on Wed Mar 01 2017, Edward Connell <swift-users-AT-swift.org> wrote:
> The thread sanitizer on Linux is reporting that I have race conditions in > libswiftcore. The only one we currently know about that's actually in libswiftcore is the one addressed by https://github.com/apple/swift/pull/7183 > I eliminated enough code down to this trivial example. Is there really > a race condition here or are these bogus errors? > > let count = 1000 > var items = [[UInt8]?](repeating: nil, count: count) > > DispatchQueue.concurrentPerform(iterations: count) { > items[$0] = [UInt8](repeating: 7, count: 10) > } > > My real scenario is retrieving data asynchronously, so I just threw in a > buffer assignment. > > Thanks, Ed > > ================== > WARNING: ThreadSanitizer: data race (pid=30720) > Read of size 8 at 0x7d9000008028 by thread T16: > #0 memcpy <null> (libtsan.so.0+0x00000002617a) > #1 _TwCcOs31_ClosedRangeIndexRepresentation <null> > (libswiftCore.so+0x00000027e0fa) > > Previous write of size 8 at 0x7d9000008028 by main thread: > #0 memcpy <null> (libtsan.so.0+0x00000002617a) > #1 _TwCcOs31_ClosedRangeIndexRepresentation <null> > (libswiftCore.so+0x00000027e0fa) > > Location is heap block of size 8032 at 0x7d9000008000 allocated by main > thread: > #0 malloc <null> (libtsan.so.0+0x0000000254a3) > #1 swift_slowAlloc <null> (libswiftCore.so+0x0000002ee3e5) > > Thread T16 (tid=30917, running) created by main thread at: > #0 pthread_create <null> (libtsan.so.0+0x000000027577) > #1 manager_workqueue_additem > /home/buildnode/disk2/workspace/oss-swift-3.0-package-linux-ubuntu-16_04/swift-corelibs-libdispatch/libpwq/src/posix/manager.c:815 > (libdispatch.so+0x00000007c6b1) > > SUMMARY: ThreadSanitizer: data race ??:0 memcpy > ================== > ================== > WARNING: ThreadSanitizer: data race (pid=30720) > Write of size 8 at 0x7d0c00015d80 by thread T16: > #0 free <null> (libtsan.so.0+0x000000025819) > #1 _TwXxOs31_ClosedRangeIndexRepresentation <null> > (libswiftCore.so+0x00000027e071) > > Previous write of size 8 at 0x7d0c00015d80 by main thread: > #0 malloc <null> (libtsan.so.0+0x0000000254a3) > #1 swift_slowAlloc <null> (libswiftCore.so+0x0000002ee3e5) > > Thread T16 (tid=30917, running) created by main thread at: > #0 pthread_create <null> (libtsan.so.0+0x000000027577) > #1 manager_workqueue_additem > /home/buildnode/disk2/workspace/oss-swift-3.0-package-linux-ubuntu-16_04/swift-corelibs-libdispatch/libpwq/src/posix/manager.c:815 > (libdispatch.so+0x00000007c6b1) > > SUMMARY: ThreadSanitizer: data race ??:0 __interceptor_free > ================== > ================== > WARNING: ThreadSanitizer: data race (pid=30720) > Write of size 8 at 0x7d900000a028 by thread T20: > #0 free <null> (libtsan.so.0+0x000000025819) > #1 _TZFSa11_copyBufferfRGVs22_ContiguousArrayBufferx_T_ <null> > (libswiftCore.so+0x00000010884e) > > Previous read of size 8 at 0x7d900000a028 by thread T17: > #0 memcpy <null> (libtsan.so.0+0x00000002617a) > #1 _TwCcOs31_ClosedRangeIndexRepresentation <null> > (libswiftCore.so+0x00000027e0fa) > > Thread T20 (tid=30921, running) created by main thread at: > #0 pthread_create <null> (libtsan.so.0+0x000000027577) > #1 manager_workqueue_additem > /home/buildnode/disk2/workspace/oss-swift-3.0-package-linux-ubuntu-16_04/swift-corelibs-libdispatch/libpwq/src/posix/manager.c:815 > (libdispatch.so+0x00000007c6b1) > > Thread T17 (tid=30918, running) created by main thread at: > #0 pthread_create <null> (libtsan.so.0+0x000000027577) > #1 manager_workqueue_additem > /home/buildnode/disk2/workspace/oss-swift-3.0-package-linux-ubuntu-16_04/swift-corelibs-libdispatch/libpwq/src/posix/manager.c:815 > (libdispatch.so+0x00000007c6b1) > > SUMMARY: ThreadSanitizer: data race ??:0 __interceptor_free > ================== > ================== > WARNING: ThreadSanitizer: data race (pid=30720) > Read of size 8 at 0x7d9000006028 by thread T23: > #0 memcpy <null> (libtsan.so.0+0x00000002617a) > #1 _TwCcOs31_ClosedRangeIndexRepresentation <null> > (libswiftCore.so+0x00000027e0fa) > > Previous write of size 8 at 0x7d9000006028 by main thread: > #0 malloc <null> (libtsan.so.0+0x0000000254a3) > #1 swift_slowAlloc <null> (libswiftCore.so+0x0000002ee3e5) > > Location is heap block of size 8032 at 0x7d9000006000 allocated by main > thread: > #0 malloc <null> (libtsan.so.0+0x0000000254a3) > #1 swift_slowAlloc <null> (libswiftCore.so+0x0000002ee3e5) > > Thread T23 (tid=30924, running) created by main thread at: > #0 pthread_create <null> (libtsan.so.0+0x000000027577) > #1 manager_workqueue_additem > /home/buildnode/disk2/workspace/oss-swift-3.0-package-linux-ubuntu-16_04/swift-corelibs-libdispatch/libpwq/src/posix/manager.c:815 > (libdispatch.so+0x00000007c6b1) > > SUMMARY: ThreadSanitizer: data race ??:0 memcpy > ================== > ================== > WARNING: ThreadSanitizer: data race (pid=30720) > Write of size 8 at 0x7d900002e000 by thread T19: > #0 free <null> (libtsan.so.0+0x000000025819) > #1 _TZFSa11_copyBufferfRGVs22_ContiguousArrayBufferx_T_ <null> > (libswiftCore.so+0x000000108859) > > Previous write of size 8 at 0x7d900002e000 by thread T20: > #0 malloc <null> (libtsan.so.0+0x0000000254a3) > #1 swift_slowAlloc <null> (libswiftCore.so+0x0000002ee3e5) > > Thread T19 (tid=30920, running) created by main thread at: > #0 pthread_create <null> (libtsan.so.0+0x000000027577) > #1 manager_workqueue_additem > /home/buildnode/disk2/workspace/oss-swift-3.0-package-linux-ubuntu-16_04/swift-corelibs-libdispatch/libpwq/src/posix/manager.c:815 > (libdispatch.so+0x00000007c6b1) > > Thread T20 (tid=30921, running) created by main thread at: > #0 pthread_create <null> (libtsan.so.0+0x000000027577) > #1 manager_workqueue_additem > /home/buildnode/disk2/workspace/oss-swift-3.0-package-linux-ubuntu-16_04/swift-corelibs-libdispatch/libpwq/src/posix/manager.c:815 > (libdispatch.so+0x00000007c6b1) > > SUMMARY: ThreadSanitizer: data race ??:0 __interceptor_free > ================== > ================== > WARNING: ThreadSanitizer: data race (pid=30720) > Write of size 8 at 0x7d9000004000 by thread T17: > #0 free <null> (libtsan.so.0+0x000000025819) > #1 _TZFSa11_copyBufferfRGVs22_ContiguousArrayBufferx_T_ <null> > (libswiftCore.so+0x00000010884e) > > Previous write of size 8 at 0x7d9000004000 by main thread: > #0 malloc <null> (libtsan.so.0+0x0000000254a3) > #1 swift_slowAlloc <null> (libswiftCore.so+0x0000002ee3e5) > > Thread T17 (tid=30918, running) created by main thread at: > #0 pthread_create <null> (libtsan.so.0+0x000000027577) > #1 manager_workqueue_additem > /home/buildnode/disk2/workspace/oss-swift-3.0-package-linux-ubuntu-16_04/swift-corelibs-libdispatch/libpwq/src/posix/manager.c:815 > (libdispatch.so+0x00000007c6b1) > > SUMMARY: ThreadSanitizer: data race ??:0 __interceptor_free > ================== > _______________________________________________ > swift-users mailing list > swift-users@swift.org > https://lists.swift.org/mailman/listinfo/swift-users > -- -Dave _______________________________________________ swift-users mailing list swift-users@swift.org https://lists.swift.org/mailman/listinfo/swift-users
