| |
| /*--------------------------------------------------------------------*/ |
| /*--- Thread scheduling. vg_scheduler.c ---*/ |
| /*--------------------------------------------------------------------*/ |
| |
| /* |
| This file is part of Valgrind, an extensible x86 protected-mode |
| emulator for monitoring program execution on x86-Unixes. |
| |
| Copyright (C) 2000-2005 Julian Seward |
| jseward@acm.org |
| |
| This program 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 2 of the |
| License, or (at your option) any later version. |
| |
| This program 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. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307, USA. |
| |
| The GNU General Public License is contained in the file COPYING. |
| */ |
| |
| /* |
| Overview |
| |
| Valgrind tries to emulate the kernel's threading as closely as |
| possible. The client does all threading via the normal syscalls |
| (on Linux: clone, etc). Valgrind emulates this by creating exactly |
| the same process structure as would be created without Valgrind. |
| There are no extra threads. |
| |
| The main difference is that Valgrind only allows one client thread |
| to run at once. This is controlled with the VCPU semaphore, |
| "run_sema". Any time a thread wants to run client code or |
| manipulate any shared state (which is anything other than its own |
| ThreadState entry), it must hold the run_sema. |
| |
| When a thread is about to block in a blocking syscall, it releases |
| run_sema, and re-takes it when it becomes runnable again (either |
| because the syscall finished, or we took a signal). |
| |
| VG_(scheduler) therefore runs in each thread. It returns only when |
| the thread is exiting, either because it exited itself, or it was |
| told to exit by another thread. |
| |
| This file is almost entirely OS-independent. The details of how |
| the OS handles threading and signalling are abstracted away and |
| implemented elsewhere. |
| */ |
| |
| #include "valgrind.h" /* for VG_USERREQ__RUNNING_ON_VALGRIND and |
| VG_USERREQ__DISCARD_TRANSLATIONS, and others */ |
| #include "core.h" |
| |
| #include "pub_core_stacktrace.h" |
| |
| |
| /* --------------------------------------------------------------------- |
| Types and globals for the scheduler. |
| ------------------------------------------------------------------ */ |
| |
| /* ThreadId and ThreadState are defined in core.h. */ |
| |
| /* Defines the thread-scheduling timeslice, in terms of the number of |
| basic blocks we attempt to run each thread for. Smaller values |
| give finer interleaving but much increased scheduling overheads. */ |
| #define SCHEDULING_QUANTUM 50000 |
| |
| /* Globals. A statically allocated array of threads. NOTE: [0] is |
| never used, to simplify the simulation of initialisers for |
| LinuxThreads. */ |
| ThreadState VG_(threads)[VG_N_THREADS]; |
| |
| /* If true, a fault is Valgrind-internal (ie, a bug) */ |
| Bool VG_(my_fault) = True; |
| |
| /* Forwards */ |
| static void do_client_request ( ThreadId tid ); |
| static void scheduler_sanity ( ThreadId tid ); |
| static void mostly_clear_thread_record ( ThreadId tid ); |
| static const HChar *name_of_thread_state ( ThreadStatus ); |
| |
| /* Stats. */ |
| static UInt n_scheduling_events_MINOR = 0; |
| static UInt n_scheduling_events_MAJOR = 0; |
| |
| |
| void VG_(print_scheduler_stats)(void) |
| { |
| VG_(message)(Vg_DebugMsg, |
| " %d/%d major/minor sched events.", |
| n_scheduling_events_MAJOR, n_scheduling_events_MINOR); |
| } |
| |
| /* CPU semaphore, so that threads can run exclusively */ |
| static vg_sema_t run_sema; |
| static ThreadId running_tid = VG_INVALID_THREADID; |
| |
| |
| /* --------------------------------------------------------------------- |
| Helper functions for the scheduler. |
| ------------------------------------------------------------------ */ |
| |
| __inline__ |
| Bool VG_(is_valid_tid) ( ThreadId tid ) |
| { |
| /* tid is unsigned, hence no < 0 test. */ |
| if (tid == 0) return False; |
| if (tid >= VG_N_THREADS) return False; |
| if (VG_(threads)[tid].status == VgTs_Empty) return False; |
| return True; |
| } |
| |
| |
| __inline__ |
| static Bool is_valid_or_empty_tid ( ThreadId tid ) |
| { |
| /* tid is unsigned, hence no < 0 test. */ |
| if (tid == 0) return False; |
| if (tid >= VG_N_THREADS) return False; |
| return True; |
| } |
| |
| |
| /* For constructing error messages only: try and identify a thread |
| whose stack satisfies the predicate p, or return VG_INVALID_THREADID |
| if none do. |
| */ |
| ThreadId VG_(first_matching_thread_stack) |
| ( Bool (*p) ( Addr stack_min, Addr stack_max, void* d ), |
| void* d ) |
| { |
| ThreadId tid; |
| |
| for (tid = 1; tid < VG_N_THREADS; tid++) { |
