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1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. | 1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #include "base/os_compat_android.h" | 5 #include "base/os_compat_android.h" |
6 | 6 |
| 7 #include <errno.h> |
| 8 #include <math.h> |
| 9 #include <sys/stat.h> |
7 #include <time64.h> | 10 #include <time64.h> |
8 | 11 |
| 12 #include "base/rand_util.h" |
| 13 #include "base/string_piece.h" |
9 #include "base/stringprintf.h" | 14 #include "base/stringprintf.h" |
10 | 15 |
11 // There is no futimes() avaiable in Bionic, so we provide our own | 16 // There is no futimes() avaiable in Bionic, so we provide our own |
12 // implementation until it is there. | 17 // implementation until it is there. |
13 extern "C" { | 18 extern "C" { |
14 | 19 |
15 int futimes(int fd, const struct timeval tv[2]) { | 20 int futimes(int fd, const struct timeval tv[2]) { |
16 const std::string fd_path = StringPrintf("/proc/self/fd/%d", fd); | 21 const std::string fd_path = StringPrintf("/proc/self/fd/%d", fd); |
17 return utimes(fd_path.c_str(), tv); | 22 return utimes(fd_path.c_str(), tv); |
18 } | 23 } |
19 | 24 |
20 // Android has only timegm64() and no timegm(). | 25 // Android has only timegm64() and no timegm(). |
21 // We replicate the behaviour of timegm() when the result overflows time_t. | 26 // We replicate the behaviour of timegm() when the result overflows time_t. |
22 time_t timegm(struct tm* const t) { | 27 time_t timegm(struct tm* const t) { |
23 // time_t is signed on Android. | 28 // time_t is signed on Android. |
24 static const time_t kTimeMax = ~(1 << (sizeof(time_t) * CHAR_BIT - 1)); | 29 static const time_t kTimeMax = ~(1 << (sizeof(time_t) * CHAR_BIT - 1)); |
25 static const time_t kTimeMin = (1 << (sizeof(time_t) * CHAR_BIT - 1)); | 30 static const time_t kTimeMin = (1 << (sizeof(time_t) * CHAR_BIT - 1)); |
26 time64_t result = timegm64(t); | 31 time64_t result = timegm64(t); |
27 if (result < kTimeMin || result > kTimeMax) | 32 if (result < kTimeMin || result > kTimeMax) |
28 return -1; | 33 return -1; |
29 return result; | 34 return result; |
30 } | 35 } |
31 | 36 |
| 37 // The following is only needed when building with GCC 4.6 or higher |
| 38 // (i.e. not with Android GCC 4.4.3, nor with Clang). |
| 39 // |
| 40 // GCC is now capable of optimizing successive calls to sin() and cos() into |
| 41 // a single call to sincos(). This means that source code that looks like: |
| 42 // |
| 43 // double c, s; |
| 44 // c = cos(angle); |
| 45 // s = sin(angle); |
| 46 // |
| 47 // Will generate machine code that looks like: |
| 48 // |
| 49 // double c, s; |
| 50 // sincos(angle, &s, &c); |
| 51 // |
| 52 // Unfortunately, sincos() and friends are not part of the Android libm.so |
| 53 // library provided by the NDK for API level 9. When the optimization kicks |
| 54 // in, it makes the final build fail with a puzzling message (puzzling |
| 55 // because 'sincos' doesn't appear anywhere in the sources!). |
| 56 // |
| 57 // To solve this, we provide our own implementation of the sincos() function |
| 58 // and related friends. Note that we must also explicitely tell GCC to disable |
| 59 // optimizations when generating these. Otherwise, the generated machine code |
| 60 // for each function would simply end up calling itself, resulting in a |
