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WARNING: ThreadSanitizer: data race (pid=28159)
  Atomic write of size 8 at 0xffffeea00078 by thread T2 (mutexes: write M0):
    #0 __wt_atomic_store64 /home/ubuntu/work/git/wiredtiger/src/include/gcc.h:115:1 (libwiredtiger.so.12.0.0+0x4e9650)
    #1 __log_file_server /home/ubuntu/work/git/wiredtiger/src/log/log_mgr.c:703:17 (libwiredtiger.so.12.0.0+0x4eb218)  Previous read of size 4 at 0xffffeea0007c by main thread (mutexes: write M1, write M2):
    #0 __wti_log_release /home/ubuntu/work/git/wiredtiger/src/log/log.c:1992:29 (libwiredtiger.so.12.0.0+0x4c2a24)
    #1 __log_write_internal /home/ubuntu/work/git/wiredtiger/src/log/log.c:2708:9 (libwiredtiger.so.12.0.0+0x4c97a8)
    #2 __wt_log_write /home/ubuntu/work/git/wiredtiger/src/log/log.c:2591:11 (libwiredtiger.so.12.0.0+0x4c8e1c)
    #3 __wt_checkpoint_log /home/ubuntu/work/git/wiredtiger/src/txn/txn_log.c:537:9 (libwiredtiger.so.12.0.0+0x77fe54)
    #4 __checkpoint_db_internal /home/ubuntu/work/git/wiredtiger/src/checkpoint/checkpoint_txn.c:1653:9 (libwiredtiger.so.12.0.0+0x2a81d4)
    #5 __checkpoint_db_wrapper /home/ubuntu/work/git/wiredtiger/src/checkpoint/checkpoint_txn.c:1742:11 (libwiredtiger.so.12.0.0+0x2a0088)
    #6 __wt_checkpoint_db /home/ubuntu/work/git/wiredtiger/src/checkpoint/checkpoint_txn.c:1821:9 (libwiredtiger.so.12.0.0+0x29f744)
    #7 __session_checkpoint /home/ubuntu/work/git/wiredtiger/src/session/session_api.c:2433:11 (libwiredtiger.so.12.0.0+0x668cd8)
    #8 main /home/ubuntu/work/git/wiredtiger/examples/c/ex_backup.c:452:13 (ex_backup+0xf6808)  Location is heap block of size 15976 at 0xffffeea00000 allocated by main thread:
    #0 calloc /data/mci/ba5f99bf532bf97594fd652a66ea3a2b/toolchain-builder/tmp/build-llvm-v5.sh-vLt/llvm-project-llvmorg/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:686:5 (ex_backup+0x67ca4)
    #1 __wt_calloc /home/ubuntu/work/git/wiredtiger/src/os_common/os_alloc.c:68:14 (libwiredtiger.so.12.0.0+0x51cde8)
    #2 __wt_logmgr_create /home/ubuntu/work/git/wiredtiger/src/log/log_mgr.c:1052:5 (libwiredtiger.so.12.0.0+0x4e9bec)
    #3 __wti_connection_workers /home/ubuntu/work/git/wiredtiger/src/conn/conn_open.c:242:5 (libwiredtiger.so.12.0.0+0x3288dc)
    #4 wiredtiger_open /home/ubuntu/work/git/wiredtiger/src/conn/conn_api.c:3471:5 (libwiredtiger.so.12.0.0+0x2d46ec)
    #5 main /home/ubuntu/work/git/wiredtiger/examples/c/ex_backup.c:433:5 (ex_backup+0xf6490)  Mutex M0 (0xffffeea00170) created at:
    #0 pthread_mutex_init /data/mci/ba5f99bf532bf97594fd652a66ea3a2b/toolchain-builder/tmp/build-llvm-v5.sh-vLt/llvm-project-llvmorg/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:1327:3 (ex_backup+0x6b8b4)
    #1 __wt_spin_init /home/ubuntu/work/git/wiredtiger/src/include/mutex_inline.h:142:5 (libwiredtiger.so.12.0.0+0x4ea1c8)
    #2 __wt_logmgr_create /home/ubuntu/work/git/wiredtiger/src/log/log_mgr.c:1057:5 (libwiredtiger.so.12.0.0+0x4e9d88)
