it runs
authorcompudj <compudj@04897980-b3bd-0310-b5e0-8ef037075253>
Wed, 8 Mar 2006 19:23:25 +0000 (19:23 +0000)
committercompudj <compudj@04897980-b3bd-0310-b5e0-8ef037075253>
Wed, 8 Mar 2006 19:23:25 +0000 (19:23 +0000)
git-svn-id: http://ltt.polymtl.ca/svn@1620 04897980-b3bd-0310-b5e0-8ef037075253

usertrace-fast/Makefile
usertrace-fast/ltt-instrument-functions.c
usertrace-fast/ltt-usertrace-fast.c
usertrace-fast/ltt-usertrace-fast.h [deleted file]
usertrace-fast/ltt/ltt-usertrace-fast.h [new file with mode: 0644]
usertrace-fast/test.c

index ced8f6fbeed2ae76fb6a4fa15b063a0efee76c65..a154f8863ea16e2b20dfc30c8ab2424e7f96ab92 100644 (file)
@@ -1,25 +1,29 @@
 
+LIB_DIR=/usr/lib
+INCLUDE_DIR=/usr/include
+
 RANLIB=ranlib
 
 CC=gcc
+CFLAGS=-I. -g
 
 all: test sample-instrument-fct libltt-instrument-functions.a libltt-instrument-functions.so.0
 
 test: test.c ltt-usertrace-fast.c
-       $(CC) $(CFLAGS) -lpthread -o $@ $^
+       $(CC) $(CFLAGS) -I. -lpthread -o $@ $^
 
 
 sample-instrument-fct: sample-instrument-fct.c
        $(CC) $(CFLAGS) -L. -g -finstrument-functions -lltt-instrument-functions -o $@ $^
 
-libltt-instrument-functions.a: ltt-instrument-functions.o ltt-facility-loader-user_generic.o
+libltt-instrument-functions.a: ltt-instrument-functions.o ltt-facility-loader-user_generic.o ltt-usertrace-fast.o
        @rm -f libltt-instrument-functions.a
        $(AR) rc $@ $^
        $(RANLIB) $@
 
-libltt-instrument-functions.so.0: ltt-instrument-functions.o ltt-facility-loader-user_generic.o
+libltt-instrument-functions.so.0: ltt-instrument-functions.o ltt-facility-loader-user_generic.o ltt-usertrace-fast.o
        @rm -f libltt-instrument-functions.so libltt-instrument-functions.so.0
-       $(CC) $(CFLAGS) -shared -Wl,-soname,libltt-instrument-functions.so -o $@ $^
+       $(CC) $(CFLAGS) -lpthread -shared -Wl,-soname,libltt-instrument-functions.so -o $@ $^
        ln -s libltt-instrument-functions.so.0 libltt-instrument-functions.so
 
 install:
index 28c7c8e1a2a6f5346a98d79025c023a463b540ac..ed53c105d47aa4f8222fb1f513f7db7298e02eca 100644 (file)
@@ -7,7 +7,7 @@
 
 #define LTT_TRACE
 #define LTT_TRACE_FAST
-#include "ltt-usertrace-fast.h"
+#include <ltt/ltt-usertrace-fast.h>
 #include <ltt/ltt-facility-user_generic.h>
 
 void __attribute__((no_instrument_function)) __cyg_profile_func_enter (
index 55ba880ab8684f9038bc05f3f9ba4fba64fe0edf..d3f9333d8fa1b2a5e0f7b29b39a30434a08c62ed 100644 (file)
@@ -68,7 +68,7 @@
 
 _syscall0(pid_t,gettid)
 
-#include "ltt-usertrace-fast.h"
+#include <ltt/ltt-usertrace-fast.h>
 
 enum force_switch_mode { FORCE_ACTIVE, FORCE_FLUSH };
 
