diff options
Diffstat (limited to 'absl/base/thread_annotations.h')
| -rw-r--r-- | absl/base/thread_annotations.h | 31 |
1 files changed, 22 insertions, 9 deletions
diff --git a/absl/base/thread_annotations.h b/absl/base/thread_annotations.h index 0da3badc4e2d..8d30b9324b52 100644 --- a/absl/base/thread_annotations.h +++ b/absl/base/thread_annotations.h @@ -47,10 +47,17 @@ // mutex. GUARDED_BY() allows the user to specify a particular mutex that // should be held when accessing the annotated variable. // +// Although this annotation (and PT_GUARDED_BY, below) cannot be applied to +// local variables, a local variable and its associated mutex can often be +// combined into a small class or struct, thereby allowing the annotation. +// // Example: // -// Mutex mu; -// int p1 GUARDED_BY(mu); +// class Foo { +// Mutex mu_; +// int p1_ GUARDED_BY(mu_); +// ... +// }; #define GUARDED_BY(x) THREAD_ANNOTATION_ATTRIBUTE__(guarded_by(x)) // PT_GUARDED_BY() @@ -59,17 +66,20 @@ // by a mutex when dereferencing the pointer. // // Example: -// Mutex mu; -// int *p1 PT_GUARDED_BY(mu); +// class Foo { +// Mutex mu_; +// int *p1_ PT_GUARDED_BY(mu_); +// ... +// }; // // Note that a pointer variable to a shared memory location could itself be a // shared variable. // // Example: // -// // `q`, guarded by `mu1`, points to a shared memory location that is -// // guarded by `mu2`: -// int *q GUARDED_BY(mu1) PT_GUARDED_BY(mu2); +// // `q_`, guarded by `mu1_`, points to a shared memory location that is +// // guarded by `mu2_`: +// int *q_ GUARDED_BY(mu1_) PT_GUARDED_BY(mu2_); #define PT_GUARDED_BY(x) THREAD_ANNOTATION_ATTRIBUTE__(pt_guarded_by(x)) // ACQUIRED_AFTER() / ACQUIRED_BEFORE() @@ -80,10 +90,13 @@ // (i.e. You don't have to annotate both locks with both ACQUIRED_AFTER // and ACQUIRED_BEFORE.) // +// As with GUARDED_BY, this is only applicable to mutexes that are shared +// fields or global variables. +// // Example: // -// Mutex m1; -// Mutex m2 ACQUIRED_AFTER(m1); +// Mutex m1_; +// Mutex m2_ ACQUIRED_AFTER(m1_); #define ACQUIRED_AFTER(...) \ THREAD_ANNOTATION_ATTRIBUTE__(acquired_after(__VA_ARGS__)) |