/* Copyright (C) 2008-2015 Free Software Foundation, Inc. Contributed by Richard Henderson <rth@redhat.com>. This file is part of the GNU Transactional Memory Library (libitm). Libitm is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. Libitm is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. Under Section 7 of GPL version 3, you are granted additional permissions described in the GCC Runtime Library Exception, version 3.1, as published by the Free Software Foundation. You should have received a copy of the GNU General Public License and a copy of the GCC Runtime Library Exception along with this program; see the files COPYING3 and COPYING.RUNTIME respectively. If not, see <http://www.gnu.org/licenses/>. */ /* The following are internal implementation functions and definitions. To distinguish them from those defined by the Intel ABI, they all begin with GTM/gtm. */ #ifndef LIBITM_I_H #define LIBITM_I_H 1 #include "libitm.h" #include "config.h" #include <assert.h> #include <stdlib.h> #include <string.h> #include <unwind.h> #include "local_type_traits" #include "local_atomic" /* Don't require libgcc_s.so for exceptions. */ extern void _Unwind_DeleteException (_Unwind_Exception*) __attribute__((weak)); #include "common.h" namespace GTM HIDDEN { using namespace std; // A helper template for accessing an unsigned integral of SIZE bytes. template<size_t SIZE> struct sized_integral { }; template<> struct sized_integral<1> { typedef uint8_t type; }; template<> struct sized_integral<2> { typedef uint16_t type; }; template<> struct sized_integral<4> { typedef uint32_t type; }; template<> struct sized_integral<8> { typedef uint64_t type; }; typedef unsigned int gtm_word __attribute__((mode (word))); // These values are given to GTM_restart_transaction and indicate the // reason for the restart. The reason is used to decide what STM // implementation should be used during the next iteration. enum gtm_restart_reason { RESTART_REALLOCATE, RESTART_LOCKED_READ, RESTART_LOCKED_WRITE, RESTART_VALIDATE_READ, RESTART_VALIDATE_WRITE, RESTART_VALIDATE_COMMIT, RESTART_SERIAL_IRR, RESTART_NOT_READONLY, RESTART_CLOSED_NESTING, RESTART_INIT_METHOD_GROUP, NUM_RESTARTS, NO_RESTART = NUM_RESTARTS }; } // namespace GTM #include "target.h" #include "rwlock.h" #include "aatree.h" #include "cacheline.h" #include "stmlock.h" #include "dispatch.h" #include "containers.h" #ifdef __USER_LABEL_PREFIX__ # define UPFX UPFX1(__USER_LABEL_PREFIX__) # define UPFX1(t) UPFX2(t) # define UPFX2(t) #t #else # define UPFX #endif namespace GTM HIDDEN { // This type is private to alloc.c, but needs to be defined so that // the template used inside gtm_thread can instantiate. struct gtm_alloc_action { void (*free_fn)(void *); bool allocated; }; struct gtm_thread; // A transaction checkpoint: data that has to saved and restored when doing // closed nesting. struct gtm_transaction_cp { gtm_jmpbuf jb; size_t undolog_size; aa_tree<uintptr_t, gtm_alloc_action> alloc_actions; size_t user_actions_size; _ITM_transactionId_t id; uint32_t prop; uint32_t cxa_catch_count; void *cxa_unthrown; // We might want to use a different but compatible dispatch method for // a nested transaction. abi_dispatch *disp; // Nesting level of this checkpoint (1 means that this is a checkpoint of // the outermost transaction). uint32_t nesting; void save(gtm_thread* tx); void commit(gtm_thread* tx); }; // An undo log for writes. struct gtm_undolog { vector<gtm_word> undolog; // Log the previous value at a certain address. // The easiest way to inline this is to just define this here. void log(const void *ptr, size_t len) { size_t words = (len + sizeof(gtm_word) - 1) / sizeof(gtm_word); gtm_word *undo = undolog.push(words + 2); memcpy(undo, ptr, len); undo[words] = len; undo[words + 1] = (gtm_word) ptr; } void commit () { undolog.clear(); } size_t size() const { return undolog.size(); } // In local.cc void rollback (gtm_thread* tx, size_t until_size = 0); }; // An entry of a read or write log. Used by multi-lock TM methods. struct gtm_rwlog_entry { atomic<gtm_word> *orec; gtm_word value; }; // Contains all thread-specific data required by the entire library. // This includes all data relevant to a single transaction. Because most // thread-specific data is about the current transaction, we also refer to // the transaction-specific parts of gtm_thread as "the transaction" (the // same applies to names of variables and arguments). // All but the shared part of this data structure are thread-local data. // gtm_thread could be split into transaction-specific structures and other // per-thread data (with those parts then nested in gtm_thread), but this // would make it harder to later rearrange individual members to optimize data // accesses. Thus, for now we keep one flat object, and will only split it if // the code gets too messy. struct gtm_thread { struct user_action { _ITM_userCommitFunction fn; void *arg; bool on_commit; _ITM_transactionId_t resuming_id; }; // The jump buffer by which GTM_longjmp restarts the transaction. // This field *must* be at the beginning of the transaction. gtm_jmpbuf jb; // Data used by local.c for the undo log for both local and shared memory. gtm_undolog undolog; // Read and write logs. Used by multi-lock TM methods. vector<gtm_rwlog_entry> readlog; vector<gtm_rwlog_entry> writelog; // Data used by alloc.c for the malloc/free undo log. aa_tree<uintptr_t, gtm_alloc_action> alloc_actions; // Data