@@ -533,8 +533,13 @@ void ltt_rw_init(void)
                        printf("LTT Error in pthread_sigmask\n");
                }
        } else if(pid == 0) {
+               pid_t sid;
                /* Child */
                role = LTT_ROLE_READER;
+               sid = setsid();
+               if(sid < 0) {
+                       perror("Error setting sid");
+               }
                ltt_usertrace_fast_daemon(shared_trace_info, oldset, l_traced_pid,
                                        l_traced_tid);
                /* Should never return */
diff --git a/usertrace-fast/ltt-usertrace-fast.h b/usertrace-fast/ltt-usertrace-fast.h
deleted file mode 100644 (file)
index e4930d7..0000000
+++ /dev/null
@@ -1,637 +0,0 @@
-
-/* LTTng user-space "fast" tracing header
- *
- * Copyright 2006 Mathieu Desnoyers
- *
- */
-
-#ifndef _LTT_USERTRACE_FAST_H
-#define _LTT_USERTRACE_FAST_H
-
-#ifdef LTT_TRACE
-
-#include <errno.h>
-#include <asm/atomic.h>
-#include <pthread.h>
-#include <stdint.h>
-#include <syscall.h>
-#include <linux/futex.h>
-
-#include <ltt/ltt-facility-id-user_generic.h>
-#include <ltt/ltt-generic.h>
-
-#ifndef futex
-static inline __attribute__((no_instrument_function))
-       _syscall6(long, futex, unsigned long, uaddr, int, op, int, val,
-               unsigned long, timeout, unsigned long, uaddr2, int, val2)
-#endif //futex
-
-
-
-#ifndef        LTT_N_SUBBUFS
-#define LTT_N_SUBBUFS 2
-#endif //LTT_N_SUBBUFS
-
-#ifndef        LTT_SUBBUF_SIZE_CPU
-#define LTT_SUBBUF_SIZE_CPU 1048576
-#endif //LTT_BUF_SIZE_CPU
-
-#define LTT_BUF_SIZE_CPU (LTT_SUBBUF_SIZE_CPU * LTT_N_SUBBUFS)
-
-#ifndef        LTT_SUBBUF_SIZE_FACILITIES
-#define LTT_SUBBUF_SIZE_FACILITIES 4096
-#endif //LTT_BUF_SIZE_FACILITIES
-
-#define LTT_BUF_SIZE_FACILITIES  (LTT_SUBBUF_SIZE_FACILITIES * LTT_N_SUBBUFS)
-
-#ifndef LTT_USERTRACE_ROOT
-#define LTT_USERTRACE_ROOT "/tmp/ltt-usertrace"
-#endif //LTT_USERTRACE_ROOT
-
-
-/* Buffer offset macros */
-
-#define BUFFER_OFFSET(offset, buf) (offset & (buf->alloc_size-1))
-#define SUBBUF_OFFSET(offset, buf) (offset & (buf->subbuf_size-1))
-#define SUBBUF_ALIGN(offset, buf) \
-  (((offset) + buf->subbuf_size) & (~(buf->subbuf_size-1)))
-#define SUBBUF_TRUNC(offset, buf) \
-  ((offset) & (~(buf->subbuf_size-1)))
-#define SUBBUF_INDEX(offset, buf) \
-  (BUFFER_OFFSET(offset,buf)/buf->subbuf_size)
-
-
-#define LTT_TRACER_MAGIC_NUMBER                 0x00D6B7ED
-#define LTT_TRACER_VERSION_MAJOR               0
-#define LTT_TRACER_VERSION_MINOR               7
-
-#ifndef atomic_cmpxchg
-#define atomic_cmpxchg(v, old, new) ((int)cmpxchg(&((v)->counter), old, new))
-#endif //atomic_cmpxchg
-
-typedef unsigned int ltt_facility_t;
-       
-struct ltt_trace_header {
-       uint32_t                                magic_number;
-       uint32_t                                arch_type;
-       uint32_t                                arch_variant;
-       uint32_t                                float_word_order;        /* Only useful for user space traces */
-       uint8_t                                 arch_size;
-       //uint32_t                              system_type;
-       uint8_t                                 major_version;
-       uint8_t                                 minor_version;
-       uint8_t                                 flight_recorder;
-       uint8_t                                 has_heartbeat;
-       uint8_t                                 has_alignment;  /* Event header alignment */
-       uint32_t                                freq_scale;
-       uint64_t                                start_freq;
-       uint64_t                                start_tsc;
-       uint64_t                                start_monotonic;
-  uint64_t        start_time_sec;
-  uint64_t        start_time_usec;
-} __attribute((packed));
-
-
-struct ltt_block_start_header {
-       struct { 
-               uint64_t                                                                cycle_count;
-               uint64_t                                                                freq; /* khz */
-       } begin;
-       struct { 
-               uint64_t                                                                cycle_count;
-               uint64_t                                                                freq; /* khz */
-       } end;
-       uint32_t                                                                lost_size;      /* Size unused at the end of the buffer */
-       uint32_t                                                                buf_size;               /* The size of this sub-buffer */
-       struct ltt_trace_header trace;
-} __attribute((packed));
-
-
-
-struct ltt_buf {
-       void                    *start;
-       atomic_t        offset;
-       atomic_t        consumed;
-       atomic_t        reserve_count[LTT_N_SUBBUFS];
-       atomic_t        commit_count[LTT_N_SUBBUFS];
-
-       atomic_t        events_lost;
-       atomic_t        corrupted_subbuffers;
-       atomic_t        full;   /* futex on which the writer waits : 1 : full */
-       unsigned int    alloc_size;
-       unsigned int    subbuf_size;
-};
-
-struct ltt_trace_info {
-       int init;
-       int filter;
-       pid_t daemon_id;
-       int nesting;
-       struct {
-               struct ltt_buf facilities;
-               struct ltt_buf cpu;
-               char facilities_buf[LTT_BUF_SIZE_FACILITIES] __attribute__ ((aligned (8)));
-               char cpu_buf[LTT_BUF_SIZE_CPU] __attribute__ ((aligned (8)));
-       } channel;
-};
-
-
-struct ltt_event_header_nohb {
-  uint64_t      timestamp;
-  unsigned char facility_id;
-  unsigned char event_id;
-  uint16_t      event_size;
-} __attribute((packed));
-
-extern __thread struct ltt_trace_info *thread_trace_info;
-
-void ltt_thread_init(void);
-
-void __attribute__((no_instrument_function))
-       ltt_usertrace_fast_buffer_switch(void);
-
-/* Get the offset of the channel in the ltt_trace_struct */
-#define GET_CHANNEL_INDEX(chan) \
-  (unsigned int)&((struct ltt_trace_info*)NULL)->channel.chan
-
-/* ltt_get_index_from_facility
- *
- * Get channel index from facility and event id.
- * 
- * @fID : facility ID
- * @eID : event number
- *
- * Get the channel index into which events must be written for the given
- * facility and event number. We get this structure offset as soon as possible
- * and remember it so we pass through this logic only once per trace call (not
- * for every trace).
- */
-static inline unsigned int __attribute__((no_instrument_function))
-               ltt_get_index_from_facility(ltt_facility_t fID,
-                                                                                                                               uint8_t eID)
-{
-       return GET_CHANNEL_INDEX(cpu);
-}
-
-
-static inline struct ltt_buf * __attribute__((no_instrument_function))
-       ltt_get_channel_from_index(
-               struct ltt_trace_info *trace, unsigned int index)
-{
-       return *(struct ltt_buf **)((void*)trace+index);
-}
-
-
-/*
- * ltt_get_header_size
- *
- * Calculate alignment offset for arch size void*. This is the
- * alignment offset of the event header.
- *
- * Important note :
- * The event header must be a size multiple of the void* size. This is necessary
- * to be able to calculate statically the alignment offset of the variable
- * length data fields that follows. The total offset calculated here :
