njn | 278b3d6 | 2005-05-30 23:20:51 +0000 | [diff] [blame] | 1 | |
| 2 | /*--------------------------------------------------------------------*/ |
| 3 | /*--- The scheduler. pub_core_scheduler.h ---*/ |
| 4 | /*--------------------------------------------------------------------*/ |
| 5 | |
| 6 | /* |
| 7 | This file is part of Valgrind, a dynamic binary instrumentation |
| 8 | framework. |
| 9 | |
| 10 | Copyright (C) 2000-2005 Julian Seward |
| 11 | jseward@acm.org |
| 12 | |
| 13 | This program is free software; you can redistribute it and/or |
| 14 | modify it under the terms of the GNU General Public License as |
| 15 | published by the Free Software Foundation; either version 2 of the |
| 16 | License, or (at your option) any later version. |
| 17 | |
| 18 | This program is distributed in the hope that it will be useful, but |
| 19 | WITHOUT ANY WARRANTY; without even the implied warranty of |
| 20 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 21 | General Public License for more details. |
| 22 | |
| 23 | You should have received a copy of the GNU General Public License |
| 24 | along with this program; if not, write to the Free Software |
| 25 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 26 | 02111-1307, USA. |
| 27 | |
| 28 | The GNU General Public License is contained in the file COPYING. |
| 29 | */ |
| 30 | |
| 31 | #ifndef __PUB_CORE_SCHEDULER_H |
| 32 | #define __PUB_CORE_SCHEDULER_H |
| 33 | |
| 34 | //-------------------------------------------------------------------- |
| 35 | // PURPOSE: This module is the scheduler, which is the main loop |
| 36 | // controlling the running of all the program's threads. |
| 37 | // It's at the centre of everything. |
| 38 | //-------------------------------------------------------------------- |
| 39 | |
| 40 | /* |
| 41 | Thread state machine: |
| 42 | |
| 43 | Empty -> Init -> Runnable <=> WaitSys/Yielding |
| 44 | ^ | |
| 45 | \---- Zombie -----/ |
| 46 | */ |
| 47 | typedef |
| 48 | enum ThreadStatus { |
| 49 | VgTs_Empty, /* this slot is not in use */ |
| 50 | VgTs_Init, /* just allocated */ |
| 51 | VgTs_Runnable, /* ready to run */ |
| 52 | VgTs_WaitSys, /* waiting for a syscall to complete */ |
| 53 | VgTs_Yielding, /* temporarily yielding the CPU */ |
| 54 | VgTs_Zombie, /* transient state just before exiting */ |
| 55 | } |
| 56 | ThreadStatus; |
| 57 | |
| 58 | /* Return codes from the scheduler. */ |
| 59 | typedef |
| 60 | enum { |
| 61 | VgSrc_None, /* not exiting yet */ |
| 62 | VgSrc_ExitSyscall, /* client called exit(). This is the normal |
| 63 | route out. */ |
| 64 | VgSrc_FatalSig /* Killed by the default action of a fatal |
| 65 | signal */ |
| 66 | } |
| 67 | VgSchedReturnCode; |
| 68 | |
| 69 | |
| 70 | #if defined(VGA_x86) |
| 71 | typedef VexGuestX86State VexGuestArchState; |
| 72 | #elif defined(VGA_amd64) |
| 73 | typedef VexGuestAMD64State VexGuestArchState; |
| 74 | #elif defined(VGA_arm) |
| 75 | typedef VexGuestARMState VexGuestArchState; |
| 76 | #else |
| 77 | # error Unknown architecture |
| 78 | #endif |
| 79 | |
| 80 | |
| 81 | typedef |
| 82 | struct { |
| 83 | /* --- BEGIN vex-mandated guest state --- */ |
| 84 | |
| 85 | /* Saved machine context. */ |
| 86 | VexGuestArchState vex; |
| 87 | |
| 88 | /* Saved shadow context. */ |
| 89 | VexGuestArchState vex_shadow; |
| 90 | |
| 91 | /* Spill area. */ |
| 92 | UChar vex_spill[LibVEX_N_SPILL_BYTES]; |
| 93 | |
| 94 | /* --- END vex-mandated guest state --- */ |
| 95 | } |
| 96 | ThreadArchState; |
| 97 | |
| 98 | |
| 99 | typedef struct { |
| 100 | /* ThreadId == 0 (and hence vg_threads[0]) is NEVER USED. |
| 101 | The thread identity is simply the index in vg_threads[]. |
