new tcmalloc

Summary: Support the brand-new TCMalloc version that was just released.

Reviewed By: luciang

Differential Revision: D19943852

fbshipit-source-id: 10ae07051d2bc56a502ee0d5e5767035cf53794f

folly/memory/Malloc.h

@@ -132,13 +132,69 @@ FOLLY_NOINLINE inline bool usingJEMalloc() noexcept {
 }
 #endif
 
+inline bool getTCMallocNumericProperty(const char* name, size_t* out) noexcept {
+  return MallocExtension_Internal_GetNumericProperty(name, strlen(name), out);
+}
+
+#if defined(FOLLY_ASSUME_NO_TCMALLOC) || FOLLY_SANITIZE
+  inline bool usingTCMalloc() noexcept {
+    return false;
+  }
+#elif defined(USE_TCMALLOC) && !FOLLY_SANITIZE
+  inline bool usingTCMalloc() noexcept {
+    return true;
+  }
+#else
+FOLLY_NOINLINE inline bool usingTCMalloc() noexcept {
+  static const bool result = []() noexcept {
+    // Some platforms (*cough* OSX *cough*) require weak symbol checks to be
+    // in the form if (mallctl != nullptr). Not if (mallctl) or if (!mallctl)
+    // (!!). http://goo.gl/xpmctm
+    if (MallocExtension_Internal_GetNumericProperty == nullptr ||
+        sdallocx == nullptr || nallocx == nullptr) {
+      return false;
+    }
+    static const char kAllocBytes[] = "generic.current_allocated_bytes";
+
+    size_t before_bytes = 0;
+    getTCMallocNumericProperty(kAllocBytes, &before_bytes);
+
+    static void* volatile ptr = malloc(1);
+    if (!ptr) {
+      // wtf, failing to allocate 1 byte
+      return false;
+    }
+
+    size_t after_bytes = 0;
+    getTCMallocNumericProperty(kAllocBytes, &after_bytes);
+    
+    free(ptr);
+
+    return (before_bytes != after_bytes);
+  }
+  ();
+
+  return result;
+}
+#endif
+
+FOLLY_NOINLINE inline bool canSdallocx() noexcept {
+  static bool rv = usingJEMalloc() || usingTCMalloc();
+  return rv;
+}
+
+FOLLY_NOINLINE inline bool canNallocx() noexcept {
+  static bool rv = usingJEMalloc() || usingTCMalloc();
+  return rv;
+}
+
 inline size_t goodMallocSize(size_t minSize) noexcept {
   if (minSize == 0) {
     return 0;
   }
 
-  if (!usingJEMalloc()) {
-    // Not using jemalloc - no smarts
+  if (!canNallocx()) {
+    // No nallocx - no smarts
     return minSize;
   }
 
@@ -183,7 +239,7 @@ inline void* checkedRealloc(void* ptr, size_t size) {
 }
 
 inline void sizedFree(void* ptr, size_t size) {
-  if (usingJEMalloc()) {
+  if (canSdallocx()) {
     sdallocx(ptr, size, 0);
   } else {
     free(ptr);

folly/memory/detail/MallocImpl.cpp

@@ -31,6 +31,7 @@ const char* nallocxWeak = nullptr;
 const char* mallctlWeak = nullptr;
 const char* mallctlnametomibWeak = nullptr;
 const char* mallctlbymibWeak = nullptr;
+const char* MallocExtension_Internal_GetNumericPropertyWeak = nullptr;
 #elif !FOLLY_HAVE_WEAK_SYMBOLS
 void* (*mallocx)(size_t, int) = nullptr;
 void* (*rallocx)(void*, size_t, int) = nullptr;
@@ -43,5 +44,9 @@ int (*mallctl)(const char*, void*, size_t*, void*, size_t) = nullptr;
 int (*mallctlnametomib)(const char*, size_t*, size_t*) = nullptr;
 int (*mallctlbymib)(const size_t*, size_t, void*, size_t*, void*, size_t) =
     nullptr;
+bool (*MallocExtension_Internal_GetNumericProperty)(
+    const char*,
+    size_t,
+    size_t*) = nullptr;
 #endif
 }

folly/memory/detail/MallocImpl.h

@@ -38,6 +38,8 @@ int mallctlnametomib(const char*, size_t*, size_t*)
     __attribute__((__nothrow__, __weak__));
 int mallctlbymib(const size_t*, size_t, void*, size_t*, void*, size_t)
     __attribute__((__nothrow__, __weak__));
+bool MallocExtension_Internal_GetNumericProperty(const char*, size_t, size_t*)
+    __attribute__((__weak__));
 #endif
 #else
 extern void* (*mallocx)(size_t, int);
@@ -51,6 +53,8 @@ extern int (*mallctl)(const char*, void*, size_t*, void*, size_t);
 extern int (*mallctlnametomib)(const char*, size_t*, size_t*);
 extern int (
     *mallctlbymib)(const size_t*, size_t, void*, size_t*, void*, size_t);
+extern bool (
+    *MallocExtension_Internal_GetNumericProperty)(const char*, size_t, size_t*);
 #ifdef _MSC_VER
 // We emulate weak linkage for MSVC. The symbols we're
 // aliasing to are hiding in MallocImpl.cpp
@@ -66,6 +70,9 @@ extern int (
 #pragma comment( \
     linker, "/alternatename:_mallctlnametomib=_mallctlnametomibWeak")
 #pragma comment(linker, "/alternatename:_mallctlbymib=_mallctlbymibWeak")
+#pragma comment( \
+    linker,      \
+    "/alternatename:_MallocExtension_Internal_GetNumericProperty=_MallocExtension_Internal_GetNumericPropertyWeak")
 #else
 #pragma comment(linker, "/alternatename:mallocx=mallocxWeak")
 #pragma comment(linker, "/alternatename:rallocx=rallocxWeak")
@@ -77,6 +84,9 @@ extern int (
 #pragma comment(linker, "/alternatename:mallctl=mallctlWeak")
 #pragma comment(linker, "/alternatename:mallctlnametomib=mallctlnametomibWeak")
 #pragma comment(linker, "/alternatename:mallctlbymib=mallctlbymibWeak")
+#pragma comment( \
+    linker,      \
+    "/alternatename:MallocExtension_Internal_GetNumericProperty=MallocExtension_Internal_GetNumericPropertyWeak")
 #endif
 #endif
 #endif