- *
- *   Alignment of header struct on arch size
- * + sizeof(header struct)
- * + padding added to end of struct to align on arch size.
- * */
-static inline unsigned char __attribute__((no_instrument_function))
-                                                                                                               ltt_get_header_size(struct ltt_trace_info *trace,
-                                                void *address,
-                                                size_t *before_hdr_pad,
-                                                size_t *after_hdr_pad,
-                                                size_t *header_size)
-{
-  unsigned int padding;
-  unsigned int header;
-
-  header = sizeof(struct ltt_event_header_nohb);
-
-  /* Padding before the header. Calculated dynamically */
-  *before_hdr_pad = ltt_align((unsigned long)address, header);
-  padding = *before_hdr_pad;
-
-  /* Padding after header, considering header aligned on ltt_align.
-   * Calculated statically if header size if known. */
-  *after_hdr_pad = ltt_align(header, sizeof(void*));
-  padding += *after_hdr_pad;
-
-  *header_size = header;
-
-  return header+padding;
-}
-
-
-/* ltt_write_event_header
- *
- * Writes the event header to the pointer.
- *
- * @channel : pointer to the channel structure
- * @ptr : buffer pointer
- * @fID : facility ID
- * @eID : event ID
- * @event_size : size of the event, excluding the event header.
- * @offset : offset of the beginning of the header, for alignment.
- *                                      Calculated by ltt_get_event_header_size.
- * @tsc : time stamp counter.
- */
-static inline void __attribute__((no_instrument_function))
-       ltt_write_event_header(
-               struct ltt_trace_info *trace, struct ltt_buf *buf,
-               void *ptr, ltt_facility_t fID, uint32_t eID, size_t event_size,
-               size_t offset, uint64_t tsc)
-{
-       struct ltt_event_header_nohb *nohb;
-       
-       event_size = min(event_size, 0xFFFFU);
-       nohb = (struct ltt_event_header_nohb *)(ptr+offset);
-       nohb->timestamp = (uint64_t)tsc;
-       nohb->facility_id = fID;
-       nohb->event_id = eID;
-       nohb->event_size = (uint16_t)event_size;
-}
-
-
-
-static inline uint64_t __attribute__((no_instrument_function))
-ltt_get_timestamp()
-{
-       return get_cycles();
-}
-
-static inline unsigned int __attribute__((no_instrument_function))
-ltt_subbuf_header_len(struct ltt_buf *buf)
-{
-       return sizeof(struct ltt_block_start_header);
-}
-
-
-
-static inline void __attribute__((no_instrument_function))
-ltt_write_trace_header(struct ltt_trace_header *header)
-{
-       header->magic_number = LTT_TRACER_MAGIC_NUMBER;
-       header->major_version = LTT_TRACER_VERSION_MAJOR;
-       header->minor_version = LTT_TRACER_VERSION_MINOR;
-       header->float_word_order = 0;   //FIXME
-       header->arch_type = 0; //FIXME LTT_ARCH_TYPE;
-       header->arch_size = sizeof(void*);
-       header->arch_variant = 0; //FIXME LTT_ARCH_VARIANT;
-       header->flight_recorder = 0;
-       header->has_heartbeat = 0;
-
-#ifndef LTT_PACK
-       header->has_alignment = sizeof(void*);
-#else
-       header->has_alignment = 0;
-#endif
-       
-       //FIXME
-       header->freq_scale = 0;
-       header->start_freq = 0;
-       header->start_tsc = 0;
-       header->start_monotonic = 0;
-       header->start_time_sec = 0;
-       header->start_time_usec = 0;
-}
-
-
-static inline void __attribute__((no_instrument_function))
-ltt_buffer_begin_callback(struct ltt_buf *buf,
-                     uint64_t tsc, unsigned int subbuf_idx)
-{
-       struct ltt_block_start_header *header = 
-                                       (struct ltt_block_start_header*)
-                                               (buf->start + (subbuf_idx*buf->subbuf_size));
-       
-       header->begin.cycle_count = tsc;
-       header->begin.freq = 0; //ltt_frequency();
-
-       header->lost_size = 0xFFFFFFFF; // for debugging...
-       
-       header->buf_size = buf->subbuf_size;
-       
-       ltt_write_trace_header(&header->trace);
-
-}
-
-
-
-static inline void __attribute__((no_instrument_function))
-ltt_buffer_end_callback(struct ltt_buf *buf,
-                     uint64_t tsc, unsigned int offset, unsigned int subbuf_idx)
-{
-       struct ltt_block_start_header *header = 
-                                               (struct ltt_block_start_header*)
-                                                               (buf->start + (subbuf_idx*buf->subbuf_size));
-  /* offset is assumed to never be 0 here : never deliver a completely
-   * empty subbuffer. */
-  /* The lost size is between 0 and subbuf_size-1 */
-       header->lost_size = SUBBUF_OFFSET((buf->subbuf_size - offset),
-                                                                                                                                               buf);
-       header->end.cycle_count = tsc;
-       header->end.freq = 0; //ltt_frequency();
-}
-
-
-static inline void __attribute__((no_instrument_function))
-ltt_deliver_callback(struct ltt_buf *buf,
-    unsigned subbuf_idx,
-    void *subbuf)
-{
-       ltt_usertrace_fast_buffer_switch();
-}
-
-
-/* ltt_reserve_slot
- *
- * Atomic slot reservation in a LTTng buffer. It will take care of
- * sub-buffer switching.
- *
- * Parameters:
- *
- * @trace : the trace structure to log to.
- * @buf : the buffer to reserve space into.
- * @data_size : size of the variable length data to log.
- * @slot_size : pointer to total size of the slot (out)
- * @tsc : pointer to the tsc at the slot reservation (out)
- * @before_hdr_pad : dynamic padding before the event header.
- * @after_hdr_pad : dynamic padding after the event header.
- *
- * Return : NULL if not enough space, else returns the pointer
- *                                     to the beginning of the reserved slot. */
-static inline void * __attribute__((no_instrument_function)) ltt_reserve_slot(
-                                                                                                                       struct ltt_trace_info *trace,
-                                                                                                                       struct ltt_buf *ltt_buf,
-                                                                                                                       unsigned int data_size,
-                                                                                                                       unsigned int *slot_size,
-                                                                                                                       uint64_t *tsc,
-                                                                                                                       size_t *before_hdr_pad,
-                                                                                                                       size_t *after_hdr_pad,
-                                                                                                                       size_t *header_size)
-{
-       int offset_begin, offset_end, offset_old;
-       //int has_switch;
-       int begin_switch, end_switch_current, end_switch_old;
-       int reserve_commit_diff = 0;
-       unsigned int size;
-       int consumed_old, consumed_new;
-       int commit_count, reserve_count;
