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Diffstat (limited to 'src/gc/unix/gcenv.unix.cpp')
-rw-r--r-- | src/gc/unix/gcenv.unix.cpp | 627 |
1 files changed, 627 insertions, 0 deletions
diff --git a/src/gc/unix/gcenv.unix.cpp b/src/gc/unix/gcenv.unix.cpp new file mode 100644 index 0000000000..34a45b3cc1 --- /dev/null +++ b/src/gc/unix/gcenv.unix.cpp @@ -0,0 +1,627 @@ +// Licensed to the .NET Foundation under one or more agreements. +// The .NET Foundation licenses this file to you under the MIT license. +// See the LICENSE file in the project root for more information. + +#include <cstdint> +#include <cstddef> +#include <cassert> +#include <memory> + +// The CoreCLR PAL defines _POSIX_C_SOURCE to avoid calling non-posix pthread functions. +// This isn't something we want, because we're totally fine using non-posix functions. +#if defined(__APPLE__) + #define _DARWIN_C_SOURCE +#endif // definfed(__APPLE__) + +#include <pthread.h> +#include <signal.h> +#include "config.h" + +// clang typedefs uint64_t to be unsigned long long, which clashes with +// PAL/MSVC's unsigned long, causing linker errors. This ugly hack +// will go away once the GC doesn't depend on PAL headers. +typedef unsigned long uint64_t_hack; +#define uint64_t uint64_t_hack +static_assert(sizeof(uint64_t) == 8, "unsigned long isn't 8 bytes"); + +#ifndef __out_z +#define __out_z +#endif // __out_z + +#include "gcenv.structs.h" +#include "gcenv.base.h" +#include "gcenv.os.h" + +#ifndef FEATURE_STANDALONE_GC + #error "A GC-private implementation of GCToOSInterface should only be used with FEATURE_STANDALONE_GC" +#endif // FEATURE_STANDALONE_GC + +#ifdef HAVE_SYS_TIME_H + #include <sys/time.h> +#else + #error "sys/time.h required by GC PAL for the time being" +#endif // HAVE_SYS_TIME_ + +#ifdef HAVE_SYS_MMAN_H + #include <sys/mman.h> +#else + #error "sys/mman.h required by GC PAL" +#endif // HAVE_SYS_MMAN_H + +#ifdef __linux__ + #include <sys/syscall.h> +#endif // __linux__ + +#include <time.h> // nanosleep +#include <sched.h> // sched_yield +#include <errno.h> +#include <unistd.h> // sysconf + +// The number of milliseconds in a second. +static const int tccSecondsToMilliSeconds = 1000; + +// The number of microseconds in a second. +static const int tccSecondsToMicroSeconds = 1000000; + +// The number of microseconds in a millisecond. +static const int tccMilliSecondsToMicroSeconds = 1000; + +// The number of nanoseconds in a millisecond. +static const int tccMilliSecondsToNanoSeconds = 1000000; + +// The cachced number of logical CPUs observed. +static uint32_t g_logicalCpuCount = 0; + +// Helper memory page used by the FlushProcessWriteBuffers +static uint8_t g_helperPage[OS_PAGE_SIZE] __attribute__((aligned(OS_PAGE_SIZE))); + +// Mutex to make the FlushProcessWriteBuffersMutex thread safe +static pthread_mutex_t g_flushProcessWriteBuffersMutex; + +// Initialize the interface implementation +// Return: +// true if it has succeeded, false if it has failed +bool GCToOSInterface::Initialize() +{ + // Calculate and cache the number of processors on this machine + int cpuCount = sysconf(_SC_NPROCESSORS_ONLN); + if (cpuCount == -1) + { + return false; + } + + g_logicalCpuCount = cpuCount; + + // Verify that the s_helperPage is really aligned to the g_SystemInfo.dwPageSize + assert((((size_t)g_helperPage) & (OS_PAGE_SIZE - 1)) == 0); + + // Locking the page ensures that it stays in memory during the two mprotect + // calls in the FlushProcessWriteBuffers below. If the page was unmapped between + // those calls, they would not have the expected effect of generating IPI. + int status = mlock(g_helperPage, OS_PAGE_SIZE); + + if (status != 0) + { + return false; + } + + status = pthread_mutex_init(&g_flushProcessWriteBuffersMutex, NULL); + if (status != 0) + { + munlock(g_helperPage, OS_PAGE_SIZE); + return false; + } + + return true; +} + +// Shutdown the interface implementation +void GCToOSInterface::Shutdown() +{ + int ret = munlock(g_helperPage, OS_PAGE_SIZE); + assert(ret == 0); + ret = pthread_mutex_destroy(&g_flushProcessWriteBuffersMutex); + assert(ret == 0); +} + +// Get numeric id of the current thread if possible on the +// current platform. It is indended for logging purposes only. +// Return: +// Numeric id of the current thread, as best we can retrieve it. +uint64_t GCToOSInterface::GetCurrentThreadIdForLogging() +{ +#if defined(__linux__) + return (uint64_t)syscall(SYS_gettid); +#elif HAVE_PTHREAD_GETTHREADID_NP + return (uint64_t)pthread_getthreadid_np(); +#elif HAVE_PTHREAD_THREADID_NP + unsigned long long tid; + pthread_threadid_np(pthread_self(), &tid); + return (uint64_t)tid; +#else + // Fallback in case we don't know how to get integer thread id on the current platform + return (uint64_t)pthread_self(); +#endif +} + +// Get the process ID of the process. +uint32_t GCToOSInterface::GetCurrentProcessId() +{ + return getpid(); +} + +// Set ideal affinity for the current thread +// Parameters: +// affinity - ideal processor affinity for the thread +// Return: +// true if it has succeeded, false if it has failed +bool GCToOSInterface::SetCurrentThreadIdealAffinity(GCThreadAffinity* affinity) +{ + // TODO(segilles) + return false; +} + +// Get the number of the current processor +uint32_t GCToOSInterface::GetCurrentProcessorNumber() +{ +#if HAVE_SCHED_GETCPU + int processorNumber = sched_getcpu(); + assert(processorNumber != -1); + return processorNumber; +#else + return 0; +#endif +} + +// Check if the OS supports getting current processor number +bool GCToOSInterface::CanGetCurrentProcessorNumber() +{ + return HAVE_SCHED_GETCPU; +} + +// Flush write buffers of processors that are executing threads of the current process +void GCToOSInterface::FlushProcessWriteBuffers() +{ + int status = pthread_mutex_lock(&g_flushProcessWriteBuffersMutex); + assert(status == 0 && "Failed to lock the flushProcessWriteBuffersMutex lock"); + + // Changing a helper memory page protection from read / write to no access + // causes the OS to issue IPI to flush TLBs on all processors. This also + // results in flushing the processor buffers. + status = mprotect(g_helperPage, OS_PAGE_SIZE, PROT_READ | PROT_WRITE); + assert(status == 0 && "Failed to change helper page protection to read / write"); + + // Ensure that the page is dirty before we change the protection so that + // we prevent the OS from skipping the global TLB flush. + __sync_add_and_fetch((size_t*)g_helperPage, 1); + + status = mprotect(g_helperPage, OS_PAGE_SIZE, PROT_NONE); + assert(status == 0 && "Failed to change helper page protection to no access"); + + status = pthread_mutex_unlock(&g_flushProcessWriteBuffersMutex); + assert(status == 0 && "Failed to unlock the flushProcessWriteBuffersMutex lock"); +} + +// Break into a debugger. Uses a compiler intrinsic if one is available, +// otherwise raises a SIGTRAP. +void GCToOSInterface::DebugBreak() +{ + // __has_builtin is only defined by clang. GCC doesn't have a debug + // trap intrinsic anyway. +#ifndef __has_builtin + #define __has_builtin(x) 0 +#endif // __has_builtin + +#if __has_builtin(__builtin_debugtrap) + __builtin_debugtrap(); +#else + raise(SIGTRAP); +#endif +} + +// Get number of logical processors +uint32_t GCToOSInterface::GetLogicalCpuCount() +{ + return g_logicalCpuCount; +} + +// Causes the calling thread to sleep for the specified number of milliseconds +// Parameters: +// sleepMSec - time to sleep before switching to another thread +void GCToOSInterface::Sleep(uint32_t sleepMSec) +{ + if (sleepMSec == 0) + { + return; + } + + timespec requested; + requested.tv_sec = sleepMSec / tccSecondsToMilliSeconds; + requested.tv_nsec = (sleepMSec - requested.tv_sec * tccSecondsToMilliSeconds) * tccMilliSecondsToNanoSeconds; + + timespec remaining; + while (nanosleep(&requested, &remaining) == EINTR) + { + requested = remaining; + } +} + +// Causes the calling thread to yield execution to another thread that is ready to run on the current processor. +// Parameters: +// switchCount - number of times the YieldThread was called in a loop +void GCToOSInterface::YieldThread(uint32_t switchCount) +{ + int ret = sched_yield(); + + // sched_yield never fails on Linux, unclear about other OSes + assert(ret == 0); +} + +// Reserve virtual memory range. +// Parameters: +// size - size of the virtual memory range +// alignment - requested memory alignment, 0 means no specific alignment requested +// flags - flags to control special settings like write watching +// Return: +// Starting virtual address of the reserved range +void* GCToOSInterface::VirtualReserve(size_t size, size_t alignment, uint32_t flags) +{ + assert(!(flags & VirtualReserveFlags::WriteWatch) && "WriteWatch not supported on Unix"); + if (alignment == 0) + { + alignment = OS_PAGE_SIZE; + } + + size_t alignedSize = size + (alignment - OS_PAGE_SIZE); + void * pRetVal = mmap(nullptr, alignedSize, PROT_NONE, MAP_ANON | MAP_PRIVATE, -1, 0); + + if (pRetVal != NULL) + { + void * pAlignedRetVal = (void *)(((size_t)pRetVal + (alignment - 1)) & ~(alignment - 1)); + size_t startPadding = (size_t)pAlignedRetVal - (size_t)pRetVal; + if (startPadding != 0) + { + int ret = munmap(pRetVal, startPadding); + assert(ret == 0); + } + + size_t endPadding = alignedSize - (startPadding + size); + if (endPadding != 0) + { + int ret = munmap((void *)((size_t)pAlignedRetVal + size), endPadding); + assert(ret == 0); + } + + pRetVal = pAlignedRetVal; + } + + return pRetVal; +} + +// Release virtual memory range previously reserved using VirtualReserve +// Parameters: +// address - starting virtual address +// size - size of the virtual memory range +// Return: +// true if it has succeeded, false if it has failed +bool GCToOSInterface::VirtualRelease(void* address, size_t size) +{ + int ret = munmap(address, size); + + return (ret == 0); +} + +// Commit virtual memory range. It must be part of a range reserved using VirtualReserve. +// Parameters: +// address - starting virtual address +// size - size of the virtual memory range +// Return: +// true if it has succeeded, false if it has failed +bool GCToOSInterface::VirtualCommit(void* address, size_t size) +{ + return mprotect(address, size, PROT_WRITE | PROT_READ) == 0; +} + +// Decomit virtual memory range. +// Parameters: +// address - starting virtual address +// size - size of the virtual memory range +// Return: +// true if it has succeeded, false if it has failed +bool GCToOSInterface::VirtualDecommit(void* address, size_t size) +{ + return mprotect(address, size, PROT_NONE) == 0; +} + +// Reset virtual memory range. Indicates that data in the memory range specified by address and size is no +// longer of interest, but it should not be decommitted. +// Parameters: +// address - starting virtual address +// size - size of the virtual memory range +// unlock - true if the memory range should also be unlocked +// Return: +// true if it has succeeded, false if it has failed +bool GCToOSInterface::VirtualReset(void * address, size_t size, bool unlock) +{ + // TODO(CoreCLR#1259) pipe to madvise? + return false; +} + +// Check if the OS supports write watching +bool GCToOSInterface::SupportsWriteWatch() +{ + return false; +} + +// Reset the write tracking state for the specified virtual memory range. +// Parameters: +// address - starting virtual address +// size - size of the virtual memory range +void GCToOSInterface::ResetWriteWatch(void* address, size_t size) +{ + assert(!"should never call ResetWriteWatch on Unix"); +} + +// Retrieve addresses of the pages that are written to in a region of virtual memory +// Parameters: +// resetState - true indicates to reset the write tracking state +// address - starting virtual address +// size - size