diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/xfunc.sgml | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 756a9d07fb0..7e92e898460 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -3619,17 +3619,20 @@ INJECTION_POINT(name); </para> <para> - An injection point with a given <literal>name</literal> can be loaded - using macro: + Executing an injection point can require allocating a small amount of + memory, which can fail. If you need to have an injection point in a + critical section where dynamic allocations are not allowed, you can use + a two-step approach with the following macros: <programlisting> INJECTION_POINT_LOAD(name); +INJECTION_POINT_CACHED(name); </programlisting> - This will load the injection point callback into the process cache, - doing all memory allocations at this stage without running the callback. - This is useful when an injection point is attached in a critical section - where no memory can be allocated: load the injection point outside the - critical section, then run it in the critical section. + Before entering the critical section, + call <function>INJECTION_POINT_LOAD</function>. It checks the shared + memory state, and loads the callback into backend-private memory if it is + active. Inside the critical section, use + <function>INJECTION_POINT_CACHED</function> to execute the callback. </para> <para> |