| 1 | #ifndef LTT_H |
| 2 | #define LTT_H |
| 3 | |
| 4 | #include <ltt/LTTTypes.h> |
| 5 | |
| 6 | /* A trace is associated with a tracing session run on a single, possibly |
| 7 | multi-cpu, system. It is defined as a pathname to a directory containing |
| 8 | all the relevant trace files. All the tracefiles for a trace were |
| 9 | generated in a single system for the same time period by the same |
| 10 | trace daemon. They simply contain different events. Typically control |
| 11 | tracefiles contain the important events (process creations and registering |
| 12 | tracing facilities) for all CPUs, and one file for each CPU contains all |
| 13 | the events for that CPU. All the tracefiles within the same trace directory |
| 14 | then use the exact same id numbers for event types. |
| 15 | |
| 16 | A tracefile (LttTracefile) contains a list of events (LttEvent) sorted |
| 17 | by time for each CPU; events from different CPUs may be slightly out of |
| 18 | order, especially using the (possibly drifting) cycle counters as |
| 19 | time unit. |
| 20 | |
| 21 | A facility is a list of event types (LttEventType), declared in a special |
| 22 | eventdefs file. A corresponding checksum differentiates different |
| 23 | facilities which would have the same name but a different content |
| 24 | (e.g., different versions). The files are stored within the trace |
| 25 | directory and are accessed automatically upon opening a trace. |
| 26 | The list of facilities (and associated checksum) used in a trace |
| 27 | must be known in order to properly decode the contained events. An event |
| 28 | is stored in the "facilities" control tracefile to denote each different |
| 29 | facility used. |
| 30 | |
| 31 | Event types (LttEventType) refer to data types (LttType) describing |
| 32 | their content. The data types supported are integer and unsigned integer |
| 33 | (of various length), enumerations (a special form of unsigned integer), |
| 34 | floating point (of various length), fixed size arrays, sequence |
| 35 | (variable sized arrays), structures and null terminated strings. |
| 36 | The elements of arrays and sequences, and the data members for |
| 37 | structures, may be of any nested data type (LttType). |
| 38 | |
| 39 | An LttField is a special object to denote a specific, possibly nested, |
| 40 | field within an event type. Suppose an event type socket_connect is a |
| 41 | structure containing two data members, source and destination, of type |
| 42 | socket_address. Type socket_address contains two unsigned integer |
| 43 | data members, ip and port. An LttField is different from a data type |
| 44 | structure member since it can denote a specific nested field, like the |
| 45 | source port, and store associated access information (byte offset within |
| 46 | the event data). The LttField objects are trace specific since the |
| 47 | contained information (byte offsets) may vary with the architecture |
| 48 | associated to the trace. */ |
| 49 | |
| 50 | typedef struct _LttTrace LttTrace; |
| 51 | |
| 52 | typedef struct _LttTracefile LttTracefile; |
| 53 | |
| 54 | typedef struct _LttFacility LttFacility; |
| 55 | |
| 56 | typedef struct _LttEventType LttEventType; |
| 57 | |
| 58 | typedef struct _LttType LttType; |
| 59 | |
| 60 | typedef struct _LttField LttField; |
| 61 | |
| 62 | typedef struct _LttEvent LttEvent; |
| 63 | |
| 64 | typedef struct _LttSystemDescription LttSystemDescription; |
| 65 | |
| 66 | /* Checksums are used to differentiate facilities which have the same name |
| 67 | but differ. */ |
| 68 | |
| 69 | typedef unsigned long LttChecksum; |
| 70 | |
| 71 | |
| 72 | /* Events are usually stored with the easily obtained CPU clock cycle count, |
| 73 | ltt_cycle_count. This can be converted to the real time value, ltt_time, |
| 74 | using linear interpolation between regularly sampled values (e.g. a few |
| 75 | times per second) of the real time clock with their corresponding |
| 76 | cycle count values. */ |
| 77 | |
| 78 | typedef struct _LttTime { |
| 79 | unsigned long tv_sec; |
| 80 | unsigned long tv_nsec; |
| 81 | } LttTime; |
| 82 | |
| 83 | typedef uint64_t LttCycleCount; |
| 84 | |
| 85 | |
| 86 | /* Differences between architectures include word sizes, endianess, |
| 87 | alignment, floating point format and calling conventions. For a |
| 88 | packed binary trace, endianess and size matter, assuming that the |
| 89 | floating point format is standard (and is seldom used anyway). */ |
| 90 | |
| 91 | typedef enum _LttArchSize |
| 92 | { LTT_LP32, LTT_ILP32, LTT_LP64, LTT_ILP64, LTT_UNKNOWN |
| 93 | } LttArchSize; |
| 94 | |
| 95 | |
| 96 | typedef enum _LttArchEndian |
| 97 | { LTT_LITTLE_ENDIAN, LTT_BIG_ENDIAN |
| 98 | } LttArchEndian; |
| 99 | |
| 100 | /* Time operation macros for LttTime (struct timespec) */ |
| 101 | /* (T3 = T2 - T1) */ |
| 102 | #define TimeSub(T3, T2, T1) \ |
| 103 | do \ |
| 104 | {\ |
| 105 | (T3).tv_sec = (T2).tv_sec - (T1).tv_sec; \ |
| 106 | (T3).tv_nsec = (T2).tv_nsec - (T1).tv_nsec; \ |
| 107 | if((T3).tv_nsec < 0)\ |
| 108 | {\ |
| 109 | (T3).tv_sec--;\ |
| 110 | (T3).tv_nsec += 1000000000;\ |
| 111 | }\ |
| 112 | } while(0) |
| 113 | |
| 114 | /* (T3 = T2 + T1) */ |
| 115 | #define TimeAdd(T3, T2, T1) \ |
| 116 | do \ |
| 117 | {\ |
| 118 | (T3).tv_sec = (T2).tv_sec + (T1).tv_sec; \ |
| 119 | (T3).tv_nsec = (T2).tv_nsec + (T1).tv_nsec; \ |
| 120 | if((T3).tv_nsec >= 1000000000)\ |
| 121 | {\ |
| 122 | (T3).tv_sec += (T3).tv_nsec / 1000000000;\ |
| 123 | (T3).tv_nsec = (T3).tv_nsec % 1000000000;\ |
| 124 | }\ |
| 125 | } while(0) |
| 126 | |
| 127 | /* (T2 = T1 * FLOAT) */ |
| 128 | /* WARNING : use this multiplicator carefully : on 32 bits, multiplying |
| 129 | * by more than 4 could overflow the tv_nsec. |
| 130 | */ |
| 131 | #define TimeMul(T2, T1, FLOAT) \ |
| 132 | do \ |
| 133 | {\ |
| 134 | (T2).tv_sec = (T1).tv_sec * (FLOAT); \ |
| 135 | (T2).tv_nsec = (T1).tv_nsec * (FLOAT); \ |
| 136 | if((T2).tv_nsec >= 1000000000)\ |
| 137 | {\ |
| 138 | (T2).tv_sec += (T3).tv_nsec / 1000000000;\ |
| 139 | (T2).tv_nsec = (T3).tv_nsec % 1000000000;\ |
| 140 | }\ |
| 141 | } while(0) |
| 142 | |
| 143 | |
| 144 | |
| 145 | |
| 146 | #include <ltt/ltt-private.h> |
| 147 | |
| 148 | |
| 149 | #endif // LTT_H |