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2011-11-13Use generic lock-free queue for misc aux workRickard Green
2011-11-13Implement generic lock-free queueRickard Green
The implementation of an ERTS internal, generic, many to one, lock-free queue for communication between threads. The many to one scenario is very common in ERTS, so it can be used in a lot of places in the future. Changing to this queue from a lock based queue, however, often requires some redesigning. This since we have often used the lock of the queue to protect other information too.
2011-11-13Replace system block with thread progress blockRickard Green
The ERTS internal system block functionality has been replaced by new functionality for blocking the system. The old system block functionality had contention issues and complexity issues. The new functionality piggy-backs on thread progress tracking functionality needed by newly introduced lock-free synchronization in the runtime system. When the functionality for blocking the system isn't used there is more or less no overhead at all. This since the functionality for tracking thread progress is there and needed anyway.
2011-11-13Optimize memory allocationRickard Green
A number of memory allocation optimizations have been implemented. Most optimizations reduce contention caused by synchronization between threads during allocation and deallocation of memory. Most notably: * Synchronization of memory management in scheduler specific allocator instances has been rewritten to use lock-free synchronization. * Synchronization of memory management in scheduler specific pre-allocators has been rewritten to use lock-free synchronization. * The 'mseg_alloc' memory segment allocator now use scheduler specific instances instead of one instance. Apart from reducing contention this also ensures that memory allocators always create memory segments on the local NUMA node on a NUMA system.
2011-10-14Merge branch 'rickard/atomics-api/OTP-9014' and OTP_R14B04Rickard Green
Conflicts: erts/aclocal.m4 erts/emulator/beam/erl_db.c erts/emulator/sys/win32/sys.c erts/include/internal/ethread_header_config.h.in
2011-09-29Update copyright yearsBjörn-Egil Dahlberg
2011-09-28Prevent valgrind warning for erts_alloc_permanent_cache_alignedSverker Eriksson
2011-09-28[erts] Fix memory leak in erts_make_stub_module (hipe loading)Sverker Eriksson
Code area allocation was done twice; first in read_code_header() and then in erts_make_stub_module() itself.
2011-09-24Merge branch 'rickard/aux-work-bug/OTP-9567' into devRickard Green
* rickard/aux-work-bug/OTP-9567: Fix lost wakeup of scheduler when enqueuing auxiliary work
2011-09-22Fix lost wakeup of scheduler when enqueuing auxiliary workRickard Green
When auxiliary work was enqueued on a scheduler, the wakeup of the scheduler in order to handle this work could be lost. Wakeups in order to handle ordinary work were not effected by this bug. The bug only effected runtime systems with SMP support as follows: * Deallocation of some ETS data structures could be delayed. * On Linux systems not using the NPTL thread library (typically ancient systems with kernel versions prior to 2.6) and Windows systems, the {Port, {exit_status, Status}} message from a terminating port program could be delayed. That is, it only effected port programs which had been started by passing exit_status as an option to open_port/2.
2011-09-20Merge branch 'ta/docs-fixes' into devHenrik Nord
* ta/docs-fixes: Fix misspelling of intermediate Fix typos in erts/preloaded/src Fix more misspellings of compatibility Fix misspelling of kept Fix misspelling of compatibility in ssl_basic_SUITE Fix misspelling of compatibility Fix misspelling of accommodate Fix misspelling of exceed Fix misspelling of accidentally Fix misspelling of erroneous in xmerl_xsd Fix misspelling of erroneous Fix misspelling of successful Fix typos in instrument(3) Fix typos in dbg(3) dialyzer: fix a small typo in list_to_bitstring test Fix typos in cover.erl Fix typos (variable name) in erl_nif(3) Fix typos in mod_esi(3) Fix trivial typos in erlang(3) OTP-9555
2011-09-19Merge branch 'rickard/glibc-mutex-destroy-bug/OTP-9373' into devRickard Green
* rickard/glibc-mutex-destroy-bug/OTP-9373: Do not abort emulator when buggy pthread impl return EBUSY
2011-09-16Merge branch 'pan/erl-bif-types/OTP-9496' into devBjörn-Egil Dahlberg
* pan/erl-bif-types/OTP-9496: Cleanup ETS bif's in hipe:erl_bif_types.erl (for dialyzer)
2011-09-16Merge branch 'pan/win_erlsrv_stop/OTP-9344' into devBjörn-Egil Dahlberg
* pan/win_erlsrv_stop/OTP-9344: Move init of smp rw mutex from init to sys_args to make sure that it is initialized before the first erts_sys_getenv call Move erts_sys_env_init() to erts_sys_pre_init() Remove _DEBUG from start_erl.c Spelling correction in erlsrv doc Convert windows start_erl to take rootdir on command line Add command start_disabled to erlsrv Add global lock for erlsrv to avoid races Change start order so that service_event gets initialized before it's used
2011-09-15Fix more misspellings of compatibilityTuncer Ayaz
2011-09-12Make sure we have a run_queueBjörn-Egil Dahlberg
* In rare cases we could have no run_queue in schedule misc ops
2011-09-12Cleanup ETS bif's in hipe:erl_bif_types.erl (for dialyzer)Patrik Nyblom
2011-09-08Merge branch 'fm/enif_compare-64-to-32bits-cast' into devHenrik Nord
* fm/enif_compare-64-to-32bits-cast: Fix enif_compare on 64bits machines OTP-9533
2011-09-02Fix enif_compare on 64bits machinesFilipe David Manana
In 64bits machines the Sint type has a size of 8 bytes, while on 32bits machines it has a 4 bytes size. enif_compare was ignoring this and therefore returning incorrect values when the result of the CMP function (which returns a Sint value) doesn't fit in 4 bytes. For example, passing the operands -1294536544000 and -1178704800000 to enif_compare would trigger the bug.
