tlibthread: delete NetBSD special case - plan9port - [fork] Plan 9 from user space
(HTM) git clone git://src.adamsgaard.dk/plan9port
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---
(DIR) commit 5b37d9126474864b5299426e27b2af37fcc96dd0
(DIR) parent 69439fae6705a125047246c889384ed3aeb4d104
(HTM) Author: Russ Cox <rsc@swtch.com>
Date: Wed, 30 Dec 2020 00:06:35 -0500
libthread: delete NetBSD special case
I added a direct call from thread.c to pthread.c's _threadpthreadstart
in May, and no one has complained about NetBSD being broken.
So probably no one is using this on NetBSD at all.
Make pthread the only option.
Diffstat:
D src/libthread/NetBSD-386-asm.s | 7 -------
D src/libthread/NetBSD-power-asm.s | 16 ----------------
D src/libthread/NetBSD.c | 437 -------------------------------
M src/libthread/sysofiles.sh | 9 ++++-----
4 files changed, 4 insertions(+), 465 deletions(-)
---
(DIR) diff --git a/src/libthread/NetBSD-386-asm.s b/src/libthread/NetBSD-386-asm.s
t@@ -1,7 +0,0 @@
-.globl _tas
-_tas:
- movl $0xCAFEBABE, %eax
- movl 4(%esp), %ecx
- xchgl %eax, 0(%ecx)
- ret
-
(DIR) diff --git a/src/libthread/NetBSD-power-asm.s b/src/libthread/NetBSD-power-asm.s
t@@ -1,16 +0,0 @@
- .globl _tas
-_tas:
- li %r0, 0
- mr %r4, %r3
- lis %r5, 0xcafe
- ori %r5, %r5, 0xbabe
-1:
- lwarx %r3, %r0, %r4
- cmpwi %r3, 0
- bne 2f
- stwcx. %r5, %r0, %r4
- bne- 1b
-2:
- sync
- blr
-
(DIR) diff --git a/src/libthread/NetBSD.c b/src/libthread/NetBSD.c
t@@ -1,437 +0,0 @@
-#include "threadimpl.h"
-
-#undef exits
-#undef _exits
-
-static int
-timefmt(Fmt *fmt)
-{
- static char *mon[] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
- "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
- vlong ns;
- Tm tm;
- ns = nsec();
- tm = *localtime(time(0));
- return fmtprint(fmt, "%s %2d %02d:%02d:%02d.%03d",
- mon[tm.mon], tm.mday, tm.hour, tm.min, tm.sec,
- (int)(ns%1000000000)/1000000);
-}
-
-/*
- * spin locks
- */
-extern int _tas(int*);
-
-void
-_threadunlock(Lock *l, ulong pc)
-{
- USED(pc);
-
- l->held = 0;
-}
-
-int
-_threadlock(Lock *l, int block, ulong pc)
-{
- int i;
-static int first=1;
-if(first) {first=0; fmtinstall('\001', timefmt);}
-
- USED(pc);
-
- /* once fast */
- if(!_tas(&l->held))
- return 1;
- if(!block)
- return 0;
-
- /* a thousand times pretty fast */
- for(i=0; i<1000; i++){
- if(!_tas(&l->held))
- return 1;
- sched_yield();
- }
- /* now increasingly slow */
- for(i=0; i<10; i++){
- if(!_tas(&l->held))
- return 1;
- usleep(1);
- }
-fprint(2, "%\001 %s: lock loop1 %p from %lux\n", argv0, l, pc);
- for(i=0; i<10; i++){
- if(!_tas(&l->held))
- return 1;
- usleep(10);
- }
-fprint(2, "%\001 %s: lock loop2 %p from %lux\n", argv0, l, pc);
- for(i=0; i<10; i++){
- if(!_tas(&l->held))
- return 1;
- usleep(100);
- }
-fprint(2, "%\001 %s: lock loop3 %p from %lux\n", argv0, l, pc);
- for(i=0; i<10; i++){
- if(!_tas(&l->held))
- return 1;
- usleep(1000);
- }
-fprint(2, "%\001 %s: lock loop4 %p from %lux\n", argv0, l, pc);
- for(i=0; i<10; i++){
- if(!_tas(&l->held))
- return 1;
- usleep(10*1000);
- }
-fprint(2, "%\001 %s: lock loop5 %p from %lux\n", argv0, l, pc);
- for(i=0; i<1000; i++){
- if(!_tas(&l->held))
- return 1;
- usleep(100*1000);
- }
-fprint(2, "%\001 %s: lock loop6 %p from %lux\n", argv0, l, pc);
- /* take your time */
- while(_tas(&l->held))
- usleep(1000*1000);
- return 1;
-}
-
-/*
- * sleep and wakeup
- */
-static void
-ign(int x)
-{
- USED(x);
-}
-
-static void /*__attribute__((constructor))*/
-ignusr1(int restart)
-{
- struct sigaction sa;
-
- memset(&sa, 0, sizeof sa);
- sa.sa_handler = ign;
- sigemptyset(&sa.sa_mask);
- sigaddset(&sa.sa_mask, SIGUSR1);
- if(restart)
- sa.sa_flags = SA_RESTART;
- sigaction(SIGUSR1, &sa, nil);
-}
-
-void
-_procsleep(_Procrendez *r)
-{
- sigset_t mask;
-
- /*
- * Go to sleep.
