Ok, here is that rather major internal redesign hinted
at in the three previous commits. Its need was quickly
revealed after adapting top then attempting to display
newly added 'CGNAME' fields and an existing 'CGROUPS'.
That very quickly generated a SEGV. And the reason was
just as quickly recognized. Both fields relied on that
proc_t.cgroup member yet whichever result structure is
first in a stack is the one which assumes ownership of
of the vectored sting by resetting its cgroup to NULL.
So this commit introduces reference counting for a few
of the fields in the proc_t. Specifically there are 17
entries in the Item_table dealing with strings/vectors
where ownership is transferred to newlib. Now whenever
such fields are represented more than once in a stack,
the strings will be duplicated instead of transferred.
In this way we can generally remain optimized avoiding
string copies, yet still accommodate them when needed.
There's an exception to this scheme: those true string
vectors (CGROUP_V, CMDLINE_V and ENVIRON_V). When such
fields are duplicated in a stack the result structures
beyond the first will be set to NULL, which the caller
will (should) already be equipped to deal with anyway.
Signed-off-by: Jim Warner <james.warner@comcast.net>
The ps program was modified to print the control group
names, based on the library provided list of all those
control groups to which a process belongs. But this is
probably something the newlib should be doing for all.
So this commit borrows the ps approach to cg names and
thus will make that available to all future consumers.
[ but stay tuned! there is a commit coming soon that ]
[ represents a rather major internal redesign, which ]
[ was prompted by the ps and top adaptation testing. ]
Signed-off-by: Jim Warner <james.warner@comcast.net>
The above function was the sole public function in the
<pids> interface to use the word 'stacks' in its name.
All of the others dealt exclusively with their duties,
So this commit normalizes that outlier by renaming it.
Signed-off-by: Jim Warner <james.warner@comcast.net>
The above function had been disabled via '#if 0' so as
to prevent a compiler warning. But it really should be
called by that 'procps_pids_read_shut' function rather
than it duplicating/reinventing the same logic itself.
Signed-off-by: Jim Warner <james.warner@comcast.net>
Gosh, just because nobody uses some newlib provision I
guess, since it is being offered, it ought to actually
be tested at some point. Well, that point just arrived
and guess what? A surprise: some bugs were discovered.
The procps_pids_select function established a for loop
wherein readproc is called until the passed 'maxthese'
limit. Unfortunately this was incorrect for 2 reasons:
1. For PROCPS_FILL_PID results are limited by what the
oldlib finds, having established the pid list at open.
Total found already cannot exceed a passed 'maxthese';
2. With PROCPS_FILL_UID, returned results could exceed
a 'maxthese' thus making the for loop incorrect again.
[ plus yours truly neglected to forward the required ]
[ UIDs total to our old library, another oops biggie ]
In summary: the loop should have been forever, exiting
only when all those identified procs had been located.
So, while addressing those bugs, I've consolidated all
the retrieval code (initialize, iterate, summarize) in
a single helper function which will now serve both the
procps_pids_reap and select functions. And as a result
those guys were reduced to quite trivial housekeeping.
This patch, hopefully, completes the normalization for
reap/select (fill), which began with references shown.
Reference(s):
commit 0c953eccc5
commit 747dfc5987
Signed-off-by: Jim Warner <james.warner@comcast.net>
This patch contains the following minor modifications:
. When assigning to boot_seconds from a double, a cast
to 'unsigned long' was employed that in reality should
have been 'unsigned long long'. But, on second thought
it's probably best if the compiler makes the decision.
. Results for ID_TGID do not require an 'f_status' flg
since both tid and tgid will be available by virtue of
the 'simple_nextpid' function normal operations. Thus,
that flag has been removed from the <pids> Item_table.
. When the pids_stacks structure was eliminated with a
change to the alloc/dealloc functions in the reference
below, several casts became redundant and are removed.
Reference(s):
commit 747dfc5987.
Signed-off-by: Jim Warner <james.warner@comcast.net>
After simplifying that select/fill interface, there is
no longer a need for public 'alloc' & 'dealloc' stacks
functions. There is now only one instance of stacks as
an input parameter found in procps_pids_stacks_sort().
But sorting 'empty' stacks serves no possible purpose.
So this commit retains both functions, since they will
still be needed, but designates them private (static).
Additionally, with their demise we will eliminate that
pids_stacks structure from the header file, internally
using what always was the true 'stacks_extent' struct.
Signed-off-by: Jim Warner <james.warner@comcast.net>
After wrestling with the conversion of both top and ps
the differences between reap (all) & fill (select) has
become increasingly inconvenient. So this patch simply
normalizes that API making returned results identical.
