Add lttng-modules detection for tests

[lttng-tools.git] / ltt-kconsumerd / ltt-kconsumerd.c

diff --git a/ltt-kconsumerd/ltt-kconsumerd.c b/ltt-kconsumerd/ltt-kconsumerd.c
index cd4b00e0128013f59a602323557a6704c2fd8ec3..7eab42e522d0f45bcb126e101f90d4d543a604e4 100644 (file)
--- a/ltt-kconsumerd/ltt-kconsumerd.c
+++ b/ltt-kconsumerd/ltt-kconsumerd.c
@@ -36,6 +36,7 @@
 #include <poll.h>
 #include <unistd.h>
 #include <sys/mman.h>
+#include <assert.h>
 
 #include <lttng/lttng-kconsumerd.h>
 
@@ -207,7 +208,13 @@ static int read_subbuffer(struct lttng_kconsumerd_fd *kconsumerd_fd)
        err = kernctl_get_next_subbuf(infd);
        if (err != 0) {
                ret = errno;
-               perror("Reserving sub buffer failed (everything is normal, "
+               /*
+                * This is a debug message even for single-threaded consumer,
+                * because poll() have more relaxed criterions than get subbuf,
+                * so get_subbuf may fail for short race windows where poll()
+                * would issue wakeups.
+                */
+               DBG("Reserving sub buffer failed (everything is normal, "
                                "it is due to concurrency)");
                goto end;
        }
@@ -271,6 +278,54 @@ end:
        return ret;
 }
 
+static int on_recv_fd(struct lttng_kconsumerd_fd *kconsumerd_fd)
+{
+       int ret;
+
+       /* Opening the tracefile in write mode */
+       if (kconsumerd_fd->path_name != NULL) {
+               ret = open(kconsumerd_fd->path_name,
+                               O_WRONLY|O_CREAT|O_TRUNC, S_IRWXU|S_IRWXG|S_IRWXO);
+               if (ret < 0) {
+                       ERR("Opening %s", kconsumerd_fd->path_name);
+                       perror("open");
+                       goto error;
+               }
+               kconsumerd_fd->out_fd = ret;
+       }
+
+       if (kconsumerd_fd->output == LTTNG_EVENT_MMAP) {
+               /* get the len of the mmap region */
+               ret = kernctl_get_mmap_len(kconsumerd_fd->consumerd_fd, &kconsumerd_fd->mmap_len);
+               if (ret != 0) {
+                       ret = errno;
+                       perror("kernctl_get_mmap_len");
+                       goto error_close_fd;
+               }
+
+               kconsumerd_fd->mmap_base = mmap(NULL, kconsumerd_fd->mmap_len,
+                               PROT_READ, MAP_PRIVATE, kconsumerd_fd->consumerd_fd, 0);
+               if (kconsumerd_fd->mmap_base == MAP_FAILED) {
+                       perror("Error mmaping");
+                       ret = -1;
+                       goto error_close_fd;
+               }
+       }
+
+       /* we return 0 to let the library handle the FD internally */
+       return 0;
+
+error_close_fd:
+       {
+               int err;
+
+               err = close(kconsumerd_fd->out_fd);
+               assert(!err);
+       }
+error:
+       return ret;
+}
+
 /*
  * main
  */
@@ -297,8 +352,8 @@ int main(int argc, char **argv)
                snprintf(command_sock_path, PATH_MAX,
                                KCONSUMERD_CMD_SOCK_PATH);
        }
-       /* create the pipe to wake to receiving thread when needed */
-       ctx = lttng_kconsumerd_create(read_subbuffer);
+       /* create the consumer instance with and assign the callbacks */
+       ctx = lttng_kconsumerd_create(read_subbuffer, on_recv_fd, NULL);
        if (ctx == NULL) {
                goto error;
        }