| // Copyright (c) 2016, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| #include "platform/globals.h" |
| #if defined(DART_HOST_OS_FUCHSIA) |
| |
| #include "vm/thread_interrupter.h" |
| |
| #include <zircon/process.h> |
| #include <zircon/status.h> |
| #include <zircon/syscalls.h> |
| #include <zircon/syscalls/debug.h> |
| #include <zircon/syscalls/object.h> |
| #include <zircon/types.h> |
| |
| #include "vm/flags.h" |
| #include "vm/instructions.h" |
| #include "vm/os.h" |
| #include "vm/profiler.h" |
| |
| namespace dart { |
| |
| #ifndef PRODUCT |
| |
| DECLARE_FLAG(bool, trace_thread_interrupter); |
| |
| // TODO(ZX-430): Currently, CPU profiling for Fuchsia is arranged very similarly |
| // to our Windows profiling. That is, the interrupter thread iterates over |
| // all threads, suspends them, samples various things, and then resumes them. |
| // When ZX-430 is resolved, the code below should be rewritten to use whatever |
| // feature is added for it. |
| |
| // A scope within which a target thread is suspended. When the scope is exited, |
| // the thread is resumed and its handle is closed. |
| class ThreadSuspendScope { |
| public: |
| explicit ThreadSuspendScope(zx_handle_t thread_handle) |
| : thread_handle_(thread_handle), suspend_token_(ZX_HANDLE_INVALID) { |
| zx_status_t status = zx_task_suspend_token(thread_handle, &suspend_token_); |
| // If a thread is somewhere where suspend is impossible, zx_task_suspend() |
| // can return ZX_ERR_NOT_SUPPORTED. |
| if (status != ZX_OK) { |
| if (FLAG_trace_thread_interrupter) { |
| OS::PrintErr("ThreadInterrupter: zx_task_suspend failed: %s\n", |
| zx_status_get_string(status)); |
| } |
| } |
| } |
| |
| ~ThreadSuspendScope() { |
| if (suspend_token_ != ZX_HANDLE_INVALID) { |
| zx_handle_close(suspend_token_); |
| } |
| zx_handle_close(thread_handle_); |
| } |
| |
| bool suspended() const { return suspend_token_ != ZX_HANDLE_INVALID; } |
| |
| private: |
| zx_handle_t thread_handle_; |
| zx_handle_t suspend_token_; // ZX_HANDLE_INVALID when not suspended. |
| |
| DISALLOW_ALLOCATION(); |
| DISALLOW_COPY_AND_ASSIGN(ThreadSuspendScope); |
| }; |
| |
| class ThreadInterrupterFuchsia : public AllStatic { |
| public: |
| static bool GrabRegisters(zx_handle_t thread, InterruptedThreadState* state) { |
| zx_thread_state_general_regs_t regs; |
| zx_status_t status = zx_thread_read_state( |
| thread, ZX_THREAD_STATE_GENERAL_REGS, ®s, sizeof(regs)); |
| if (status != ZX_OK) { |
| if (FLAG_trace_thread_interrupter) { |
| OS::PrintErr("ThreadInterrupter failed to get registers: %s\n", |
| zx_status_get_string(status)); |
| } |
| return false; |
| } |
| #if defined(TARGET_ARCH_X64) |
| state->pc = static_cast<uintptr_t>(regs.rip); |
| state->fp = static_cast<uintptr_t>(regs.rbp); |
| state->csp = static_cast<uintptr_t>(regs.rsp); |
| state->dsp = static_cast<uintptr_t>(regs.rsp); |
| state->lr = 0; |
| #elif defined(TARGET_ARCH_ARM64) |
| state->pc = static_cast<uintptr_t>(regs.pc); |
| state->fp = static_cast<uintptr_t>(regs.r[FPREG]); |
| state->csp = static_cast<uintptr_t>(regs.sp); |
| state->dsp = static_cast<uintptr_t>(regs.r[SPREG]); |
| state->lr = static_cast<uintptr_t>(regs.lr); |
| #elif defined(TARGET_ARCH_RISCV64) |
| state->pc = static_cast<uintptr_t>(regs.pc); |
| state->fp = static_cast<uintptr_t>(regs.r[FPREG]); |
| state->csp = static_cast<uintptr_t>(regs.r[SPREG]); |
| state->dsp = static_cast<uintptr_t>(regs.r[SPREG]); |
| state->lr = static_cast<uintptr_t>(regs.r[LINK_REGISTER]); |
| #else |
| #error "Unsupported architecture" |
| #endif |
| return true; |
| } |
| |
| static void Interrupt(OSThread* os_thread) { |
| ASSERT(os_thread->id() != ZX_KOID_INVALID); |
| ASSERT(!OSThread::Compare(OSThread::GetCurrentThreadId(), os_thread->id())); |
| zx_status_t status; |
| |
| // Get a handle on the target thread. |
| const zx_koid_t target_thread_koid = os_thread->id(); |
| if (FLAG_trace_thread_interrupter) { |
| OS::PrintErr("ThreadInterrupter: interrupting thread with koid=%ld\n", |
| target_thread_koid); |
| } |
| zx_handle_t target_thread_handle; |
