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authorGravatar Abseil Team <absl-team@google.com>2020-10-13 08:26:15 -0700
committerGravatar Derek Mauro <dmauro@google.com>2020-10-13 12:49:13 -0400
commitf3f785ab59478dd0312bf1b5df65d380650bf0dc (patch)
treec6cb0ba6e13b43ccfc1c60bf4dfed9ea0d38e62f /absl
parent4b2fbb4adba905eede6c61b4494acfdb660a3bb7 (diff)
Export of internal Abseil changes
-- 5bd06440e700fefd6eadd577d7d69c51f15c63e0 by Abseil Team <absl-team@google.com>: Add if-guard to futex.h so that it doesn't fail to parse for unsupported platforms PiperOrigin-RevId: 336880375 -- 8b3d3bb4ad123fc9f648f0e397b2eddd88dc0c02 by Derek Mauro <dmauro@google.com>: Fix race in AddressIsReadable file descriptors using stronger memory ordering PiperOrigin-RevId: 336874423 -- 1d8bf23747009cca29129b80c2793bc91443dd55 by Derek Mauro <dmauro@google.com>: Avoid -Wundef warnings on ABSL_HAVE_THREAD_LOCAL PiperOrigin-RevId: 336792406 -- 562a480f029c600c1d3b1428da6a9b09e8952a74 by Derek Mauro <dmauro@google.com>: Fix preprocessor condition for symbols __tsan_mutex_read_lock and __tsan_mutex_try_lock PiperOrigin-RevId: 336732571 GitOrigin-RevId: 5bd06440e700fefd6eadd577d7d69c51f15c63e0 Change-Id: Id9bb331baec74b9d80c7b228959a7739bc30e694
Diffstat (limited to 'absl')
-rw-r--r--absl/base/internal/exponential_biased_test.cc2
-rw-r--r--absl/base/internal/sysinfo.cc2
-rw-r--r--absl/container/internal/raw_hash_set.cc2
-rw-r--r--absl/debugging/internal/address_is_readable.cc9
-rw-r--r--absl/synchronization/internal/futex.h15
-rw-r--r--absl/synchronization/internal/waiter.cc4
-rw-r--r--absl/synchronization/internal/waiter.h8
-rw-r--r--absl/synchronization/mutex.cc5
8 files changed, 28 insertions, 19 deletions
diff --git a/absl/base/internal/exponential_biased_test.cc b/absl/base/internal/exponential_biased_test.cc
index 90a482d2..075583ca 100644
--- a/absl/base/internal/exponential_biased_test.cc
+++ b/absl/base/internal/exponential_biased_test.cc
@@ -185,7 +185,7 @@ TEST(ExponentialBiasedTest, InitializationModes) {
ABSL_CONST_INIT static ExponentialBiased eb_static;
EXPECT_THAT(eb_static.GetSkipCount(2), Ge(0));
-#if ABSL_HAVE_THREAD_LOCAL
+#ifdef ABSL_HAVE_THREAD_LOCAL
thread_local ExponentialBiased eb_thread;
EXPECT_THAT(eb_thread.GetSkipCount(2), Ge(0));
#endif
diff --git a/absl/base/internal/sysinfo.cc b/absl/base/internal/sysinfo.cc
index 349d9268..4a3b2050 100644
--- a/absl/base/internal/sysinfo.cc
+++ b/absl/base/internal/sysinfo.cc
@@ -426,7 +426,7 @@ pid_t GetTID() {
// userspace construct) to avoid unnecessary system calls. Without this caching,
// it can take roughly 98ns, while it takes roughly 1ns with this caching.
pid_t GetCachedTID() {
-#if ABSL_HAVE_THREAD_LOCAL
+#ifdef ABSL_HAVE_THREAD_LOCAL
static thread_local pid_t thread_id = GetTID();
return thread_id;
#else
diff --git a/absl/container/internal/raw_hash_set.cc b/absl/container/internal/raw_hash_set.cc
index 919ac074..2f744a6e 100644
--- a/absl/container/internal/raw_hash_set.cc
+++ b/absl/container/internal/raw_hash_set.cc
@@ -27,7 +27,7 @@ constexpr size_t Group::kWidth;
// Returns "random" seed.
