Migrate the C use of SbAtomic to compiler built-ins.

b/310724224 Change-Id: I3b2dbbac4455e1aa2da6df1db368d7f59beeefac
youtube · Sep 23, 2024 · cfab2ed · cfab2ed
1 parent 948d0bf
commit cfab2ed
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Showing 6 changed files with 18 additions and 28 deletions.
diff --git a/starboard/atomic.h b/starboard/atomic.h
@@ -26,6 +26,10 @@
 #include "starboard/configuration.h"
 #include "starboard/types.h"
 
+#ifndef __cplusplus
+#error "This headers should not be included in C source code"
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif

diff --git a/starboard/nplb/include_all.c b/starboard/nplb/include_all.c
@@ -14,7 +14,6 @@
 
 // Includes all headers in a C context to make sure they compile as C files.
 
-#include "starboard/atomic.h"
 #include "starboard/audio_sink.h"
 #include "starboard/configuration.h"
 #include "starboard/cpu_features.h"

diff --git a/third_party/boringssl/src/crypto/internal.h b/third_party/boringssl/src/crypto/internal.h
@@ -121,7 +121,6 @@
 #ifdef STARBOARD
 #include <pthread.h>
 
-#include "starboard/atomic.h"
 #include "starboard/thread.h"
 #endif
 
@@ -606,7 +605,7 @@ OPENSSL_EXPORT int CRYPTO_refcount_dec_and_test_zero(CRYPTO_refcount_t *count);
 
 #if defined(STARBOARD)
 struct CRYPTO_STATIC_MUTEX {
-  SbAtomic32 initialized;
+  uint32_t initialized;
   CRYPTO_MUTEX mutex;
 };
 #define CRYPTO_STATIC_MUTEX_INIT { 0 }

diff --git a/third_party/boringssl/src/crypto/refcount_starboard.c b/third_party/boringssl/src/crypto/refcount_starboard.c
@@ -18,24 +18,20 @@
 
 #if defined(STARBOARD)
 
-#include "starboard/atomic.h"
-
 void CRYPTO_refcount_inc(CRYPTO_refcount_t *count) {
-  CRYPTO_refcount_t expected = SbAtomicNoBarrier_Load(count);
+  CRYPTO_refcount_t expected = __atomic_load_n(count, __ATOMIC_RELAXED);
 
   while (expected != CRYPTO_REFCOUNT_MAX) {
     CRYPTO_refcount_t new_value = expected + 1;
-    CRYPTO_refcount_t old_value = SbAtomicNoBarrier_CompareAndSwap(
-        count, expected, new_value);
-    if (old_value == expected) {
+    if (__atomic_compare_exchange_n(count, &expected, new_value, false,
+                                    __ATOMIC_RELAXED, __ATOMIC_RELAXED)) {
       break;
     }
-    expected = old_value;
   }
 }
 
 int CRYPTO_refcount_dec_and_test_zero(CRYPTO_refcount_t *count) {
-  CRYPTO_refcount_t expected = SbAtomicNoBarrier_Load(count);
+  CRYPTO_refcount_t expected = __atomic_load_n(count, __ATOMIC_RELAXED);
 
   for (;;) {
     if (expected == 0) {
@@ -44,12 +40,10 @@ int CRYPTO_refcount_dec_and_test_zero(CRYPTO_refcount_t *count) {
       return 0;
     } else {
       CRYPTO_refcount_t new_value = expected - 1;
-      CRYPTO_refcount_t old_value = SbAtomicNoBarrier_CompareAndSwap(
-          count, expected, new_value);
-      if (old_value == expected) {
+      if (__atomic_compare_exchange_n(count, &expected, new_value, false,
+                                      __ATOMIC_RELAXED, __ATOMIC_RELAXED)) {
         return new_value == 0;
       }
-      expected = old_value;
     }
   }
 }

diff --git a/third_party/boringssl/src/crypto/thread_starboard.cc b/third_party/boringssl/src/crypto/thread_starboard.cc
@@ -62,16 +62,18 @@ void EnsureInitialized(struct CRYPTO_STATIC_MUTEX* lock) {
     kInitialized
   };
 
-  if (SbAtomicNoBarrier_Load(&lock->initialized) == kInitialized) {
+  if (__atomic_load_n(&lock->initialized, __ATOMIC_RELAXED) == kInitialized) {
     return;
   }
-  if (SbAtomicNoBarrier_CompareAndSwap(&lock->initialized,
-      kUninitialized, kInitializing) == kUninitialized) {
+
+  uint32_t expected = kUninitialized;
+  if (__atomic_compare_exchange_n(&lock->initialized, &expected, kInitializing,
+                                  false, __ATOMIC_RELAXED, __ATOMIC_RELAXED)) {
     CRYPTO_MUTEX_init(&lock->mutex);
-    SbAtomicNoBarrier_Store(&lock->initialized, kInitialized);
+    __atomic_store_n(&lock->initialized, kInitialized, __ATOMIC_RELAXED);
     return;
   }
-  while (SbAtomicNoBarrier_Load(&lock->initialized) != kInitialized) {
+  while (__atomic_load_n(&lock->initialized, __ATOMIC_RELAXED) != kInitialized) {
     usleep(1000);  // 1ms
   }
 }

diff --git a/third_party/boringssl/src/include/openssl/thread.h b/third_party/boringssl/src/include/openssl/thread.h
@@ -61,10 +61,6 @@
 
 #include <openssl/base.h>
 
-#ifdef STARBOARD
-#include "starboard/atomic.h"
-#endif
-
 #if defined(__cplusplus)
 extern "C" {
 #endif
@@ -114,11 +110,7 @@ typedef union crypto_mutex_st {
 // as C code that might not set -std=c11. So, in practice, it's not possible to
 // do that. Instead we statically assert that the size and native alignment of
 // a plain uint32_t and an _Atomic uint32_t are equal in refcount_c11.c.
-#if defined(STARBOARD)
-typedef SbAtomic32 CRYPTO_refcount_t;
-#else
 typedef uint32_t CRYPTO_refcount_t;
-#endif
 
 
 // Deprecated functions.