X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fcommon%2Fcompat%2Fcompat-poll.c;h=2318920aed84a7c9dcdb5c1668035913ecb0ff10;hb=a1de8fcc86468f9ae88786634face3e327e2f3b3;hp=cc280c7640ce4d011904da27fac43712ce1df272;hpb=a9b0dbc2405118ef5c69b7834f7cb4617b883cd1;p=lttng-tools.git

diff --git a/src/common/compat/compat-poll.c b/src/common/compat/compat-poll.c
index cc280c764..2318920ae 100644
--- a/src/common/compat/compat-poll.c
+++ b/src/common/compat/compat-poll.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (C)  2011 - David Goulet <david.goulet@polymtl.ca>
+ * Copyright (C)  2019 - Yannick Lamarre <ylamarre@efficios.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License, version 2 only,
@@ -20,6 +21,7 @@
 #include <stdlib.h>
 #include <sys/resource.h>
 #include <sys/time.h>
+#include <stdbool.h>
 
 #include <common/defaults.h>
 #include <common/error.h>
@@ -111,8 +113,9 @@ int compat_poll_create(struct lttng_poll_event *events, int size)
 	}
 
 	if (!poll_max_size) {
-		ERR("poll_max_size not initialized yet");
-		goto error;
+		if (lttng_poll_set_max_size()) {
+			goto error;
+		}
 	}
 
 	/* Don't bust the limit here */
@@ -195,16 +198,53 @@ error:
 	return -1;
 }
 
+/*
+ * Modify an fd's events..
+ */
+int compat_poll_mod(struct lttng_poll_event *events, int fd,
+		uint32_t req_events)
+{
+	int i;
+	struct compat_poll_event_array *current;
+
+	if (events == NULL || events->current.nb_fd == 0 ||
+			events->current.events == NULL || fd < 0) {
+		ERR("Bad compat poll mod arguments");
+		goto error;
+	}
+
+	current = &events->current;
+
+	for (i = 0; i < current->nb_fd; i++) {
+		if (current->events[i].fd == fd) {
+			current->events[i].events = req_events;
+			events->need_update = 1;
+			break;
+		}
+	}
+
+	/*
+	 * The epoll flavor doesn't flag modifying a non-included FD as an
+	 * error.
+	 */
+
+	return 0;
+
+error:
+	return -1;
+}
+
 /*
  * Remove a fd from the pollfd structure.
  */
 int compat_poll_del(struct lttng_poll_event *events, int fd)
 {
-	int new_size, i, count = 0, ret;
+	int i, count = 0, ret;
+	uint32_t new_size;
 	struct compat_poll_event_array *current;
 
-	if (events == NULL || events->current.events == NULL || fd < 0) {
-		ERR("Wrong arguments for poll del");
+	if (events == NULL || events->current.nb_fd == 0 ||
+			events->current.events == NULL || fd < 0) {
 		goto error;
 	}
 
@@ -219,13 +259,20 @@ int compat_poll_del(struct lttng_poll_event *events, int fd)
 			count++;
 		}
 	}
+
+	/* The fd was not in our set, return no error as with epoll. */
+	if (current->nb_fd == count) {
+		goto end;
+	}
+
 	/* No fd duplicate should be ever added into array. */
 	assert(current->nb_fd - 1 == count);
 	current->nb_fd = count;
 
 	/* Resize array if needed. */
 	new_size = 1U << utils_get_count_order_u32(current->nb_fd);
-	if (new_size != current->alloc_size && new_size >= current->init_size) {
+	if (new_size != current->alloc_size && new_size >= current->init_size
+			&& current->nb_fd != 0) {
 		ret = resize_poll_event(current, new_size);
 		if (ret < 0) {
 			goto error;
@@ -234,6 +281,7 @@ int compat_poll_del(struct lttng_poll_event *events, int fd)
 
 	events->need_update = 1;
 
+end:
 	return 0;
 
 error: