diff options
Diffstat (limited to 'absl/base/internal')
-rw-r--r-- | absl/base/internal/spinlock_akaros.inc | 35 | ||||
-rw-r--r-- | absl/base/internal/spinlock_wait.cc | 2 | ||||
-rw-r--r-- | absl/base/internal/sysinfo.cc | 24 |
3 files changed, 61 insertions, 0 deletions
diff --git a/absl/base/internal/spinlock_akaros.inc b/absl/base/internal/spinlock_akaros.inc new file mode 100644 index 00000000..051c8cf8 --- /dev/null +++ b/absl/base/internal/spinlock_akaros.inc @@ -0,0 +1,35 @@ +// Copyright 2017 The Abseil Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. +// +// This file is an Akaros-specific part of spinlock_wait.cc + +#include <atomic> + +#include "absl/base/internal/scheduling_mode.h" + +extern "C" { + +ABSL_ATTRIBUTE_WEAK void AbslInternalSpinLockDelay( + std::atomic<uint32_t>* /* lock_word */, uint32_t /* value */, + int /* loop */, absl::base_internal::SchedulingMode /* mode */) { + // In Akaros, one must take care not to call anything that could cause a + // malloc(), a blocking system call, or a uthread_yield() while holding a + // spinlock. Our callers assume will not call into libraries or other + // arbitrary code. +} + +ABSL_ATTRIBUTE_WEAK void AbslInternalSpinLockWake( + std::atomic<uint32_t>* /* lock_word */, bool /* all */) {} + +} // extern "C" diff --git a/absl/base/internal/spinlock_wait.cc b/absl/base/internal/spinlock_wait.cc index 0fd36286..8f951b66 100644 --- a/absl/base/internal/spinlock_wait.cc +++ b/absl/base/internal/spinlock_wait.cc @@ -23,6 +23,8 @@ #if defined(_WIN32) #include "absl/base/internal/spinlock_win32.inc" +#elif defined(__akaros__) +#include "absl/base/internal/spinlock_akaros.inc" #else #include "absl/base/internal/spinlock_posix.inc" #endif diff --git a/absl/base/internal/sysinfo.cc b/absl/base/internal/sysinfo.cc index 9e0140fa..00e98b66 100644 --- a/absl/base/internal/sysinfo.cc +++ b/absl/base/internal/sysinfo.cc @@ -284,6 +284,30 @@ pid_t GetTID() { return syscall(SYS_gettid); } +#elif defined(__akaros__) + +pid_t GetTID() { + // Akaros has a concept of "vcore context", which is the state the program + // is forced into when we need to make a user-level scheduling decision, or + // run a signal handler. This is analogous to the interrupt context that a + // CPU might enter if it encounters some kind of exception. + // + // There is no current thread context in vcore context, but we need to give + // a reasonable answer if asked for a thread ID (e.g., in a signal handler). + // Thread 0 always exists, so if we are in vcore context, we return that. + // + // Otherwise, we know (since we are using pthreads) that the uthread struct + // current_uthread is pointing to is the first element of a + // struct pthread_tcb, so we extract and return the thread ID from that. + // + // TODO(dcross): Akaros anticipates moving the thread ID to the uthread + // structure at some point. We should modify this code to remove the cast + // when that happens. + if (in_vcore_context()) + return 0; + return reinterpret_cast<struct pthread_tcb *>(current_uthread)->id; +} + #else // Fallback implementation of GetTID using pthread_getspecific. |