of the virtual memory range +// pageAddresses - buffer that receives an array of page addresses in the memory region +// pageAddressesCount - on input, size of the lpAddresses array, in array elements +// on output, the number of page addresses that are returned in the array. +// Return: +// true if it has succeeded, false if it has failed +bool GCToOSInterface::GetWriteWatch(bool resetState, void* address, size_t size, void** pageAddresses, uintptr_t* pageAddressesCount) +{ + assert(!"should never call GetWriteWatch on Unix"); + return false; +} + +// Get size of the largest cache on the processor die +// Parameters: +// trueSize - true to return true cache size, false to return scaled up size based on +// the processor architecture +// Return: +// Size of the cache +size_t GCToOSInterface::GetLargestOnDieCacheSize(bool trueSize) +{ + // TODO(segilles) processor detection + return 0; +} + +// Get affinity mask of the current process +// Parameters: +// processMask - affinity mask for the specified process +// systemMask - affinity mask for the system +// Return: +// true if it has succeeded, false if it has failed +// Remarks: +// A process affinity mask is a bit vector in which each bit represents the processors that +// a process is allowed to run on. A system affinity mask is a bit vector in which each bit +// represents the processors that are configured into a system. +// A process affinity mask is a subset of the system affinity mask. A process is only allowed +// to run on the processors configured into a system. Therefore, the process affinity mask cannot +// specify a 1 bit for a processor when the system affinity mask specifies a 0 bit for that processor. +bool GCToOSInterface::GetCurrentProcessAffinityMask(uintptr_t* processMask, uintptr_t* systemMask) +{ + // TODO(segilles) processor detection + return false; +} + +// Get number of processors assigned to the current process +// Return: +// The number of processors +uint32_t GCToOSInterface::GetCurrentProcessCpuCount() +{ + return g_logicalCpuCount; +} + +// Return the size of the user-mode portion of the virtual address space of this process. +// Return: +// non zero if it has succeeded, 0 if it has failed +size_t GCToOSInterface::GetVirtualMemoryLimit() +{ +#ifdef BIT64 + // There is no API to get the total virtual address space size on + // Unix, so we use a constant value representing 128TB, which is + // the approximate size of total user virtual address space on + // the currently supported Unix systems. + static const uint64_t _128TB = (1ull << 47); + return _128TB; +#else + return (size_t)-1; +#endif +} + +// Get the physical memory that this process can use. +// Return: +// non zero if it has succeeded, 0 if it has failed +// Remarks: +// If a process runs with a restricted memory limit, it returns the limit. If there's no limit +// specified, it returns amount of actual physical memory. +uint64_t GCToOSInterface::GetPhysicalMemoryLimit() +{ + long pages = sysconf(_SC_PHYS_PAGES); + if (pages == -1) + { + return 0; + } + + long pageSize = sysconf(_SC_PAGE_SIZE); + if (pageSize == -1) + { + return 0; + } + + return pages * pageSize; +} + +// Get memory status +// Parameters: +// memory_load - A number between 0 and 100 that specifies the approximate percentage of physical memory +// that is in use (0 indicates no memory use and 100 indicates full memory use). +// available_physical - The amount of physical memory currently available, in bytes. +// available_page_file - The maximum amount of memory the current process can commit, in bytes. +void GCToOSInterface::GetMemoryStatus(uint32_t* memory_load, uint64_t* available_physical, uint64_t* available_page_file) +{ + if (memory_load != nullptr || available_physical != nullptr) + { + uint64_t total = GetPhysicalMemoryLimit(); + + uint64_t available = 0; + uint32_t load = 0; + + // Get the physical memory in use - from