When building on a 32-bit system, the compiler warned that the
following line uses a constant whose value is the overflow result
of a compile-time computation:
Process.c (line 109): } else if (number < 10000 * ONE_M) {
Namely, this constant expression:
10000 * ONE_M
was intended to produce the following value:
10485760000
However, the result overflowed to produce:
1895825408
The reason for this overflow is as follows:
o The macros are expanded:
10000 * (ONE_K * ONE_K)
10000 * (1024L * 1024L)
o The untyped constant expression "10000" is typed:
10000U * (1024L * 1024L)
o The parenthesized expression is evaluated:
10000U * (1048576L)
o The left operand ("10000U") is converted:
10000L * (1048576L)
Unbound by integer sizes, that last multiplication
would produce the following value:
10485760000
However, on a 32-bit machine, where a long is 32 bits
(really 31 bits when talking about positive numbers),
the maximum value that can be computed is 2**31-1:
2147483647
Consequently, the computation overflows.
o The compiler produces a long int value that is the
the result of overflow (10485760000 % 2**31):
1895825408L
Actually, I think this overflow is implementation-defined,
so it's not even a portable description of what happens.
The solution is to use a long long int (or, even better,
an unsigned long long int) type for the constant expression;
the C standard mandates a sufficiently large maximum value
for such types.
Hence, the following change is made to the bad line:
- } else if (number < 10000 * ONE_M) {
+ } else if (number < 10000ULL * ONE_M) {
However, the whole line is now patently silly, because the
variable "number" is typed "unsigned long", and so it will
always be less than the constant expression (the compiler
will warn about this, too).
Hence, "number" must be typed "unsigned long long"; however,
this necessitates changing all of the string formats from
something like "%lu" to something like "%llu".
Et voila! This commit is born.
Then, for the sake of completeness, the declared types of the
constant-expression macros are updated:
o ONE_K is made unsigned (a "UL" instead of "L")
o ONE_T is computed by introducing "1ULL *"
o Similar changes are made for ONE_DECIMAL_{K,T}
Also, a non-portable overflow-conversion to a signed value
has been replaced with a portable comparison:
- if ((long long) number == -1LL) {
+ if (number == ULLONG_MAX) {
It might be worth reviewing the rest of the code for other
cases where overflows are not handled correctly; even at
runtime, it's often necessary to check for overflow unless
such behavior is expected (especially for signed integer
values, for which overflow has implementation-defined
behavior).
- `CRT_fatalError()` is declared twice in CRT.h
- `Process_pidFormat`, `Process_writeField()` and `Process_compare` are
declared twice in Process.h
- `btime` is defined in LinuxProcess.c and also declared in
LinuxProcess.h, so drop in LinuxProcessList.h
This is a straightforward extension of the existing multi-column CPU meter
code, which now allows for up CPU meters to be displayed in up to 16 columns.
This also adds the meter declarations to all the platform-specific code.
Instead of scanning the meter name to determine the number of columns in a
CPU meter, move the common code behind some wrapper functions, and specify the
number of columns as an explicit parameter when called from the wrappers.
While this does add a bit of code for all the necessary wrapper functions, this
should be less brittle in case of future changes to the CPU meter code.
This commit is based on a patch originally by @edef1c. The ZFS ARC is a cache
(it's in the name), which will be evicted by the kernel if memory pressure so
requires. Hence, the ARC should not be counted towards a system's total used
memory, and should instead be grouped with the other caches in the system.
Signed-off-by: edef <edef@edef.eu>
htop.c:112:13: warning: 'break' will never be executed [-Wunreachable-code-break]
break;
^~~~~
htop.c:109:13: warning: 'break' will never be executed [-Wunreachable-code-break]
break;
^~~~~
linux/Platform.c:142:17: warning: cast from function call of type 'double' to non-matching type 'int' [-Wbad-function-cast]
return (int) floor(uptime);
^~~~~~~~~~~~~
Use the more portable sysfs node /sys/devices/system/cpu/cpuX/cpufreq/scaling_cur_freq
to get the CPU frequency.
In case of an error fall back to /proc/cpuinfo .
Also use a fixed width of 4 for the frequency to avoid position jumps
in case the frequency moves in the range 900-1100 MHz.
For a process with a very long command, especially with many long
command line arguments, inspecting the command and its arguments could
become inconvenient.
Meanwhile htop supports the concept of "screen", or window, which is
extended here to create a dedicated "CommandScreen", making it possible
to display the command of the selected process in a separate window
meanwhile being wrapped into multiple lines.
Another benefit of using a command screen is, the user can navigate
through the wrapped lines of the command and perform actions like
searching and filtering.
unsigned integer overflows are well-defined, but they might point to a counting issue.
Having the code free of unsigned overflows makes it easier to spot potential bugs.
Action.c:332:27: runtime error: implicit conversion from type 'int' of value -1 (32-bit, signed) to type 'uid_t' (aka 'unsigned int') changed the value to 4294967295 (32-bit, unsigned)
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior Action.c:332:27 in
Bart Joy