This is yet another step into unlocking some parts of the memory
contexts. All the regularly updated variables has been turned into
atomic types, so we can later remove the locks when updating various
counters.
Also unlock as much code as possible without breaking anything.
On 24-core machine, the tests would crash because we would run out of
the hazard pointers. We now adjust the number of hazard pointers to be
in the <128,256> interval based on the number of available cores.
Note: This is just a band-aid and needs a proper fix.
Previously, the applications using libisc would be able to override the
internal memory methods with own implementation. This was no longer
possible, but the extra level of indirection was not removed. This
commit removes the extra level of indirection for the memory methods and
the default_memalloc() and default_memfree().
The internal memory allocator had an extra code to keep a list of blocks
for small size allocation. This would help to reduce the interactions
with the system malloc as the memory would be already allocated from the
system, but there's an extra cost associated with that - all the
allocations/deallocations must be locked, effectively eliminating any
optimizations in the system allocator targeted at multi-threaded
applications. While the isc_mem API is still using locks pretty heavily,
this is a first step into reducing the memory allocation/deallocation
contention.
Created isc_refcount_decrement_expect macro to test conditionally
the return value to ensure it is in expected range. Converted
unchecked isc_refcount_decrement to use isc_refcount_decrement_expect.
Converted INSIST(isc_refcount_decrement()...) to isc_refcount_decrement_expect.
mem.c:add_trace_entry() -> isc_hash_function() -> isc_siphash24()
129 for (; in != end; in += 8) {
6. byte_swapping: Performing a byte swapping operation on
in implies that it came from an external source, and is
therefore tainted.
130 uint64_t m = U8TO64_LE(in);
this corrects some style glitches such as:
```
long_function_call(arg, arg2, arg3, arg4, arg5, "str"
"ing");
```
...by adjusting the penalties for breaking strings and call
parameter lists.
This commits removes superfluous checks when using the isc_refcount API.
Examples of superfluous checks:
1. The isc_refcount_decrement function ensures there was not underflow,
so this check is superfluous:
INSIST(isc_refcount_decrement(&r) > 0);
2 .The isc_refcount_destroy() includes check whether the counter
is zero, therefore this is superfluous:
INSIST(isc_refcount_decrement(&r) == 1 && isc_refcount_destroy(&r));
Previously the libisc allocator had ability to run unlocked when threading was
disabled. As the threading is now always on, remove the ISC_MEMFLAG_NOLOCK
memory flag as it serves no purpose.
The isc_mem_createx() function was only used in the tests to eliminate using the
default flags (which as of writing this commit message was ISC_MEMFLAG_INTERNAL
and ISC_MEMFLAG_FILL). This commit removes the isc_mem_createx() function from
the public API.
Previously, the isc_mem_create() and isc_mem_createx() functions took `max_size`
and `target_size` as first two arguments. Those values were never used in the
BIND 9 code. The refactoring removes those arguments and let BIND 9 always use
the default values.
Previously, the isc_mem_create() and isc_mem_createx() functions could have
failed because of failed memory allocation. As this was no longer true and the
functions have always returned ISC_R_SUCCESS, the have been refactored to return
void.
- removed some dead code
- dns_zone_setdbtype is now void as it could no longer return
anything but ISC_R_SUCCESS; calls to it no longer check for a result
- controlkeylist_fromconfig() is also now void
- fixed a whitespace error
The json-c have previously leaked into the global namespace leading
to forced -I<include_path> for every compilation unit using isc/xml.h
header. This MR fixes the usage making the caller object opaque.
The libxml2 have previously leaked into the global namespace leading
to forced -I<include_path> for every compilation unit using isc/xml.h
header. This MR fixes the usage making the caller object opaque.
- this enables memory to be allocated and freed in dyndb modules
when named is linked statically. when we standardize on libtool,
this should become unnecessary.
- also, simplified the isc_mem_create/createx API by removing
extra compatibility functions
This properly orders clearing the freed pointer and calling isc_refcount_destroy
as early as possible to have ability to put proper memory barrier when cleaning
up reference counting.
