TagNameKey contains a pointer to a std::string and a std::string_view,
such it can both own a string or reference a different string. This
is meant to be a memory optimization.
This, however, is actually a net pessimization. Due to these three
below cases and typical usage pattern.
Cases:
1) In the case where TagNameKey owns the string, 3 words are wasted,
one for the pointer and two for the std::string_view.
2) In the case where TagNameKey references a short string, the same 3
words are wasted. This is because std::string has a feature called
"Short String Optimization" that means std::string does not allocate
for strings of sizes <= 10 on 32bit devices and <= 22 on 64bit
devices.
3) In the case where TagNameKey references a longer string than the
"Short String Optimization" limits, then this saves the string's
length in bytes.
Usage pattern:
After boot on 32 bit cuttlefish, there were 679 entries for the first
case, and only 69 in the third case. The 679 entries have an overhead
of 679 * 3 * sizeof(void*) = 679 * 12 = 8148 bytes. The 69 strings in
the third case have a total length and therefore savings of 1352
bytes. This is a net pessimization of 6796 bytes.
I expect this same ratio to be similar throughout the device's uptime.
This situation is worse on 64 bit devices. If cuttlefish were 64 bit,
then there would have been only 18 items in the third case due to the
larger "Short String Optimization" capacity, and the cost for the
first case would have doubled.
Given the above and the cost of maintaining extra code, this
optimization is removed and a std::string is used as the hash table
key instead.
Test: logging unit tests
Change-Id: I957c519b19edca4f7fc531d96b7144cf68bf4e16
The keys are already available when iterating through the maps, so
this only serves to waste memory.
Test: unit tests
Change-Id: Iaf4e389eb0f0990e7113cd78be1773e767a356d4
We can use libbase logging to output to the kernel log instead of the
'prdebug' function, so use that instead.
Bonus #1: we can now use CHECK().
Bonus #2: logging unit tests automatically output to stderr.
Bonus #3: We see dependent library's logs instead of losing them to
the void.
Test: logging unit tests
Test: logs show appropriately in dmesg / stderr
Test: CHECK() works
Change-Id: I92f8056b4820dc4998996cf46460568085299700
Kernel modules may be located within directories in /lib/modules.
Attempt to load kernel modules from each directory that has a name starting with
the major and minor version of the currently running kernel. If a single
kernel module is successfully loaded from a directory, that directory is
treated as the correct kernel module directory for the system. No other
kernel module directories are searched and any kernel module load errors
in that directory are fatal. If the attempt to load the first kernel
module from a directory fails, or if there are no kernel modules in a
directory, then the search proceeds to the next directory.
If no kernel module is successfully loaded from any directory as above,
an attempt is made to load kernel modules from the top level at
/lib/modules/.
Bug: 157645635
Change-Id: I92eadd8617f03a645da460ccb776bc04fa541f00
In the short term this will be used to help implement support for
multiple kernel module directories but it may be useful in other
contexts as well.
Bug: 157645635
Change-Id: I15a252b6e9394292c8f3557ed65112c935830441
This way if an unknown device returns anything but a clear
success report from an incremental installation adb would retry
non-incrementally
Bug: 158006039
Test: manual install on R and Q
Change-Id: I9950273bd60ba75fe12a3706d2ccbee136987d13
Limit the block size to 64 MB before fastboot executable binary for
windows 64-bit is released.
Bug: 156057250
Change-Id: Ic4edb963a3d99f718d7630aba3f351729a84e994
Other log buffers may not use LogBufferElement, so we should decouple
the two classes. This uses an intermediate LogStatisticsElement
structs instead of passing a large number of parameters to each
function.
This additionally moves IsBinary() and the GetTag() functions out into
LogUtils.h since they can be used generically by other users.
Test: logging unit tests
Change-Id: I71f53257342c067bcccd5aa00bae47f714cd7c66
This logic isn't generic, so it should not be in the generic
LogReaderThread.
Moreover, it's currently broken in essentially every case except when
filtering by UID, because it runs as in the filter functions before
the actual filtering by pid/etc takes place. For example, when
filtering by pid, it's possible to get leading chatty messages. The
newly added test was failing previously but is fixed by this change.
It's fundamentally broken in the tail case. Take this example:
1: Normal message
2: Chatty message
3: Normal message
4: Normal message
If you read that log buffer with a tail value of 3, there are three
possible outcomes:
1) Messages #2-4, however this would include a leading chatty message,
which is not allowed.
2) Messages #3-4, however this is only 2, not 3 messages.
3) Messages #1-4, however this is 4, more than the 3 requested
messages.
This code chooses 2) as the correct solution, in this case, we don't
need to account for leading chatty messages when counting the total
logs in the buffer. A test is added for this case as well.
Test: new unit test
Change-Id: Id02eb81a8e77390aba4f85aac659c6cab498dbcd
This has become useless after refactoring; we instead ensure that the
LOG_ID_SECURITY bit isn't set in log_mask, instead of having this
additional check.
Test: logging unit tests
Change-Id: Id47b288d056ebf2b5bd26be94006f17c24fafd31
ChattyLogBuffer::FlushTo() needs an array of pid_t's to differentiate
between deduplication and spam removal chatty messages, but that won't
be useful to other log buffers, so it doesn't deserve its own entry in
the abstruct LogBuffer::FlushTo() function.
Other log buffers may need their own data stored for each reader, so
we create an interface that the reader itself owns and passes to the
log buffer. It uses a unique_ptr, such that the when the reader is
destroyed, so will this state.
FlushToState will additionally contain the start point, that it will
increment itself and the log mask, which LogBuffers can use to
efficiently keep track of the next elements that will be read during a
call to FlushTo().
Side benefit: this allows ChattyLogBufferTests to correctly report
'identical' instead of 'expired' lines the deduplication tests.
Side benefit #2: This updates LogReaderThread::start() more
aggressively, which should result in readers being disconnected less
often, particularly readers who read only a certain UID.
Test: logging unit tests
Change-Id: I969565eb2996afb1431f20e7ccaaa906fcb8f6d1
SimpleLogBuffer::FlushTo() attempts to find the iterator matching a
given sequence number, but the logic is wrong and will always skip one
element forward. This change fixes this and adds a test for the
situation.
This likely contributed to some test instability in the past, but was
identified because subsequent changes that track the start value
closer exacerbated this issue.
Test: existing and new unit tests
Change-Id: Iba2e654e94234693dba20d4747a60bc79d195673
Enable libsnapshot to export the size of the COW image, representing the
fraction of the COW device that is temporarily created in the /data
partition, computed just before initializing a merge operation.
Thise additional information can be used by other components (i.e.,
update engine) to enrich Virtual A/B metrics.
Bug: 154016862
Test: manual OTA
Signed-off-by: Alessio Balsini <balsini@google.com>
Change-Id: I4faa0785f23884e26161e0d51268dd7a305d86bf
Merged-In: I4faa0785f23884e26161e0d51268dd7a305d86bf
Rick Yiu