From d472655c75767d8a5956a01435f769c71db499b7 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Tue, 25 Apr 2000 07:40:56 +0000 Subject: Update. 2000-04-25 Ulrich Drepper * elf/dl-profile.c (_dl_mcount): Try to be thread-safe while not setting the state to GMON_PROF_BUSY. --- elf/dl-profile.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) (limited to 'elf/dl-profile.c') diff --git a/elf/dl-profile.c b/elf/dl-profile.c index 023ac1783b..5d69b718e1 100644 --- a/elf/dl-profile.c +++ b/elf/dl-profile.c @@ -154,11 +154,11 @@ struct here_fromstruct uint16_t link; }; -static uint16_t *tos; +static volatile uint16_t *tos; static struct here_fromstruct *froms; -static size_t fromlimit; -static size_t fromidx; +static uint32_t fromlimit; +static volatile uint32_t fromidx; static uintptr_t lowpc; static size_t textsize; @@ -431,12 +431,15 @@ _dl_start_profile (struct link_map *map, const char *output_dir) void _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc) { - uint16_t *topcindex; + volatile uint16_t *topcindex; size_t i, fromindex; struct here_fromstruct *fromp; +#if 0 + /* XXX I think this is now not necessary anymore. */ if (! compare_and_swap (&state, GMON_PROF_ON, GMON_PROF_BUSY)) return; +#endif /* Compute relative addresses. The shared object can be loaded at any address. The value of frompc could be anything. We cannot @@ -491,31 +494,32 @@ _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc) size_t newfromidx; to_index = (data[narcs].self_pc / (hashfraction * sizeof (*tos))); - newfromidx = fromidx++; + newfromidx = exchange_and_add (&fromidx, 1) + 1; froms[newfromidx].here = &data[narcs]; froms[newfromidx].link = tos[to_index]; tos[to_index] = newfromidx; - ++narcs; + atomic_add (&narcs, 1); } /* If we still have no entry stop searching and insert. */ if (*topcindex == 0) { - size_t newarc = 1 + exchange_and_add (narcsp, 1); + uint_fast32_t newarc = 1 + exchange_and_add (narcsp, 1); /* In rare cases it could happen that all entries in FROMS are occupied. So we cannot count this anymore. */ if (newarc >= fromlimit) goto done; - fromp = &froms[*topcindex = fromidx++]; + *topcindex = exchange_and_add (&fromidx, 1) + 1; + fromp = &froms[*topcindex]; fromp->here = &data[newarc]; data[newarc].from_pc = frompc; data[newarc].self_pc = selfpc; data[newarc].count = 0; fromp->link = 0; - ++narcs; + atomic_add (&narcs, 1); break; } @@ -531,5 +535,8 @@ _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc) atomic_add (&fromp->here->count, 1); done: +#if 0 + /* XXX See above, Shouldn't be necessary anymore. */ state = GMON_PROF_ON; +#endif } -- cgit v1.2.3