From f1488baef95e8d18a1c95e09e8d2a9122ce84128 Mon Sep 17 00:00:00 2001
From: Fred Wright <fw@fwright.net>
Date: Fri, 15 Nov 2024 15:50:16 -0800
Subject: [PATCH] pthread_get_stacksize_np: Cache dlsym() result.
This avoids repeatedly looking up the symbol for the OS call.
Also cleans up indentation.
TESTED:
Passes tests on all platforms.
---
src/pthread_get_stacksize_np.c | 50 ++++++++++++++++++----------------
1 file changed, 27 insertions(+), 23 deletions(-)
diff --git a/src/pthread_get_stacksize_np.c b/src/pthread_get_stacksize_np.c
index 1bbd720..4ffb38b 100644
--- a/src/pthread_get_stacksize_np.c
+++ b/src/pthread_get_stacksize_np.c
@@ -43,29 +43,33 @@ size_t pthread_get_stacksize_np(pthread_t t) {
} *thread = (void*) t;
int is_main_thread = ((thread->detached & 4) == 4);
#endif
- if ( is_main_thread ) {
- /* use LLVM workaround */
- /* see https://github.com/llvm/llvm-project/blob/617a15a9eac96088ae5e9134248d8236e34b91b1/compiler-rt/lib/sanitizer_common/sanitizer_mac.cpp#L414 */
- /* OpenJDK also has a workaround */
- /* see https://github.com/openjdk/jdk/blob/e833bfc8ac6104522d037e7eb300f5aa112688bb/src/hotspot/os_cpu/bsd_x86/os_bsd_x86.cpp#L715 */
- struct rlimit limit;
- if( getrlimit(RLIMIT_STACK, &limit) ) {
- exit(EXIT_FAILURE);
- }
- if( limit.rlim_cur < kMaxThreadStackSize ) {
- return limit.rlim_cur;
- } else {
- return kMaxThreadStackSize;
- }
- } else {
- /* bug only affects main thread */
- size_t (*real_pthread_get_stacksize_np)(pthread_t);
- real_pthread_get_stacksize_np = dlsym(RTLD_NEXT, "pthread_get_stacksize_np");
- if (real_pthread_get_stacksize_np == NULL) {
- exit(EXIT_FAILURE);
- }
- return real_pthread_get_stacksize_np(t);
- }
+ if ( is_main_thread ) {
+ /* use LLVM workaround */
+ /* see https://github.com/llvm/llvm-project/blob/617a15a9eac96088ae5e9134248d8236e34b91b1/compiler-rt/lib/sanitizer_common/sanitizer_mac.cpp#L414 */
+ /* OpenJDK also has a workaround */
+ /* see https://github.com/openjdk/jdk/blob/e833bfc8ac6104522d037e7eb300f5aa112688bb/src/hotspot/os_cpu/bsd_x86/os_bsd_x86.cpp#L715 */
+ struct rlimit limit;
+ if( getrlimit(RLIMIT_STACK, &limit) ) {
+ exit(EXIT_FAILURE);
+ }
+ if( limit.rlim_cur < kMaxThreadStackSize ) {
+ return limit.rlim_cur;
+ } else {
+ return kMaxThreadStackSize;
+ }
+ } else {
+ /* bug only affects main thread */
+ static size_t (*os_pthread_get_stacksize_np)(pthread_t);
+ if (!os_pthread_get_stacksize_np) {
+ os_pthread_get_stacksize_np =
+ dlsym(RTLD_NEXT, "pthread_get_stacksize_np");
+ /* Something's badly broken if this fails */
+ if (!os_pthread_get_stacksize_np) {
+ abort();
+ }
+ }
+ return (*os_pthread_get_stacksize_np)(t);
+ }
}
#endif /* __MPLS_LIB_SUPPORT_PTHREAD_GET_STACKSIZE_NP_FIX__ */
--
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