- *
- * Block USR1, set the handler to interrupt system calls,
- * unlock the vouslock so our waker can wake us,
- * and then suspend.
- */
-again:
- r->asleep = 1;
- r->pid = getpid();
-
- sigprocmask(SIG_SETMASK, nil, &mask);
- sigaddset(&mask, SIGUSR1);
- sigprocmask(SIG_SETMASK, &mask, nil);
- ignusr1(0);
- unlock(r->l);
- sigdelset(&mask, SIGUSR1);
- sigsuspend(&mask);
-
- /*
- * We're awake. Make USR1 not interrupt system calls.
- */
- lock(r->l);
- ignusr1(1);
- if(r->asleep && r->pid == getpid()){
- /* Didn't really wake up - signal from something else */
- goto again;
- }
-}
-
-void
-_procwakeupandunlock(_Procrendez *r)
-{
- int pid;
-
- pid = 0;
- if(r->asleep){
- r->asleep = 0;
- assert(r->pid >= 1);
- pid = r->pid;
- }
- assert(r->l);
- unlock(r->l);
- if(pid)
- kill(pid, SIGUSR1);
-}
-
-/*
- * process creation and exit
- */
-typedef struct Stackfree Stackfree;
-struct Stackfree
-{
- Stackfree *next;
- int pid;
- int pid1;
-};
-static Lock stacklock;
-static Stackfree *stackfree;
-
-static void
-delayfreestack(uchar *stk, int pid, int pid1)
-{
- Stackfree *sf;
-
- sf = (Stackfree*)stk;
- sf->pid = pid;
- sf->pid1 = pid1;
- lock(&stacklock);
- sf->next = stackfree;
- stackfree = sf;
- unlock(&stacklock);
-}
-
-static void
-dofreestacks(void)
-{
- Stackfree *sf, *last, *next;
-
- if(stackfree==nil || !canlock(&stacklock))
- return;
-
- for(last=nil,sf=stackfree; sf; last=sf,sf=next){
- next = sf->next;
- if(sf->pid >= 1 && kill(sf->pid, 0) < 0 && errno == ESRCH)
- if(sf->pid1 >= 1 && kill(sf->pid1, 0) < 0 && errno == ESRCH){
- free(sf);
- if(last)
- last->next = next;
- else
- stackfree = next;
- sf = last;
- }
- }
- unlock(&stacklock);
-}
-
-static int
-startprocfn(void *v)
-{
- void **a;
- uchar *stk;
- void (*fn)(void*);
- Proc *p;
- int pid0, pid1;
-
- a = (void**)v;
- fn = a[0];
- p = a[1];
- stk = a[2];
- pid0 = (int)a[4];
- pid1 = getpid();
- free(a);
- p->osprocid = pid1;
-
- (*fn)(p);
-
- delayfreestack(stk, pid0, pid1);
- _exit(0);
- return 0;
-}
-
-/*
- * indirect through here so that parent need not wait for child zombie
- *
- * slight race - if child exits and then another process starts before we
- * manage to exit, we'll be running on a freed stack.
