diff options
Diffstat (limited to 'absl/base')
| -rw-r--r-- | absl/base/BUILD.bazel | 4 | ||||
| -rw-r--r-- | absl/base/CMakeLists.txt | 8 | ||||
| -rw-r--r-- | absl/base/attributes.h | 6 | ||||
| -rw-r--r-- | absl/base/call_once.h | 13 | ||||
| -rw-r--r-- | absl/base/policy_checks.h | 10 |
5 files changed, 24 insertions, 17 deletions
diff --git a/absl/base/BUILD.bazel b/absl/base/BUILD.bazel index 6fc712d..7e234bc 100644 --- a/absl/base/BUILD.bazel +++ b/absl/base/BUILD.bazel @@ -192,7 +192,9 @@ cc_library( ], copts = ABSL_DEFAULT_COPTS, linkopts = select({ - "//absl:windows": [], + "//absl:windows": [ + "-DEFAULTLIB:shlwapi.lib", + ], "//conditions:default": ["-pthread"], }) + ABSL_DEFAULT_LINKOPTS, deps = [ diff --git a/absl/base/CMakeLists.txt b/absl/base/CMakeLists.txt index 9550cdb..7ab6955 100644 --- a/absl/base/CMakeLists.txt +++ b/absl/base/CMakeLists.txt @@ -14,6 +14,8 @@ # limitations under the License. # +find_library(LIBRT rt) + absl_cc_library( NAME atomic_hook @@ -163,16 +165,18 @@ absl_cc_library( "internal/thread_identity.h" "internal/tsan_mutex_interface.h" "internal/unscaledcycleclock.h" - "log_severity.h" SRCS "internal/cycleclock.cc" "internal/spinlock.cc" "internal/sysinfo.cc" "internal/thread_identity.cc" "internal/unscaledcycleclock.cc" - "log_severity.cc" COPTS ${ABSL_DEFAULT_COPTS} + LINKOPTS + ${ABSL_DEFAULT_LINKOPTS} + $<$<BOOL:${LIBRT}>:${LIBRT}> + $<$<BOOL:${MINGW}>:"shlwapi"> DEPS absl::atomic_hook absl::base_internal diff --git a/absl/base/attributes.h b/absl/base/attributes.h index 7b7656a..acd1c52 100644 --- a/absl/base/attributes.h +++ b/absl/base/attributes.h @@ -158,9 +158,11 @@ // Weak attributes currently do not work properly in LLVM's Windows backend, // so disable them there. See https://bugs.llvm.org/show_bug.cgi?id=37598 // for further information. -#if (ABSL_HAVE_ATTRIBUTE(weak) || \ +// The MinGW compiler doesn't complain about the weak attribute until the link +// step, presumably because Windows doesn't use ELF binaries. +#if (ABSL_HAVE_ATTRIBUTE(weak) || \ (defined(__GNUC__) && !defined(__clang__))) && \ - !(defined(__llvm__) && defined(_WIN32)) + !(defined(__llvm__) && defined(_WIN32)) && !defined(__MINGW32__) #undef ABSL_ATTRIBUTE_WEAK #define ABSL_ATTRIBUTE_WEAK __attribute__((weak)) #define ABSL_HAVE_ATTRIBUTE_WEAK 1 diff --git a/absl/base/call_once.h b/absl/base/call_once.h index 4aa6360..e1614e5 100644 --- a/absl/base/call_once.h +++ b/absl/base/call_once.h @@ -148,7 +148,7 @@ void CallOnceImpl(std::atomic<uint32_t>* control, Args&&... args) { #ifndef NDEBUG { - uint32_t old_control = control->load(std::memory_order_acquire); + uint32_t old_control = control->load(std::memory_order_relaxed); if (old_control != kOnceInit && old_control != kOnceRunning && old_control != kOnceWaiter && @@ -166,14 +166,23 @@ void CallOnceImpl(std::atomic<uint32_t>* control, // Must do this before potentially modifying control word's state. base_internal::SchedulingHelper maybe_disable_scheduling(scheduling_mode); // Short circuit the simplest case to avoid procedure call overhead. + // The base_internal::SpinLockWait() call returns either kOnceInit or + // kOnceDone. If it returns kOnceDone, it must have loaded the control word + // with std::memory_order_acquire and seen a value of kOnceDone. uint32_t old_control = kOnceInit; if (control->compare_exchange_strong(old_control, kOnceRunning, - std::memory_order_acquire, std::memory_order_relaxed) || base_internal::SpinLockWait(control, ABSL_ARRAYSIZE(trans), trans, scheduling_mode) == kOnceInit) { base_internal::Invoke(std::forward<Callable>(fn), std::forward<Args>(args)...); + // The call to SpinLockWake below is an optimization, because the waiter + // in SpinLockWait is waiting with a short timeout. The atomic load/store + // sequence is slightly faster than an atomic exchange: + // old_control = control->exchange(base_internal::kOnceDone, + // std::memory_order_release); + // We opt for a slightly faster case when there are no waiters, in spite + // of longer tail latency when there are waiters. old_control = control->load(std::memory_order_relaxed); control->store(base_internal::kOnceDone, std::memory_order_release); if (old_control == base_internal::kOnceWaiter) { diff --git a/absl/base/policy_checks.h b/absl/base/policy_checks.h index 699fb1a..4dfa49e 100644 --- a/absl/base/policy_checks.h +++ b/absl/base/policy_checks.h @@ -82,16 +82,6 @@ // Standard Library Check // ----------------------------------------------------------------------------- -// We have chosen glibc 2.12 as the minimum as it was tagged for release -// in May, 2010 and includes some functionality used in Google software -// (for instance pthread_setname_np): -// https://sourceware.org/ml/libc-alpha/2010-05/msg00000.html -#if defined(__GLIBC__) && defined(__GLIBC_PREREQ) -#if !__GLIBC_PREREQ(2, 12) -#error "Minimum required version of glibc is 2.12." -#endif -#endif - #if defined(_STLPORT_VERSION) #error "STLPort is not supported." #endif |