2011-08-27Add erlang:external_size/2 BIFFilipe David Manana
This BIF's second parameter is a list of options. Currently the only allowed option is {minor_version, Version} where version is either 0 (default) or 1.
2011-08-25Add erlang:check_old_code/1Björn Gustavsson
Add erlang:check_old_code/1 to quickly check whether a module has old code. If there is no old code, there is no need to call erlang:check_process_code/2 for all processes, which will save some time if there are many processes.
2011-08-25check_process_code/2: Quickly return 'false' if there is no old codeBjörn Gustavsson
There is no need to suspend the process if the module has no old code. Measurements show that this change will make erlang:check_process_code/2 in an SMP emulator about four times faster if the module has no old code.
2011-08-24Merge branch 'rc/r14-gc-fix' into devHenrik Nord
* rc/r14-gc-fix: fix 64-bit issues in the garbage collection OTP-9488
2011-08-15fix 64-bit issues in the garbage collectionRichard Carlsson
We discovered that if a single Erlang process tried to grow above 32 GB (i.e., more 64-bit words than can be counted by a 32-bit number), the VM failed to find the next larger heap size, even though there were plenty more heap sizes left to pick from and even though we had a lot more memory available on the machine. (Obviously, this is only applicable on 64-bit Erlang.) It turned out to be due to some 'int' variables in the heap resizing parts of erl_gc.c not being properly updated to 'Uint' or 'Sint'. Once that was fixed, I got segfaults instead as soon as the heap got larger than 2^32 words, due to even more 'int' declarations in the same file, but now in the GC code. After fixing this as well, I successfully ran an Erlang node in which a single Erlang process had a heap so large that I'm not at liberty to divulge the exact size, but I think the scientific term is "humongous", and I'm confident that there are no further immediate problems with very very large individual process heaps.
2011-08-03Fix binary construction with huge literal sizesBjörn Gustavsson
Constructing binaries using the bit syntax with literals sizes that would not fit in an Uint will either cause an emulator crash or the loading to be aborted. Use the new TAG_o tag introduced in the previous commit to make sure that the attempt to create huge binary literals will generate a system_limit exception at run-time.
2011-08-03beam_load.c: Add overflow check of tag valuesBjörn Gustavsson
The handling of large values for other tags than TAG_i (integer) is buggy. Any tag value equal to or greater than 2^40 (5 bytes) will abort loading. Tag values fitting in 5 bytes will be truncated to 4 bytes values. Those bugs cause real problems because the bs_init2/6 and bs_init_bits/6 instructions unfortunately use TAG_u to encode literal sizes (using TAG_i would have been a better choice, but it is too late to change that now). Any binary size that cannot fit in an Uint should cause a system_limit exception at run-time, but instead the buggy handling will either cause an emulator crash (for values in the range 2^32 to 2^40-1) or abort loading. In this commit, implement overflow checking of tag values as a preparation for fixing the binary construction instructions. If any tag value cannot fit in an Uint (except for TAG_i), change the tag to the special TAG_o overflow tag.
2011-08-03Fix construction of <<0:((1 bsl 32)-1)>>Björn Gustavsson
Attempting to construct <<0:((1 bsl 32)-1)>>, the largest bitstring allowed in a 32 bit emulator, would cause an emulator crash because of integer overflow. Fix the problem by using an Uint64 to avoid integer overflow. Do not attempt to handle construction of <<0:((1 bsl 64)-1>> in a 64-bit emulator, because that will certainly cause the emulator to terminate anyway because of insufficient memory.
