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-rw-r--r--absl/base/internal/low_level_scheduling.h28
-rw-r--r--absl/base/thread_annotations.h128
2 files changed, 117 insertions, 39 deletions
diff --git a/absl/base/internal/low_level_scheduling.h b/absl/base/internal/low_level_scheduling.h
index ed0b4bfa..6ef79fbf 100644
--- a/absl/base/internal/low_level_scheduling.h
+++ b/absl/base/internal/low_level_scheduling.h
@@ -18,6 +18,7 @@
#ifndef ABSL_BASE_INTERNAL_LOW_LEVEL_SCHEDULING_H_
#define ABSL_BASE_INTERNAL_LOW_LEVEL_SCHEDULING_H_
+#include "absl/base/internal/raw_logging.h"
#include "absl/base/internal/scheduling_mode.h"
#include "absl/base/macros.h"
@@ -29,6 +30,13 @@ extern "C" void __google_enable_rescheduling(bool disable_result);
namespace absl {
ABSL_NAMESPACE_BEGIN
+class CondVar;
+class Mutex;
+
+namespace synchronization_internal {
+int MutexDelay(int32_t c, int mode);
+} // namespace synchronization_internal
+
namespace base_internal {
class SchedulingHelper; // To allow use of SchedulingGuard.
@@ -76,9 +84,23 @@ class SchedulingGuard {
bool disabled;
};
+ // A scoped helper to enable rescheduling temporarily.
+ // REQUIRES: destructor must run in same thread as constructor.
+ class ScopedEnable {
+ public:
+ ScopedEnable();
+ ~ScopedEnable();
+
+ private:
+ int scheduling_disabled_depth_;
+ };
+
// Access to SchedulingGuard is explicitly permitted.
+ friend class absl::CondVar;
+ friend class absl::Mutex;
friend class SchedulingHelper;
friend class SpinLock;
+ friend int absl::synchronization_internal::MutexDelay(int32_t c, int mode);
SchedulingGuard(const SchedulingGuard&) = delete;
SchedulingGuard& operator=(const SchedulingGuard&) = delete;
@@ -100,6 +122,12 @@ inline void SchedulingGuard::EnableRescheduling(bool /* disable_result */) {
return;
}
+inline SchedulingGuard::ScopedEnable::ScopedEnable()
+ : scheduling_disabled_depth_(0) {}
+inline SchedulingGuard::ScopedEnable::~ScopedEnable() {
+ ABSL_RAW_CHECK(scheduling_disabled_depth_ == 0, "disable unused warning");
+}
+
} // namespace base_internal
ABSL_NAMESPACE_END
} // namespace absl
diff --git a/absl/base/thread_annotations.h b/absl/base/thread_annotations.h
index 6a7112df..e23fff1d 100644
--- a/absl/base/thread_annotations.h
+++ b/absl/base/thread_annotations.h
@@ -39,12 +39,6 @@
// TODO(mbonadei): Remove after the backward compatibility period.
#include "absl/base/internal/thread_annotations.h" // IWYU pragma: export
-#if defined(__clang__)
-#define ABSL_INTERNAL_THREAD_ANNOTATION_ATTRIBUTE(x) __attribute__((x))
-#else
-#define ABSL_INTERNAL_THREAD_ANNOTATION_ATTRIBUTE(x) // no-op
-#endif
-
// ABSL_GUARDED_BY()
//
// Documents if a shared field or global variable needs to be protected by a
@@ -62,8 +56,11 @@
// int p1_ ABSL_GUARDED_BY(mu_);
// ...
// };
-#define ABSL_GUARDED_BY(x) \
- ABSL_INTERNAL_THREAD_ANNOTATION_ATTRIBUTE(guarded_by(x))
+#if ABSL_HAVE_ATTRIBUTE(guarded_by)
+#define ABSL_GUARDED_BY(x) __attribute__((guarded_by(x)))
+#else
+#define ABSL_GUARDED_BY(x)
+#endif
// ABSL_PT_GUARDED_BY()
//
@@ -85,8 +82,11 @@
// // `q_`, guarded by `mu1_`, points to a shared memory location that is
// // guarded by `mu2_`:
// int *q_ ABSL_GUARDED_BY(mu1_) ABSL_PT_GUARDED_BY(mu2_);
-#define ABSL_PT_GUARDED_BY(x) \
- ABSL_INTERNAL_THREAD_ANNOTATION_ATTRIBUTE(pt_guarded_by(x))
+#if ABSL_HAVE_ATTRIBUTE(pt_guarded_by)
+#define ABSL_PT_GUARDED_BY(x) __attribute__((pt_guarded_by(x)))
+#else
+#define ABSL_PT_GUARDED_BY(x)
+#endif
// ABSL_ACQUIRED_AFTER() / ABSL_ACQUIRED_BEFORE()
//
@@ -103,11 +103,17 @@
//
// Mutex m1_;
// Mutex m2_ ABSL_ACQUIRED_AFTER(m1_);
-#define ABSL_ACQUIRED_AFTER(...) \
- ABSL_INTERNAL_THREAD_ANNOTATION_ATTRIBUTE(acquired_after(__VA_ARGS__))
+#if ABSL_HAVE_ATTRIBUTE(acquired_after)
+#define ABSL_ACQUIRED_AFTER(...) __attribute__((acquired_after(__VA_ARGS__)))
+#else
+#define ABSL_ACQUIRED_AFTER(...)