The former procps_pids_stacks_fill identifier will now
be known as procps_pids_select which serves as logical
counterpart to the existing procps_pids_reap function.
Signed-off-by: Jim Warner <james.warner@comcast.net>
Shoot, here's yet another bow to ps needs. But it's ok
because it makes a lot of sense. Rather than force all
users into their own calculations do but it once here.
As an aside this need arose during ps testing when the
sorts were using TIME_START or TICS_ALL. That was just
fine for almost every need except 'etime' plus 'time'.
That 'etime' was sorting the opposite of what's wanted
when using TIME_START (of course) while 'time' yielded
some weird ordering because TICS_ALL was too granular.
Signed-off-by: Jim Warner <james.warner@comcast.net>
While not documented in the man page, ps allows 'tty4'
as a valid output specifier complimenting 'tty8' & its
derivatives. So, in order to eliminate a dev_to_name()
call in the ps program the library will now offer this
abbreviated tty version (consisting of a number only).
Signed-off-by: Jim Warner <james.warner@comcast.net>
The 'PROCPS_PIDS_extra' enumerator already enjoys some
special place wherein it's zeroed with each iteration.
This patch simply extends the special handling to also
include support for sorting. It will be treated as the
'ull_int' data type, since that encompasses the entire
scope of that union within all pids_result structures.
[ plus, we've also corrected the actual 'extra' name ]
This change was prompted by the conversion of ps which
needs that enumerator to store the former 'pcpu' data,
so it will be available for sorting (not for display).
Signed-off-by: Jim Warner <james.warner@comcast.net>
The way that the passed sort order was validated would
allow the invalid 0 to fall between the sofa cushions.
So this patch will simply close that former oversight.
Signed-off-by: Jim Warner <james.warner@comcast.net>
The values of PROCPS_SORT_ASCEND & PROCPS_SORT_DESCEND
were a tad unintuitive. This patch will just make them
a more natural +1 for ascending and -1 for descending.
[ plus it still allows that fast path multiplication ]
[ instead of a comparison for signed numbers/strings ]
Signed-off-by: Jim Warner <james.warner@comcast.net>
After peeking at possible conversion of the ps program
it appeared that we may ultimately need the concept of
a 'static' pids_stack in suport of look_up_our_self().
In other words, one not impacted by procps_pids_reset.
This patch simply sets the stage for that possibility.
Signed-off-by: Jim Warner <james.warner@comcast.net>
Work on converting ps has revealed the desirability of
trading a void pointer for that ul_int type. There was
much arithmetic employed against such values and casts
would otherwise have been required. Even pmap needed a
cast on occasions when comparing an internal variable.
Besides, there is much to be said for reducing demands
on (and the complexity of) the result structure union.
[ we choose ul_int over ull_int since that former is ]
[ the exact same size and capacity as a void pointer ]
[ regardless of whether compiled as 32-bit or 64-bit ]
Signed-off-by: Jim Warner <james.warner@comcast.net>
OK, ok, this was kind of a huge omission. So please do
not select the TTY field for display in top quite yet,
at least until a next patch has been pushed to GitLab.
And to produce a correct sort order for this new field
the GNU 'strverscmp' routine was a necessary addition.
Signed-off-by: Jim Warner <james.warner@comcast.net>
This commit is an outgrowth of the research into a bug
that recently surfaced with the 'w' program. And while
that program was just a victim several inconsistencies
were found in the handling of library flags during the
research. This patch just address such irregularities.
Reference(s):
http://www.freelists.org/post/procps/newlib-at-the-precipice,4
Signed-off-by: Jim Warner <james.warner@comcast.net>
I can't remember during what sleepy hour that enum was
added to pids.h, but it damn sure fell short of a full
implementation by approximately 1,000,000 miles or so.
Strangely it surfaced on Craig's system seemingly ggdb
related whereas on mine, a segmentation fault was only
seen when that -h (no header) argument was being used.
Oh well, the road to its resolution also offered us an
opportunity to cleanup some other items along the way.
Reference(s):
http://www.freelists.org/post/procps/newlib-at-the-precipice,4
Signed-off-by: Jim Warner <james.warner@comcast.net>
A patch containing the following miscellaneous tweaks:
. make a supposedly robust parameter test truly robust
[ ensure the largest enum value used with validation ]
. remove duplicate item test in cleanup_stack function
[ is already subordinate to test of PROCPS_PIDS_noop ]
Signed-off-by: Jim Warner <james.warner@comcast.net>
Functions related to namespaces were half-in half-out of the
procps library and didn't fit the standard naming scheme.
While struct { long ns[x]} is a bit clunky, its the only way
to "lock in" x. The alternative is to use ns_* variables.
This work was needed before pgrep could be converted.