-       int ret;
-
-       do {
-               offset_old = atomic_read(&ltt_buf->offset);
-               offset_begin = offset_old;
-               //has_switch = 0;
-               begin_switch = 0;
-               end_switch_current = 0;
-               end_switch_old = 0;
-               *tsc = ltt_get_timestamp();
-               if(*tsc == 0) {
-                       /* Error in getting the timestamp, event lost */
-                       atomic_inc(&ltt_buf->events_lost);
-                       return NULL;
-               }
-
-               if(SUBBUF_OFFSET(offset_begin, ltt_buf) == 0) {
-                       begin_switch = 1; /* For offset_begin */
-               } else {
-                       size = ltt_get_header_size(trace, ltt_buf->start + offset_begin,
-                                                                                                                                before_hdr_pad, after_hdr_pad, header_size)
-                                                + data_size;
-
-                       if((SUBBUF_OFFSET(offset_begin, ltt_buf)+size)>ltt_buf->subbuf_size) {
-                               //has_switch = 1;
-                               end_switch_old = 1;     /* For offset_old */
-                               begin_switch = 1;       /* For offset_begin */
-                       }
-               }
-
-               if(begin_switch) {
-                       if(end_switch_old) {
-                               offset_begin = SUBBUF_ALIGN(offset_begin, ltt_buf);
-                       }
-                       offset_begin = offset_begin + ltt_subbuf_header_len(ltt_buf);
-                       /* Test new buffer integrity */
-                       reserve_commit_diff =
-                               atomic_read(&ltt_buf->reserve_count[SUBBUF_INDEX(offset_begin,
-                                                                                                                                                                                                                                ltt_buf)])
-                               - atomic_read(&ltt_buf->commit_count[SUBBUF_INDEX(offset_begin,
-                                                                                                                                                                                ltt_buf)]);
-                       if(reserve_commit_diff == 0) {
-                               /* Next buffer not corrupted. */
-                               if((SUBBUF_TRUNC(offset_begin, ltt_buf) 
-                                                               - SUBBUF_TRUNC(atomic_read(&ltt_buf->consumed), ltt_buf))
-                                                                       >= ltt_buf->alloc_size) {
-                                       /* We block until the reader unblocks us */
-                                       atomic_set(&ltt_buf->full, 1);
-                                       /* We block until the reader tells us to wake up.
-                                                Signals will simply cause this loop to restart.
-                                                */
-                                       do {
-                                               ret = futex((unsigned long)&ltt_buf->full, FUTEX_WAIT, 1, 0, 0, 0);
-                                       } while(ret != 0 && ret != EWOULDBLOCK);
-                                       /* go on with the write */
-
-                               } else {
-                                       /* next buffer not corrupted, we are either in overwrite mode or
-                                        * the buffer is not full. It's safe to write in this new subbuffer.*/
-                               }
-                       } else {
-                               /* Next subbuffer corrupted. Force pushing reader even in normal
-                                * mode. It's safe to write in this new subbuffer. */
-                       }
-                       size = ltt_get_header_size(trace, ltt_buf->start + offset_begin,
-                                       before_hdr_pad, after_hdr_pad, header_size) + data_size;
-                       if((SUBBUF_OFFSET(offset_begin,ltt_buf)+size)>ltt_buf->subbuf_size) {
-                               /* Event too big for subbuffers, report error, don't complete 
-                                * the sub-buffer switch. */
-                               atomic_inc(&ltt_buf->events_lost);
-                               return NULL;
-                       } else {
-                               /* We just made a successful buffer switch and the event fits in the
-                                * new subbuffer. Let's write. */
-                       }
-               } else {
-                       /* Event fits in the current buffer and we are not on a switch boundary.
-                        * It's safe to write */
-               }
-               offset_end = offset_begin + size;
-
-               if((SUBBUF_OFFSET(offset_end, ltt_buf)) == 0) {
-                       /* The offset_end will fall at the very beginning of the next subbuffer.
-                        */
-                       end_switch_current = 1; /* For offset_begin */
-               }
-
-       } while(atomic_cmpxchg(&ltt_buf->offset, offset_old, offset_end)
-                                                       != offset_old);
-
-
-       /* Push the reader if necessary */
-       do {
-               consumed_old = atomic_read(&ltt_buf->consumed);
-               /* If buffer is in overwrite mode, push the reader consumed count if
-                        the write position has reached it and we are not at the first
-                        iteration (don't push the reader farther than the writer). 
-                        This operation can be done concurrently by many writers in the
-                        same buffer, the writer being at the fartest write position sub-buffer
-                        index in the buffer being the one which will win this loop. */
-               /* If the buffer is not in overwrite mode, pushing the reader only
-                        happen if a sub-buffer is corrupted */
-               if((SUBBUF_TRUNC(offset_end, ltt_buf) 
-                                       - SUBBUF_TRUNC(consumed_old, ltt_buf)) 
-                                                       >= ltt_buf->alloc_size)
-                       consumed_new = SUBBUF_ALIGN(consumed_old, ltt_buf);
-               else {
-                       consumed_new = consumed_old;
-                       break;
-               }
-       } while(atomic_cmpxchg(&ltt_buf->consumed, consumed_old, consumed_new)
-                                               != consumed_old);
-
-       if(consumed_old != consumed_new) {
-               /* Reader pushed : we are the winner of the push, we can therefore
-                        reequilibrate reserve and commit. Atomic increment of the commit
-                        count permits other writers to play around with this variable
-                        before us. We keep track of corrupted_subbuffers even in overwrite mode :
-                        we never want to write over a non completely committed sub-buffer : 
-                        possible causes : the buffer size is too low compared to the unordered