| if (VG_(threads)[tid].status == VgTs_Empty) continue; |
| |
| if ( p ( STACK_PTR(VG_(threads)[tid].arch), |
| VG_(threads)[tid].stack_highest_word, d ) ) |
| return tid; |
| } |
| return VG_INVALID_THREADID; |
| } |
| |
| void VG_(mark_from_registers)(void (*mark_addr)(Addr)) |
| { |
| ThreadId tid; |
| |
| for(tid = 1; tid < VG_N_THREADS; tid++) { |
| if (!VG_(is_valid_tid)(tid)) |
| continue; |
| VGA_(mark_from_registers)(tid, mark_addr); |
| } |
| } |
| |
| /* Print the scheduler status. */ |
| void VG_(pp_sched_status) ( void ) |
| { |
| Int i; |
| VG_(printf)("\nsched status:\n"); |
| VG_(printf)(" running_tid=%d\n", running_tid); |
| for (i = 1; i < VG_N_THREADS; i++) { |
| if (VG_(threads)[i].status == VgTs_Empty) continue; |
| VG_(printf)("\nThread %d: status = %s\n", i, name_of_thread_state(VG_(threads)[i].status)); |
| VG_(get_and_pp_StackTrace)( i, VG_(clo_backtrace_size) ); |
| } |
| VG_(printf)("\n"); |
| } |
| |
| static |
| void print_sched_event ( ThreadId tid, Char* what ) |
| { |
| VG_(message)(Vg_DebugMsg, " SCHED[%d]: %s", tid, what ); |
| } |
| |
| static |
| HChar* name_of_sched_event ( UInt event ) |
| { |
| switch (event) { |
| case VEX_TRC_JMP_SYSCALL: return "SYSCALL"; |
| case VEX_TRC_JMP_CLIENTREQ: return "CLIENTREQ"; |
| case VEX_TRC_JMP_YIELD: return "YIELD"; |
| case VEX_TRC_JMP_NODECODE: return "NODECODE"; |
| case VG_TRC_INNER_COUNTERZERO: return "COUNTERZERO"; |
| case VG_TRC_INNER_FASTMISS: return "FASTMISS"; |
| case VG_TRC_FAULT_SIGNAL: return "FAULTSIGNAL"; |
| default: return "??UNKNOWN??"; |
| } |
| } |
| |
| static |
| const HChar* name_of_thread_state ( ThreadStatus state ) |
| { |
| switch (state) { |
| case VgTs_Empty: return "VgTs_Empty"; |
| case VgTs_Init: return "VgTs_Init"; |
| case VgTs_Runnable: return "VgTs_Runnable"; |
| case VgTs_WaitSys: return "VgTs_WaitSys"; |
| case VgTs_Yielding: return "VgTs_Yielding"; |
| case VgTs_Zombie: return "VgTs_Zombie"; |
| default: return "VgTs_???"; |
| } |
| } |
| |
| /* Allocate a completely empty ThreadState record. */ |
| ThreadId VG_(alloc_ThreadState) ( void ) |
| { |
| Int i; |
| for (i = 1; i < VG_N_THREADS; i++) { |
| if (VG_(threads)[i].status == VgTs_Empty) { |
| VG_(threads)[i].status = VgTs_Init; |
| VG_(threads)[i].exitreason = VgSrc_None; |
| return i; |
| } |
| } |
| VG_(printf)("vg_alloc_ThreadState: no free slots available\n"); |
| VG_(printf)("Increase VG_N_THREADS, rebuild and try again.\n"); |
| VG_(core_panic)("VG_N_THREADS is too low"); |
| /*NOTREACHED*/ |
| } |
| |
| ThreadState *VG_(get_ThreadState)(ThreadId tid) |
| { |
| vg_assert(tid >= 0 && tid < VG_N_THREADS); |
| return &VG_(threads)[tid]; |
| } |
| |
| /* Given an LWP id (ie, real kernel thread id), find the corresponding |
| ThreadId */ |
| ThreadId VG_(get_lwp_tid)(Int lwp) |
| { |
| ThreadId tid; |
| |
| for(tid = 1; tid <= VG_N_THREADS; tid++) |
| if (VG_(threads)[tid].status != VgTs_Empty && VG_(threads)[tid].os_state.lwpid == lwp) |
| return tid; |
| |
| return VG_INVALID_THREADID; |
| } |
| |
| /* |
| Mark a thread as Runnable. This will block until the run_sema is |
| available, so that we get exclusive access to all the shared |
| structures and the CPU. Up until we get the sema, we must not |
| touch any shared state. |
| |
| When this returns, we'll actually be running. |
| */ |
| void VG_(set_running)(ThreadId tid) |
| { |
| ThreadState *tst = VG_(get_ThreadState)(tid); |
| |
| vg_assert(tst->status != VgTs_Runnable); |
| |
| tst->status = VgTs_Runnable; |
| |
| VG_(sema_down)(&run_sema); |
| if (running_tid != VG_INVALID_THREADID) |
| VG_(printf)("tid %d found %d running\n", tid, running_tid); |
| vg_assert(running_tid == VG_INVALID_THREADID); |
| running_tid = tid; |
| |
| if (VG_(clo_trace_sched)) |
| print_sched_event(tid, "now running"); |
| } |
| |
| ThreadId VG_(get_running_tid)(void) |
| { |
| return running_tid; |
| } |
| |
| Bool VG_(is_running_thread)(ThreadId tid) |
| { |
| ThreadState *tst = VG_(get_ThreadState)(tid); |
| |
| return |
| // tst->os_state.lwpid == VG_(gettid)() && /* check we're this tid */ |
| running_tid == tid && /* and that we've got the lock */ |
| tst->status == VgTs_Runnable; /* and we're runnable */ |
| } |
| |
| /* Return the number of non-dead Threads */ |
| Int VG_(count_living_threads)(void) |
| { |
| Int count = 0; |
| ThreadId tid; |
| |
| for(tid = 1; tid < VG_N_THREADS; tid++) |
| if (VG_(threads)[tid].status != VgTs_Empty && |
| VG_(threads)[tid].status != VgTs_Zombie) |
| count++; |
| |
| return count; |
| } |
| |
| /* |
| Set a thread into a sleeping state, and give up exclusive access to |
| the CPU. On return, the thread must be prepared to block until it |
| is ready to run again (generally this means blocking in a syscall, |
