X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-ust-comm.c;h=7d885a551e2f289f4f11728613d1d1fdc4a38d52;hb=932cfadbd7427a4ac5d5560cca049a121722d400;hp=b290204024afcd4a761778cb5e359d42501a9ba5;hpb=cf73e0fea355d408180a66a88ba7a33cfbd17c33;p=lttng-ust.git diff --git a/liblttng-ust/lttng-ust-comm.c b/liblttng-ust/lttng-ust-comm.c index b2902040..7d885a55 100644 --- a/liblttng-ust/lttng-ust-comm.c +++ b/liblttng-ust/lttng-ust-comm.c @@ -1120,8 +1120,6 @@ error: static void wait_for_sessiond(struct sock_info *sock_info) { - int ret; - if (ust_lock()) { goto quit; } @@ -1137,23 +1135,32 @@ void wait_for_sessiond(struct sock_info *sock_info) DBG("Waiting for %s apps sessiond", sock_info->name); /* Wait for futex wakeup */ - if (uatomic_read((int32_t *) sock_info->wait_shm_mmap) == 0) { - ret = futex_async((int32_t *) sock_info->wait_shm_mmap, - FUTEX_WAIT, 0, NULL, NULL, 0); - if (ret < 0) { - if (errno == EFAULT) { - wait_poll_fallback = 1; - DBG( + if (uatomic_read((int32_t *) sock_info->wait_shm_mmap)) + goto end_wait; + + while (futex_async((int32_t *) sock_info->wait_shm_mmap, + FUTEX_WAIT, 0, NULL, NULL, 0)) { + switch (errno) { + case EWOULDBLOCK: + /* Value already changed. */ + goto end_wait; + case EINTR: + /* Retry if interrupted by signal. */ + break; /* Get out of switch. */ + case EFAULT: + wait_poll_fallback = 1; + DBG( "Linux kernels 2.6.33 to 3.0 (with the exception of stable versions) " "do not support FUTEX_WAKE on read-only memory mappings correctly. " "Please upgrade your kernel " "(fix is commit 9ea71503a8ed9184d2d0b8ccc4d269d05f7940ae in Linux kernel " "mainline). LTTng-UST will use polling mode fallback."); - if (ust_debug()) - PERROR("futex"); - } + if (ust_debug()) + PERROR("futex"); + goto end_wait; } } +end_wait: return; quit: @@ -1554,9 +1561,7 @@ static void lttng_ust_cleanup(int exiting) { cleanup_sock_info(&global_apps, exiting); - if (local_apps.allowed) { - cleanup_sock_info(&local_apps, exiting); - } + cleanup_sock_info(&local_apps, exiting); /* * The teardown in this function all affect data structures * accessed under the UST lock by the listener thread. This