Protect shared variables with log lock. #13306
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Fixes reports by helgrind: ``` ==00:00:00:01.769 44512== Possible data race during read of size 8 at 0x9767B0 by thread #4 ==00:00:00:01.769 44512== Locks held: none ==00:00:00:01.769 44512== at 0x17CB56: error_log_limit (log.c:627) ==00:00:00:01.769 44512== by 0x17CEC0: info_int (log.c:716) ==00:00:00:01.769 44512== by 0x18949F: thread_start (threads.c:173) ==00:00:00:01.769 44512== by 0x484A486: ??? (in /usr/libexec/valgrind/vgpreload_helgrind-amd64-linux.so) ==00:00:00:01.769 44512== by 0x4E9CD7F: start_thread (pthread_create.c:481) ==00:00:00:01.769 44512== by 0x532F76E: clone (clone.S:95) ==00:00:00:01.769 44512== ==00:00:00:01.769 44512== This conflicts with a previous write of size 8 by thread #3 ==00:00:00:01.769 44512== Locks held: none ==00:00:00:01.769 44512== at 0x17CB61: error_log_limit (log.c:627) ==00:00:00:01.769 44512== by 0x17CEC0: info_int (log.c:716) ==00:00:00:01.769 44512== by 0x18949F: thread_start (threads.c:173) ==00:00:00:01.769 44512== by 0x484A486: ??? (in /usr/libexec/valgrind/vgpreload_helgrind-amd64-linux.so) ==00:00:00:01.769 44512== by 0x4E9CD7F: start_thread (pthread_create.c:481) ==00:00:00:01.769 44512== by 0x532F76E: clone (clone.S:95) ==00:00:00:01.769 44512== Address 0x9767b0 is 0 bytes inside data symbol "counter.1" ``` ``` ==00:00:00:44.536 47685== Lock at 0x976720 was first observed ==00:00:00:44.536 47685== at 0x48477EF: ??? (in /usr/libexec/valgrind/vgpreload_helgrind-amd64-linux.so) ==00:00:00:44.536 47685== by 0x17BBF4: __netdata_mutex_lock (locks.c:86) ==00:00:00:44.536 47685== by 0x17C514: log_lock (log.c:471) ==00:00:00:44.536 47685== by 0x17CEC0: info_int (log.c:715) ==00:00:00:44.536 47685== by 0x458C9E: compute_multidb_diskspace (rrdenginelib.c:279) ==00:00:00:44.536 47685== by 0x15B170: get_netdata_configured_variables (main.c:671) ==00:00:00:44.536 47685== by 0x15CE6C: main (main.c:1263) ==00:00:00:44.536 47685== Address 0x976720 is 0 bytes inside data symbol "log_mutex" ==00:00:00:44.536 47685== ==00:00:00:44.536 47685== Possible data race during write of size 8 at 0x9767A0 by thread #1 ==00:00:00:44.536 47685== Locks held: none ==00:00:00:44.536 47685== at 0x17CB39: error_log_limit (log.c:621) ==00:00:00:44.536 47685== by 0x15E234: signals_handle (signals.c:258) ==00:00:00:44.536 47685== by 0x15D880: main (main.c:1534) ==00:00:00:44.536 47685== ==00:00:00:44.536 47685== This conflicts with a previous read of size 8 by thread #9 ==00:00:00:44.536 47685== Locks held: 1, at address 0x976720 ==00:00:00:44.536 47685== at 0x17CAA3: error_log_limit (log.c:604) ==00:00:00:44.536 47685== by 0x17CECA: info_int (log.c:718) ==00:00:00:44.536 47685== by 0x4624D2: rrdset_done_push (rrdpush.c:344) ==00:00:00:44.536 47685== by 0x36190C: rrdset_done (rrdset.c:1351) ==00:00:00:44.536 47685== by 0x1B07E7: Chart::update(unsigned long) (plugin_profile.cc:82) ==00:00:00:44.536 47685== by 0x1B01D4: updateCharts(std::vector<Chart*, std::allocator<Chart*> >, unsigned long) (plugin_profile.cc:126) ==00:00:00:44.536 47685== by 0x1B02AC: profile_main (plugin_profile.cc:144) ==00:00:00:44.536 47685== by 0x1895D4: thread_start (threads.c:185) ==00:00:00:44.536 47685== Address 0x9767a0 is 0 bytes inside data symbol "start.3" ```
thiagoftsm
approved these changes
Jul 7, 2022
MrZammler
approved these changes
Jul 7, 2022
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Summary
Fixes reports by helgrind:
Test Plan
Run with/without this patch the agent under helgrind and check the logs.
Additional Information
#13298