| but it may mean that we remain in a Runnable state and we're just |
| yielding the CPU to another thread). |
| */ |
| void VG_(set_sleeping)(ThreadId tid, ThreadStatus sleepstate) |
| { |
| ThreadState *tst = VG_(get_ThreadState)(tid); |
| |
| vg_assert(tst->status == VgTs_Runnable); |
| |
| vg_assert(sleepstate == VgTs_WaitSys || |
| sleepstate == VgTs_Yielding); |
| |
| tst->status = sleepstate; |
| |
| vg_assert(running_tid == tid); |
| running_tid = VG_INVALID_THREADID; |
| |
| /* Release the run_sema; this will reschedule any runnable |
| thread. */ |
| VG_(sema_up)(&run_sema); |
| |
| if (VG_(clo_trace_sched)) { |
| Char buf[50]; |
| VG_(sprintf)(buf, "now sleeping in state %s", name_of_thread_state(sleepstate)); |
| print_sched_event(tid, buf); |
| } |
| } |
| |
| /* Return true if the thread is still alive but in the process of |
| exiting. */ |
| inline Bool VG_(is_exiting)(ThreadId tid) |
| { |
| vg_assert(VG_(is_valid_tid)(tid)); |
| return VG_(threads)[tid].exitreason != VgSrc_None; |
| } |
| |
| /* Clear out the ThreadState and release the semaphore. Leaves the |
| ThreadState in VgTs_Zombie state, so that it doesn't get |
| reallocated until the caller is really ready. */ |
| void VG_(exit_thread)(ThreadId tid) |
| { |
| vg_assert(VG_(is_valid_tid)(tid)); |
| vg_assert(VG_(is_running_thread)(tid)); |
| vg_assert(VG_(is_exiting)(tid)); |
| |
| /* It's stack is now off-limits |
| |
| XXX Don't do this - the client thread implementation can touch |
| the stack after thread death... */ |
| if (0 && VG_(threads)[tid].stack_base) { |
| Segment *seg = VG_(find_segment)( VG_(threads)[tid].stack_base ); |
| if (seg) |
| VG_TRACK( die_mem_stack, seg->addr, seg->len ); |
| } |
| |
| VGA_(cleanup_thread)( &VG_(threads)[tid].arch ); |
| |
| mostly_clear_thread_record(tid); |
| running_tid = VG_INVALID_THREADID; |
| |
| /* There should still be a valid exitreason for this thread */ |
| vg_assert(VG_(threads)[tid].exitreason != VgSrc_None); |
| |
| VG_(sema_up)(&run_sema); |
| } |
| |
| /* Kill a thread. This interrupts whatever a thread is doing, and |
| makes it exit ASAP. This does not set the exitreason or |
| exitcode. */ |
| void VG_(kill_thread)(ThreadId tid) |
| { |
| vg_assert(VG_(is_valid_tid)(tid)); |
| vg_assert(!VG_(is_running_thread)(tid)); |
| vg_assert(VG_(is_exiting)(tid)); |
| |
| if (VG_(threads)[tid].status == VgTs_WaitSys) { |
| if (VG_(clo_trace_signals)) |
| VG_(message)(Vg_DebugMsg, "kill_thread zaps tid %d lwp %d", |
| tid, VG_(threads)[tid].os_state.lwpid); |
| VG_(tkill)(VG_(threads)[tid].os_state.lwpid, VKI_SIGVGKILL); |
| } |
| } |
| |
| /* |
| Yield the CPU for a short time to let some other thread run. |
| */ |
| void VG_(vg_yield)(void) |
| { |
| struct vki_timespec ts = { 0, 1 }; |
| ThreadId tid = running_tid; |
| |
| vg_assert(tid != VG_INVALID_THREADID); |
| vg_assert(VG_(threads)[tid].os_state.lwpid == VG_(gettid)()); |
| |
| VG_(set_sleeping)(tid, VgTs_Yielding); |
| |
| //VG_(printf)("tid %d yielding EIP=%p\n", tid, VG_(threads)[tid].arch.m_eip); |
| |
| /* |
| Tell the kernel we're yielding. |
| */ |
| if (1) |
| VG_(do_syscall0)(__NR_sched_yield); |
| else |
| VG_(nanosleep)(&ts); |
| |
| VG_(set_running)(tid); |
| |
| VG_(poll_signals)(tid); /* something might have happened */ |
| } |
| |
| |
| void VG_(resume_scheduler)(ThreadId tid) |
| { |
| ThreadState *tst = VG_(get_ThreadState)(tid); |
| |
| vg_assert(tst->os_state.lwpid == VG_(gettid)()); |
| |
| if (tst->sched_jmpbuf_valid) { |
| /* Can't continue; must longjmp back to the scheduler and thus |
| enter the sighandler immediately. */ |
| |
| LONGJMP(tst->sched_jmpbuf, True); |
| } |
| } |
| |
| #define SCHEDSETJMP(tid, jumped, stmt) \ |
| do { \ |
| ThreadState * volatile _qq_tst = VG_(get_ThreadState)(tid); \ |
| \ |
| (jumped) = SETJMP(_qq_tst->sched_jmpbuf); \ |
| if ((jumped) == 0) { \ |
| vg_assert(!_qq_tst->sched_jmpbuf_valid); \ |
| _qq_tst->sched_jmpbuf_valid = True; \ |
| stmt; \ |
| } else if (VG_(clo_trace_sched)) \ |
| VG_(printf)("SCHEDSETJMP(line %d) tid %d, jumped=%d\n", __LINE__, tid, jumped); \ |
| vg_assert(_qq_tst->sched_jmpbuf_valid); \ |
| _qq_tst->sched_jmpbuf_valid = False; \ |
| } while(0) |
| |
| /* Run the thread tid for a while, and return a VG_TRC_* value to the |
| scheduler indicating what happened. */ |
| static |
| UInt run_thread_for_a_while ( ThreadId tid ) |
| { |
| volatile Bool jumped; |
| volatile ThreadState *tst = VG_(get_ThreadState)(tid); |
| //volatile Addr EIP = tst->arch.m_eip; |
| //volatile Addr nextEIP; |
| |
| volatile UInt trc = 0; |
| volatile Int dispatch_ctr_SAVED = VG_(dispatch_ctr); |
| volatile Int done_this_time; |
| |
| /* For paranoia purposes only */ |
