir_fd);
-               return -1;
+               goto fail;
        }
 
        if (open_socket_fd() < 0) {
-               close(dir_fd);
-               return -1;
+               goto fail;
        }
 
-       if (rte_ctrl_thread_create(&mp_handle_tid, "rte_mp_handle",
-                       NULL, mp_handle, NULL) < 0) {
-               RTE_LOG(ERR, EAL, "failed to create mp thead: %s\n",
-                       strerror(errno));
-               close(mp_fd);
-               close(dir_fd);
-               mp_fd = -1;
-               return -1;
+       ipc_intr_handle.fd = mp_fd;
+       ipc_intr_handle.type = RTE_INTR_HANDLE_IPC;
+
+       if (rte_intr_callback_register(&ipc_intr_handle, mp_handle, NULL) < 0) {
+               RTE_LOG(ERR, EAL, "failed to register IPC interrupt callback: 
%s\n",
+                               strerror(errno));
+               goto fail;
        }
 
        /* unlock the directory */
@@ -622,6 +619,13 @@ rte_mp_channel_init(void)
        close(dir_fd);
 
        return 0;
+fail:
+       if (dir_fd >= 0)
+               close(dir_fd);
+       if (mp_fd >= 0)
+               close(mp_fd);
+       mp_fd = -1;
+       return -1;
 }
 
 /**
-- 
2.17.0