    #3 __wti_connection_workers /home/ubuntu/work/git/wiredtiger/src/conn/conn_open.c:242:5 (libwiredtiger.so.12.0.0+0x3288dc)
    #4 wiredtiger_open /home/ubuntu/work/git/wiredtiger/src/conn/conn_api.c:3471:5 (libwiredtiger.so.12.0.0+0x2d46ec)
    #5 main /home/ubuntu/work/git/wiredtiger/examples/c/ex_backup.c:433:5 (ex_backup+0xf6490)  Mutex M1 (0xfffff61b25e8) created at:
    #0 pthread_mutex_init /data/mci/ba5f99bf532bf97594fd652a66ea3a2b/toolchain-builder/tmp/build-llvm-v5.sh-vLt/llvm-project-llvmorg/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:1327:3 (ex_backup+0x6b8b4)
    #1 __wt_spin_init /home/ubuntu/work/git/wiredtiger/src/include/mutex_inline.h:142:5 (libwiredtiger.so.12.0.0+0x67b188)
    #2 __open_session /home/ubuntu/work/git/wiredtiger/src/session/session_api.c:2586:5 (libwiredtiger.so.12.0.0+0x64cc44)
    #3 __wt_open_session /home/ubuntu/work/git/wiredtiger/src/session/session_api.c:2709:5 (libwiredtiger.so.12.0.0+0x64c4e0)
    #4 __conn_open_session /home/ubuntu/work/git/wiredtiger/src/conn/conn_api.c:1379:5 (libwiredtiger.so.12.0.0+0x2dc208)
    #5 main /home/ubuntu/work/git/wiredtiger/examples/c/ex_backup.c:436:5 (ex_backup+0xf6524)  Mutex M2 (0xfffff38007e0) created at:
    #0 pthread_mutex_init /data/mci/ba5f99bf532bf97594fd652a66ea3a2b/toolchain-builder/tmp/build-llvm-v5.sh-vLt/llvm-project-llvmorg/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:1327:3 (ex_backup+0x6b8b4)
    #1 __wt_spin_init /home/ubuntu/work/git/wiredtiger/src/include/mutex_inline.h:142:5 (libwiredtiger.so.12.0.0+0x30d5d8)
    #2 __wti_connection_init /home/ubuntu/work/git/wiredtiger/src/conn/conn_handle.c:50:5 (libwiredtiger.so.12.0.0+0x30c378)
    #3 wiredtiger_open /home/ubuntu/work/git/wiredtiger/src/conn/conn_api.c:3058:5 (libwiredtiger.so.12.0.0+0x2d0904)
    #4 main /home/ubuntu/work/git/wiredtiger/examples/c/ex_backup.c:433:5 (ex_backup+0xf6490)  Thread T2 'log-close-serve' (tid=28165, running) created by main thread at:
    #0 pthread_create /data/mci/ba5f99bf532bf97594fd652a66ea3a2b/toolchain-builder/tmp/build-llvm-v5.sh-vLt/llvm-project-llvmorg/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:1023:3 (ex_backup+0x699d4)
    #1 __wt_thread_create /home/ubuntu/work/git/wiredtiger/src/os_posix/os_thread.c:60:5 (libwiredtiger.so.12.0.0+0x5385c4)
    #2 __wt_logmgr_open /home/ubuntu/work/git/wiredtiger/src/log/log_mgr.c:1118:5 (libwiredtiger.so.12.0.0+0x4ea4b4)
    #3 __wti_connection_workers /home/ubuntu/work/git/wiredtiger/src/conn/conn_open.c:293:5 (libwiredtiger.so.12.0.0+0x328c40)
    #4 wiredtiger_open /home/ubuntu/work/git/wiredtiger/src/conn/conn_api.c:3471:5 (libwiredtiger.so.12.0.0+0x2d46ec)
    #5 main /home/ubuntu/work/git/wiredtiger/examples/c/ex_backup.c:433:5 (ex_backup+0xf6490)SUMMARY: ThreadSanitizer: data race /home/ubuntu/work/git/wiredtiger/src/include/gcc.h:115:1 in __wt_atomic_store64
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