Remove portability/Stdlib.{h,cpp}

Summary: This was wrong and is like better solved, not with a shim layer, but by not using such a platform-specific function in the first place.

Reviewed By: yfeldblum

Differential Revision: D3001253

fb-gh-sync-id: 460cc46b1c9adc3d229a07cb290270f7afbbb1e0
shipit-source-id: 460cc46b1c9adc3d229a07cb290270f7afbbb1e0

folly/Makefile.am

@@ -271,7 +271,7 @@ nobase_follyinclude_HEADERS = \
 	portability/Constexpr.h \
 	portability/Environment.h \
 	portability/GFlags.h \
-	portability/Stdlib.h \
+	portability/Memory.h \
 	portability/Strings.h \
 	portability/Syscall.h \
 	portability/SysStat.h \
@@ -406,7 +406,6 @@ libfolly_la_SOURCES = \
 	MacAddress.cpp \
 	MemoryMapping.cpp \
 	portability/Environment.cpp \
-	portability/Stdlib.cpp \
 	portability/Strings.cpp \
 	portability/SysStat.cpp \
 	portability/SysTime.cpp \

folly/Memory.h

@@ -18,6 +18,7 @@
 #define FOLLY_MEMORY_H_
 
 #include <folly/Traits.h>
+#include <folly/portability/Memory.h>
 
 #include <cstddef>
 #include <cstdlib>

folly/portability/Stdlib.cpp → folly/portability/Memory.cpp

@@ -14,29 +14,42 @@
  * limitations under the License.
  */
 
-#include <folly/portability/Stdlib.h>
+#include <folly/portability/Memory.h>
 
-#include <errno.h>
-
-#if defined(__ANDROID__)
+#include <cerrno>
+#include <cstdlib>
 
+#ifdef __ANDROID__
 #include <android/api-level.h>
+#endif
+
+namespace folly {
+namespace detail {
+
+#ifdef _WIN32
+void* aligned_malloc(size_t size, size_t align) { return nullptr; }
+
+void aligned_free(void* aligned_ptr) {}
+#elif defined(__ANDROID__) && (__ANDROID_API__ <= 15)
 
-#if (__ANDROID_API__ <= 15)
+void* aligned_malloc(size_t size, size_t align) { return memalign(align, size) }
 
-int posix_memalign(void** memptr, size_t alignment, size_t size) {
-  int rc = 0;
-  int saved_errno = errno;
+void aligned_free(void* aligned_ptr) { free(aligned_ptr); }
+
+#else
+// Use poxis_memalign, but mimic the behavior of memalign
+void* aligned_malloc(size_t size, size_t align) {
   void* ptr = nullptr;
-  ptr = memalign(alignment, size);
-  if (nullptr == ptr) {
-    rc = errno;
-  } else {
-    *memptr = ptr;
+  int rc = posix_memalign(&ptr, align, size);
+  if (rc == 0) {
+    return ptr;
   }
-  errno = saved_errno;
-  return rc;
+  errno = rc;
+  return nullptr;
 }
 
+void aligned_free(void* aligned_ptr) { free(aligned_ptr); }
+
 #endif
-#endif
+}
+}

folly/portability/Stdlib.h → folly/portability/Memory.h

@@ -18,4 +18,11 @@
 
 #include <cstdlib>
 
-extern int posix_memalign(void** memptr, size_t alignment, size_t size);
+namespace folly {
+namespace detail {
+
+void* aligned_malloc(size_t size, size_t align);
+
+void aligned_free(void* aligned_ptr);
+}
+}

folly/test/RangeTest.cpp

@@ -19,7 +19,7 @@
 
 #include <folly/Range.h>
 
-#include <folly/portability/Stdlib.h>
+#include <folly/portability/Memory.h>
 
 #include <sys/mman.h>
 #include <array>
@@ -34,6 +34,7 @@
 #include <gtest/gtest.h>
 
 using namespace folly;
+using namespace folly::detail;
 using namespace std;
 
 static_assert(std::is_literal_type<StringPiece>::value, "");
@@ -977,18 +978,19 @@ const size_t kPageSize = 4096;
 void createProtectedBuf(StringPiece& contents, char** buf) {
   ASSERT_LE(contents.size(), kPageSize);
   const size_t kSuccess = 0;
-  if (kSuccess != posix_memalign((void**)buf, kPageSize, 4 * kPageSize)) {
-    ASSERT_FALSE(true);
-  }
-  mprotect(*buf + kPageSize, kPageSize, PROT_NONE);
+  char* pageAlignedBuf = (char*)aligned_malloc(2 * kPageSize, kPageSize);
+  // Protect the page after the first full page-aligned region of the
+  // malloc'ed buffer
+  mprotect(pageAlignedBuf + kPageSize, kPageSize, PROT_NONE);
   size_t newBegin = kPageSize - contents.size();
-  memcpy(*buf + newBegin, contents.data(), contents.size());
-  contents.reset(*buf + newBegin, contents.size());
+  memcpy(pageAlignedBuf + newBegin, contents.data(), contents.size());
+  contents.reset(pageAlignedBuf + newBegin, contents.size());
+  *buf = pageAlignedBuf;
 }
 
 void freeProtectedBuf(char* buf) {
   mprotect(buf + kPageSize, kPageSize, PROT_READ | PROT_WRITE);
-  free(buf);
+  aligned_free(buf);
 }
 
 TYPED_TEST(NeedleFinderTest, NoSegFault) {