genode/repos/base-linux/lib/mk/lx_hybrid.mk

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SRC_CC += lx_hybrid.cc new_delete.cc capability_space.cc
SRC_CC += signal_transmitter.cc signal.cc
SRC_C += libgcc.c
2011-12-22 15:19:25 +00:00
cxx: missing operator delete with align_val_t arg When rebasing my local branch on top of sculpt-21.10 tag I've noticed two problems. The code in new_delete.cc does not include new header file. This works fine with GCC, but fails with clang because std::align_val_t type is not defined anywhere according to clang. It looks like GCC pulls this header indirectly somehow. The second problem can be seen if one disallows undefined symbols in executables and shared_libraries. This can be seen with both GCC and clang by adding --no-undefined to LD_OPT. With such change in place core fails to link due to: ld.lld: error: undefined symbol: operator delete(void*, std::align_val_t) >>> referenced by thread.h:448 (/home/tworaz/devel/genode/repos/base-hw/src/core/kernel/thread.h:448) >>> thread.o:(Kernel::Core_main_thread::~Core_main_thread()) in archive debug/core-hw-virt_qemu.a >>> referenced by thread.h:448 (/home/tworaz/devel/genode/repos/base-hw/src/core/kernel/thread.h:448) >>> thread.o:(non-virtual thunk to Kernel::Core_main_thread::~Core_main_thread()) in archive debug/core-hw-virt_qemu.a >>> did you mean: operator delete(void*, unsigned long, std::align_val_t) >>> defined in: debug/core-hw-virt_qemu.a(supc++.o) If the code would somehow manage call such undefined symbol it'd crash. Since I generally prefer link time failures to runtime crashes I link all genode binaries with --no-undefined. To fix this problem just add a dummy implementation of missing delete operator. Fixes #4298
2021-10-14 20:27:07 +00:00
# new_delete.cc uses libsupc++ which means we need to access
# its include directory.
STDINC := yes
vpath new_delete.cc $(BASE_DIR)/src/lib/cxx
vpath lx_hybrid.cc $(REP_DIR)/src/lib/lx_hybrid
vpath libgcc.c $(REP_DIR)/src/lib/lx_hybrid
# add parts of the base library that are shared with core
os/timer: interpolate time via timestamps Previously, the Genode::Timer::curr_time always used the Timer_session::elapsed_ms RPC as back end. Now, Genode::Timer reads this remote time only in a periodic fashion independently from the calls to Genode::Timer::curr_time. If now one calls Genode::Timer::curr_time, the function takes the last read remote time value and adapts it using the timestamp difference since the remote-time read. The conversion factor from timestamps to time is estimated on every remote-time read using the last read remote-time value and the timestamp difference since the last remote time read. This commit also re-works the timeout test. The test now has two stages. In the first stage, it tests fast polling of the Genode::Timer::curr_time. This stage checks the error between locally interpolated and timer-driver time as well as wether the locally interpolated time is monotone and sufficiently homogeneous. In the second stage several periodic and one-shot timeouts are scheduled at once. This stage checks if the timeouts trigger sufficiently precise. This commit adds the new Kernel::time syscall to base-hw. The syscall is solely used by the Genode::Timer on base-hw as substitute for the timestamp. This is because on ARM, the timestamp function uses the ARM performance counter that stops counting when the WFI (wait for interrupt) instruction is active. This instruction, however is used by the base-hw idle contexts that get active when no user thread needs to be scheduled. Thus, the ARM performance counter is not a good choice for time interpolation and we use the kernel internal time instead. With this commit, the timeout library becomes a basic library. That means that it is linked against the LDSO which then provides it to the program it serves. Furthermore, you can't use the timeout library anymore without the LDSO because through the kernel-dependent LDSO make-files we can achieve a kernel-dependent timeout implementation. This commit introduces a structured Duration type that shall successively replace the use of Microseconds, Milliseconds, and integer types for duration values. Open issues: * The timeout test fails on Raspberry PI because of precision errors in the first stage. However, this does not render the framework unusable in general on the RPI but merely is an issue when speaking of microseconds precision. * If we run on ARM with another Kernel than HW the timestamp speed may continuously vary from almost 0 up to CPU speed. The Timer, however, only uses interpolation if the timestamp speed remained stable (12.5% tolerance) for at least 3 observation periods. Currently, one period is 100ms, so its 300ms. As long as this is not the case, Timer_session::elapsed_ms is called instead. Anyway, it might happen that the CPU load was stable for some time so interpolation becomes active and now the timestamp speed drops. In the worst case, we would now have 100ms of slowed down time. The bad thing about it would be, that this also affects the timeout of the period. Thus, it might "freeze" the local time for more than 100ms. On the other hand, if the timestamp speed suddenly raises after some stable time, interpolated time can get too fast. This would shorten the period but nonetheless may result in drifting away into the far future. Now we would have the problem that we can't deliver the real time anymore until it has caught up because the output of Timer::curr_time shall be monotone. So, effectively local time might "freeze" again for more than 100ms. It would be a solution to not use the Trace::timestamp on ARM w/o HW but a function whose return value causes the Timer to never use interpolation because of its stability policy. Fixes #2400
2017-04-21 22:52:23 +00:00
LIBS += base-linux-common timeout
# non-core parts of the base library (except for the startup code)
include $(REP_DIR)/lib/mk/base-linux.inc