+#endif
-#define ABSL_ACQUIRED_BEFORE(...) \
- ABSL_INTERNAL_THREAD_ANNOTATION_ATTRIBUTE(acquired_before(__VA_ARGS__))
+#if ABSL_HAVE_ATTRIBUTE(acquired_before)
+#define ABSL_ACQUIRED_BEFORE(...) __attribute__((acquired_before(__VA_ARGS__)))
+#else
+#define ABSL_ACQUIRED_BEFORE(...)
+#endif
// ABSL_EXCLUSIVE_LOCKS_REQUIRED() / ABSL_SHARED_LOCKS_REQUIRED()
//
@@ -132,20 +138,30 @@
//
// void foo() ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu1, mu2) { ... }
// void bar() const ABSL_SHARED_LOCKS_REQUIRED(mu1, mu2) { ... }
-#define ABSL_EXCLUSIVE_LOCKS_REQUIRED(...) \
- ABSL_INTERNAL_THREAD_ANNOTATION_ATTRIBUTE( \
- exclusive_locks_required(__VA_ARGS__))
+#if ABSL_HAVE_ATTRIBUTE(exclusive_locks_required)
+#define ABSL_EXCLUSIVE_LOCKS_REQUIRED(...) \
+ __attribute__((exclusive_locks_required(__VA_ARGS__)))
+#else
+#define ABSL_EXCLUSIVE_LOCKS_REQUIRED(...)
+#endif
+#if ABSL_HAVE_ATTRIBUTE(shared_locks_required)
#define ABSL_SHARED_LOCKS_REQUIRED(...) \
- ABSL_INTERNAL_THREAD_ANNOTATION_ATTRIBUTE(shared_locks_required(__VA_ARGS__))
+ __attribute__((shared_locks_required(__VA_ARGS__)))
+#else
+#define ABSL_SHARED_LOCKS_REQUIRED(...)
+#endif
// ABSL_LOCKS_EXCLUDED()
//
// Documents the locks acquired in the body of the function. These locks
// cannot be held when calling this function (as Abseil's `Mutex` locks are
// non-reentrant).
-#define ABSL_LOCKS_EXCLUDED(...) \
- ABSL_INTERNAL_THREAD_ANNOTATION_ATTRIBUTE(locks_excluded(__VA_ARGS__))
+#if ABSL_HAVE_ATTRIBUTE(locks_excluded)
+#define ABSL_LOCKS_EXCLUDED(...) __attribute__((locks_excluded(__VA_ARGS__)))
+#else
+#define ABSL_LOCKS_EXCLUDED(...)
+#endif
// ABSL_LOCK_RETURNED()
//
@@ -153,8 +169,7 @@
// a public getter method that returns a pointer to a private mutex should
// be annotated with ABSL_LOCK_RETURNED.
#if ABSL_HAVE_ATTRIBUTE(lock_returned)
-#define ABSL_LOCK_RETURNED(x) \
- ABSL_INTERNAL_THREAD_ANNOTATION_ATTRIBUTE(lock_returned(x))
+#define ABSL_LOCK_RETURNED(x) __attribute__((lock_returned(x)))
#else
#define ABSL_LOCK_RETURNED(x)
#endif
@@ -162,7 +177,11 @@
// ABSL_LOCKABLE
//
// Documents if a class/type is a lockable type (such as the `Mutex` class).
-#define ABSL_LOCKABLE ABSL_INTERNAL_THREAD_ANNOTATION_ATTRIBUTE(lockable)
+#if ABSL_HAVE_ATTRIBUTE(lockable)
+#define ABSL_LOCKABLE __attribute__((lockable))
+#else
+#define ABSL_LOCKABLE
+#endif
// ABSL_SCOPED_LOCKABLE
//
@@ -171,30 +190,43 @@
// acquired, and the destructor should use `UNLOCK_FUNCTION()` with no
// arguments; the analysis will assume that the destructor unlocks whatever the
// constructor locked.
-#define ABSL_SCOPED_LOCKABLE \
- ABSL_INTERNAL_THREAD_ANNOTATION_ATTRIBUTE(scoped_lockable)
+#if ABSL_HAVE_ATTRIBUTE(scoped_lockable)
+#define ABSL_SCOPED_LOCKABLE __attribute__((scoped_lockable))
+#else
+#define ABSL_SCOPED_LOCKABLE
+#endif
// ABSL_EXCLUSIVE_LOCK_FUNCTION()
//
// Documents functions that acquire a lock in the body of a function, and do
// not release it.