| 102 | ThreadId == 1 is the root thread and has the special property |
| 103 | that we don't try and allocate or deallocate its stack. For |
| 104 | convenience of generating error message, we also put the |
| 105 | ThreadId in this tid field, but be aware that it should |
| 106 | ALWAYS == the index in vg_threads[]. */ |
| 107 | ThreadId tid; |
| 108 | |
| 109 | /* Current scheduling status. */ |
| 110 | ThreadStatus status; |
| 111 | |
| 112 | /* This is set if the thread is in the process of exiting for any |
| 113 | reason. The precise details of the exit are in the OS-specific |
| 114 | state. */ |
| 115 | VgSchedReturnCode exitreason; |
| 116 | |
| 117 | /* Architecture-specific thread state. */ |
| 118 | ThreadArchState arch; |
| 119 | |
| 120 | /* This thread's blocked-signals mask. Semantics is that for a |
| 121 | signal to be delivered to this thread, the signal must not be |
| 122 | blocked by this signal mask. If more than one thread accepts a |
| 123 | signal, then it will be delivered to one at random. If all |
| 124 | threads block the signal, it will remain pending until either a |
| 125 | thread unblocks it or someone uses sigwaitsig/sigtimedwait. */ |
| 126 | vki_sigset_t sig_mask; |
| 127 | |
| 128 | /* tmp_sig_mask is usually the same as sig_mask, and is kept in |
| 129 | sync whenever sig_mask is changed. The only time they have |
| 130 | different values is during the execution of a sigsuspend, where |
| 131 | tmp_sig_mask is the temporary mask which sigsuspend installs. |
| 132 | It is only consulted to compute the signal mask applied to a |
| 133 | signal handler. */ |
| 134 | vki_sigset_t tmp_sig_mask; |
| 135 | |
| 136 | /* A little signal queue for signals we can't get the kernel to |
| 137 | queue for us. This is only allocated as needed, since it should |
| 138 | be rare. */ |
| 139 | struct SigQueue *sig_queue; |
| 140 | |
| 141 | /* Syscall the Thread is currently running; -1 if none. Should only |
| 142 | be set while Thread is in VgTs_WaitSys. */ |
| 143 | Int syscallno; |
| 144 | |
| 145 | /* Client stacks. When a thread slot is freed, we don't deallocate its |
| 146 | stack; we just leave it lying around for the next use of the |
| 147 | slot. If the next use of the slot requires a larger stack, |
| 148 | only then is the old one deallocated and a new one |
| 149 | allocated. |
| 150 | |
| 151 | For the main thread (threadid == 0), this mechanism doesn't |
| 152 | apply. We don't know the size of the stack since we didn't |
| 153 | allocate it, and furthermore we never reallocate it. */ |
| 154 | |
| 155 | /* The allocated size of this thread's stack (permanently zero |
| 156 | if this is ThreadId == 0, since we didn't allocate its stack) */ |
| 157 | SizeT client_stack_szB; |
| 158 | |
| 159 | /* Address of the highest legitimate word in this stack. This is |
| 160 | used for error messages only -- not critical for execution |
| 161 | correctness. Is is set for all stacks, specifically including |
| 162 | ThreadId == 0 (the main thread). */ |
| 163 | Addr client_stack_highest_word; |
| 164 | |
| 165 | /* Alternate signal stack */ |
| 166 | vki_stack_t altstack; |
| 167 | |
| 168 | /* OS-specific thread state */ |
| 169 | os_thread_t os_state; |
| 170 | |
| 171 | /* Used in the syscall handlers. Set to True to indicate that the |
| 172 | PRE routine for a syscall has set the syscall result already and |
| 173 | so the syscall does not need to be handed to the kernel. */ |
| 174 | Bool syscall_result_set; |
| 175 | |
| 176 | /* Per-thread jmp_buf to resume scheduler after a signal */ |
| 177 | Bool sched_jmpbuf_valid; |
| 178 | jmp_buf sched_jmpbuf; |
| 179 | } |
| 180 | ThreadState; |
| 181 | |
| 182 | |
