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//===-- xray_log_interface.cc ---------------------------------------------===//
//
// 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;
}
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