diff options
Diffstat (limited to 'winsup/cygwin/resource.cc')
| -rw-r--r-- | winsup/cygwin/resource.cc | 85 |
1 files changed, 59 insertions, 26 deletions
diff --git a/winsup/cygwin/resource.cc b/winsup/cygwin/resource.cc index 895ba7f33..a5a23a4d8 100644 --- a/winsup/cygwin/resource.cc +++ b/winsup/cygwin/resource.cc @@ -111,6 +111,61 @@ getrusage (int intwho, struct rusage *rusage_in) return res; } +/* Default stacksize in case RLIMIT_STACK is RLIM_INFINITY is 2 Megs with + system-dependent number of guard pages. The pthread stacksize does not + include the guardpage size, so we have to subtract the default guardpage + size. Additionally the Windows stack handling disallows to commit the + last page, so we subtract it, too. */ +#define DEFAULT_STACKSIZE (2 * 1024 * 1024) +#define DEFAULT_STACKGUARD (wincap.def_guard_page_size() + wincap.page_size ()) + +muto NO_COPY rlimit_stack_guard; +static struct rlimit rlimit_stack = { 0, RLIM_INFINITY }; + +static void +__set_rlimit_stack (const struct rlimit *rlp) +{ + rlimit_stack_guard.init ("rlimit_stack_guard")->acquire (); + rlimit_stack = *rlp; + rlimit_stack_guard.release (); +} + +static void +__get_rlimit_stack (struct rlimit *rlp) +{ + rlimit_stack_guard.init ("rlimit_stack_guard")->acquire (); + if (!rlimit_stack.rlim_cur) + { + /* Fetch the default stacksize from the executable header... */ + PIMAGE_DOS_HEADER dosheader; + PIMAGE_NT_HEADERS ntheader; + + dosheader = (PIMAGE_DOS_HEADER) GetModuleHandle (NULL); + ntheader = (PIMAGE_NT_HEADERS) ((PBYTE) dosheader + dosheader->e_lfanew); + rlimit_stack.rlim_cur = ntheader->OptionalHeader.SizeOfStackReserve; + /* ...and subtract the guardpages. */ + rlimit_stack.rlim_cur -= DEFAULT_STACKGUARD; + } + *rlp = rlimit_stack; + rlimit_stack_guard.release (); +} + +size_t +get_rlimit_stack (void) +{ + struct rlimit rl; + + __get_rlimit_stack (&rl); + /* RLIM_INFINITY doesn't make much sense. As in glibc, use an + "architecture-specific default". */ + if (rl.rlim_cur == RLIM_INFINITY) + rl.rlim_cur = DEFAULT_STACKSIZE - DEFAULT_STACKGUARD; + /* Always return at least minimum stacksize. */ + else if (rl.rlim_cur < PTHREAD_STACK_MIN) + rl.rlim_cur = PTHREAD_STACK_MIN; + return (size_t) rl.rlim_cur; +} + extern "C" int getrlimit (int resource, struct rlimit *rlp) { @@ -127,32 +182,7 @@ getrlimit (int resource, struct rlimit *rlp) case RLIMIT_AS: break; case RLIMIT_STACK: - PTEB teb; - /* 2015-06-26: Originally rlim_cur returned the size of the still - available stack area on the current stack, rlim_max the total size - of the current stack. Two problems: - - - Per POSIX, RLIMIT_STACK returns "the maximum size of the initial - thread's stack, in bytes. The implementation does not - automatically grow the stack beyond this limit". - - - With the implementation of sigaltstack, the current stack is not - necessarily the "initial thread's stack" anymore. Rather, when - called from a signal handler running on the alternate stack, - RLIMIT_STACK should return the size of the original stack. - - rlim_cur is now the size of the stack. For system-provided stacks - it's the size between DeallocationStack and StackBase. For - application-provided stacks (via pthread_attr_setstack), - DeallocationStack is NULL, but StackLimit points to the bottom - of the stack. - - rlim_max is set to RLIM_INFINITY since there's no hard limit - for stack sizes on Windows. */ - teb = NtCurrentTeb (); - rlp->rlim_cur = (rlim_t) teb->Tib.StackBase - - (rlim_t) (teb->DeallocationStack - ?: teb->Tib.StackLimit); + __get_rlimit_stack (rlp); break; case RLIMIT_NOFILE: rlp->rlim_cur = getdtablesize (); @@ -206,6 +236,9 @@ setrlimit (int resource, const struct rlimit *rlp) if (rlp->rlim_cur != RLIM_INFINITY) return setdtablesize (rlp->rlim_cur); break; + case RLIMIT_STACK: + __set_rlimit_stack (rlp); + break; default: set_errno (EINVAL); __leave; |