src/runtime/thread.c

   1 #include <stdlib.h>
   2 #include <stdio.h>
   3 #include <sched.h>
   4 #include <stddef.h>
   5 #ifndef CLONE_PARENT            /* lameass glibc 2.2  doesn't define this */
   6 #define CLONE_PARENT 0x00008000 /* even though the manpage documents it */
   7 #endif
   8 #include "runtime.h"
   9 #include "sbcl.h"
  10 #include "validate.h"           /* for CONTROL_STACK_SIZE etc */
  11 #include "thread.h"
  12 #include "arch.h"
  13 #include "target-arch-os.h"
  14 #include "os.h"
  15 #include "globals.h"
  16 #ifdef LISP_FEATURE_GENCGC
  17 #include "gencgc.h"
  18 #endif
  19 #include "dynbind.h"
  20 #include "genesis/cons.h"
  21 #define ALIEN_STACK_SIZE (1*1024*1024) /* 1Mb size chosen at random */
  22
  23 int dynamic_values_bytes=4096*sizeof(lispobj);  /* same for all threads */
  24 struct thread *all_threads;
  25 lispobj all_threads_lock;
  26 extern struct interrupt_data * global_interrupt_data;
  27
  28 void get_spinlock(lispobj *word,int value);
  29
  30 /* this is the first thing that clone() runs in the child (which is
  31  * why the silly calling convention).  Basically it calls the user's
  32  * requested lisp function after doing arch_os_thread_init and
  33  * whatever other bookkeeping needs to be done
  34  */
  35
  36 /* set go to 0 to stop the thread before it starts.  Convenient if you
  37 * want to attach a debugger to it before it does anything */
  38 volatile int go=1;
  39
  40 int
  41 new_thread_trampoline(struct thread *th)
  42 {
  43     lispobj function;
  44     lispobj *args = NULL;
  45     function = th->unbound_marker;
  46     if(go==0) {
  47         fprintf(stderr, "/pausing 0x%lx(%d,%d) before new_thread_trampoline(0x%lx)\n",
  48                 (unsigned long)th,th->pid,getpid(),(unsigned long)function);
  49         while(go==0) ;
  50         fprintf(stderr, "/continue\n");
  51     }
  52     th->unbound_marker = UNBOUND_MARKER_WIDETAG;
  53     /* wait here until our thread is linked into all_threads: see below */
  54     while(th->pid<1) sched_yield();
  55
  56     if(arch_os_thread_init(th)==0)
  57         return 1;               /* failure.  no, really */
  58 #if !defined(LISP_FEATURE_SB_THREAD) && defined(LISP_FEATURE_X86)
  59     return call_into_lisp_first_time(function,args,0);
  60 #else
  61     return funcall0(function);
  62 #endif
  63 }
  64
  65 /* this is called from any other thread to create the new one, and
  66  * initialize all parts of it that can be initialized from another
  67  * thread
  68  */
  69
  70 pid_t create_thread(lispobj initial_function) {
  71     union per_thread_data *per_thread;
  72     struct thread *th=0;        /*  subdue gcc */
  73     void *spaces=0;
  74     pid_t kid_pid;
  75
  76     /* may as well allocate all the spaces at once: it saves us from
  77      * having to decide what to do if only some of the allocations
  78      * succeed */
  79     spaces=os_validate(0,
  80                        THREAD_CONTROL_STACK_SIZE+
  81                        BINDING_STACK_SIZE+
  82                        ALIEN_STACK_SIZE+
  83                        dynamic_values_bytes+
  84                        32*SIGSTKSZ
  85                        );
  86     if(!spaces) goto cleanup;
  87     per_thread=(union per_thread_data *)
  88         (spaces+
  89          THREAD_CONTROL_STACK_SIZE+
  90          BINDING_STACK_SIZE+
  91          ALIEN_STACK_SIZE);
  92
  93     th=&per_thread->thread;
  94     if(all_threads) {
  95         memcpy(per_thread,arch_os_get_current_thread(),
  96                dynamic_values_bytes);
  97     } else {
  98 #ifdef LISP_FEATURE_SB_THREAD
  99         int i;
 100         for(i=0;i<(dynamic_values_bytes/sizeof(lispobj));i++)
 101             per_thread->dynamic_values[i]=UNBOUND_MARKER_WIDETAG;
 102         if(SymbolValue(FREE_TLS_INDEX,0)==UNBOUND_MARKER_WIDETAG)
 103             SetSymbolValue
 104                 (FREE_TLS_INDEX,
 105                  make_fixnum(MAX_INTERRUPTS+
 106                              sizeof(struct thread)/sizeof(lispobj)),
 107                  0);
 108 #define STATIC_TLS_INIT(sym,field) \
 109   ((struct symbol *)(sym-OTHER_POINTER_LOWTAG))->tls_index= \
 110   make_fixnum(THREAD_SLOT_OFFSET_WORDS(field))
 111
 112         STATIC_TLS_INIT(BINDING_STACK_START,binding_stack_start);
 113         STATIC_TLS_INIT(BINDING_STACK_POINTER,binding_stack_pointer);
 114         STATIC_TLS_INIT(CONTROL_STACK_START,control_stack_start);
 115         STATIC_TLS_INIT(CONTROL_STACK_END,control_stack_end);
 116         STATIC_TLS_INIT(ALIEN_STACK,alien_stack_pointer);
 117         STATIC_TLS_INIT(PSEUDO_ATOMIC_ATOMIC,pseudo_atomic_atomic);
 118         STATIC_TLS_INIT(PSEUDO_ATOMIC_INTERRUPTED,pseudo_atomic_interrupted);
 119 #undef STATIC_TLS_INIT
 120 #endif
 121     }
 122
 123     th->control_stack_start = spaces;
 124     th->binding_stack_start=
 125         (lispobj*)((void*)th->control_stack_start+THREAD_CONTROL_STACK_SIZE);
 126     th->control_stack_end = th->binding_stack_start;
 127     th->alien_stack_start=
 128         (lispobj*)((void*)th->binding_stack_start+BINDING_STACK_SIZE);
 129     th->binding_stack_pointer=th->binding_stack_start;
 130     th->this=th;
 131     th->pid=0;
 132 #ifdef LISP_FEATURE_STACK_GROWS_DOWNWARD_NOT_UPWARD
 133     th->alien_stack_pointer=((void *)th->alien_stack_start
 134                              + ALIEN_STACK_SIZE-4); /* naked 4.  FIXME */
 135 #else
 136     th->alien_stack_pointer=((void *)th->alien_stack_start);
 137 #endif
 138     th->pseudo_atomic_interrupted=0;
 139     /* runtime.c used to set PSEUDO_ATOMIC_ATOMIC =1 globally.  I'm not
 140      * sure why, but it appears to help */
 141     th->pseudo_atomic_atomic=make_fixnum(1);
 142 #ifdef LISP_FEATURE_GENCGC
 143     gc_set_region_empty(&th->alloc_region);
 144 #endif
 145
 146 #ifndef LISP_FEATURE_SB_THREAD
 147     /* the tls-points-into-struct-thread trick is only good for threaded
 148      * sbcl, because unithread sbcl doesn't have tls.  So, we copy the
 149      * appropriate values from struct thread here, and make sure that
 150      * we use the appropriate SymbolValue macros to access any of the
 151      * variable quantities from the C runtime.  It's not quite OAOOM,
 152      * it just feels like it */
 153     SetSymbolValue(BINDING_STACK_START,th->binding_stack_start,th);
 154     SetSymbolValue(CONTROL_STACK_START,th->control_stack_start,th);
 155     SetSymbolValue(CONTROL_STACK_END,th->control_stack_end,th);
 156 #ifdef LISP_FEATURE_X86
 157     SetSymbolValue(BINDING_STACK_POINTER,th->binding_stack_pointer,th);
 158     SetSymbolValue(ALIEN_STACK,th->alien_stack_pointer,th);
 159     SetSymbolValue(PSEUDO_ATOMIC_ATOMIC,th->pseudo_atomic_atomic,th);
 160     SetSymbolValue(PSEUDO_ATOMIC_INTERRUPTED,th->pseudo_atomic_interrupted,th);
 161 #else
 162     current_binding_stack_pointer=th->binding_stack_pointer;
 163     current_control_stack_pointer=th->control_stack_start;
 164 #endif
 165 #endif
 166     bind_variable(CURRENT_CATCH_BLOCK,make_fixnum(0),th);
 167     bind_variable(CURRENT_UNWIND_PROTECT_BLOCK,make_fixnum(0),th);
 168     bind_variable(FREE_INTERRUPT_CONTEXT_INDEX,make_fixnum(0),th);
 169     bind_variable(INTERRUPT_PENDING, NIL,th);
