如果在tsan中出现：
ThreadSanitizer: signal-unsafe call inside of a signal (pid=149999)
这一类warrning，那么大概率你是犯了下面的错。
https://man7.org/linux/man-pages/man7/signal-safety.7.html
https://owasp.org/www-community/vulnerabilities/Unsafe_function_call_from_a_signal_handler

下面的signal handler比如是一个pthread_once().

An async-signal-safe function is one that can be safely called
from within a signal handler. Many functions are not async-
signal-safe. In particular, nonreentrant functions are generally
unsafe to call from a signal handler.

   The kinds of issues that render a function unsafe can be quicklyunderstood when one considers the implementation of the stdiolibrary, all of whose functions are not async-signal-safe.When performing buffered I/O on a file, the stdio functions mustmaintain a statically allocated data buffer along with associatedcounters and indexes (or pointers) that record the amount of dataand the current position in the buffer.  Suppose that the mainprogram is in the middle of a call to a stdio function such asprintf(3) where the buffer and associated variables have beenpartially updated.  If, at that moment, the program isinterrupted by a signal handler that also calls printf(3), thenthe second call to printf(3) will operate on inconsistent data,with unpredictable results.To avoid problems with unsafe functions, there are two possiblechoices:(a)  Ensure that (1) the signal handler calls only async-signal-safe functions, and (2) the signal handler itself isreentrant with respect to global variables in the mainprogram.``(b)  Block signal delivery in the main program when callingfunctions that are unsafe or operating on global data thatis also accessed by the signal handler.Generally, the second choice is difficult in programs of anycomplexity, so the first choice is taken.