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-rw-r--r--lib/xray/xray_log_interface.cpp209
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diff --git a/lib/xray/xray_log_interface.cpp b/lib/xray/xray_log_interface.cpp
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+//===-- xray_log_interface.cpp --------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of XRay, a function call tracing system.
+//
+//===----------------------------------------------------------------------===//
+#include "xray/xray_log_interface.h"
+
+#include "sanitizer_common/sanitizer_allocator_internal.h"
+#include "sanitizer_common/sanitizer_atomic.h"
+#include "sanitizer_common/sanitizer_mutex.h"
+#include "xray/xray_interface.h"
+#include "xray_defs.h"
+
+namespace __xray {
+static SpinMutex XRayImplMutex;
+static XRayLogImpl CurrentXRayImpl{nullptr, nullptr, nullptr, nullptr};
+static XRayLogImpl *GlobalXRayImpl = nullptr;
+
+// This is the default implementation of a buffer iterator, which always yields
+// a null buffer.
+XRayBuffer NullBufferIterator(XRayBuffer) XRAY_NEVER_INSTRUMENT {
+ return {nullptr, 0};
+}
+
+// This is the global function responsible for iterating through given buffers.
+atomic_uintptr_t XRayBufferIterator{
+ reinterpret_cast<uintptr_t>(&NullBufferIterator)};
+
+// We use a linked list of Mode to XRayLogImpl mappings. This is a linked list
+// when it should be a map because we're avoiding having to depend on C++
+// standard library data structures at this level of the implementation.
+struct ModeImpl {
+ ModeImpl *Next;
+ const char *Mode;
+ XRayLogImpl Impl;
+};
+
+static ModeImpl SentinelModeImpl{
+ nullptr, nullptr, {nullptr, nullptr, nullptr, nullptr}};
+static ModeImpl *ModeImpls = &SentinelModeImpl;
+static const ModeImpl *CurrentMode = nullptr;
+
+} // namespace __xray
+
+using namespace __xray;
+
+void __xray_log_set_buffer_iterator(XRayBuffer (*Iterator)(XRayBuffer))
+ XRAY_NEVER_INSTRUMENT {
+ atomic_store(&__xray::XRayBufferIterator,
+ reinterpret_cast<uintptr_t>(Iterator), memory_order_release);
+}
+
+void __xray_log_remove_buffer_iterator() XRAY_NEVER_INSTRUMENT {
+ __xray_log_set_buffer_iterator(&NullBufferIterator);
+}
+
+XRayLogRegisterStatus
+__xray_log_register_mode(const char *Mode,
+ XRayLogImpl Impl) XRAY_NEVER_INSTRUMENT {
+ if (Impl.flush_log == nullptr || Impl.handle_arg0 == nullptr ||
+ Impl.log_finalize == nullptr || Impl.log_init == nullptr)
+ return XRayLogRegisterStatus::XRAY_INCOMPLETE_IMPL;
+
+ SpinMutexLock Guard(&XRayImplMutex);
+ // First, look for whether the mode already has a registered implementation.
+ for (ModeImpl *it = ModeImpls; it != &SentinelModeImpl; it = it->Next) {
+ if (!internal_strcmp(Mode, it->Mode))
+ return XRayLogRegisterStatus::XRAY_DUPLICATE_MODE;
+ }
+ auto *NewModeImpl = static_cast<ModeImpl *>(InternalAlloc(sizeof(ModeImpl)));
+ NewModeImpl->Next = ModeImpls;
+ NewModeImpl->Mode = internal_strdup(Mode);
+ NewModeImpl->Impl = Impl;
+ ModeImpls = NewModeImpl;
+ return XRayLogRegisterStatus::XRAY_REGISTRATION_OK;
+}
+
+XRayLogRegisterStatus
+__xray_log_select_mode(const char *Mode) XRAY_NEVER_INSTRUMENT {
+ SpinMutexLock Guard(&XRayImplMutex);
+ for (ModeImpl *it = ModeImpls; it != &SentinelModeImpl; it = it->Next) {
+ if (!internal_strcmp(Mode, it->Mode)) {
+ CurrentMode = it;
+ CurrentXRayImpl = it->Impl;
+ GlobalXRayImpl = &CurrentXRayImpl;
+ __xray_set_handler(it->Impl.handle_arg0);
+ return XRayLogRegisterStatus::XRAY_REGISTRATION_OK;
+ }
+ }
+ return XRayLogRegisterStatus::XRAY_MODE_NOT_FOUND;
+}
+
+const char *__xray_log_get_current_mode() XRAY_NEVER_INSTRUMENT {
+ SpinMutexLock Guard(&XRayImplMutex);
+ if (CurrentMode != nullptr)
+ return CurrentMode->Mode;
+ return nullptr;
+}
+
+void __xray_set_log_impl(XRayLogImpl Impl) XRAY_NEVER_INSTRUMENT {
