Add ftrigr_checksa(), rewrite s6_svlisten_loop() around it

 - Fixes the race condition hit by permanent failure, i.e. two ftrig events close to each other
 - Requires storing the sequence of events client-side, so an additional stralloc, bleh
 - The visible struct ftrigr_s changes, so a major bump is needed -> prepare for 2.6.0.0
 - ftrigr_check() is now a trivial wrapper around ftrigr_checksa()

1 files changed, 21 insertions, 0 deletions

diff --git a/doc/libs6/ftrigr.html b/doc/libs6/ftrigr.html
index 3a32c7e..cc9e37a 100644
--- a/doc/libs6/ftrigr.html
+++ b/doc/libs6/ftrigr.html
@@ -266,5 +266,26 @@ times that an event happened to this identifier since the last
 call to <tt>ftrigr_check()</tt>. </li>
 </ul>
 
+<pre>
+int ftrigr_checksa (ftrigr_t *a, uint16_t id, stralloc *what)
+</pre>
+
+<p>
+ Checks whether an event happened to <em>id</em>. Use after a
+call to <tt>ftrigr_update()</tt>, as an alternative to <tt>ftrigr_check()</tt>.
+</p>
+
+<ul>
+ <li> If an error occurred, returns -1 and sets errno. The error
+number may have been transmitted from
+<a href="s6-ftrigrd.html">s6-ftrigrd</a>. </li>
+ <li> If no notification happened yet, returns 0. </li>
+ <li> If something happened, appends one character to the end of the <em>what</em>
+<a href="//skarnet.org/software/skalibs/libstddjb/stralloc.html">stralloc</a>
+for every time a notification was triggered since the last call
+to <tt>ftrigr_check()</tt>. Each character is the one that triggered
+a notification. The function then returns 1. </li>
+</ul>
+
 </body>
 </html>