I was surprised to find that ol' gcc silently converts
a single (different) enum into an address where one or
more enums were expected to be dereferenced. Of course
this was just yet another way to generate an old SEGV.
So this commit will strengthen those parameter checks.
[ we will *not* blame Craig for a failure to consult ]
[ the documentation, since it doesn't even exist yet ]
Reference(s):
http://www.freelists.org/post/procps/newlib-ps-fix,8
Signed-off-by: Jim Warner <james.warner@comcast.net>
A patch containing the following miscellaneous tweaks:
. avoided distortions unique to PROCPS_PIDS_TICS_DELTA
. addressed several smatch warnings and/or suggestions
. ensured oldproc_close invoked should tally_proc fail
. keeping that namespace clean, added a missing #undef
. added 2 comments acknowledging pids_item as unsigned
. added/clarified comments regarding proc flags & strv
From smatch analysis:
. these were indeed boo-boos
pids.c:580 make_hist() warn: the 'Hr' macro might need parens
pids.c:1058 procps_pids_reap() warn: variable dereferenced before check 'info' (see line 1056)
. these were not errors (and we did double check)
pids.c:1067 procps_pids_reap() warn: double check that we're allocating correct size: 8 vs 128
pids.c:1068 procps_pids_reap() warn: double check that we're allocating correct size: 8 vs 128
Signed-off-by: Jim Warner <james.warner@comcast.net>
After experimenting with an adaptation of pidof to the
new pids interface, it became apparent that vectorized
versions of those command lines would be necessary. So
this commit adds that option and the strv result type.
And since the stage had been set, a vectorized version
of PROCPS_PIDS_ENVIRON & PROCPS_PIDS_CGROUP was added.
Lastly, any use of 'const' in the result structure was
removed so callers need not be bothered with casts and
compiler warnings. Hopefully, they'll respect a stack.
Signed-off-by: Jim Warner <james.warner@comcast.net>
To ease the transition to the new interface, for other
than that top program, individual read provisions have
been added to the <proc/pids.h> API. This represents a
refinement of a position stated in a post noted below.
Reference(s):
http://www.freelists.org/post/procps/newlib-ps-fix
Signed-off-by: Jim Warner <james.warner@comcast.net>
In my zeal to finalize the initial pids implementation
I omitted some quite important parameter checking from
the above function. Thank goodness top was kind to us.
Also, in anticipation of the additions of single stack
read and supporting functions some items were renamed.
Signed-off-by: Jim Warner <james.warner@comcast.net>
. traded a complex misaligned memory allocation scheme
in the make_hist function for a simple aligned scheme.
plus memory allocation increases are globally defined.
. changed 1 parameter for procps_pids_stacks_sort() to
better reflect the 'array of pointers', not an address
of a pointer as is used with guys such as 'new/unref'.
. the pids_reap struct was changed slightly to make it
more reflective of it's actual implementation details.
. the Item_table member .mustfree is now .needfree and
that .makehist was now made .needhist for consistency.
. reduced the number of separate 'return NULL;' source
statements in that primary procps_pids_reap() routine.
. ensured consistent reference to sizeof(void *) & not
occasional reference to sizeof(void*) without a space.
. rather than enable/disable validate_stacks via a #if
in the function body, it is now handled via a #define.
. some comments in the procps_pids_reset function were
adjusted to reflect this current implementation. shown
originally, they reflected an aborted attempt to avoid
a testing aberration not fully understood at the time.
. added a summary of the memory overhead cost of HST_t
processing to that UNREF_RPTHASH output at unref time.
. a 'PIDs at max depth:' portion of that UNREF_RPTHASH
enabled #define is now published only when the maximum
depth of hash table entry chains exceed depths of one.
Signed-off-by: Jim Warner <james.warner@comcast.net>
This commit is the culmination of efforts to modernize
the library api. It should be treated as a first blush
attempt, especially since I have absolutely no library
design experience. But I did have a very strong desire
to lessen the new library's impact on the top program.
Under this new api, a 'stack' is the equivalent of the
old proc_t. It can be seen as a variable length record
whose contents & order is under complete user control.
That initial stack/record configuration is established
at procps_pids_new() time and will probably serve most
program needs. But, a dynamic & demanding program like
top will later change a stack via procps_pids_reset().
For programs like top & ps, procps_pids_reap() will be
the function that will retrieve all tasks and threads.
Any program that needs to filter / select only certain
processes or users have available other functions that
can be used: procps_pids_stacks_alloc, fill & dealloc.
This implementation attempts to maximize that existing
proven libprocps code base. As we gain more experience
such actual code can be migrated into the pids.c file.
Signed-off-by: Jim Warner <james.warner@comcast.net>