inline size_t RandomSeed() {
-#if ABSL_HAVE_THREAD_LOCAL
+#ifdef ABSL_HAVE_THREAD_LOCAL
static thread_local size_t counter = 0;
size_t value = ++counter;
#else // ABSL_HAVE_THREAD_LOCAL
diff --git a/absl/debugging/internal/address_is_readable.cc b/absl/debugging/internal/address_is_readable.cc
index 65376063..329c285f 100644
--- a/absl/debugging/internal/address_is_readable.cc
+++ b/absl/debugging/internal/address_is_readable.cc
@@ -68,6 +68,7 @@ static void Unpack(uint64_t x, int *pid, int *read_fd, int *write_fd) {
// unimplemented.
// This is a namespace-scoped variable for correct zero-initialization.
static std::atomic<uint64_t> pid_and_fds; // initially 0, an invalid pid.
+
bool AddressIsReadable(const void *addr) {
absl::base_internal::ErrnoSaver errno_saver;
// We test whether a byte is readable by using write(). Normally, this would
@@ -86,7 +87,7 @@ bool AddressIsReadable(const void *addr) {
int pid;
int read_fd;
int write_fd;
- uint64_t local_pid_and_fds = pid_and_fds.load(std::memory_order_relaxed);
+ uint64_t local_pid_and_fds = pid_and_fds.load(std::memory_order_acquire);
Unpack(local_pid_and_fds, &pid, &read_fd, &write_fd);
while (current_pid != pid) {
int p[2];
@@ -98,13 +99,13 @@ bool AddressIsReadable(const void *addr) {
fcntl(p[1], F_SETFD, FD_CLOEXEC);
uint64_t new_pid_and_fds = Pack(current_pid, p[0], p[1]);
if (pid_and_fds.compare_exchange_strong(
- local_pid_and_fds, new_pid_and_fds, std::memory_order_relaxed,
+ local_pid_and_fds, new_pid_and_fds, std::memory_order_release,
std::memory_order_relaxed)) {
local_pid_and_fds = new_pid_and_fds; // fds exposed to other threads
} else { // fds not exposed to other threads; we can close them.
close(p[0]);
close(p[1]);
- local_pid_and_fds = pid_and_fds.load(std::memory_order_relaxed);
+ local_pid_and_fds = pid_and_fds.load(std::memory_order_acquire);
}
Unpack(local_pid_and_fds, &pid, &read_fd, &write_fd);
}
@@ -124,7 +125,7 @@ bool AddressIsReadable(const void *addr) {
// If pid_and_fds contains the problematic file descriptors we just used,
// this call will forget them, and the loop will try again.
pid_and_fds.compare_exchange_strong(local_pid_and_fds, 0,
- std::memory_order_relaxed,
+ std::memory_order_release,
std::memory_order_relaxed);
}
} while (errno == EBADF);
diff --git a/absl/synchronization/internal/futex.h b/absl/synchronization/internal/futex.h
index 3539f491..06fbd6d0 100644
--- a/absl/synchronization/internal/futex.h
+++ b/absl/synchronization/internal/futex.h
@@ -38,6 +38,19 @@
#include "absl/base/optimization.h"
#include "absl/synchronization/internal/kernel_timeout.h"
+#ifdef ABSL_INTERNAL_HAVE_FUTEX
+#error ABSL_INTERNAL_HAVE_FUTEX may not be set on the command line
+#elif defined(__BIONIC__)
+// Bionic supports all the futex operations we need even when some of the futex
+// definitions are missing.
+#define ABSL_INTERNAL_HAVE_FUTEX
+#elif defined(__linux__) && defined(FUTEX_CLOCK_REALTIME)
+// FUTEX_CLOCK_REALTIME requires Linux >= 2.6.28.