+ if (Impl.log_init == nullptr || Impl.log_finalize == nullptr ||
+ Impl.handle_arg0 == nullptr || Impl.flush_log == nullptr) {
+ SpinMutexLock Guard(&XRayImplMutex);
+ GlobalXRayImpl = nullptr;
+ CurrentMode = nullptr;
+ __xray_remove_handler();
+ __xray_remove_handler_arg1();
+ return;
+ }
+
+ SpinMutexLock Guard(&XRayImplMutex);
+ CurrentXRayImpl = Impl;
+ GlobalXRayImpl = &CurrentXRayImpl;
+ __xray_set_handler(Impl.handle_arg0);
+}
+
+void __xray_remove_log_impl() XRAY_NEVER_INSTRUMENT {
+ SpinMutexLock Guard(&XRayImplMutex);
+ GlobalXRayImpl = nullptr;
+ __xray_remove_handler();
+ __xray_remove_handler_arg1();
+}
+
+XRayLogInitStatus __xray_log_init(size_t BufferSize, size_t MaxBuffers,
+ void *Args,
+ size_t ArgsSize) XRAY_NEVER_INSTRUMENT {
+ SpinMutexLock Guard(&XRayImplMutex);
+ if (!GlobalXRayImpl)
+ return XRayLogInitStatus::XRAY_LOG_UNINITIALIZED;
+ return GlobalXRayImpl->log_init(BufferSize, MaxBuffers, Args, ArgsSize);
+}
+
+XRayLogInitStatus __xray_log_init_mode(const char *Mode, const char *Config)
+ XRAY_NEVER_INSTRUMENT {
+ SpinMutexLock Guard(&XRayImplMutex);
+ if (!GlobalXRayImpl)
+ return XRayLogInitStatus::XRAY_LOG_UNINITIALIZED;
+
+ if (Config == nullptr)
+ return XRayLogInitStatus::XRAY_LOG_UNINITIALIZED;
+
+ // Check first whether the current mode is the same as what we expect.
+ if (CurrentMode == nullptr || internal_strcmp(CurrentMode->Mode, Mode) != 0)
+ return XRayLogInitStatus::XRAY_LOG_UNINITIALIZED;
+
+ // Here we do some work to coerce the pointer we're provided, so that
+ // the implementations that still take void* pointers can handle the
+ // data provided in the Config argument.
+ return GlobalXRayImpl->log_init(
+ 0, 0, const_cast<void *>(static_cast<const void *>(Config)), 0);
+}
+
+XRayLogInitStatus
+__xray_log_init_mode_bin(const char *Mode, const char *Config,
+ size_t ConfigSize) XRAY_NEVER_INSTRUMENT {
+ SpinMutexLock Guard(&XRayImplMutex);
+ if (!GlobalXRayImpl)
+ return XRayLogInitStatus::XRAY_LOG_UNINITIALIZED;
+
+ if (Config == nullptr)
+ return XRayLogInitStatus::XRAY_LOG_UNINITIALIZED;
+
+ // Check first whether the current mode is the same as what we expect.
+ if (CurrentMode == nullptr || internal_strcmp(CurrentMode->Mode, Mode) != 0)
+ return XRayLogInitStatus::XRAY_LOG_UNINITIALIZED;
+
+ // Here we do some work to coerce the pointer we're provided, so that
+ // the implementations that still take void* pointers can handle the
+ // data provided in the Config argument.
+ return GlobalXRayImpl->log_init(
+ 0, 0, const_cast<void *>(static_cast<const void *>(Config)), ConfigSize);
+}
+
+XRayLogInitStatus __xray_log_finalize() XRAY_NEVER_INSTRUMENT {
+ SpinMutexLock Guard(&XRayImplMutex);
+ if (!GlobalXRayImpl)
+ return XRayLogInitStatus::XRAY_LOG_UNINITIALIZED;
+ return GlobalXRayImpl->log_finalize();
+}
+
+XRayLogFlushStatus __xray_log_flushLog() XRAY_NEVER_INSTRUMENT {
+ SpinMutexLock Guard(&XRayImplMutex);
+ if (!GlobalXRayImpl)
+ return XRayLogFlushStatus::XRAY_LOG_NOT_FLUSHING;
+ return GlobalXRayImpl->flush_log();
+}
+
+XRayLogFlushStatus __xray_log_process_buffers(
+ void (*Processor)(const char *, XRayBuffer)) XRAY_NEVER_INSTRUMENT {
+ // We want to make sure that there will be no changes to the global state for
+ // the log by synchronising on the XRayBufferIteratorMutex.
+ if (!GlobalXRayImpl)
+ return XRayLogFlushStatus::XRAY_LOG_NOT_FLUSHING;
+ auto Iterator = reinterpret_cast<XRayBuffer (*)(XRayBuffer)>(
+ atomic_load(&XRayBufferIterator, memory_order_acquire));
+ auto Buffer = (*Iterator)(XRayBuffer{nullptr, 0});
+ auto Mode = CurrentMode ? CurrentMode->Mode : nullptr;
+ while (Buffer.Data != nullptr) {
+ (*Processor)(Mode, Buffer);
+ Buffer = (*Iterator)(Buffer);
+ }
+ return XRayLogFlushStatus::XRAY_LOG_FLUSHED;
+}