-                        data input, or there is a writer who died between the reserve and the
-                        commit. */
-               if(reserve_commit_diff) {
-                       /* We have to alter the sub-buffer commit count : a sub-buffer is
-                                corrupted. We do not deliver it. */
-                       atomic_add(reserve_commit_diff,
-                                                               &ltt_buf->commit_count[SUBBUF_INDEX(offset_begin, ltt_buf)]);
-                       atomic_inc(&ltt_buf->corrupted_subbuffers);
-               }
-       }
-
-
-       if(end_switch_old) {
-               /* old subbuffer */
-               /* Concurrency safe because we are the last and only thread to alter this
-                        sub-buffer. As long as it is not delivered and read, no other thread can
-                        alter the offset, alter the reserve_count or call the
-                        client_buffer_end_callback on this sub-buffer.
-                        The only remaining threads could be the ones with pending commits. They
-                        will have to do the deliver themself.
-                        Not concurrency safe in overwrite mode. We detect corrupted subbuffers 
-                        with commit and reserve counts. We keep a corrupted sub-buffers count
-                        and push the readers across these sub-buffers.
-                        Not concurrency safe if a writer is stalled in a subbuffer and
-                        another writer switches in, finding out it's corrupted. The result will
-                        be than the old (uncommited) subbuffer will be declared corrupted, and
-                        that the new subbuffer will be declared corrupted too because of the
-                        commit count adjustment.
-                        Note : offset_old should never be 0 here.*/
-               ltt_buffer_end_callback(ltt_buf, *tsc, offset_old, 
-                                                                                                               SUBBUF_INDEX((offset_old-1), ltt_buf));
-               /* Setting this reserve_count will allow the sub-buffer to be delivered by
-                        the last committer. */
-               reserve_count = 
-                                                atomic_add_return((SUBBUF_OFFSET((offset_old-1), ltt_buf)+1),
-                                                &ltt_buf->reserve_count[SUBBUF_INDEX((offset_old-1), ltt_buf)]);
-               if(reserve_count 
-                                       == atomic_read(&ltt_buf->commit_count[SUBBUF_INDEX((offset_old-1),
-                                                                                                                                                                                                                                                       ltt_buf)])) {
-                       ltt_deliver_callback(ltt_buf, SUBBUF_INDEX((offset_old-1), ltt_buf),
-                                                                                                                NULL);
-               }
-       }
-
-       if(begin_switch) {
-               /* New sub-buffer */
-               /* This code can be executed unordered : writers may already have written
-                        to the sub-buffer before this code gets executed, caution. */
-               /* The commit makes sure that this code is executed before the deliver
-                        of this sub-buffer */
-               ltt_buffer_begin_callback(ltt_buf, *tsc, SUBBUF_INDEX(offset_begin, ltt_buf));
-               commit_count = atomic_add_return(ltt_subbuf_header_len(ltt_buf),
-                                                        &ltt_buf->commit_count[SUBBUF_INDEX(offset_begin, ltt_buf)]);
-               /* Check if the written buffer has to be delivered */
-               if(commit_count
-                                       == atomic_read(&ltt_buf->reserve_count[SUBBUF_INDEX(offset_begin,
-                                                                                                                                                                                                                                                       ltt_buf)])) {
-                       ltt_deliver_callback(ltt_buf, SUBBUF_INDEX(offset_begin, ltt_buf), NULL);
-               }
-       }
-
-       if(end_switch_current) {
-               /* current subbuffer */
-               /* Concurrency safe because we are the last and only thread to alter this
-                        sub-buffer. As long as it is not delivered and read, no other thread can
-                        alter the offset, alter the reserve_count or call the
-                        client_buffer_end_callback on this sub-buffer.
-                        The only remaining threads could be the ones with pending commits. They
-                        will have to do the deliver themself.
-                        Not concurrency safe in overwrite mode. We detect corrupted subbuffers 
-                        with commit and reserve counts. We keep a corrupted sub-buffers count
-                        and push the readers across these sub-buffers.
-                        Not concurrency safe if a writer is stalled in a subbuffer and
-                        another writer switches in, finding out it's corrupted. The result will
-                        be than the old (uncommited) subbuffer will be declared corrupted, and
-                        that the new subbuffer will be declared corrupted too because of the
-                        commit count adjustment. */
-               ltt_buffer_end_callback(ltt_buf, *tsc, offset_end,
-                                                                                                               SUBBUF_INDEX((offset_end-1), ltt_buf));
-               /* Setting this reserve_count will allow the sub-buffer to be delivered by
-                        the last committer. */
-               reserve_count = 
-      atomic_add_return((SUBBUF_OFFSET((offset_end-1), ltt_buf)+1),
-                       &ltt_buf->reserve_count[SUBBUF_INDEX((offset_end-1), ltt_buf)]);
-               if(reserve_count 
-                                       == atomic_read(&ltt_buf->commit_count[SUBBUF_INDEX((offset_end-1),
-                                                                                                                                                                                                                                                       ltt_buf)])) {
-                       ltt_deliver_callback(ltt_buf, SUBBUF_INDEX((offset_end-1), ltt_buf), NULL);
-               }
-       }
-
-       *slot_size = size;
-
-       //BUG_ON(*slot_size != (data_size + *before_hdr_pad + *after_hdr_pad + *header_size));
-       //BUG_ON(*slot_size != (offset_end - offset_begin));
-       
-       return ltt_buf->start + BUFFER_OFFSET(offset_begin, ltt_buf);
-}
-       
-       
-/* ltt_commit_slot
- *
- * Atomic unordered slot commit. Increments the commit count in the
- * specified sub-buffer, and delivers it if necessary.
- *
- * Parameters:
- *
- * @buf : the buffer to commit to.
- * @reserved : address of the beginnig of the reserved slot.
- * @slot_size : size of the reserved slot.
- *
- */
-static inline void __attribute__((no_instrument_function)) ltt_commit_slot(
