path: root/.tsan-suppressions
AgeCommit message (Collapse)Author
2020-01-17replace-object: make replace operations thread-safeMatheus Tavares
replace-object functions are very close to being thread-safe: the only current racy section is the lazy initialization at prepare_replace_object(). The following patches will protect some object reading operations to be called threaded, but before that, replace functions must be protected. To do so, add a mutex to struct raw_object_store and acquire it before lazy initializing the replace_map. This won't cause any noticeable performance drop as the mutex will no longer be used after the replace_map is initialized. Later, when the replace functions are called in parallel, thread debuggers might point our use of the added replace_map_initialized flag as a data race. However, as this boolean variable is initialized as false and it's only updated once, there's no real harm. It's perfectly fine if the value is updated right after a thread read it in replace-map.h:lookup_replace_object() (there'll only be a performance penalty for the affected threads at that moment). We could cease the debugger warning protecting the variable reading at the said function. However, this would negatively affect performance for all threads calling it, at any time, so it's not really worthy since the warning doesn't represent a real problem. Instead, to make sure we don't get false positives (at ThreadSanitizer, at least) an entry for the respective function is added to .tsan-suppressions. Signed-off-by: Matheus Tavares <> Signed-off-by: Junio C Hamano <>
2017-08-23ThreadSanitizer: add suppressionsMartin Ågren
Add a file .tsan-suppressions and list two functions in it: want_color() and transfer_debug(). Both of these use the pattern static int foo = -1; if (foo < 0) foo = bar(); where bar always returns the same non-negative value. This can cause ThreadSanitizer to diagnose a race when foo is written from two threads. That is indeed a race, although it arguably doesn't matter in practice since it's always the same value that is written. Add NEEDSWORK-comments to the functions so that this problem is not forever swept way under the carpet. The suppressions-file is used by setting the environment variable TSAN_OPTIONS to, e.g., "suppressions=$(pwd)/.tsan-suppressions". Observe that relative paths such as ".tsan-suppressions" might not work. Signed-off-by: Martin Ågren <> Signed-off-by: Junio C Hamano <>