| volatile Addr a_vex = (Addr) & VG_(threads)[tid].arch.vex; |
| volatile Addr a_vexsh = (Addr) & VG_(threads)[tid].arch.vex_shadow; |
| volatile Addr a_spill = (Addr) & VG_(threads)[tid].arch.vex_spill; |
| volatile UInt sz_vex = (UInt) sizeof VG_(threads)[tid].arch.vex; |
| volatile UInt sz_vexsh = (UInt) sizeof VG_(threads)[tid].arch.vex_shadow; |
| volatile UInt sz_spill = (UInt) sizeof VG_(threads)[tid].arch.vex_spill; |
| |
| /* Paranoia */ |
| vg_assert(VG_(is_valid_tid)(tid)); |
| vg_assert(VG_(is_valid_tid)(tid)); |
| vg_assert(VG_(is_running_thread)(tid)); |
| vg_assert(!VG_(is_exiting)(tid)); |
| |
| /* Even more paranoia. Check that what we have matches |
| Vex's guest state layout requirements. */ |
| if (0) |
| VG_(printf)("%p %d %p %d %p %d\n", |
| (void*)a_vex, sz_vex, (void*)a_vexsh, sz_vexsh, |
| (void*)a_spill, sz_spill ); |
| |
| vg_assert(IS_8_ALIGNED(sz_vex)); |
| vg_assert(IS_8_ALIGNED(sz_vexsh)); |
| vg_assert(IS_16_ALIGNED(sz_spill)); |
| |
| vg_assert(IS_4_ALIGNED(a_vex)); |
| vg_assert(IS_4_ALIGNED(a_vexsh)); |
| vg_assert(IS_4_ALIGNED(a_spill)); |
| |
| vg_assert(sz_vex == sz_vexsh); |
| vg_assert(a_vex + sz_vex == a_vexsh); |
| |
| vg_assert(sz_spill == LibVEX_N_SPILL_BYTES); |
| vg_assert(a_vex + 2 * sz_vex == a_spill); |
| |
| vg_assert(VG_(instr_ptr_offset) >= 0); |
| vg_assert(VG_(instr_ptr_offset) <= 10000); /* let's say */ |
| vg_assert(sizeof VG_(instr_ptr_offset) == sizeof(HWord)); |
| |
| VGP_PUSHCC(VgpRun); |
| |
| /* there should be no undealt-with signals */ |
| //vg_assert(VG_(threads)[tid].siginfo.si_signo == 0); |
| |
| //VG_(printf)("running EIP = %p ESP=%p\n", VG_(threads)[tid].arch.m_eip, VG_(threads)[tid].arch.m_esp); |
| |
| vg_assert(VG_(my_fault)); |
| VG_(my_fault) = False; |
| |
| SCHEDSETJMP(tid, jumped, trc = VG_(run_innerloop)( (void*)&tst->arch.vex )); |
| |
| //nextEIP = tst->arch.m_eip; |
| //if (nextEIP >= VG_(client_end)) |
| // VG_(printf)("trc=%d jump to %p from %p\n", |
| // trc, nextEIP, EIP); |
| |
| VG_(my_fault) = True; |
| |
| if (jumped) { |
| /* We get here if the client took a fault, which caused our |
| signal handler to longjmp. */ |
| vg_assert(trc == 0); |
| trc = VG_TRC_FAULT_SIGNAL; |
| VG_(block_signals)(tid); |
| } |
| |
| done_this_time = (Int)dispatch_ctr_SAVED - (Int)VG_(dispatch_ctr) - 0; |
| |
| vg_assert(done_this_time >= 0); |
| VG_(bbs_done) += (ULong)done_this_time; |
| |
| VGP_POPCC(VgpRun); |
| return trc; |
| } |
| |
| |
| static |
| void mostly_clear_thread_record ( ThreadId tid ) |
| { |
| vki_sigset_t savedmask; |
| |
| vg_assert(tid >= 0 && tid < VG_N_THREADS); |
| VGA_(cleanup_thread)(&VG_(threads)[tid].arch); |
| VG_(threads)[tid].tid = tid; |
| |
| /* Leave the thread in Zombie, so that it doesn't get reallocated |
| until the caller is finally done with the thread stack. */ |
| VG_(threads)[tid].status = VgTs_Zombie; |
| |
| VG_(threads)[tid].syscallno = -1; |
| |
| VG_(sigemptyset)(&VG_(threads)[tid].sig_mask); |
| VG_(sigemptyset)(&VG_(threads)[tid].tmp_sig_mask); |
| |
| VGA_(os_state_clear)(&VG_(threads)[tid]); |
| |
| /* start with no altstack */ |
| VG_(threads)[tid].altstack.ss_sp = (void *)0xdeadbeef; |
| VG_(threads)[tid].altstack.ss_size = 0; |
| VG_(threads)[tid].altstack.ss_flags = VKI_SS_DISABLE; |
| |
| /* clear out queued signals */ |
| VG_(block_all_host_signals)(&savedmask); |
| if (VG_(threads)[tid].sig_queue != NULL) { |
| VG_(arena_free)(VG_AR_CORE, VG_(threads)[tid].sig_queue); |
| VG_(threads)[tid].sig_queue = NULL; |
| } |
| VG_(restore_all_host_signals)(&savedmask); |
| |
| VG_(threads)[tid].sched_jmpbuf_valid = False; |
| } |
| |
| /* |
| Called in the child after fork. If the parent has multiple |
| threads, then we've inhereted a VG_(threads) array describing them, |
| but only the thread which called fork() is actually alive in the |
| child. This functions needs to clean up all those other thread |
| structures. |
| |
| Whichever tid in the parent which called fork() becomes the |
| master_tid in the child. That's because the only living slot in |
| VG_(threads) in the child after fork is VG_(threads)[tid], and it |
| would be too hard to try to re-number the thread and relocate the |
| thread state down to VG_(threads)[1]. |
| |
| This function also needs to reinitialize the run_sema, since |
| otherwise we may end up sharing its state with the parent, which |
| would be deeply confusing. |
| */ |
| static void sched_fork_cleanup(ThreadId me) |
| { |
| ThreadId tid; |
| vg_assert(running_tid == me); |
| |
| VG_(master_tid) = me; |
| |
| VG_(threads)[me].os_state.lwpid = VG_(gettid)(); |
| VG_(threads)[me].os_state.threadgroup = VG_(getpid)(); |
| |
| /* clear out all the unused thread slots */ |
| for (tid = 1; tid < VG_N_THREADS; tid++) { |