-#define ABSL_EXCLUSIVE_LOCK_FUNCTION(...) \
- ABSL_INTERNAL_THREAD_ANNOTATION_ATTRIBUTE( \
- exclusive_lock_function(__VA_ARGS__))
+#if ABSL_HAVE_ATTRIBUTE(exclusive_lock_function)
+#define ABSL_EXCLUSIVE_LOCK_FUNCTION(...) \
+ __attribute__((exclusive_lock_function(__VA_ARGS__)))
+#else
+#define ABSL_EXCLUSIVE_LOCK_FUNCTION(...)
+#endif
// ABSL_SHARED_LOCK_FUNCTION()
//
// Documents functions that acquire a shared (reader) lock in the body of a
// function, and do not release it.
+#if ABSL_HAVE_ATTRIBUTE(shared_lock_function)
#define ABSL_SHARED_LOCK_FUNCTION(...) \
- ABSL_INTERNAL_THREAD_ANNOTATION_ATTRIBUTE(shared_lock_function(__VA_ARGS__))
+ __attribute__((shared_lock_function(__VA_ARGS__)))
+#else
+#define ABSL_SHARED_LOCK_FUNCTION(...)
+#endif
// ABSL_UNLOCK_FUNCTION()
//
// Documents functions that expect a lock to be held on entry to the function,
// and release it in the body of the function.
-#define ABSL_UNLOCK_FUNCTION(...) \
- ABSL_INTERNAL_THREAD_ANNOTATION_ATTRIBUTE(unlock_function(__VA_ARGS__))
+#if ABSL_HAVE_ATTRIBUTE(unlock_function)
+#define ABSL_UNLOCK_FUNCTION(...) __attribute__((unlock_function(__VA_ARGS__)))
+#else
+#define ABSL_UNLOCK_FUNCTION(...)
+#endif
// ABSL_EXCLUSIVE_TRYLOCK_FUNCTION() / ABSL_SHARED_TRYLOCK_FUNCTION()
//
@@ -204,31 +236,49 @@
// success, or `false` for functions that return `false` on success. The second
// argument specifies the mutex that is locked on success. If unspecified, this
// mutex is assumed to be `this`.
+#if ABSL_HAVE_ATTRIBUTE(exclusive_trylock_function)
#define ABSL_EXCLUSIVE_TRYLOCK_FUNCTION(...) \
- ABSL_INTERNAL_THREAD_ANNOTATION_ATTRIBUTE( \
- exclusive_trylock_function(__VA_ARGS__))
+ __attribute__((exclusive_trylock_function(__VA_ARGS__)))
+#else
+#define ABSL_EXCLUSIVE_TRYLOCK_FUNCTION(...)
+#endif
-#define ABSL_SHARED_TRYLOCK_FUNCTION(...) \
- ABSL_INTERNAL_THREAD_ANNOTATION_ATTRIBUTE( \
- shared_trylock_function(__VA_ARGS__))
+#if ABSL_HAVE_ATTRIBUTE(shared_trylock_function)
+#define ABSL_SHARED_TRYLOCK_FUNCTION(...) \
+ __attribute__((shared_trylock_function(__VA_ARGS__)))
+#else
+#define ABSL_SHARED_TRYLOCK_FUNCTION(...)
+#endif
// ABSL_ASSERT_EXCLUSIVE_LOCK() / ABSL_ASSERT_SHARED_LOCK()
//
// Documents functions that dynamically check to see if a lock is held, and fail
// if it is not held.
+#if ABSL_HAVE_ATTRIBUTE(assert_exclusive_lock)
#define ABSL_ASSERT_EXCLUSIVE_LOCK(...) \
- ABSL_INTERNAL_THREAD_ANNOTATION_ATTRIBUTE(assert_exclusive_lock(__VA_ARGS__))
+ __attribute__((assert_exclusive_lock(__VA_ARGS__)))
+#else
+#define ABSL_ASSERT_EXCLUSIVE_LOCK(...)
+#endif
+#if ABSL_HAVE_ATTRIBUTE(assert_shared_lock)
#define ABSL_ASSERT_SHARED_LOCK(...) \
- ABSL_INTERNAL_THREAD_ANNOTATION_ATTRIBUTE(assert_shared_lock(__VA_ARGS__))
+ __attribute__((assert_shared_lock(__VA_ARGS__)))
+#else
+#define ABSL_ASSERT_SHARED_LOCK(...)
+#endif
// ABSL_NO_THREAD_SAFETY_ANALYSIS
//
// Turns off thread safety checking within the body of a particular function.
// This annotation is used to mark functions that are known to be correct, but
// the locking behavior is more complicated than the analyzer can handle.
+#if ABSL_HAVE_ATTRIBUTE(no_thread_safety_analysis)
#define ABSL_NO_THREAD_SAFETY_ANALYSIS \
- ABSL_INTERNAL_THREAD_ANNOTATION_ATTRIBUTE(no_thread_safety_analysis)
+ __attribute__((no_thread_safety_analysis))
+#else
+#define ABSL_NO_THREAD_SAFETY_ANALYSIS
+#endif
//------------------------------------------------------------------------------
// Tool-Supplied Annotations