X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=src%2Fcommon%2Futils.c;h=5ce597f5eaa59528e7df8fe38b47cf4159de1a7d;hb=bdafebb5195cfda710b32b019f9cac6c4d86f42a;hp=24c3b8ca146ff1fafe8de8da3dd059c7f947f415;hpb=b61e1dca934c1cda7632d154c243dcf56aabac60;p=deliverable%2Flttng-tools.git

diff --git a/src/common/utils.c b/src/common/utils.c
index 24c3b8ca1..5ce597f5e 100644
--- a/src/common/utils.c
+++ b/src/common/utils.c
@@ -712,7 +712,8 @@ int utils_mkdir_recursive(const char *path, mode_t mode, int uid, int gid)
  *
  * Return 0 on success or else a negative value.
  */
-static int utils_stream_file_name(char *path,
+LTTNG_HIDDEN
+int utils_stream_file_name(char *path,
 		const char *path_name, const char *file_name,
 		uint64_t size, uint64_t count,
 		const char *suffix)
@@ -831,6 +832,36 @@ error:
 	return ret;
 }
 
+LTTNG_HIDDEN
+void utils_stream_file_rotation_get_new_count(uint64_t count,
+		uint64_t *new_count, bool *should_unlink)
+{
+	if (count > 0) {
+		/*
+		 * In tracefile rotation, for the relay daemon we need
+		 * to unlink the old file if present, because it may
+		 * still be open in reading by the live thread, and we
+		 * need to ensure that we do not overwrite the content
+		 * between get_index and get_packet. Since we have no
+		 * way to verify integrity of the data content compared
+		 * to the associated index, we need to ensure the reader
+		 * has exclusive access to the file content, and that
+		 * the open of the data file is performed in get_index.
+		 * Unlinking the old file rather than overwriting it
+		 * achieves this.
+		 */
+		if (new_count) {
+			*new_count = (*new_count + 1) % count;
+		}
+		*should_unlink = true;
+	} else {
+		if (new_count) {
+			(*new_count)++;
+		}
+		*should_unlink = false;
+	}
+}
+
 /*
  * Change the output tracefile according to the given size and count The
  * new_count pointer is set during this operation.
@@ -846,9 +877,13 @@ int utils_rotate_stream_file(char *path_name, char *file_name, uint64_t size,
 		int *stream_fd)
 {
 	int ret;
+	bool should_unlink;
 
 	assert(stream_fd);
 
+	utils_stream_file_rotation_get_new_count(count, new_count,
+			&should_unlink);
+
 	ret = close(out_fd);
 	if (ret < 0) {
 		PERROR("Closing tracefile");
@@ -856,32 +891,12 @@ int utils_rotate_stream_file(char *path_name, char *file_name, uint64_t size,
 	}
 	*stream_fd = -1;
 
-	if (count > 0) {
-		/*
-		 * In tracefile rotation, for the relay daemon we need
-		 * to unlink the old file if present, because it may
-		 * still be open in reading by the live thread, and we
-		 * need to ensure that we do not overwrite the content
-		 * between get_index and get_packet. Since we have no
-		 * way to verify integrity of the data content compared
-		 * to the associated index, we need to ensure the reader
-		 * has exclusive access to the file content, and that
-		 * the open of the data file is performed in get_index.
-		 * Unlinking the old file rather than overwriting it
-		 * achieves this.
-		 */
-		if (new_count) {
-			*new_count = (*new_count + 1) % count;
-		}
+	if (should_unlink) {
 		ret = utils_unlink_stream_file(path_name, file_name, size,
 				new_count ? *new_count : 0, uid, gid, 0);
 		if (ret < 0 && errno != ENOENT) {
 			goto error;
 		}
-	} else {
-		if (new_count) {
-			(*new_count)++;
-		}
 	}
 
 	ret = utils_create_stream_file(path_name, file_name, size,
@@ -1017,6 +1032,59 @@ static inline unsigned int fls_u32(uint32_t x)
 #define HAS_FLS_U32
 #endif
 
+#if defined(__x86_64)
+static inline
+unsigned int fls_u64(uint64_t x)
+{
+	long r;
+
+	asm("bsrq %1,%0\n\t"
+	    "jnz 1f\n\t"
+	    "movq $-1,%0\n\t"
+	    "1:\n\t"
+	    : "=r" (r) : "rm" (x));
+	return r + 1;
+}
+#define HAS_FLS_U64
+#endif
+
+#ifndef HAS_FLS_U64
+static __attribute__((unused))
+unsigned int fls_u64(uint64_t x)
+{
+	unsigned int r = 64;
+
+	if (!x)
+		return 0;
+
+	if (!(x & 0xFFFFFFFF00000000ULL)) {
+		x <<= 32;
+		r -= 32;
+	}
+	if (!(x & 0xFFFF000000000000ULL)) {
+		x <<= 16;
+		r -= 16;
+	}
+	if (!(x & 0xFF00000000000000ULL)) {
+		x <<= 8;
+		r -= 8;
+	}
+	if (!(x & 0xF000000000000000ULL)) {
+		x <<= 4;
+		r -= 4;
+	}
+	if (!(x & 0xC000000000000000ULL)) {
+		x <<= 2;
+		r -= 2;
+	}
+	if (!(x & 0x8000000000000000ULL)) {
+		x <<= 1;
+		r -= 1;
+	}
+	return r;
+}
+#endif
+
 #ifndef HAS_FLS_U32
 static __attribute__((unused)) unsigned int fls_u32(uint32_t x)
 {
@@ -1063,6 +1131,20 @@ int utils_get_count_order_u32(uint32_t x)
 	return fls_u32(x - 1);
 }
 
+/*
+ * Return the minimum order for which x <= (1UL << order).
+ * Return -1 if x is 0.
+ */
+LTTNG_HIDDEN
+int utils_get_count_order_u64(uint64_t x)
+{
+	if (!x) {
+		return -1;
+	}
+
+	return fls_u64(x - 1);
+}
+
 /**
  * Obtain the value of LTTNG_HOME environment variable, if exists.
  * Otherwise returns the value of HOME.
@@ -1385,3 +1467,33 @@ int utils_show_man_page(int section, const char *page_name)
 		section_string, page_name, NULL);
 	return ret;
 }
+
+LTTNG_HIDDEN
+int utils_change_working_dir(const char *path)
+{
+	int ret;
+
+	assert(path);
+
+	ret = chdir(path);
+	if (ret) {
+		PERROR("Failed to change working directory: %s", path);
+		goto end;
+	}
+
+	/* Check for write access */
+	if (access(path, W_OK)) {
+		if (errno == EACCES) {
+			/*
+			 * Do not treat this as an error since the permission
+			 * might change in the lifetime of the process
+			 */
+			DBG("Working directory is not writable: %s", path);
+		} else {
+			PERROR("access");
+		}
+	}
+
+end:
+	return ret;
+}