| if (tid != me) { |
| mostly_clear_thread_record(tid); |
| VG_(threads)[tid].status = VgTs_Empty; |
| } |
| } |
| |
| /* re-init and take the sema */ |
| VG_(sema_deinit)(&run_sema); |
| VG_(sema_init)(&run_sema); |
| VG_(sema_down)(&run_sema); |
| } |
| |
| |
| /* Initialise the scheduler. Create a single "main" thread ready to |
| run, with special ThreadId of one. This is called at startup. The |
| caller subsequently initialises the guest state components of this |
| main thread, thread 1. |
| */ |
| void VG_(scheduler_init) ( void ) |
| { |
| Int i; |
| ThreadId tid_main; |
| |
| VG_(sema_init)(&run_sema); |
| |
| for (i = 0 /* NB; not 1 */; i < VG_N_THREADS; i++) { |
| VG_(threads)[i].sig_queue = NULL; |
| |
| VGA_(os_state_init)(&VG_(threads)[i]); |
| mostly_clear_thread_record(i); |
| |
| VG_(threads)[i].status = VgTs_Empty; |
| VG_(threads)[i].stack_size = 0; |
| VG_(threads)[i].stack_base = (Addr)NULL; |
| VG_(threads)[i].stack_highest_word = (Addr)NULL; |
| } |
| |
| tid_main = VG_(alloc_ThreadState)(); |
| |
| VG_(master_tid) = tid_main; |
| |
| /* Initial thread's stack is the original process stack */ |
| VG_(threads)[tid_main].stack_highest_word = VG_(clstk_end) - sizeof(UInt); |
| VG_(threads)[tid_main].stack_base = VG_(clstk_base); |
| VG_(threads)[tid_main].stack_size = VG_(client_rlimit_stack).rlim_cur; |
| |
| VG_(atfork)(NULL, NULL, sched_fork_cleanup); |
| } |
| |
| |
| /* --------------------------------------------------------------------- |
| The scheduler proper. |
| ------------------------------------------------------------------ */ |
| |
| static void handle_tt_miss ( ThreadId tid ) |
| { |
| Bool found; |
| Addr ip = INSTR_PTR(VG_(threads)[tid].arch); |
| |
| /* Trivial event. Miss in the fast-cache. Do a full |
| lookup for it. */ |
| found = VG_(search_transtab)( NULL, |
| ip, True/*upd_fast_cache*/ ); |
| if (!found) { |
| /* Not found; we need to request a translation. */ |
| if (VG_(translate)( tid, ip, /*debug*/False, 0/*not verbose*/ )) { |
| found = VG_(search_transtab)( NULL, ip, True ); |
| if (!found) |
| VG_(core_panic)("VG_TRC_INNER_FASTMISS: missing tt_fast entry"); |
| } else { |
| // If VG_(translate)() fails, it's because it had to throw a |
| // signal because the client jumped to a bad address. That |
| // means that either a signal has been set up for delivery, |
| // or the thread has been marked for termination. Either |
| // way, we just need to go back into the scheduler loop. |
| } |
| } |
| } |
| |
| static void handle_syscall(ThreadId tid) |
| { |
| ThreadState *tst = VG_(get_ThreadState)(tid); |
| Bool jumped; |
| |
| /* Syscall may or may not block; either way, it will be |
| complete by the time this call returns, and we'll be |
| runnable again. We could take a signal while the |
| syscall runs. */ |
| SCHEDSETJMP(tid, jumped, VG_(client_syscall)(tid)); |
| |
| if (!VG_(is_running_thread)(tid)) |
| VG_(printf)("tid %d not running; running_tid=%d, tid %d status %d\n", |
| tid, running_tid, tid, tst->status); |
| vg_assert(VG_(is_running_thread)(tid)); |
| |
| if (jumped) { |
| VG_(block_signals)(tid); |
| VG_(poll_signals)(tid); |
| } |
| } |
| |
| /* |
| Run a thread until it wants to exit. |
| |
| We assume that the caller has already called VG_(set_running) for |
| us, so we own the VCPU. Also, all signals are blocked. |
| */ |
| VgSchedReturnCode VG_(scheduler) ( ThreadId tid ) |
| { |
| UInt trc; |
| ThreadState *tst = VG_(get_ThreadState)(tid); |
| |
| if (VG_(clo_trace_sched)) |
| print_sched_event(tid, "entering VG_(scheduler)"); |
| |
| VGP_PUSHCC(VgpSched); |
| |
| /* set the proper running signal mask */ |
| VG_(block_signals)(tid); |
| |
| vg_assert(VG_(is_running_thread)(tid)); |
| |
| VG_(dispatch_ctr) = SCHEDULING_QUANTUM + 1; |
| |
| while(!VG_(is_exiting)(tid)) { |
| if (VG_(dispatch_ctr) == 1) { |
| /* Our slice is done, so yield the CPU to another thread. This |
| doesn't sleep between sleeping and running, since that would |
| take too much time. */ |
| VG_(set_sleeping)(tid, VgTs_Yielding); |
| /* nothing */ |
| VG_(set_running)(tid); |
| //VG_(tm_thread_switchto)(tid); |
| |
| /* OK, do some relatively expensive housekeeping stuff */ |
| scheduler_sanity(tid); |
| VG_(sanity_check_general)(False); |
| |
| /* Look for any pending signals for this thread, and set them up |
| for delivery */ |
| VG_(poll_signals)(tid); |
| |
| if (VG_(is_exiting)(tid)) |
| break; /* poll_signals picked up a fatal signal */ |
| |
| /* For stats purposes only. */ |
| n_scheduling_events_MAJOR++; |
| |
| /* Figure out how many bbs to ask vg_run_innerloop to do. Note |
| that it decrements the counter before testing it for zero, so |
| that if tst->dispatch_ctr is set to N you get at most N-1 |