it, we can get the physical memory available. + // We do this only when we have the total physical memory available. + if (total > 0) + { + available = sysconf(_SC_PHYS_PAGES) * sysconf(_SC_PAGE_SIZE); + uint64_t used = total - available; + load = (uint32_t)((used * 100) / total); + } + + if (memory_load != nullptr) + *memory_load = load; + if (available_physical != nullptr) + *available_physical = available; + } + + if (available_page_file != nullptr) + *available_page_file = 0; +} + +// Get a high precision performance counter +// Return: +// The counter value +int64_t GCToOSInterface::QueryPerformanceCounter() +{ + // TODO: This is not a particularly efficient implementation - we certainly could + // do much more specific platform-dependent versions if we find that this method + // runs hot. However, most likely it does not. + struct timeval tv; + if (gettimeofday(&tv, NULL) == -1) + { + assert(!"gettimeofday() failed"); + // TODO (segilles) unconditional asserts + return 0; + } + return (int64_t) tv.tv_sec * (int64_t) tccSecondsToMicroSeconds + (int64_t) tv.tv_usec; +} + +// Get a frequency of the high precision performance counter +// Return: +// The counter frequency +int64_t GCToOSInterface::QueryPerformanceFrequency() +{ + // The counter frequency of gettimeofday is in microseconds. + return tccSecondsToMicroSeconds; +} + +// Get a time stamp with a low precision +// Return: +// Time stamp in milliseconds +uint32_t GCToOSInterface::GetLowPrecisionTimeStamp() +{ + // TODO(segilles) this is pretty naive, we can do better + uint64_t retval = 0; + struct timeval tv; + if (gettimeofday(&tv, NULL) == 0) + { + retval = (tv.tv_sec * tccSecondsToMilliSeconds) + (tv.tv_usec / tccMilliSecondsToMicroSeconds); + } + else + { + assert(!"gettimeofday() failed\n"); + } + + return retval; +} + +// Parameters of the GC thread stub +struct GCThreadStubParam +{ + GCThreadFunction GCThreadFunction; + void* GCThreadParam; +}; + +// GC thread stub to convert GC thread function to an OS specific thread function +static void* GCThreadStub(void* param) +{ + GCThreadStubParam *stubParam = (GCThreadStubParam*)param; + GCThreadFunction function = stubParam->GCThreadFunction; + void* threadParam = stubParam->GCThreadParam; + + delete stubParam; + + function(threadParam); + + return NULL; +} + +// Create a new thread for GC use +// Parameters: +// function - the function to be executed by the thread +// param - parameters of the thread +// affinity - processor affinity of the thread +// Return: +// true if it has succeeded, false if it has failed +bool GCToOSInterface::CreateThread(GCThreadFunction function, void* param, GCThreadAffinity* affinity) +{ + std::unique_ptr<GCThreadStubParam> stubParam(new (std::nothrow) GCThreadStubParam()); + if (!stubParam) + { + return false; + } + + stubParam->GCThreadFunction = function; + stubParam->GCThreadParam = param; + + pthread_attr_t attrs; + + int st = pthread_attr_init(&attrs); + assert(st == 0); + + // Create the thread as detached, that means not joinable + st = pthread_attr_setdetachstate(&attrs, PTHREAD_CREATE_DETACHED); + assert(st == 0); + + pthread_t threadId; + st = pthread_create(&threadId, &attrs, GCThreadStub, stubParam.get()); + + if (st == 0) + { + stubParam.release(); + } + + int st2 = pthread_attr_destroy(&attrs); + assert(st2 == 0); + + return (st == 0); +} + +// Initialize the critical section +void CLRCriticalSection::Initialize() +{ + int st = pthread_mutex_init(&m_cs.mutex, NULL); + assert(st == 0); +} + +// Destroy the critical section +void CLRCriticalSection::Destroy() +{ + int st = pthread_mutex_destroy(&m_cs.mutex); + assert(st == 0); +} + +// Enter the critical section. Blocks until the section can be entered. +void CLRCriticalSection::Enter() +{ + pthread_mutex_lock(&m_cs.mutex); +} + +// Leave the critical section +void CLRCriticalSection::Leave() +{ + pthread_mutex_unlock(&m_cs.mutex); +} |