 170     bind_variable(INTERRUPTS_ENABLED,T,th);
 171
 172     th->interrupt_data=malloc(sizeof (struct interrupt_data));
 173     if(all_threads)
 174         memcpy(th->interrupt_data,
 175                arch_os_get_current_thread()->interrupt_data,
 176                sizeof (struct interrupt_data));
 177     else
 178         memcpy(th->interrupt_data,global_interrupt_data,
 179                sizeof (struct interrupt_data));
 180
 181     th->unbound_marker=initial_function;
 182 #ifdef LISP_FEATURE_SB_THREAD
 183 #if defined(LISP_FEATURE_X86) && defined (LISP_FEATURE_LINUX)
 184     kid_pid=
 185         clone(new_thread_trampoline,
 186               (((void*)th->control_stack_start)+THREAD_CONTROL_STACK_SIZE-4),
 187               (((getpid()!=parent_pid)?(CLONE_PARENT):0)
 188                |CLONE_FILES|SIGALRM|CLONE_VM),th);
 189     if(kid_pid<=0)
 190         goto cleanup;
 191 #else
 192 #error this stuff presently only works on x86 Linux
 193 #endif
 194 #else
 195     kid_pid=getpid();
 196 #endif
 197     get_spinlock(&all_threads_lock,kid_pid);
 198     th->next=all_threads;
 199     all_threads=th;
 200     /* note that th->pid is 0 at this time.  We rely on all_threads_lock
 201      * to ensure that we don't have >1 thread with pid=0 on the list at once
 202      */
 203     protect_control_stack_guard_page(th->pid,1);
 204     all_threads_lock=0;
 205     th->pid=kid_pid;            /* child will not start until this is set */
 206 #ifndef LISP_FEATURE_SB_THREAD
 207     new_thread_trampoline(all_threads); /*  call_into_lisp */
 208     lose("Clever child?  Idiot savant, verging on the.");
 209 #endif
 210
 211     return th->pid;
 212  cleanup:
 213     /* if(th && th->tls_cookie>=0) os_free_tls_pointer(th); */
 214     if(spaces) os_invalidate(spaces,
 215                              THREAD_CONTROL_STACK_SIZE+BINDING_STACK_SIZE+
 216                              ALIEN_STACK_SIZE+dynamic_values_bytes);
 217     return 0;
 218 }
 219
 220 void destroy_thread (struct thread *th)
 221 {
 222     /* precondition: the unix task has already been killed and exited.
 223      * This is called by the parent */
 224 #ifdef LISP_FEATURE_GENCGC
 225     gc_alloc_update_page_tables(0, &th->alloc_region);
 226 #endif
 227     get_spinlock(&all_threads_lock,th->pid);
 228     if(th==all_threads)
 229         all_threads=th->next;
 230     else {
 231         struct thread *th1=all_threads;
 232         while(th1->next!=th) th1=th1->next;
 233         th1->next=th->next;     /* unlink */
 234     }
 235     all_threads_lock=0;
 236     if(th && th->tls_cookie>=0) arch_os_thread_cleanup(th);
 237     os_invalidate((os_vm_address_t) th->control_stack_start,
 238                   THREAD_CONTROL_STACK_SIZE+BINDING_STACK_SIZE+
 239                   ALIEN_STACK_SIZE+dynamic_values_bytes+
 240                   32*SIGSTKSZ);
 241 }
 242
 243
 244 struct thread *find_thread_by_pid(pid_t pid)
 245 {
 246     struct thread *th;
 247     for_each_thread(th)
 248         if(th->pid==pid) return th;
 249     return 0;
 250 }
 251
 252
 253
 254 void block_sigcont(void)
 255 {
 256     /* don't allow ourselves to receive SIGCONT while we're in the
 257      * "ambiguous" state of being on the queue but not actually stopped.
 258      */
 259     sigset_t newset;
 260     sigemptyset(&newset);
 261     sigaddset(&newset,SIGCONT);
 262     sigprocmask(SIG_BLOCK, &newset, 0);
 263 }
 264
 265 void unblock_sigcont_and_sleep(void)
 266 {
 267     sigset_t set;
 268     sigemptyset(&set);
 269     sigaddset(&set,SIGCONT);
 270     sigwaitinfo(&set,0);
 271     sigprocmask(SIG_UNBLOCK,&set,0);
 272 }
 273