libuv expects file descriptors <= STDERR_FILENO are in use. otherwise,
it may abort when closing a file descriptor it opened.
See https://github.com/libuv/libuv/pull/4559Closes#5226
This required couple of internal changes to the isc_mem_debugging.
The isc_mem_debugging is now internal to isc_mem unit and there are
three new functions:
1. isc_mem_setdebugging() can change the debugging setting for an
individual memory context. This is need for the memory contexts used
for OpenSSL, libxml and libuv accounting as recording and tracing
memory is broken there.
2. isc_mem_debugon() / isc_mem_debugoff() can be used to change default
memory debugging flags as well as debugging flags for isc_g_mctx.
Additionally, the memory debugging is inconsistent across the code-base.
For now, we are keeping the existing flags, but three new environment
variables have been added 'ISC_MEM_DEBUGRECORD', 'ISC_MEM_DEBUGTRACE'
and 'ISC_MEM_DEBUGUSAGE' to set the global debugging flags at any
program using the memory contexts.
Instead of giving the memory context names with an explicit call to
isc_mem_setname(), add the name to isc_mem_create() call to have all the
memory contexts an unconditional name.
As well as clearing the fresh memory, `calloc()`-like functions must
ensure that the count and size do not overflow when multiplied.
Use `isc_mem_callocate()` in `isc__uv_calloc()`.
Add new semantic patch to replace the straightfoward uses of:
ptr = isc_mem_{get,allocate}(..., size);
memset(ptr, 0, size);
with the new API call:
ptr = isc_mem_{get,allocate}x(..., size, ISC_MEM_ZERO);
The libuv library provides a way to replace the default allocator with
user supplied allocator (malloc, realloc, calloc and free).
Create a memory context specifically for libuv to allow tracking the
memory usage that has originated from within libuv. This requires
libuv >= 1.38.0 which provides uv_library_shutdown() function that
assures no more allocations will be made.
By bumping the minimum libuv version to 1.34.0, it allows us to remove
all libuv shims we ever had and makes the code much cleaner. The
up-to-date libuv is available in all distributions supported by BIND
9.19+ either natively or as a backport.
Somewhere in the move from netmgr/uv-compat.h to uv.c, the
uv_os_getenv() implementation was lost in the process. Restore the
implementation, so we can support Debian stretch for couple more months.
As we are going to use libuv outside of the netmgr, we need the shims to
be readily available for the rest of the codebase.
Move the "netmgr/uv-compat.h" to <isc/uv.h> and netmgr/uv-compat.c to
uv.c, and as a rule of thumb, the users of libuv should include
<isc/uv.h> instead of <uv.h> directly.
Additionally, merge netmgr/uverr2result.c into uv.c and rename the
single function from isc__nm_uverr2result() to isc_uverr2result().
