| /* Copyright (C) 2008-2024 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_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; |
| |
| 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 "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 { |
| |
| // A log of (de)allocation actions. We defer handling of some actions until |
| // a commit of the outermost transaction. We also rely on potentially having |
| // both an allocation and a deallocation for the same piece of memory in the |
| // log; the order in which such entries are processed does not matter because |
| // the actions are not in conflict (see below). |
| // 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 |
| { |
| // Iff free_fn_sz is nonzero, it must be used instead of free_fn, and vice |
| // versa. |
| void (*free_fn)(void *); |
| void (*free_fn_sz)(void *, size_t); |
| size_t sz; |
| // If true, this is an allocation; we discard the log entry on outermost |
| // commit, and deallocate on abort. If false, this is a deallocation and |
| // we deallocate on outermost commit and discard the log entry on abort. |
| 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; |
| unsigned int cxa_uncaught_count; |
| // 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; |
| // If cxa_uncaught_count_ptr is 0, we don't need to roll back exceptions. |
| unsigned int *cxa_uncaught_count_ptr; |
| unsigned int cxa_uncaught_count; |
| 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 acquires |
| // 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 forget_allocation (void *, size_t, void (*)(void *, size_t)); |
| void discard_allocation (const void *ptr) |
| { |
| 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 init_cpp_exceptions (); |
| 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(); |
| |
| |
| } // namespace GTM |
| |
| #endif // LIBITM_I_H |