2011-07-29Merge branch 'sverker/allocator-aoff/OTP-9424' into devSverker Eriksson
* sverker/allocator-aoff/OTP-9424: New allocator: Address order first fit (aoff)
2011-07-20Small fixups for rickard/sbmbc/OTP-9339Sverker Eriksson
alloc_no of sbmbc_low_alloc was set to ERTS_ALC_A_STANDARD_LOW
2011-07-18New allocator: Address order first fit (aoff)Sverker Eriksson
2011-07-13Merge branch 'sverker/enif_make_int64-halfword/OTP-9394' into devSverker Eriksson
* sverker/enif_make_int64-halfword/OTP-9394: Fix halfword bug in enif_make_int64
2011-07-11Merge branch 'rickard/sbmbc/OTP-9339' into maint-r14Erlang/OTP
* rickard/sbmbc/OTP-9339: Use separate memory carriers for small blocks
2011-07-11Merge branch 'sverker/ets_delete-deadlock-race/OTP-9423' into maint-r14Erlang/OTP
* sverker/ets_delete-deadlock-race/OTP-9423: Fix bug in ets:delete for write_concurrency that could lead to deadlock
2011-07-08Use separate memory carriers for small blocksRickard Green
2011-07-07Fix a match-spec trace bug that could cause emulator crashSverker Eriksson
A trace matchspec with 'enable_trace' or 'disable_trace' in body could cause an emulator crash if a concurrent process altered the trace setting of the traced function by calling erlang:trace_pattern. The effect was a deallocation of the binary holding the matchspec program while it was running. Fixed by increasing reference count of ms-binary in the cases when 'enable_trace' or 'disable_trace' may cause a system block that may alter the ongoing trace. The paradox here is that db_prog_match() is using erts_smp_block_system() to do 'enable_trace' and 'disable_trace' in a safe (atomic) way. But that also have the (non-atomic) effect that racing thread might block the system and change the trace settings with erlang:trace_pattern.
2011-07-07Fix bug in ets:delete for write_concurrency that could lead to deadlockSverker Eriksson
Relocking in ets_delete_1() and remove_named_tab() was done by unlocking the table without clearing the is_thread_safe flag. A racing thread could then read-lock the table and then incorrectly write-unlock the table as db_unlock() looked at is_thread_safe to determine which kind of lock to unlock. Several fixes: 1. Make db_unlock() use argument 'kind' instead of is_thread_safe to determine lock type. 2. Make relock logic use db_lock() and db_unlock() instead of directly accessing lock primitives. 3. Do ownership transfer earlier in ets_delete_1 to avoid racing owner process to also start deleting the same table.
2011-06-30Fix halfword bug in enif_make_int64Sverker Eriksson
The bug was creating an invalid bignum instead of a small integer, causing strange comparing behavior (=:= failed but == succeeded).
2011-06-14Use new atomic API in runtime systemRickard Green
All uses of the old deprecated atomic API in the runtime system have been replaced with the use of the new atomic API. In a lot of places this change imply a relaxation of memory barriers used.
2011-06-14Improve ethread atomicsRickard Green
The ethread atomics API now also provide double word size atomics. Double word size atomics are implemented using native atomic instructions on x86 (when the cmpxchg8b instruction is available) and on x86_64 (when the cmpxchg16b instruction is available). On other hardware where 32-bit atomics or word size atomics are available, an optimized fallback is used; otherwise, a spinlock, or a mutex based fallback is used. The ethread library now performs runtime tests for presence of hardware features, such as for example SSE2 instructions, instead of requiring this to be determined at compile time. There are now functions implementing each atomic operation with the following implied memory barrier semantics: none, read, write, acquire, release, and full. Some of the operation-barrier combinations aren't especially useful. But instead of filtering useful ones out, and potentially miss a useful one, we implement them all. A much smaller set of functionality for native atomics are required to be implemented than before. More or less only cmpxchg and a membar macro are required to be implemented for each atomic size. Other functions will automatically be constructed from these. It is, of course, often wise to implement more that this if possible from a performance perspective.
2011-06-13Do not abort emulator when buggy pthread impl return EBUSYRickard Green
2011-05-26Change start order so that service_event gets initialized before it's usedPatrik Nyblom
2011-05-20Update copyright yearsBjörn-Egil Dahlberg
2011-05-19Merge branch 'rickard/driver_async_cancel/OTP-9302' into devRikard Green
* rickard/driver_async_cancel/OTP-9302: Fix driver_async_cancel()
2011-05-18Fix driver_async_cancel()Rickard Green
2011-05-13Merge branch 'sverker/hipe-misc-fixing/OTP-9298' into devBjörn-Egil Dahlberg
* sverker/hipe-misc-fixing/OTP-9298: hipe_mkliterals print argv[0] in generated files Fix code:is_module_native segv on deleted module lock checking fix in hipe_bif2.c
2011-05-13Merge branch 'rickard/barriers/OTP-9281' into devRickard Green
* rickard/barriers/OTP-9281: Silence warnings Fix build with hipe on amd64 Reduce number of atomic ops Use 32-bit atomic for port snapshot Remove pointless erts_ports_alive variable Ensure quick break Ensure that all rehashing information are seen when done Ensure that stack updates are seen when stack is released Add needed barriers for write_concurrency tables Homogenize memory barriers on atomics
2011-05-13Silence warningsRickard Green
2011-05-13Fix build with hipe on amd64Rickard Green
2011-05-13Reduce number of atomic opsRickard Green
Counters for active, and used schedulers have been coalesced in order to reduce the amount of atomic operations needed. Some currently not strictly necessary barriers have also been added in order to be future proof.
2011-05-13Use 32-bit atomic for port snapshotRickard Green