- */
-static int
-trampnowait(void *v)
-{
- void **a;
- int *kidpid;
-
- a = (void*)v;
- kidpid = a[3];
- a[4] = (void*)getpid();
- *kidpid = clone(startprocfn, a[2]+65536-512, CLONE_VM|CLONE_FILES, a);
- _exit(0);
- return 0;
-}
-
-void
-_procstart(Proc *p, void (*fn)(Proc*))
-{
- void **a;
- uchar *stk;
- int pid, kidpid, status;
-
- dofreestacks();
- a = malloc(5*sizeof a[0]);
- if(a == nil)
- sysfatal("_procstart malloc: %r");
- stk = malloc(65536);
- if(stk == nil)
- sysfatal("_procstart malloc stack: %r");
-
- a[0] = fn;
- a[1] = p;
- a[2] = stk;
- a[3] = &kidpid;
- kidpid = -1;
-
- pid = clone(trampnowait, stk+65536-16, CLONE_VM|CLONE_FILES, a);
- if(pid > 0)
- if(wait4(pid, &status, __WALL, 0) < 0)
- fprint(2, "ffork wait4: %r\n");
- if(pid < 0 || kidpid < 0){
- fprint(2, "_procstart clone: %r\n");
- abort();
- }
-}
-
-static char *threadexitsmsg;
-void
-sigusr2handler(int s)
-{
-/* fprint(2, "%d usr2 %d\n", time(0), getpid()); */
- if(threadexitsmsg)
- _exits(threadexitsmsg);
-}
-
-void
-threadexitsall(char *msg)
-{
- static int pid[1024];
- int i, npid, mypid;
- Proc *p;
-
- if(msg == nil)
- msg = "";
-
- /*
- * Only one guy, ever, gets to run this.
- * If two guys do it, inevitably they end up
- * tripping over each other in the underlying
- * C library exit() implementation, which is
- * trying to run the atexit handlers and apparently
- * not thread safe. This has been observed on
- * both Linux and OpenBSD. Sigh.
- */
- {
- static Lock onelock;
- if(!canlock(&onelock))
- _exits(threadexitsmsg);
- threadexitsmsg = msg;
- }
-
- mypid = getpid();
- lock(&_threadprocslock);
- npid = 0;
- for(p=_threadprocs; p; p=p->next)
- if(p->osprocid != mypid && p->osprocid >= 1)
- pid[npid++] = p->osprocid;
- for(i=0; i<npid; i++)
- kill(pid[i], SIGUSR2);
- unlock(&_threadprocslock);
- exits(msg);
-}
-
-/*
- * per-process data, indexed by pid
- *
- * could use modify_ldt and a segment register
- * to avoid the many calls to getpid(), but i don't
- * care -- this is compatibility code. linux 2.6 with
- * nptl is a good enough pthreads to avoid this whole file.
- */
-typedef struct Perproc Perproc;
-struct Perproc
-{
- int pid;
- Proc *proc;
-};
-
-static Lock perlock;
-static Perproc perproc[1024];
-#define P ((Proc*)-1)
-
-static Perproc*
-myperproc(void)
-{
- int i, pid, h;
- Perproc *p;
-
- pid = getpid();
- h = pid%nelem(perproc);
- for(i=0; i<nelem(perproc); i++){
- p = &perproc[(i+h)%nelem(perproc)];
- if(p->pid == pid)
- return p;
- if(p->pid == 0){
- print("found 0 at %d (h=%d)\n", (i+h)%nelem(perproc), h);
- break;
- }
- }
- fprint(2, "myperproc %d (%s): cannot find self\n", pid, argv0);
- abort();
- return nil;
-}
-
-static Perproc*
-newperproc(void)
-{
- int i, pid, h;
- Perproc *p;
-
- lock(&perlock);
- pid = getpid();
- h = pid%nelem(perproc);
- for(i=0; i<nelem(perproc); i++){
- p = &perproc[(i+h)%nelem(perproc)];
- if(p->pid == pid || p->pid == -1 || p->pid == 0){
- p->pid = pid;
- unlock(&perlock);
- return p;
- }
- }
- fprint(2, "newperproc %d: out of procs\n", pid);
- abort();
- return nil;
-}
-
-Proc*
-_threadproc(void)
-{
- return myperproc()->proc;
-}
-
-void
-_threadsetproc(Proc *p)
-{
- Perproc *pp;
-
- if(p)
- p->osprocid = getpid();
- pp = newperproc();
- pp->proc = p;
- if(p == nil)
- pp->pid = -1;
-}
-
-void
-_pthreadinit(void)
-{
- signal(SIGUSR2, sigusr2handler);
-}
-
-void
-_threadpexit(void)
-{
- _exit(0);
-}
(DIR) diff --git a/src/libthread/sysofiles.sh b/src/libthread/sysofiles.sh
t@@ -2,15 +2,14 @@
test -f $PLAN9/config && . $PLAN9/config
+echo pthread.o
+
case "$SYSNAME" in
-NetBSD)
- echo ${SYSNAME}-${OBJTYPE}-asm.o $SYSNAME.o stkmalloc.o
- ;;
OpenBSD)
- echo pthread.o stkmmap.o
+ echo stkmmap.o
;;
*)
- echo pthread.o stkmalloc.o
+ echo stkmalloc.o
esac
# Various libc don't supply swapcontext, makecontext, so we do.