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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 char* mkdtemp(char* path) { | |
89 if (path == NULL) { | |
90 errno = EINVAL; | |
91 return NULL; | |
92 } | |
93 | |
94 const int path_len = strlen(path); | |
95 | |
96 // The last six characters of 'path' must be XXXXXX. | |
97 const base::StringPiece kSuffix("XXXXXX"); | |
98 const int kSuffixLen = kSuffix.length(); | |
99 if (!base::StringPiece(path, path_len).ends_with(kSuffix)) { | |
100 errno = EINVAL; | |
101 return NULL; | |
102 } | |
103 | |
104 // If the path contains a directory, as in /tmp/foo/XXXXXXXX, make sure | |
105 // that /tmp/foo exists, otherwise we're going to loop a really long | |
106 // time for nothing below | |
107 char* dirsep = strrchr(path, '/'); | |
108 if (dirsep != NULL) { | |
109 struct stat st; | |
110 int ret; | |
111 | |
112 *dirsep = '\0'; // Terminating directory path temporarily | |
113 | |
114 ret = stat(path, &st); | |
115 | |
116 *dirsep = '/'; // Restoring directory separator | |
117 if (ret < 0) // Directory probably does not exist | |
118 return NULL; | |
119 if (!S_ISDIR(st.st_mode)) { // Not a directory | |
120 errno = ENOTDIR; | |
121 return NULL; | |
122 } | |
123 } | |
124 | |
125 // Max number of tries using different random suffixes. | |
126 const int kMaxTries = 100; | |
127 | |
128 // Now loop until we CAN create a directory by that name or we reach the max | |
129 // number of tries. | |
130 for (int i = 0; i < kMaxTries; ++i) { | |
131 // Fill the suffix XXXXXX with a random string composed of a-z chars. | |
132 for (int pos = 0; pos < kSuffixLen; ++pos) { | |
brettw
2012/07/12 18:22:34
Style nit: you got 2 spaces.
felipeg
2012/07/13 10:17:47
Done.
| |
133 char rand_char = static_cast<char>(base::RandInt('a', 'z')); | |
134 path[path_len - kSuffixLen + pos] = rand_char; | |
135 } | |
136 if (mkdir(path, 0700) == 0) { | |
137 // We just created the directory succesfully. | |
138 return path; | |
139 } | |
140 if (errno != EEXIST) { | |
141 // The directory doesn't exist, but an error occured | |
142 return NULL; | |
143 } | |
144 } | |
145 | |
146 // We reached the max number of tries. | |
147 return NULL; | |
148 } | |
149 | |
32 } // extern "C" | 150 } // extern "C" |
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