Repo created

TMessagesProj/jni/voip/webrtc/base/os_compat_android.cc

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+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/os_compat_android.h"
+
+#include <asm/unistd.h>
+#include <errno.h>
+#include <limits.h>
+#include <math.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+#if !defined(__LP64__)
+#include <time64.h>
+#endif
+
+#include "base/files/file.h"
+#include "base/rand_util.h"
+#include "base/strings/string_piece.h"
+#include "base/strings/stringprintf.h"
+
+extern "C" {
+// There is no futimes() avaiable in Bionic, so we provide our own
+// implementation until it is there.
+int futimes(int fd, const struct timeval tv[2]) {
+  if (tv == NULL)
+    return syscall(__NR_utimensat, fd, NULL, NULL, 0);
+
+  if (tv[0].tv_usec < 0 || tv[0].tv_usec >= 1000000 ||
+      tv[1].tv_usec < 0 || tv[1].tv_usec >= 1000000) {
+    errno = EINVAL;
+    return -1;
+  }
+
+  // Convert timeval to timespec.
+  struct timespec ts[2];
+  ts[0].tv_sec = tv[0].tv_sec;
+  ts[0].tv_nsec = tv[0].tv_usec * 1000;
+  ts[1].tv_sec = tv[1].tv_sec;
+  ts[1].tv_nsec = tv[1].tv_usec * 1000;
+  return syscall(__NR_utimensat, fd, NULL, ts, 0);
+}
+
+#if !defined(__LP64__)
+// 32-bit Android has only timegm64() and not timegm().
+// We replicate the behaviour of timegm() when the result overflows time_t.
+time_t timegm(struct tm* const t) {
+  // time_t is signed on Android.
+  static const time_t kTimeMax = ~(1L << (sizeof(time_t) * CHAR_BIT - 1));
+  static const time_t kTimeMin = (1L << (sizeof(time_t) * CHAR_BIT - 1));
+  time64_t result = timegm64(t);
+  if (result < kTimeMin || result > kTimeMax)
+    return -1;
+  return result;
+}
+#endif
+
+// The following is only needed when building with GCC 4.6 or higher
+// (i.e. not with Android GCC 4.4.3, nor with Clang).
+//
+// GCC is now capable of optimizing successive calls to sin() and cos() into
+// a single call to sincos(). This means that source code that looks like:
+//
+//     double c, s;
+//     c = cos(angle);
+//     s = sin(angle);
+//
+// Will generate machine code that looks like:
+//
+//     double c, s;
+//     sincos(angle, &s, &c);
+//
+// Unfortunately, sincos() and friends are not part of the Android libm.so
+// library provided by the NDK for API level 9. When the optimization kicks
+// in, it makes the final build fail with a puzzling message (puzzling
+// because 'sincos' doesn't appear anywhere in the sources!).
+//
+// To solve this, we provide our own implementation of the sincos() function
+// and related friends. Note that we must also explicitely tell GCC to disable
+// optimizations when generating these. Otherwise, the generated machine code
+// for each function would simply end up calling itself, resulting in a
+// runtime crash due to stack overflow.
+//
+#if defined(__GNUC__) && !defined(__clang__) && \
+    !defined(ANDROID_SINCOS_PROVIDED)
+
+// For the record, Clang does not support the 'optimize' attribute.
+// In the unlikely event that it begins performing this optimization too,
+// we'll have to find a different way to achieve this. NOTE: Tested with O1
+// which still performs the optimization.
+//
+#define GCC_NO_OPTIMIZE  __attribute__((optimize("O0")))
+
+GCC_NO_OPTIMIZE
+void sincos(double angle, double* s, double *c) {
+  *c = cos(angle);
+  *s = sin(angle);
+}
+
+GCC_NO_OPTIMIZE
+void sincosf(float angle, float* s, float* c) {
+  *c = cosf(angle);
+  *s = sinf(angle);
+}
+
+#endif  // __GNUC__ && !__clang__
+
+// An implementation of mkdtemp, since it is not exposed by the NDK
+// for native API level 9 that we target.
+//
+// For any changes in the mkdtemp function, you should manually run the unittest
+// OsCompatAndroidTest.DISABLED_TestMkdTemp in your local machine to check if it
+// passes. Please don't enable it, since it creates a directory and may be
+// source of flakyness.
+char* mkdtemp(char* path) {
+  if (!path) {
+    errno = EINVAL;
+    return nullptr;
+  }
+
+  const int path_len = strlen(path);
+
+  // The last six characters of 'path' must be XXXXXX.
+  const base::StringPiece kSuffix("XXXXXX");
+  const int kSuffixLen = kSuffix.length();
+  if (!base::StringPiece(path, path_len).ends_with(kSuffix)) {
+    errno = EINVAL;
+    return nullptr;
+  }
+
+  // If the path contains a directory, as in /tmp/foo/XXXXXXXX, make sure
+  // that /tmp/foo exists, otherwise we're going to loop a really long
+  // time for nothing below
+  char* dirsep = strrchr(path, '/');
+  if (dirsep) {
+    *dirsep = '\0';  // Terminating directory path temporarily
+
+    base::stat_wrapper_t st;
+    int ret = base::File::Stat(path, &st);
+
+    *dirsep = '/';  // Restoring directory separator
+    if (ret < 0)  // Directory probably does not exist
+      return nullptr;
+    if (!S_ISDIR(st.st_mode)) {  // Not a directory
+      errno = ENOTDIR;
+      return nullptr;
+    }
+  }
+
+  // Max number of tries using different random suffixes.
+  const int kMaxTries = 100;
+
+  // Now loop until we CAN create a directory by that name or we reach the max
+  // number of tries.
+  for (int i = 0; i < kMaxTries; ++i) {
+    // Fill the suffix XXXXXX with a random string composed of a-z chars.
+    for (int pos = 0; pos < kSuffixLen; ++pos) {
+      char rand_char = static_cast<char>(base::RandInt('a', 'z'));
+      path[path_len - kSuffixLen + pos] = rand_char;
+    }
+    if (mkdir(path, 0700) == 0) {
+      // We just created the directory succesfully.
+      return path;
+    }
+    if (errno != EEXIST) {
+      // The directory doesn't exist, but an error occured
+      return nullptr;
+    }
+  }
+
+  // We reached the max number of tries.
+  return nullptr;
+}
+
+}  // extern "C"