-                                                                                                                       struct ltt_buf *ltt_buf,
-                                                                                                                       void *reserved,
-                                                                                                                       unsigned int slot_size)
-{
-       unsigned int offset_begin = reserved - ltt_buf->start;
-       int commit_count;
-
-       commit_count = atomic_add_return(slot_size,
-                                                                                                       &ltt_buf->commit_count[SUBBUF_INDEX(offset_begin,
-                                                                                                                                                                                                                                                       ltt_buf)]);
-       
-       /* Check if all commits have been done */
-       if(commit_count ==
-       atomic_read(&ltt_buf->reserve_count[SUBBUF_INDEX(offset_begin, ltt_buf)])) {
-               ltt_deliver_callback(ltt_buf, SUBBUF_INDEX(offset_begin, ltt_buf), NULL);
-       }
-}
-       
-
-#endif //LTT_TRACE
-
-
-#endif //_LTT_USERTRACE_FAST_H
diff --git a/usertrace-fast/ltt/ltt-usertrace-fast.h b/usertrace-fast/ltt/ltt-usertrace-fast.h
new file mode 100644 (file)
index 0000000..a175d89
--- /dev/null
@@ -0,0 +1,638 @@
+
+/* LTTng user-space "fast" tracing header
+ *
+ * Copyright 2006 Mathieu Desnoyers
+ *
+ */
+
+#ifndef _LTT_USERTRACE_FAST_H
+#define _LTT_USERTRACE_FAST_H
+
+#ifdef LTT_TRACE
+
+#include <errno.h>
+#include <asm/atomic.h>
+#include <pthread.h>
+#include <stdint.h>
+#include <syscall.h>
+#include <linux/futex.h>
+#include <asm/timex.h>
+
+#include <ltt/ltt-facility-id-user_generic.h>
+#include <ltt/ltt-generic.h>
+
+#ifndef futex
+static inline __attribute__((no_instrument_function))
+       _syscall6(long, futex, unsigned long, uaddr, int, op, int, val,
+               unsigned long, timeout, unsigned long, uaddr2, int, val2)
+#endif //futex
+
+
+
+#ifndef        LTT_N_SUBBUFS
+#define LTT_N_SUBBUFS 2
+#endif //LTT_N_SUBBUFS
+
+#ifndef        LTT_SUBBUF_SIZE_CPU
+#define LTT_SUBBUF_SIZE_CPU 1048576
+#endif //LTT_BUF_SIZE_CPU
+
+#define LTT_BUF_SIZE_CPU (LTT_SUBBUF_SIZE_CPU * LTT_N_SUBBUFS)
+
+#ifndef        LTT_SUBBUF_SIZE_FACILITIES
+#define LTT_SUBBUF_SIZE_FACILITIES 4096
+#endif //LTT_BUF_SIZE_FACILITIES
+
+#define LTT_BUF_SIZE_FACILITIES  (LTT_SUBBUF_SIZE_FACILITIES * LTT_N_SUBBUFS)
+
+#ifndef LTT_USERTRACE_ROOT
+#define LTT_USERTRACE_ROOT "/tmp/ltt-usertrace"
+#endif //LTT_USERTRACE_ROOT
+
+
+/* Buffer offset macros */
+
+#define BUFFER_OFFSET(offset, buf) (offset & (buf->alloc_size-1))
+#define SUBBUF_OFFSET(offset, buf) (offset & (buf->subbuf_size-1))
+#define SUBBUF_ALIGN(offset, buf) \
+  (((offset) + buf->subbuf_size) & (~(buf->subbuf_size-1)))
+#define SUBBUF_TRUNC(offset, buf) \
+  ((offset) & (~(buf->subbuf_size-1)))
+#define SUBBUF_INDEX(offset, buf) \
+  (BUFFER_OFFSET(offset,buf)/buf->subbuf_size)
+
+
+#define LTT_TRACER_MAGIC_NUMBER                 0x00D6B7ED
+#define LTT_TRACER_VERSION_MAJOR               0
+#define LTT_TRACER_VERSION_MINOR               7
+
+#ifndef atomic_cmpxchg
+#define atomic_cmpxchg(v, old, new) ((int)cmpxchg(&((v)->counter), old, new))
+#endif //atomic_cmpxchg
+
+typedef unsigned int ltt_facility_t;
+       
+struct ltt_trace_header {
+       uint32_t                                magic_number;
+       uint32_t                                arch_type;
+       uint32_t                                arch_variant;
+       uint32_t                                float_word_order;        /* Only useful for user space traces */
+       uint8_t                                 arch_size;
+       //uint32_t                              system_type;
+       uint8_t                                 major_version;
+       uint8_t                                 minor_version;
+       uint8_t                                 flight_recorder;
+       uint8_t                                 has_heartbeat;
+       uint8_t                                 has_alignment;  /* Event header alignment */
+       uint32_t                                freq_scale;
+       uint64_t                                start_freq;
+       uint64_t                                start_tsc;
+       uint64_t                                start_monotonic;
+  uint64_t        start_time_sec;
+  uint64_t        start_time_usec;
+} __attribute((packed));
+
+
+struct ltt_block_start_header {
+       struct { 
+               uint64_t                                                                cycle_count;
+               uint64_t                                                                freq; /* khz */
+       } begin;
+       struct { 
+               uint64_t                                                                cycle_count;
+               uint64_t                                                                freq; /* khz */
+       } end;
+       uint32_t                                                                lost_size;      /* Size unused at the end of the buffer */
+       uint32_t                                                                buf_size;               /* The size of this sub-buffer */
+       struct ltt_trace_header trace;
+} __attribute((packed));
+
+
+
+struct ltt_buf {
+       void                    *start;
+       atomic_t        offset;
+       atomic_t        consumed;
+       atomic_t        reserve_count[LTT_N_SUBBUFS];
+       atomic_t        commit_count[LTT_N_SUBBUFS];
+
+       atomic_t        events_lost;
+       atomic_t        corrupted_subbuffers;
+       atomic_t        full;   /* futex on which the writer waits : 1 : full */
+       unsigned int    alloc_size;
+       unsigned int    subbuf_size;
+};
+
+struct ltt_trace_info {
+       int init;
+       int filter;
+       pid_t daemon_id;
+       int nesting;
+       struct {
+               struct ltt_buf facilities;
+               struct ltt_buf cpu;
+               char facilities_buf[LTT_BUF_SIZE_FACILITIES] __attribute__ ((aligned (8)));
+               char cpu_buf[LTT_BUF_SIZE_CPU] __attribute__ ((aligned (8)));
+       } channel;
+};
+
+
+struct ltt_event_header_nohb {
+  uint64_t      timestamp;
+  unsigned char facility_id;
+  unsigned char event_id;
+  uint16_t      event_size;
+} __attribute((packed));
+
+extern __thread struct ltt_trace_info *thread_trace_info;
+
+void ltt_thread_init(void);
+
+void __attribute__((no_instrument_function))
+       ltt_usertrace_fast_buffer_switch(void);
+
+/* Get the offset of the channel in the ltt_trace_struct */
+#define GET_CHANNEL_INDEX(chan) \
+  (unsigned int)&((struct ltt_trace_info*)NULL)->channel.chan
+
+/* ltt_get_index_from_facility
+ *
+ * Get channel index from facility and event id.
+ * 
+ * @fID : facility ID
+ * @eID : event number
+ *
+ * Get the channel index into which events must be written for the given
+ * facility and event number. We get this structure offset as soon as possible
+ * and remember it so we pass through this logic only once per trace call (not
+ * for every trace).
+ */
+static inline unsigned int __attribute__((no_instrument_function))
+               ltt_get_index_from_facility(ltt_facility_t fID,
