From a2aa6667e1e4d214390d1051a5866d944032a710 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=D0=9B=D0=B5=D0=BE=D0=BD=D0=B8=D0=B4=20=D0=AE=D1=80=D1=8C?=
 =?UTF-8?q?=D0=B5=D0=B2=20=28Leonid=20Yuriev=29?= <leo@yuriev.ru>
Date: Thu, 21 Apr 2022 15:41:25 +0300
Subject: [PATCH] mdbx: avoid 32-bit Bionic/Android hang within
 `pthread_mutex_lock()`.

---
 src/core.c      |  4 ++--
 src/lck-posix.c | 23 ++++++++++++++++++++++-
 src/osal.c      |  4 ++--
 src/osal.h      | 15 +++++++++++++++
 4 files changed, 41 insertions(+), 5 deletions(-)

diff --git a/src/core.c b/src/core.c
index 31a75049..647975ca 100644
--- a/src/core.c
+++ b/src/core.c
@@ -1248,7 +1248,7 @@ static __inline void rthc_lock(void) {
 #if defined(_WIN32) || defined(_WIN64)
   EnterCriticalSection(&rthc_critical_section);
 #else
-  mdbx_ensure(nullptr, pthread_mutex_lock(&rthc_mutex) == 0);
+  mdbx_ensure(nullptr, mdbx_pthread_mutex_lock(&rthc_mutex) == 0);
 #endif
 }
 
@@ -1596,7 +1596,7 @@ static __inline void lcklist_lock(void) {
 #if defined(_WIN32) || defined(_WIN64)
   EnterCriticalSection(&lcklist_critical_section);
 #else
-  mdbx_ensure(nullptr, pthread_mutex_lock(&lcklist_mutex) == 0);
+  mdbx_ensure(nullptr, mdbx_pthread_mutex_lock(&lcklist_mutex) == 0);
 #endif
 }
 
diff --git a/src/lck-posix.c b/src/lck-posix.c
index 36522ac8..5753fdf1 100644
--- a/src/lck-posix.c
+++ b/src/lck-posix.c
@@ -812,11 +812,32 @@ __cold static int mdbx_ipclock_failed(MDBX_env *env, mdbx_ipclock_t *ipc,
   return rc;
 }
 
+#if defined(__ANDROID_API__) || defined(ANDROID) || defined(BIONIC)
+MDBX_INTERNAL_FUNC int mdbx_check_tid4bionic(void) {
+  /* avoid 32-bit Bionic bug/hang with 32-pit TID */
+  if (sizeof(pthread_mutex_t) < sizeof(pid_t) + sizeof(unsigned)) {
+    pid_t tid = gettid();
+    if (unlikely(tid > 0xffff)) {
+      mdbx_fatal("Raise the ENOSYS(%d) error to avoid hang due "
+                 "the 32-bit Bionic/Android bug with tid/thread_id 0x%08x(%i) "
+                 "that don’t fit in 16 bits, see "
+                 "https://android.googlesource.com/platform/bionic/+/master/"
+                 "docs/32-bit-abi.md#is-too-small-for-large-pids",
+                 ENOSYS, tid, tid);
+      return ENOSYS;
+    }
+  }
+  return 0;
+}
+#endif /* __ANDROID_API__ || ANDROID) || BIONIC */
+
 static int mdbx_ipclock_lock(MDBX_env *env, mdbx_ipclock_t *ipc,
                              const bool dont_wait) {
 #if MDBX_LOCKING == MDBX_LOCKING_POSIX2001 ||                                  \
     MDBX_LOCKING == MDBX_LOCKING_POSIX2008
-  int rc = dont_wait ? pthread_mutex_trylock(ipc) : pthread_mutex_lock(ipc);
+  int rc = mdbx_check_tid4bionic();
+  if (likely(rc == 0))
+    rc = dont_wait ? pthread_mutex_trylock(ipc) : pthread_mutex_lock(ipc);
   rc = (rc == EBUSY && dont_wait) ? MDBX_BUSY : rc;
 #elif MDBX_LOCKING == MDBX_LOCKING_POSIX1988
   int rc = MDBX_SUCCESS;
diff --git a/src/osal.c b/src/osal.c
index f0cb13b5..2a5cac7a 100644
--- a/src/osal.c
+++ b/src/osal.c
@@ -437,7 +437,7 @@ MDBX_INTERNAL_FUNC int mdbx_condpair_lock(mdbx_condpair_t *condpair) {
   DWORD code = WaitForSingleObject(condpair->mutex, INFINITE);
   return waitstatus2errcode(code);
 #else
-  return pthread_mutex_lock(&condpair->mutex);
+  return mdbx_pthread_mutex_lock(&condpair->mutex);
 #endif
 }
 
@@ -507,7 +507,7 @@ MDBX_INTERNAL_FUNC int mdbx_fastmutex_acquire(mdbx_fastmutex_t *fastmutex) {
   }
   return MDBX_SUCCESS;
 #else
-  return pthread_mutex_lock(fastmutex);
+  return mdbx_pthread_mutex_lock(fastmutex);
 #endif
 }
 
diff --git a/src/osal.h b/src/osal.h
index ec7b0219..31a5d1a7 100644
--- a/src/osal.h
+++ b/src/osal.h
@@ -730,6 +730,7 @@ MDBX_MAYBE_UNUSED static __inline uint32_t mdbx_getpid(void) {
 #if defined(_WIN32) || defined(_WIN64)
   return GetCurrentProcessId();
 #else
+  STATIC_ASSERT(sizeof(pid_t) <= sizeof(uint32_t));
   return getpid();
 #endif
 }
@@ -745,6 +746,20 @@ MDBX_MAYBE_UNUSED static __inline uintptr_t mdbx_thread_self(void) {
   return (uintptr_t)thunk;
 }
 
+#if !defined(_WIN32) && !defined(_WIN64)
+#if defined(__ANDROID_API__) || defined(ANDROID) || defined(BIONIC)
+MDBX_INTERNAL_FUNC int mdbx_check_tid4bionic(void);
+#else
+static __inline int mdbx_check_tid4bionic(void) { return 0; }
+#endif /* __ANDROID_API__ || ANDROID) || BIONIC */
+
+MDBX_MAYBE_UNUSED static __inline int
+mdbx_pthread_mutex_lock(pthread_mutex_t *mutex) {
+  int err = mdbx_check_tid4bionic();
+  return unlikely(err) ? err : pthread_mutex_lock(mutex);
+}
+#endif /* !Windows */
+
 MDBX_INTERNAL_FUNC uint64_t mdbx_osal_monotime(void);
 MDBX_INTERNAL_FUNC uint64_t
 mdbx_osal_16dot16_to_monotime(uint32_t seconds_16dot16);