| 183 | /* The thread table. */ |
| 184 | extern ThreadState VG_(threads)[VG_N_THREADS]; |
| 185 | |
| 186 | /* Allocate a new ThreadState */ |
| 187 | extern ThreadId VG_(alloc_ThreadState)(void); |
| 188 | |
| 189 | /* A thread exits. tid must currently be running. */ |
| 190 | extern void VG_(exit_thread)(ThreadId tid); |
| 191 | |
| 192 | /* Kill a thread. This interrupts whatever a thread is doing, and |
| 193 | makes it exit ASAP. This does not set the exitreason or |
| 194 | exitcode. */ |
| 195 | extern void VG_(kill_thread)(ThreadId tid); |
| 196 | |
| 197 | /* Check that tid is in range and denotes a non-Empty thread. */ |
| 198 | extern Bool VG_(is_valid_tid) ( ThreadId tid ); |
| 199 | |
| 200 | /* Get the ThreadState for a particular thread */ |
| 201 | extern ThreadState *VG_(get_ThreadState)(ThreadId tid); |
| 202 | |
| 203 | /* Given an LWP id (ie, real kernel thread id), find the corresponding |
| 204 | ThreadId */ |
| 205 | extern ThreadId VG_(get_lwp_tid)(Int lwpid); |
| 206 | |
| 207 | /* Returns true if a thread is currently running (ie, has the CPU lock) */ |
| 208 | extern Bool VG_(is_running_thread)(ThreadId tid); |
| 209 | |
| 210 | /* Returns true if the thread is in the process of exiting */ |
| 211 | extern Bool VG_(is_exiting)(ThreadId tid); |
| 212 | |
| 213 | /* Return the number of non-dead Threads */ |
| 214 | extern Int VG_(count_living_threads)(void); |
| 215 | |
| 216 | /* Nuke all threads except tid. */ |
| 217 | extern void VG_(nuke_all_threads_except) ( ThreadId me, |
| 218 | VgSchedReturnCode reason ); |
| 219 | |
| 220 | /* Make a thread the running thread. The thread must previously been |
| 221 | sleeping, and not holding the CPU semaphore. This will set the |
| 222 | thread state to VgTs_Runnable, and the thread will attempt to take |
| 223 | the CPU semaphore. By the time it returns, tid will be the running |
| 224 | thread. */ |
| 225 | extern void VG_(set_running) ( ThreadId tid ); |
| 226 | |
| 227 | /* Set a thread into a sleeping state. Before the call, the thread |
| 228 | must be runnable, and holding the CPU semaphore. When this call |
| 229 | returns, the thread will be set to the specified sleeping state, |
| 230 | and will not be holding the CPU semaphore. Note that another |
| 231 | thread could be running by the time this call returns, so the |
| 232 | caller must be careful not to touch any shared state. It is also |
| 233 | the caller's responsibility to actually block until the thread is |
| 234 | ready to run again. */ |
| 235 | extern void VG_(set_sleeping) ( ThreadId tid, ThreadStatus state ); |
| 236 | |
| 237 | /* Yield the CPU for a while */ |
| 238 | extern void VG_(vg_yield)(void); |
| 239 | |
| 240 | // The scheduler. |
| 241 | extern VgSchedReturnCode VG_(scheduler) ( ThreadId tid ); |
| 242 | |
| 243 | // Do everything which needs doing before the process finally ends, |
| 244 | // like printing reports, etc |
| 245 | extern void VG_(shutdown_actions_NORETURN) ( |
| 246 | ThreadId tid, |
| 247 | VgSchedReturnCode tids_schedretcode |
| 248 | ); |
| 249 | |
| 250 | extern void VG_(scheduler_init) ( void ); |
| 251 | |
| 252 | extern void VG_(pp_sched_status) ( void ); |
| 253 | |
| 254 | // Longjmp back to the scheduler and thus enter the sighandler immediately. |
| 255 | extern void VG_(resume_scheduler) ( ThreadId tid ); |
| 256 | |
| 257 | /* If true, a fault is Valgrind-internal (ie, a bug) */ |
| 258 | extern Bool VG_(my_fault); |
| 259 | |
| 260 | #endif // __PUB_CORE_SCHEDULER_H |
| 261 | |
| 262 | /*--------------------------------------------------------------------*/ |
| 263 | /*--- end ---*/ |
| 264 | /*--------------------------------------------------------------------*/ |