| status = zx_object_get_child(zx_process_self(), target_thread_koid, |
| ZX_RIGHT_SAME_RIGHTS, &target_thread_handle); |
| if (status != ZX_OK) { |
| if (FLAG_trace_thread_interrupter) { |
| OS::PrintErr("ThreadInterrupter: zx_object_get_child failed: %s\n", |
| zx_status_get_string(status)); |
| } |
| return; |
| } |
| if (target_thread_handle == ZX_HANDLE_INVALID) { |
| if (FLAG_trace_thread_interrupter) { |
| OS::PrintErr( |
| "ThreadInterrupter: zx_object_get_child gave an invalid " |
| "thread handle!"); |
| } |
| return; |
| } |
| |
| // This scope suspends the thread. When we exit the scope, the thread is |
| // resumed, and the thread handle is closed. |
| ThreadSuspendScope tss(target_thread_handle); |
| if (!tss.suspended()) { |
| return; |
| } |
| |
| // Check that the thread is suspended. |
| status = PollThreadUntilSuspended(target_thread_handle); |
| if (status != ZX_OK) { |
| return; |
| } |
| |
| // Grab the target thread's registers. |
| InterruptedThreadState its; |
| if (!GrabRegisters(target_thread_handle, &its)) { |
| return; |
| } |
| // Currently we sample only threads that are associated |
| // with an isolate. It is safe to call 'os_thread->thread()' |
| // here as the thread which is being queried is suspended. |
| Thread* thread = static_cast<Thread*>(os_thread->thread()); |
| if (thread != nullptr) { |
| ThreadInterruptScope signal_handler_scope; |
| Profiler::SampleThread(thread, its); |
| } |
| } |
| |
| private: |
| static const char* ThreadStateGetString(uint32_t state) { |
| // TODO(dje): This #ifdef is temporary to handle the transition. |
| // It can be deleted once the new version of zircon rolls out. |
| #ifdef ZX_THREAD_STATE_BASIC |
| state = ZX_THREAD_STATE_BASIC(state); |
| #endif |
| switch (state) { |
| case ZX_THREAD_STATE_NEW: |
| return "ZX_THREAD_STATE_NEW"; |
| case ZX_THREAD_STATE_RUNNING: |
| return "ZX_THREAD_STATE_RUNNING"; |
| case ZX_THREAD_STATE_SUSPENDED: |
| return "ZX_THREAD_STATE_SUSPENDED"; |
| case ZX_THREAD_STATE_BLOCKED: |
| return "ZX_THREAD_STATE_BLOCKED"; |
| case ZX_THREAD_STATE_DYING: |
| return "ZX_THREAD_STATE_DYING"; |
| case ZX_THREAD_STATE_DEAD: |
| return "ZX_THREAD_STATE_DEAD"; |
| default: |
| return "<Unknown>"; |
| } |
| } |
| |
| static zx_status_t PollThreadUntilSuspended(zx_handle_t thread_handle) { |
| const intptr_t kMaxPollAttempts = 10; |
| intptr_t poll_tries = 0; |
| while (poll_tries < kMaxPollAttempts) { |
| zx_info_thread_t thread_info; |
| zx_status_t status = |
| zx_object_get_info(thread_handle, ZX_INFO_THREAD, &thread_info, |
| sizeof(thread_info), nullptr, nullptr); |
| poll_tries++; |
| if (status != ZX_OK) { |
| if (FLAG_trace_thread_interrupter) { |
| OS::PrintErr("ThreadInterrupter: zx_object_get_info failed: %s\n", |
| zx_status_get_string(status)); |
| } |
| return status; |
| } |
| if (thread_info.state == ZX_THREAD_STATE_SUSPENDED) { |
| // Success. |
| return ZX_OK; |
| } |
| if (thread_info.state == ZX_THREAD_STATE_RUNNING) { |
| // Poll. |
| continue; |
| } |
| if (FLAG_trace_thread_interrupter) { |
| OS::PrintErr("ThreadInterrupter: Thread is not suspended: %s\n", |
| ThreadStateGetString(thread_info.state)); |
| } |
| return ZX_ERR_BAD_STATE; |
| } |
| if (FLAG_trace_thread_interrupter) { |
| OS::PrintErr("ThreadInterrupter: Exceeded max suspend poll tries\n"); |
| } |
| return ZX_ERR_BAD_STATE; |
| } |
| }; |
| |
| void ThreadInterrupter::InterruptThread(OSThread* thread) { |
| if (FLAG_trace_thread_interrupter) { |
| OS::PrintErr("ThreadInterrupter suspending %p\n", |
| reinterpret_cast<void*>(thread->id())); |
| } |
| ThreadInterrupterFuchsia::Interrupt(thread); |
| if (FLAG_trace_thread_interrupter) { |
| OS::PrintErr("ThreadInterrupter resuming %p\n", |
| reinterpret_cast<void*>(thread->id())); |
| } |
| } |
| |
| void ThreadInterrupter::InstallSignalHandler() { |
| // Nothing to do on Fuchsia. |
| } |
| |
| void ThreadInterrupter::RemoveSignalHandler() { |
| // Nothing to do on Fuchsia. |
| } |
| |
| #endif // !PRODUCT |
| |
| } // namespace dart |
| |
| #endif // defined(DART_HOST_OS_FUCHSIA) |