It's for the introduction of njs support.
For each option that supports native variable and JS template literals introduced next,
it's unified as template string.
No functional changes.
As was pointed out by the cppcheck[0] static code analysis utility we
can mark numerous function parameters as 'const'. This acts as a hint to
the compiler about our intentions and the compiler will tell us when we
deviate from them.
[0]: https://cppcheck.sourceforge.io/
Similar to how C pointers to variables can always be considered as
pointers to the first element of an array of size 1 (see the
following code for an example of how they are equivalent),
treating non-NXT_CONF_VALUE_ARRAY as if they were
NXT_CONF_VALUE_ARRAYs of size 1 allows for simpler and more
generic code.
void foo(ptrdiff_t sz, int arr[sz])
{
for (ptrdiff_t i = 0; i < sz; i++)
arr[i] = 0;
}
void bar(void)
{
int x;
int y[1];
foo(1, &x);
foo(1, y);
}
nxt_conf_array_elements_count_or_1():
Similar to nxt_conf_array_elements_count().
Return a size of 1 when input is non-array, instead of
causing undefined behavior. That value (1) makes sense
because it will be used as the limiter of a loop that
loops over the array and calls
nxt_conf_get_array_element_or_itself(), which will return
a correct element for such loops.
nxt_conf_get_array_element_or_itself():
Similar to nxt_conf_get_array_element().
Return the input pointer unmodified (i.e., a pointer to
the unique element of a hypothetical array), instead of
returning NULL, which wasn't very useful.
nxt_conf_array_qsort():
Since it's a no-op for non-arrays, this API can be reused.
- Pre-fork 'processes.spare' application processes;
- fork more processes to keep 'processes.spare' idle processes;
- fork on-demand up to 'processes.max' count;
- scale down idle application processes above 'processes.spare' after
'processes.idle_timeout';
- number of concurrently started application processes also limited by
'processes.spare' (or 1, if spare is 0).