| iterations. Also this means that tst->dispatch_ctr must |
| exceed zero before entering the innerloop. Also also, the |
| decrement is done before the bb is actually run, so you |
| always get at least one decrement even if nothing happens. */ |
| VG_(dispatch_ctr) = SCHEDULING_QUANTUM + 1; |
| |
| /* paranoia ... */ |
| vg_assert(tst->tid == tid); |
| vg_assert(tst->os_state.lwpid == VG_(gettid)()); |
| } |
| |
| /* For stats purposes only. */ |
| n_scheduling_events_MINOR++; |
| |
| if (0) |
| VG_(message)(Vg_DebugMsg, "thread %d: running for %d bbs", |
| tid, VG_(dispatch_ctr) - 1 ); |
| |
| trc = run_thread_for_a_while ( tid ); |
| |
| if (VG_(clo_trace_sched) && VG_(clo_verbosity) > 2) { |
| Char buf[50]; |
| VG_(sprintf)(buf, "TRC: %s", name_of_sched_event(trc)); |
| print_sched_event(tid, buf); |
| } |
| |
| switch(trc) { |
| case VG_TRC_INNER_FASTMISS: |
| vg_assert(VG_(dispatch_ctr) > 1); |
| handle_tt_miss(tid); |
| break; |
| |
| case VEX_TRC_JMP_CLIENTREQ: |
| do_client_request(tid); |
| break; |
| |
| case VEX_TRC_JMP_SYSCALL: |
| handle_syscall(tid); |
| if (VG_(clo_sanity_level) > 2) |
| VG_(sanity_check_general)(True); /* sanity-check every syscall */ |
| break; |
| |
| case VEX_TRC_JMP_YIELD: |
| /* Explicit yield, because this thread is in a spin-lock |
| or something. Only let the thread run for a short while |
| longer. Because swapping to another thread is expensive, |
| we're prepared to let this thread eat a little more CPU |
| before swapping to another. That means that short term |
| spins waiting for hardware to poke memory won't cause a |
| thread swap. */ |
| if (VG_(dispatch_ctr) > 100) |
| VG_(dispatch_ctr) = 100; |
| break; |
| |
| case VG_TRC_INNER_COUNTERZERO: |
| /* Timeslice is out. Let a new thread be scheduled. */ |
| vg_assert(VG_(dispatch_ctr) == 1); |
| break; |
| |
| case VG_TRC_FAULT_SIGNAL: |
| /* Everything should be set up (either we're exiting, or |
| about to start in a signal handler). */ |
| break; |
| |
| case VEX_TRC_JMP_MAPFAIL: |
| /* Failure of arch-specific address translation (x86/amd64 |
| segment override use) */ |
| /* jrs 2005 03 11: is this correct? */ |
| VG_(synth_fault)(tid); |
| break; |
| |
| case VEX_TRC_JMP_EMWARN: { |
| static Int counts[EmWarn_NUMBER]; |
| static Bool counts_initted = False; |
| VexEmWarn ew; |
| HChar* what; |
| Bool show; |
| Int q; |
| if (!counts_initted) { |
| counts_initted = True; |
| for (q = 0; q < EmWarn_NUMBER; q++) |
| counts[q] = 0; |
| } |
| ew = (VexEmWarn)VG_(threads)[tid].arch.vex.guest_EMWARN; |
| what = (ew < 0 || ew >= EmWarn_NUMBER) |
| ? "unknown (?!)" |
| : LibVEX_EmWarn_string(ew); |
| show = (ew < 0 || ew >= EmWarn_NUMBER) |
| ? True |
| : counts[ew]++ < 3; |
| if (show && VG_(clo_show_emwarns)) { |
| VG_(message)( Vg_UserMsg, |
| "Emulation warning: unsupported action:"); |
| VG_(message)( Vg_UserMsg, " %s", what); |
| VG_(get_and_pp_StackTrace)( tid, VG_(clo_backtrace_size) ); |
| } |
| break; |
| } |
| |
| case VEX_TRC_JMP_NODECODE: |
| VG_(synth_sigill)(tid, INSTR_PTR(VG_(threads)[tid].arch)); |
| break; |
| |
| default: |
| VG_(printf)("\ntrc = %d\n", trc); |
| VG_(core_panic)("VG_(scheduler), phase 3: " |
| "unexpected thread return code"); |
| /* NOTREACHED */ |
| break; |
| |
| } /* switch (trc) */ |
| } |
| |
| if (VG_(clo_trace_sched)) |
| print_sched_event(tid, "exiting VG_(scheduler)"); |
| |
| vg_assert(VG_(is_exiting)(tid)); |
| |
| VGP_POPCC(VgpSched); |
| |
| //if (VG_(clo_model_pthreads)) |
| // VG_(tm_thread_exit)(tid); |
| |
| return tst->exitreason; |
| } |
| |
| |
| /* |
| This causes all threads to forceably exit. They aren't actually |
| dead by the time this returns; you need to call |
| VGA_(reap_threads)() to wait for them. |
| */ |
| void VG_(nuke_all_threads_except) ( ThreadId me, VgSchedReturnCode src ) |
| { |
| ThreadId tid; |
| |
| vg_assert(VG_(is_running_thread)(me)); |
| |
| for (tid = 1; tid < VG_N_THREADS; tid++) { |
| if (tid == me |
| || VG_(threads)[tid].status == VgTs_Empty) |
| continue; |
| if (0) |
| VG_(printf)( |
| "VG_(nuke_all_threads_except): nuking tid %d\n", tid); |
| |
| VG_(threads)[tid].exitreason = src; |
| VG_(kill_thread)(tid); |
| } |
| } |
| |
| |
| /* --------------------------------------------------------------------- |
| Specifying shadow register values |
| ------------------------------------------------------------------ */ |
| |
| void VG_(set_shadow_regs_area) ( ThreadId tid, OffT offset, SizeT size, |
| const UChar* area ) |
| { |
| ThreadState* tst; |
| |
| vg_assert(VG_(is_valid_tid)(tid)); |
| tst = & VG_(threads)[tid]; |
| |
| // Bounds check |
| vg_assert(0 <= offset && offset < sizeof(VexGuestArchState)); |
| vg_assert(offset + size <= sizeof(VexGuestArchState)); |