+                                                                                                                               uint8_t eID)
+{
+       return GET_CHANNEL_INDEX(cpu);
+}
+
+
+static inline struct ltt_buf * __attribute__((no_instrument_function))
+       ltt_get_channel_from_index(
+               struct ltt_trace_info *trace, unsigned int index)
+{
+       return (struct ltt_buf *)((void*)trace+index);
+}
+
+
+/*
+ * ltt_get_header_size
+ *
+ * Calculate alignment offset for arch size void*. This is the
+ * alignment offset of the event header.
+ *
+ * Important note :
+ * The event header must be a size multiple of the void* size. This is necessary
+ * to be able to calculate statically the alignment offset of the variable
+ * length data fields that follows. The total offset calculated here :
+ *
+ *   Alignment of header struct on arch size
+ * + sizeof(header struct)
+ * + padding added to end of struct to align on arch size.
+ * */
+static inline unsigned char __attribute__((no_instrument_function))
+                                                                                                               ltt_get_header_size(struct ltt_trace_info *trace,
+                                                void *address,
+                                                size_t *before_hdr_pad,
+                                                size_t *after_hdr_pad,
+                                                size_t *header_size)
+{
+  unsigned int padding;
+  unsigned int header;
+
+  header = sizeof(struct ltt_event_header_nohb);
+
+  /* Padding before the header. Calculated dynamically */
+  *before_hdr_pad = ltt_align((unsigned long)address, header);
+  padding = *before_hdr_pad;
+
+  /* Padding after header, considering header aligned on ltt_align.
+   * Calculated statically if header size if known. */
+  *after_hdr_pad = ltt_align(header, sizeof(void*));
+  padding += *after_hdr_pad;
+
+  *header_size = header;
+
+  return header+padding;
+}
+
+
+/* ltt_write_event_header
+ *
+ * Writes the event header to the pointer.
+ *
+ * @channel : pointer to the channel structure
+ * @ptr : buffer pointer
+ * @fID : facility ID
+ * @eID : event ID
+ * @event_size : size of the event, excluding the event header.
+ * @offset : offset of the beginning of the header, for alignment.
+ *                                      Calculated by ltt_get_event_header_size.
+ * @tsc : time stamp counter.
+ */
+static inline void __attribute__((no_instrument_function))
+       ltt_write_event_header(
+               struct ltt_trace_info *trace, struct ltt_buf *buf,
+               void *ptr, ltt_facility_t fID, uint32_t eID, size_t event_size,
+               size_t offset, uint64_t tsc)
+{
+       struct ltt_event_header_nohb *nohb;
+       
+       event_size = min(event_size, 0xFFFFU);
+       nohb = (struct ltt_event_header_nohb *)(ptr+offset);
+       nohb->timestamp = (uint64_t)tsc;
+       nohb->facility_id = fID;
+       nohb->event_id = eID;
+       nohb->event_size = (uint16_t)event_size;
+}
+
+
+
+static inline uint64_t __attribute__((no_instrument_function))
+ltt_get_timestamp()
+{
+       return get_cycles();
+}
+
+static inline unsigned int __attribute__((no_instrument_function))
+ltt_subbuf_header_len(struct ltt_buf *buf)
+{
+       return sizeof(struct ltt_block_start_header);
+}
+
+
+
+static inline void __attribute__((no_instrument_function))
+ltt_write_trace_header(struct ltt_trace_header *header)
+{
+       header->magic_number = LTT_TRACER_MAGIC_NUMBER;
+       header->major_version = LTT_TRACER_VERSION_MAJOR;
+       header->minor_version = LTT_TRACER_VERSION_MINOR;
+       header->float_word_order = 0;   //FIXME
+       header->arch_type = 0; //FIXME LTT_ARCH_TYPE;
+       header->arch_size = sizeof(void*);
+       header->arch_variant = 0; //FIXME LTT_ARCH_VARIANT;
+       header->flight_recorder = 0;
+       header->has_heartbeat = 0;
+
+#ifndef LTT_PACK
+       header->has_alignment = sizeof(void*);
+#else
+       header->has_alignment = 0;
+#endif
+       
+       //FIXME
+       header->freq_scale = 0;
+       header->start_freq = 0;
+       header->start_tsc = 0;
+       header->start_monotonic = 0;
+       header->start_time_sec = 0;
+       header->start_time_usec = 0;
+}
+
+
+static inline void __attribute__((no_instrument_function))
+ltt_buffer_begin_callback(struct ltt_buf *buf,
+                     uint64_t tsc, unsigned int subbuf_idx)
+{
+       struct ltt_block_start_header *header = 
+                                       (struct ltt_block_start_header*)
+                                               (buf->start + (subbuf_idx*buf->subbuf_size));
+       
+       header->begin.cycle_count = tsc;
+       header->begin.freq = 0; //ltt_frequency();
+
+       header->lost_size = 0xFFFFFFFF; // for debugging...
+       
+       header->buf_size = buf->subbuf_size;
+       
+       ltt_write_trace_header(&header->trace);
+
+}
+
+
+
+static inline void __attribute__((no_instrument_function))
+ltt_buffer_end_callback(struct ltt_buf *buf,
+                     uint64_t tsc, unsigned int offset, unsigned int subbuf_idx)
+{
+       struct ltt_block_start_header *header = 
+                                               (struct ltt_block_start_header*)
+                                                               (buf->start + (subbuf_idx*buf->subbuf_size));
+  /* offset is assumed to never be 0 here : never deliver a completely
+   * empty subbuffer. */
+  /* The lost size is between 0 and subbuf_size-1 */
+       header->lost_size = SUBBUF_OFFSET((buf->subbuf_size - offset),
+                                                                                                                                               buf);
+       header->end.cycle_count = tsc;
+       header->end.freq = 0; //ltt_frequency();
+}
+
+
+static inline void __attribute__((no_instrument_function))
+ltt_deliver_callback(struct ltt_buf *buf,
+    unsigned subbuf_idx,
+    void *subbuf)
+{
+       ltt_usertrace_fast_buffer_switch();
+}
+
+
+/* ltt_reserve_slot
+ *
+ * Atomic slot reservation in a LTTng buffer. It will take care of
+ * sub-buffer switching.
+ *
+ * Parameters:
+ *
+ * @trace : the trace structure to log to.
+ * @buf : the buffer to reserve space into.
+ * @data_size : size of the variable length data to log.
+ * @slot_size : pointer to total size of the slot (out)
+ * @tsc : pointer to the tsc at the slot reservation (out)
+ * @before_hdr_pad : dynamic padding before the event header.
+ * @after_hdr_pad : dynamic padding after the event header.
+ *
+ * Return : NULL if not enough space, else returns the pointer
+ *                                     to the beginning of the reserved slot. */
+static inline void * __attribute__((no_instrument_function)) ltt_reserve_slot(
+                                                                                                                       struct ltt_trace_info *trace,
+                                                                                                                       struct ltt_buf *ltt_buf,
+                                                                                                                       unsigned int data_size,
+                                                                                                                       unsigned int *slot_size,