+#define ABSL_INTERNAL_HAVE_FUTEX
+#endif
+
+#ifdef ABSL_INTERNAL_HAVE_FUTEX
+
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace synchronization_internal {
@@ -136,4 +149,6 @@ class Futex : public FutexImpl {};
ABSL_NAMESPACE_END
} // namespace absl
+#endif // ABSL_INTERNAL_HAVE_FUTEX
+
#endif // ABSL_SYNCHRONIZATION_INTERNAL_FUTEX_H_
diff --git a/absl/synchronization/internal/waiter.cc b/absl/synchronization/internal/waiter.cc
index c51855b0..2123be60 100644
--- a/absl/synchronization/internal/waiter.cc
+++ b/absl/synchronization/internal/waiter.cc
@@ -48,10 +48,6 @@
#include "absl/base/optimization.h"
#include "absl/synchronization/internal/kernel_timeout.h"
-#if ABSL_WAITER_MODE == ABSL_WAITER_MODE_FUTEX
-#include "absl/synchronization/internal/futex.h"
-#endif
-
namespace absl {
ABSL_NAMESPACE_BEGIN
diff --git a/absl/synchronization/internal/waiter.h b/absl/synchronization/internal/waiter.h
index 887f9b1b..be3df180 100644
--- a/absl/synchronization/internal/waiter.h
+++ b/absl/synchronization/internal/waiter.h
@@ -36,6 +36,7 @@
#include <cstdint>
#include "absl/base/internal/thread_identity.h"
+#include "absl/synchronization/internal/futex.h"
#include "absl/synchronization/internal/kernel_timeout.h"
// May be chosen at compile time via -DABSL_FORCE_WAITER_MODE=<index>
@@ -48,12 +49,7 @@
#define ABSL_WAITER_MODE ABSL_FORCE_WAITER_MODE
#elif defined(_WIN32) && _WIN32_WINNT >= _WIN32_WINNT_VISTA
#define ABSL_WAITER_MODE ABSL_WAITER_MODE_WIN32
-#elif defined(__BIONIC__)
-// Bionic supports all the futex operations we need even when some of the futex
-// definitions are missing.
-#define ABSL_WAITER_MODE ABSL_WAITER_MODE_FUTEX
-#elif defined(__linux__) && defined(FUTEX_CLOCK_REALTIME)
-// FUTEX_CLOCK_REALTIME requires Linux >= 2.6.28.
+#elif defined(ABSL_INTERNAL_HAVE_FUTEX)
#define ABSL_WAITER_MODE ABSL_WAITER_MODE_FUTEX
#elif defined(ABSL_HAVE_SEMAPHORE_H)
#define ABSL_WAITER_MODE ABSL_WAITER_MODE_SEM
diff --git a/absl/synchronization/mutex.cc b/absl/synchronization/mutex.cc
index 63f09408..9e01393c 100644
--- a/absl/synchronization/mutex.cc
+++ b/absl/synchronization/mutex.cc
@@ -50,6 +50,7 @@
#include "absl/base/internal/spinlock.h"
#include "absl/base/internal/sysinfo.h"
#include "absl/base/internal/thread_identity.h"
+#include "absl/base/internal/tsan_mutex_interface.h"
#include "absl/base/port.h"
#include "absl/debugging/stacktrace.h"
#include "absl/debugging/symbolize.h"
@@ -705,7 +706,7 @@ static constexpr bool kDebugMode = false;
static constexpr bool kDebugMode = true;
#endif
-#ifdef ABSL_HAVE_THREAD_SANITIZER
+#ifdef ABSL_INTERNAL_HAVE_TSAN_INTERFACE
static unsigned TsanFlags(Mutex::MuHow how) {
return how == kShared ? __tsan_mutex_read_lock : 0;
}
@@ -1767,7 +1768,7 @@ static inline bool EvalConditionAnnotated(const Condition *cond, Mutex *mu,
// All memory accesses are ignored inside of mutex operations + for unlock
// operation tsan considers that we've already released the mutex.
bool res = false;
-#ifdef ABSL_HAVE_THREAD_SANITIZER
+#ifdef ABSL_INTERNAL_HAVE_TSAN_INTERFACE
const int flags = read_lock ? __tsan_mutex_read_lock : 0;
const int tryflags = flags | (trylock ? __tsan_mutex_try_lock : 0);
#endif