| |
| VG_(memcpy)( (void*)(((Addr)(&tst->arch.vex_shadow)) + offset), area, size); |
| } |
| |
| void VG_(get_shadow_regs_area) ( ThreadId tid, OffT offset, SizeT size, |
| UChar* area ) |
| { |
| ThreadState* tst; |
| |
| vg_assert(VG_(is_valid_tid)(tid)); |
| tst = & VG_(threads)[tid]; |
| |
| // Bounds check |
| vg_assert(0 <= offset && offset < sizeof(VexGuestArchState)); |
| vg_assert(offset + size <= sizeof(VexGuestArchState)); |
| |
| VG_(memcpy)( area, (void*)(((Addr)&(tst->arch.vex_shadow)) + offset), size); |
| } |
| |
| |
| void VG_(set_return_from_syscall_shadow) ( ThreadId tid, UWord ret_shadow ) |
| { |
| VG_(set_shadow_regs_area)(tid, O_SYSCALL_RET, sizeof(UWord), |
| (UChar*)&ret_shadow); |
| } |
| |
| UInt VG_(get_exit_status_shadow) ( ThreadId tid ) |
| { |
| UInt ret; |
| VG_(get_shadow_regs_area)(tid, O_SYSCALL_ARG1, sizeof(UInt), |
| (UChar*)&ret); |
| return ret; |
| } |
| |
| |
| /* --------------------------------------------------------------------- |
| Handle client requests. |
| ------------------------------------------------------------------ */ |
| |
| /* Do a client request for the thread tid. After the request, tid may |
| or may not still be runnable; if not, the scheduler will have to |
| choose a new thread to run. |
| */ |
| static |
| void do_client_request ( ThreadId tid ) |
| { |
| UWord* arg = (UWord*)(CLREQ_ARGS(VG_(threads)[tid].arch)); |
| UWord req_no = arg[0]; |
| |
| if (0) |
| VG_(printf)("req no = 0x%llx, arg = %p\n", (ULong)req_no, arg); |
| switch (req_no) { |
| |
| case VG_USERREQ__CLIENT_CALL0: { |
| UWord (*f)(ThreadId) = (void*)arg[1]; |
| if (f == NULL) |
| VG_(message)(Vg_DebugMsg, "VG_USERREQ__CLIENT_CALL0: func=%p\n", f); |
| else |
| SET_CLCALL_RETVAL(tid, f ( tid ), (Addr)f); |
| break; |
| } |
| case VG_USERREQ__CLIENT_CALL1: { |
| UWord (*f)(ThreadId, UWord) = (void*)arg[1]; |
| if (f == NULL) |
| VG_(message)(Vg_DebugMsg, "VG_USERREQ__CLIENT_CALL1: func=%p\n", f); |
| else |
| SET_CLCALL_RETVAL(tid, f ( tid, arg[2] ), (Addr)f ); |
| break; |
| } |
| case VG_USERREQ__CLIENT_CALL2: { |
| UWord (*f)(ThreadId, UWord, UWord) = (void*)arg[1]; |
| if (f == NULL) |
| VG_(message)(Vg_DebugMsg, "VG_USERREQ__CLIENT_CALL2: func=%p\n", f); |
| else |
| SET_CLCALL_RETVAL(tid, f ( tid, arg[2], arg[3] ), (Addr)f ); |
| break; |
| } |
| case VG_USERREQ__CLIENT_CALL3: { |
| UWord (*f)(ThreadId, UWord, UWord, UWord) = (void*)arg[1]; |
| if (f == NULL) |
| VG_(message)(Vg_DebugMsg, "VG_USERREQ__CLIENT_CALL3: func=%p\n", f); |
| else |
| SET_CLCALL_RETVAL(tid, f ( tid, arg[2], arg[3], arg[4] ), (Addr)f ); |
| break; |
| } |
| |
| /* Note: for tools that replace malloc() et al, we want to call |
| the replacement versions. For those that don't, we want to call |
| VG_(cli_malloc)() et al. We do this by calling SK_(malloc)(), which |
| malloc-replacing tools must replace, but have the default definition |
| of SK_(malloc)() call VG_(cli_malloc)(). */ |
| |
| /* Note: for MALLOC and FREE, must set the appropriate "lock"... see |
| the comment in vg_defaults.c/SK_(malloc)() for why. */ |
| case VG_USERREQ__MALLOC: |
| VG_(tl_malloc_called_by_scheduler) = True; |
| SET_PTHREQ_RETVAL( |
| tid, (Addr)TL_(malloc) ( tid, arg[1] ) |
| ); |
| VG_(tl_malloc_called_by_scheduler) = False; |
| break; |
| |
| case VG_USERREQ__FREE: |
| VG_(tl_malloc_called_by_scheduler) = True; |
| TL_(free) ( tid, (void*)arg[1] ); |
| VG_(tl_malloc_called_by_scheduler) = False; |
| SET_PTHREQ_RETVAL(tid, 0); /* irrelevant */ |
| break; |
| |
| case VG_USERREQ__RUNNING_ON_VALGRIND: |
| SET_CLREQ_RETVAL(tid, RUNNING_ON_VALGRIND+1); |
| break; |
| |
| case VG_USERREQ__READ_MILLISECOND_TIMER: |
| SET_PTHREQ_RETVAL(tid, VG_(read_millisecond_timer)()); |
| break; |
| |
| case VG_USERREQ__PRINTF: { |
| int count = |
| VG_(vmessage)( Vg_ClientMsg, (char *)arg[1], (void*)arg[2] ); |
| SET_CLREQ_RETVAL( tid, count ); |
| break; } |
| |
| case VG_USERREQ__INTERNAL_PRINTF: { |
| int count = |
| VG_(vmessage)( Vg_DebugMsg, (char *)arg[1], (void*)arg[2] ); |
| SET_CLREQ_RETVAL( tid, count ); |
| break; } |
| |
| case VG_USERREQ__PRINTF_BACKTRACE: { |
| int count = |
| VG_(vmessage)( Vg_ClientMsg, (char *)arg[1], (void*)arg[2] ); |
| VG_(get_and_pp_StackTrace)( tid, VG_(clo_backtrace_size) ); |
| SET_CLREQ_RETVAL( tid, count ); |
| break; } |
| |
| case VG_USERREQ__GET_MALLOCFUNCS: { |
| struct vg_mallocfunc_info *info = (struct vg_mallocfunc_info *)arg[1]; |
| |
| info->tl_malloc = (Addr)TL_(malloc); |
| info->tl_calloc = (Addr)TL_(calloc); |
| info->tl_realloc = (Addr)TL_(realloc); |
| info->tl_memalign = (Addr)TL_(memalign); |
| info->tl___builtin_new = (Addr)TL_(__builtin_new); |
| info->tl___builtin_vec_new = (Addr)TL_(__builtin_vec_new); |