used by useraction.c for the user-defined commit/abort handlers. vector<user_action> user_actions; // A numerical identifier for this transaction. _ITM_transactionId_t id; // The _ITM_codeProperties of this transaction as given by the compiler. uint32_t prop; // The nesting depth for subsequently started transactions. This variable // will be set to 1 when starting an outermost transaction. uint32_t nesting; // Set if this transaction owns the serial write lock. // Can be reset only when restarting the outermost transaction. static const uint32_t STATE_SERIAL = 0x0001; // Set if the serial-irrevocable dispatch table is installed. // Implies that no logging is being done, and abort is not possible. // Can be reset only when restarting the outermost transaction. static const uint32_t STATE_IRREVOCABLE = 0x0002; // A bitmask of the above. uint32_t state; // In order to reduce cacheline contention on global_tid during // beginTransaction, we allocate a block of 2**N ids to the thread // all at once. This number is the next value to be allocated from // the block, or 0 % 2**N if no such block is allocated. _ITM_transactionId_t local_tid; // Data used by eh_cpp.c for managing exceptions within the transaction. uint32_t cxa_catch_count; void *cxa_unthrown; void *eh_in_flight; // Checkpoints for closed nesting. vector<gtm_transaction_cp> parent_txns; // Data used by retry.c for deciding what STM implementation should // be used for the next iteration of the transaction. // Only restart_total is reset to zero when the transaction commits, the // other counters are total values for all previously executed transactions. // restart_total is also used by the HTM fastpath in a different way. uint32_t restart_reason[NUM_RESTARTS]; uint32_t restart_total; // *** The shared part of gtm_thread starts here. *** // Shared state is on separate cachelines to avoid false sharing with // thread-local parts of gtm_thread. // Points to the next thread in the list of all threads. gtm_thread *next_thread __attribute__((__aligned__(HW_CACHELINE_SIZE))); // If this transaction is inactive, shared_state is ~0. Otherwise, this is // an active or serial transaction. atomic<gtm_word> shared_state; // The lock that provides access to serial mode. Non-serialized // transactions acquire read locks; a serialized transaction aquires // a write lock. // Accessed from assembly language, thus the "asm" specifier on // the name, avoiding complex name mangling. static gtm_rwlock serial_lock __asm__(UPFX "gtm_serial_lock"); // The head of the list of all threads' transactions. static gtm_thread *list_of_threads; // The number of all registered threads. static unsigned number_of_threads; // In alloc.cc void commit_allocations (bool, aa_tree<uintptr_t, gtm_alloc_action>*); void record_allocation (void *, void (*)(void *)); void forget_allocation (void *, void (*)(void *)); void drop_references_allocations (const void *ptr) { this->alloc_actions.erase((uintptr_t) ptr); } // In beginend.cc void rollback (gtm_transaction_cp *cp = 0, bool aborting = false); bool trycommit (); void restart (gtm_restart_reason, bool finish_serial_upgrade = false) ITM_NORETURN; gtm_thread(); ~gtm_thread(); static void *operator new(size_t); static void operator delete(void *); // Invoked from assembly language, thus the "asm" specifier on // the name, avoiding complex name mangling. static uint32_t begin_transaction(uint32_t, const gtm_jmpbuf *) __asm__(UPFX "GTM_begin_transaction") ITM_REGPARM; // In eh_cpp.cc void revert_cpp_exceptions (gtm_transaction_cp *cp = 0); // In retry.cc // Must be called outside of transactions (i.e., after rollback). void decide_retry_strategy (gtm_restart_reason); abi_dispatch* decide_begin_dispatch (uint32_t prop); void number_of_threads_changed(unsigned previous, unsigned now); // Must be called from serial mode. Does not call set_abi_disp(). void set_default_dispatch(abi_dispatch* disp); // In method-serial.cc void serialirr_mode (); // In useraction.cc void rollback_user_actions (size_t until_size = 0); void commit_user_actions (); }; } // namespace GTM #include "tls.h" namespace GTM HIDDEN { // An unscaled count of the number of times we should spin attempting to // acquire locks before we block the current thread and defer to the OS. // This variable isn't used when the standard POSIX lock implementations // are used. extern uint64_t gtm_spin_count_var; extern "C" uint32_t GTM_longjmp (uint32_t, const gtm_jmpbuf *, uint32_t) ITM_NORETURN ITM_REGPARM; extern "C" void GTM_LB (const void *, size_t) ITM_REGPARM; extern void GTM_error (const char *fmt, ...) __attribute__((format (printf, 1, 2))); extern void GTM_fatal (const char *fmt, ...) __attribute__((noreturn, format (printf, 1, 2))); extern abi_dispatch *dispatch_serial(); extern abi_dispatch *dispatch_serialirr(); extern abi_dispatch *dispatch_serialirr_onwrite(); extern abi_dispatch *dispatch_gl_wt(); extern abi_dispatch *dispatch_ml_wt(); extern abi_dispatch *dispatch_htm(); extern gtm_cacheline_mask gtm_mask_stack(gtm_cacheline *, gtm_cacheline_mask); // Control variable for the HTM fastpath that uses serial mode as fallback. // Non-zero if the HTM fastpath is enabled. See gtm_thread::begin_transaction. // Accessed from assembly language, thus the "asm" specifier on // the name, avoiding complex name mangling. extern uint32_t htm_fastpath __asm__(UPFX "gtm_htm_fastpath"); } // namespace GTM #endif // LIBITM_I_H