| 61 // runtime crash due to stack overflow. |
| 62 // |
| 63 #if defined(__GNUC__) && !defined(__clang__) |
| 64 |
| 65 // For the record, Clang does not support the 'optimize' attribute. |
| 66 // In the unlikely event that it begins performing this optimization too, |
| 67 // we'll have to find a different way to achieve this. NOTE: Tested with O1 |
| 68 // which still performs the optimization. |
| 69 // |
| 70 #define GCC_NO_OPTIMIZE __attribute__((optimize("O0"))) |
| 71 |
| 72 GCC_NO_OPTIMIZE |
| 73 void sincos(double angle, double* s, double *c) { |
| 74 *c = cos(angle); |
| 75 *s = sin(angle); |
| 76 } |
| 77 |
| 78 GCC_NO_OPTIMIZE |
| 79 void sincosf(float angle, float* s, float* c) { |
| 80 *c = cosf(angle); |
| 81 *s = sinf(angle); |
| 82 } |
| 83 |
| 84 #endif // __GNUC__ && !__clang__ |
| 85 |
| 86 // An implementation of mkdtemp, since it is not exposed by the NDK |
| 87 // for native API level 9 that we target. |
| 88 // |
| 89 // For any changes in the mkdtemp function, you should manually run the unittest |
| 90 // OsCompatAndroidTest.DISABLED_TestMkdTemp in your local machine to check if it |
| 91 // passes. Please don't enable it, since it creates a directory and may be |
| 92 // source of flakyness. |
| 93 char* mkdtemp(char* path) { |
| 94 if (path == NULL) { |
| 95 errno = EINVAL; |
| 96 return NULL; |
| 97 } |
| 98 |
| 99 const int path_len = strlen(path); |
| 100 |
| 101 // The last six characters of 'path' must be XXXXXX. |
| 102 const base::StringPiece kSuffix("XXXXXX"); |
| 103 const int kSuffixLen = kSuffix.length(); |
| 104 if (!base::StringPiece(path, path_len).ends_with(kSuffix)) { |
| 105 errno = EINVAL; |
| 106 return NULL; |
| 107 } |
| 108 |
| 109 // If the path contains a directory, as in /tmp/foo/XXXXXXXX, make sure |
| 110 // that /tmp/foo exists, otherwise we're going to loop a really long |
| 111 // time for nothing below |
| 112 char* dirsep = strrchr(path, '/'); |
| 113 if (dirsep != NULL) { |
| 114 struct stat st; |
| 115 int ret; |
| 116 |
| 117 *dirsep = '\0'; // Terminating directory path temporarily |
| 118 |
| 119 ret = stat(path, &st); |
| 120 |
| 121 *dirsep = '/'; // Restoring directory separator |
| 122 if (ret < 0) // Directory probably does not exist |
| 123 return NULL; |
| 124 if (!S_ISDIR(st.st_mode)) { // Not a directory |
| 125 errno = ENOTDIR; |
| 126 return NULL; |
| 127 } |
| 128 } |
| 129 |
| 130 // Max number of tries using different random suffixes. |
| 131 const int kMaxTries = 100; |
| 132 |
| 133 // Now loop until we CAN create a directory by that name or we reach the max |
| 134 // number of tries. |
| 135 for (int i = 0; i < kMaxTries; ++i) { |
| 136 // Fill the suffix XXXXXX with a random string composed of a-z chars. |
| 137 for (int pos = 0; pos < kSuffixLen; ++pos) { |
| 138 char rand_char = static_cast<char>(base::RandInt('a', 'z')); |
| 139 path[path_len - kSuffixLen + pos] = rand_char; |
| 140 } |
| 141 if (mkdir(path, 0700) == 0) { |
| 142 // We just created the directory succesfully. |
| 143 return path; |
| 144 } |
| 145 if (errno != EEXIST) { |
| 146 // The directory doesn't exist, but an error occured |
| 147 return NULL; |
| 148 } |
| 149 } |
| 150 |
| 151 // We reached the max number of tries. |
| 152 return NULL; |
| 153 } |
| 154 |
32 } // extern "C" | 155 } // extern "C" |
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