diff options
author | Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> | 2011-09-05 16:31:45 +0100 |
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committer | Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> | 2011-09-21 11:29:45 +0100 |
commit | 8f6421179ad29cbdaa9d5c5b39e9c001996c0f07 (patch) | |
tree | a79d31efd1b4ea8c11cac152754786dc5c9c5edf /docs/tracing.txt | |
parent | 27cdad67a1bc23b38c765b677ed8064bfb8d3e44 (diff) |
trace: allow trace events with string arguments
String arguments are useful for producing human-readable traces without
post-processing (e.g. stderr backend). Although the simple backend
cannot handles strings all others can. Strings should be allowed and
the simple backend can be extended to support them.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Diffstat (limited to 'docs/tracing.txt')
-rw-r--r-- | docs/tracing.txt | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/docs/tracing.txt b/docs/tracing.txt index d0171aabda..2c33a62b98 100644 --- a/docs/tracing.txt +++ b/docs/tracing.txt @@ -70,11 +70,6 @@ Trace events should use types as follows: cannot include all user-defined struct declarations and it is therefore necessary to use void * for pointers to structs. - Pointers (including char *) cannot be dereferenced easily (or at all) in - some trace backends. If pointers are used, ensure they are meaningful by - themselves and do not assume the data they point to will be traced. Do - not pass in string arguments. - * For everything else, use primitive scalar types (char, int, long) with the appropriate signedness. @@ -182,6 +177,9 @@ source tree. It may not be as powerful as platform-specific or third-party trace backends but it is portable. This is the recommended trace backend unless you have specific needs for more advanced backends. +The "simple" backend currently does not capture string arguments, it simply +records the char* pointer value instead of the string that is pointed to. + ==== Monitor commands ==== * info trace |