| info->tl_free = (Addr)TL_(free); |
| info->tl___builtin_delete = (Addr)TL_(__builtin_delete); |
| info->tl___builtin_vec_delete = (Addr)TL_(__builtin_vec_delete); |
| |
| info->arena_payload_szB = (Addr)VG_(arena_payload_szB); |
| |
| info->clo_sloppy_malloc = VG_(clo_sloppy_malloc); |
| info->clo_trace_malloc = VG_(clo_trace_malloc); |
| |
| SET_CLREQ_RETVAL( tid, 0 ); /* return value is meaningless */ |
| |
| break; |
| } |
| |
| /* Requests from the client program */ |
| |
| case VG_USERREQ__DISCARD_TRANSLATIONS: |
| if (VG_(clo_verbosity) > 2) |
| VG_(printf)( "client request: DISCARD_TRANSLATIONS," |
| " addr %p, len %d\n", |
| (void*)arg[1], arg[2] ); |
| |
| VG_(discard_translations)( arg[1], arg[2] ); |
| |
| SET_CLREQ_RETVAL( tid, 0 ); /* return value is meaningless */ |
| break; |
| |
| case VG_USERREQ__COUNT_ERRORS: |
| SET_CLREQ_RETVAL( tid, VG_(get_n_errs_found)() ); |
| break; |
| |
| /* Obsolete requests: print a warning in case there's an old |
| libpthread.so still hanging around. */ |
| case VG_USERREQ__APPLY_IN_NEW_THREAD: |
| case VG_USERREQ__QUIT: |
| case VG_USERREQ__WAIT_JOINER: |
| case VG_USERREQ__PTHREAD_JOIN: |
| case VG_USERREQ__SET_CANCELSTATE: |
| case VG_USERREQ__SET_CANCELTYPE: |
| case VG_USERREQ__TESTCANCEL: |
| case VG_USERREQ__SET_CANCELPEND: |
| case VG_USERREQ__SET_OR_GET_DETACH: |
| case VG_USERREQ__PTHREAD_GET_THREADID: |
| case VG_USERREQ__PTHREAD_MUTEX_LOCK: |
| case VG_USERREQ__PTHREAD_MUTEX_TIMEDLOCK: |
| case VG_USERREQ__PTHREAD_MUTEX_TRYLOCK: |
| case VG_USERREQ__PTHREAD_MUTEX_UNLOCK: |
| case VG_USERREQ__PTHREAD_COND_WAIT: |
| case VG_USERREQ__PTHREAD_COND_TIMEDWAIT: |
| case VG_USERREQ__PTHREAD_COND_SIGNAL: |
| case VG_USERREQ__PTHREAD_COND_BROADCAST: |
| case VG_USERREQ__PTHREAD_KEY_CREATE: |
| case VG_USERREQ__PTHREAD_KEY_DELETE: |
| case VG_USERREQ__PTHREAD_SETSPECIFIC_PTR: |
| case VG_USERREQ__PTHREAD_GETSPECIFIC_PTR: |
| case VG_USERREQ__PTHREAD_SIGMASK: |
| case VG_USERREQ__SIGWAIT: |
| case VG_USERREQ__PTHREAD_KILL: |
| case VG_USERREQ__PTHREAD_YIELD: |
| case VG_USERREQ__PTHREAD_KEY_VALIDATE: |
| case VG_USERREQ__CLEANUP_PUSH: |
| case VG_USERREQ__CLEANUP_POP: |
| case VG_USERREQ__GET_KEY_D_AND_S: |
| case VG_USERREQ__NUKE_OTHER_THREADS: |
| case VG_USERREQ__GET_N_SIGS_RETURNED: |
| case VG_USERREQ__SET_FHSTACK_USED: |
| case VG_USERREQ__GET_FHSTACK_USED: |
| case VG_USERREQ__SET_FHSTACK_ENTRY: |
| case VG_USERREQ__GET_FHSTACK_ENTRY: |
| case VG_USERREQ__GET_SIGRT_MIN: |
| case VG_USERREQ__GET_SIGRT_MAX: |
| case VG_USERREQ__ALLOC_RTSIG: |
| VG_(message)(Vg_UserMsg, "It looks like you've got an old libpthread.so* "); |
| VG_(message)(Vg_UserMsg, "installed in \"%s\".", VG_(libdir)); |
| VG_(message)(Vg_UserMsg, "Please delete it and try again."); |
| VG_(exit)(99); |
| break; |
| |
| default: |
| if (VGA_(client_request)(tid, arg)) { |
| /* architecture handled the client request */ |
| } else if (VG_(needs).client_requests) { |
| UWord ret; |
| |
| if (VG_(clo_verbosity) > 2) |
| VG_(printf)("client request: code %x, addr %p, len %d\n", |
| arg[0], (void*)arg[1], arg[2] ); |
| |
| if (TL_(handle_client_request) ( tid, arg, &ret )) |
| SET_CLREQ_RETVAL(tid, ret); |
| } else { |
| static Bool whined = False; |
| |
| if (!whined && VG_(clo_verbosity) > 2) { |
| // Allow for requests in core, but defined by tools, which |
| // have 0 and 0 in their two high bytes. |
| Char c1 = (arg[0] >> 24) & 0xff; |
| Char c2 = (arg[0] >> 16) & 0xff; |
| if (c1 == 0) c1 = '_'; |
| if (c2 == 0) c2 = '_'; |
| VG_(message)(Vg_UserMsg, "Warning:\n" |
| " unhandled client request: 0x%x (%c%c+0x%x). Perhaps\n" |
| " VG_(needs).client_requests should be set?\n", |
| arg[0], c1, c2, arg[0] & 0xffff); |
| whined = True; |
| } |
| } |
| break; |
| } |
| } |
| |
| |
| /* --------------------------------------------------------------------- |
| Sanity checking. |
| ------------------------------------------------------------------ */ |
| |
| /* Internal consistency checks on the sched structures. */ |
| static |
| void scheduler_sanity ( ThreadId tid ) |
| { |
| Bool bad = False; |
| |
| if (!VG_(is_running_thread)(tid)) { |
| VG_(message)(Vg_DebugMsg, |
| "Thread %d is supposed to be running, but doesn't own run_sema (owned by %d)\n", |
| tid, running_tid); |
| bad = True; |
| } |
| |
| if (VG_(gettid)() != VG_(threads)[tid].os_state.lwpid) { |
| VG_(message)(Vg_DebugMsg, |
| "Thread %d supposed to be in LWP %d, but we're actually %d\n", |
| tid, VG_(threads)[tid].os_state.lwpid, VG_(gettid)()); |
| bad = True; |
| } |
| } |
| |
| |
| /*--------------------------------------------------------------------*/ |
| /*--- end vg_scheduler.c ---*/ |
| /*--------------------------------------------------------------------*/ |