1// Copyright (c) 2015, the Dart project authors. Please see the AUTHORS file
2// for details. All rights reserved. Use of this source code is governed by a
3// BSD-style license that can be found in the LICENSE file.
4
5#ifndef RUNTIME_VM_LOG_H_
6#define RUNTIME_VM_LOG_H_
7
8#include "vm/allocation.h"
9#include "vm/growable_array.h"
10#include "vm/os.h"
11
12namespace dart {
13
14class IsolateGroup;
15class LogBlock;
16
17#if defined(_MSC_VER)
18#define THR_Print(format, ...) Log::Current()->Print(format, __VA_ARGS__)
19#else
20#define THR_Print(format, ...) Log::Current()->Print(format, ##__VA_ARGS__)
21#endif
22
23#define THR_VPrint(format, args) Log::Current()->VPrint(format, args)
24
25typedef void (*LogPrinter)(const char* str, ...) PRINTF_ATTRIBUTE(1, 2);
26
27class Log {
28 public:
29 explicit Log(LogPrinter printer = OS::PrintErr);
30 ~Log();
31
32 static Log* Current();
33
34 // Append a formatted string to the log.
35 void Print(const char* format, ...) PRINTF_ATTRIBUTE(2, 3);
36
37 void VPrint(const char* format, va_list args);
38
39 // Flush and truncate the log. The log is flushed starting at cursor
40 // and truncated to cursor afterwards.
41 void Flush(const intptr_t cursor = 0);
42
43 // Clears the log.
44 void Clear();
45
46 // Current cursor.
47 intptr_t cursor() const;
48
49 // A logger that does nothing.
50 static Log* NoOpLog();
51
52 private:
53 void TerminateString();
54 void EnableManualFlush();
55 void DisableManualFlush(const intptr_t cursor);
56
57 // Returns true when flush is required.
58 bool ShouldFlush() const;
59
60 // Returns false if we should drop log messages related to 'isolate'.
61 static bool ShouldLogForIsolateGroup(const IsolateGroup* isolate);
62
63 static Log noop_log_;
64 LogPrinter printer_;
65 intptr_t manual_flush_;
66 MallocGrowableArray<char> buffer_;
67
68 friend class LogBlock;
69 friend class LogTestHelper;
70 DISALLOW_COPY_AND_ASSIGN(Log);
71};
72
73// Causes all log messages to be buffered until destructor is called.
74// Can be nested.
75class LogBlock : public StackResource {
76 public:
77 LogBlock(ThreadState* thread, Log* log)
78 : StackResource(thread), log_(log), cursor_(log->cursor()) {
79 Initialize();
80 }
81
82 LogBlock()
83 : StackResource(ThreadState::Current()),
84 log_(Log::Current()),
85 cursor_(Log::Current()->cursor()) {
86 Initialize();
87 }
88
89 ~LogBlock();
90
91 private:
92 void Initialize();
93
94 Log* const log_;
95 const intptr_t cursor_;
96};
97
98} // namespace dart
99
100#endif // RUNTIME_VM_LOG_H_
101