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author | 2018-10-23 12:23:49 -0700 | |
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committer | 2018-10-23 15:52:40 -0400 | |
commit | 0884a6a04e4497d11b1b398cc0e422b118bf977a (patch) | |
tree | 05d1bb9fe31a4823bf8b0dba18703573a8757f7a /absl/base/thread_annotations.h | |
parent | c16d5557cd05119b5b7b1318ef778ebe3195b4a1 (diff) |
Export of internal Abseil changes.
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fe689b30f9a3a614e8a577997cc340043d01c2f1 by Abseil Team <absl-team@google.com>:
Change arm32 linux backtrace to use the generic implementation.
PiperOrigin-RevId: 218386158
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86f8678d055d32edc989e6a4d1dc49c3a15cd350 by Abseil Team <absl-team@google.com>:
Update documentation on SHARED_LOCKS_REQUIRED and EXCLUSIVE_LOCKS_REQUIRED so that users know the differences between them.
PiperOrigin-RevId: 218365545
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22947b48ce4a1ba71ad4794f762235dac3a1df12 by Greg Falcon <gfalcon@google.com>:
The from_chars implementation incorrectly assumed `uint32_t` was `unsigned int`.
`strings_internal::BigUnsigned` had `uint32_t` and `uint64_t` constructors; when both of these types differ from `unsigned int`, `BigUnsigned(1u)` is ambiguous (neither conversion is better).
Fix this by removing the `uint32_t` constructor. When the `uint64_t` constructor is called with a literal or type that is 32 bits or narrower, the compiler is smart enough to optimize away the two-word case, so this fix is free.
PiperOrigin-RevId: 218346935
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7201ab430bb90ca0e30b102915d02564f61353eb by Abseil Team <absl-team@google.com>:
Fix formatting errors discovered during merge conflict.
PiperOrigin-RevId: 218229891
GitOrigin-RevId: fe689b30f9a3a614e8a577997cc340043d01c2f1
Change-Id: I5d382482ad227d48ffe57b243ce11b1eb44a1314
Diffstat (limited to 'absl/base/thread_annotations.h')
-rw-r--r-- | absl/base/thread_annotations.h | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/absl/base/thread_annotations.h b/absl/base/thread_annotations.h index fbb2797b..2241ace4 100644 --- a/absl/base/thread_annotations.h +++ b/absl/base/thread_annotations.h @@ -108,13 +108,23 @@ // The mutex is expected to be held both on entry to, and exit from, the // function. // +// An exclusive lock allows read-write access to the guarded data member(s), and +// only one thread can acquire a lock exclusively at any one time. A shared lock +// allows read-only access, and any number of threads can acquire a shared lock +// concurrently. +// +// Generally, non-const methods should be annotated with +// EXCLUSIVE_LOCKS_REQUIRED, while const methods should be annotated with +// SHARED_LOCKS_REQUIRED. +// // Example: // // Mutex mu1, mu2; // int a GUARDED_BY(mu1); // int b GUARDED_BY(mu2); // -// void foo() EXCLUSIVE_LOCKS_REQUIRED(mu1, mu2) { ... }; +// void foo() EXCLUSIVE_LOCKS_REQUIRED(mu1, mu2) { ... } +// void bar() const SHARED_LOCKS_REQUIRED(mu1, mu2) { ... } #define EXCLUSIVE_LOCKS_REQUIRED(...) \ THREAD_ANNOTATION_ATTRIBUTE__(exclusive_locks_required(__VA_ARGS__)) |