diff options
Diffstat (limited to 'absl/base/internal/thread_identity.h')
| -rw-r--r-- | absl/base/internal/thread_identity.h | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/absl/base/internal/thread_identity.h b/absl/base/internal/thread_identity.h index 659694b3..496ec214 100644 --- a/absl/base/internal/thread_identity.h +++ b/absl/base/internal/thread_identity.h @@ -134,6 +134,10 @@ struct PerThreadSynch { // The instances of this class are allocated in NewThreadIdentity() with an // alignment of PerThreadSynch::kAlignment. +// +// NOTE: The layout of fields in this structure is critical, please do not +// add, remove, or modify the field placements without fully auditing the +// layout. struct ThreadIdentity { // Must be the first member. The Mutex implementation requires that // the PerThreadSynch object associated with each thread is @@ -143,7 +147,7 @@ struct ThreadIdentity { // Private: Reserved for absl::synchronization_internal::Waiter. struct WaiterState { - alignas(void*) char data[128]; + alignas(void*) char data[256]; } waiter_state; // Used by PerThreadSem::{Get,Set}ThreadBlockedCounter(). @@ -166,7 +170,10 @@ struct ThreadIdentity { // // Does not malloc(*), and is async-signal safe. // [*] Technically pthread_setspecific() does malloc on first use; however this -// is handled internally within tcmalloc's initialization already. +// is handled internally within tcmalloc's initialization already. Note that +// darwin does *not* use tcmalloc, so this can catch you if using MallocHooks +// on Apple platforms. Whatever function is calling your MallocHooks will need +// to watch for recursion on Apple platforms. // // New ThreadIdentity objects can be constructed and associated with a thread // by calling GetOrCreateCurrentThreadIdentity() in per-thread-sem.h. |