+                                                                                                                       uint64_t *tsc,
+                                                                                                                       size_t *before_hdr_pad,
+                                                                                                                       size_t *after_hdr_pad,
+                                                                                                                       size_t *header_size)
+{
+       int offset_begin, offset_end, offset_old;
+       //int has_switch;
+       int begin_switch, end_switch_current, end_switch_old;
+       int reserve_commit_diff = 0;
+       unsigned int size;
+       int consumed_old, consumed_new;
+       int commit_count, reserve_count;
+       int ret;
+
+       do {
+               offset_old = atomic_read(&ltt_buf->offset);
+               offset_begin = offset_old;
+               //has_switch = 0;
+               begin_switch = 0;
+               end_switch_current = 0;
+               end_switch_old = 0;
+               *tsc = ltt_get_timestamp();
+               if(*tsc == 0) {
+                       /* Error in getting the timestamp, event lost */
+                       atomic_inc(&ltt_buf->events_lost);
+                       return NULL;
+               }
+
+               if(SUBBUF_OFFSET(offset_begin, ltt_buf) == 0) {
+                       begin_switch = 1; /* For offset_begin */
+               } else {
+                       size = ltt_get_header_size(trace, ltt_buf->start + offset_begin,
+                                                                                                                                before_hdr_pad, after_hdr_pad, header_size)
+                                                + data_size;
+
+                       if((SUBBUF_OFFSET(offset_begin, ltt_buf)+size)>ltt_buf->subbuf_size) {
+                               //has_switch = 1;
+                               end_switch_old = 1;     /* For offset_old */
+                               begin_switch = 1;       /* For offset_begin */
+                       }
+               }
+
+               if(begin_switch) {
+                       if(end_switch_old) {
+                               offset_begin = SUBBUF_ALIGN(offset_begin, ltt_buf);
+                       }
+                       offset_begin = offset_begin + ltt_subbuf_header_len(ltt_buf);
+                       /* Test new buffer integrity */
+                       reserve_commit_diff =
+                               atomic_read(&ltt_buf->reserve_count[SUBBUF_INDEX(offset_begin,
+                                                                                                                                                                                                                                ltt_buf)])
+                               - atomic_read(&ltt_buf->commit_count[SUBBUF_INDEX(offset_begin,
+                                                                                                                                                                                ltt_buf)]);
+                       if(reserve_commit_diff == 0) {
+                               /* Next buffer not corrupted. */
+                               if((SUBBUF_TRUNC(offset_begin, ltt_buf) 
+                                                               - SUBBUF_TRUNC(atomic_read(&ltt_buf->consumed), ltt_buf))
+                                                                       >= ltt_buf->alloc_size) {
+                                       /* We block until the reader unblocks us */
+                                       atomic_set(&ltt_buf->full, 1);
+                                       /* We block until the reader tells us to wake up.
+                                                Signals will simply cause this loop to restart.
+                                                */
+                                       do {
+                                               ret = futex((unsigned long)&ltt_buf->full, FUTEX_WAIT, 1, 0, 0, 0);
+                                       } while(ret != 0 && ret != EWOULDBLOCK);
+                                       /* go on with the write */
+
+                               } else {
+                                       /* next buffer not corrupted, we are either in overwrite mode or
+                                        * the buffer is not full. It's safe to write in this new subbuffer.*/
+                               }
+                       } else {
+                               /* Next subbuffer corrupted. Force pushing reader even in normal
+                                * mode. It's safe to write in this new subbuffer. */
+                       }
+                       size = ltt_get_header_size(trace, ltt_buf->start + offset_begin,
+                                       before_hdr_pad, after_hdr_pad, header_size) + data_size;
+                       if((SUBBUF_OFFSET(offset_begin,ltt_buf)+size)>ltt_buf->subbuf_size) {
+                               /* Event too big for subbuffers, report error, don't complete 
+                                * the sub-buffer switch. */
+                               atomic_inc(&ltt_buf->events_lost);
+                               return NULL;
+                       } else {
+                               /* We just made a successful buffer switch and the event fits in the
+                                * new subbuffer. Let's write. */
+                       }
+               } else {
+                       /* Event fits in the current buffer and we are not on a switch boundary.
+                        * It's safe to write */
+               }
+               offset_end = offset_begin + size;
+
+               if((SUBBUF_OFFSET(offset_end, ltt_buf)) == 0) {
+                       /* The offset_end will fall at the very beginning of the next subbuffer.
+                        */
+                       end_switch_current = 1; /* For offset_begin */
+               }
+
+       } while(atomic_cmpxchg(&ltt_buf->offset, offset_old, offset_end)
+                                                       != offset_old);
+
+
+       /* Push the reader if necessary */
+       do {
+               consumed_old = atomic_read(&ltt_buf->consumed);
+               /* If buffer is in overwrite mode, push the reader consumed count if
+                        the write position has reached it and we are not at the first
+                        iteration (don't push the reader farther than the writer). 
+                        This operation can be done concurrently by many writers in the
+                        same buffer, the writer being at the fartest write position sub-buffer
+                        index in the buffer being the one which will win this loop. */
+               /* If the buffer is not in overwrite mode, pushing the reader only
+                        happen if a sub-buffer is corrupted */
+               if((SUBBUF_TRUNC(offset_end, ltt_buf) 
+                                       - SUBBUF_TRUNC(consumed_old, ltt_buf)) 
+                                                       >= ltt_buf->alloc_size)
+                       consumed_new = SUBBUF_ALIGN(consumed_old, ltt_buf);
+               else {
+                       consumed_new = consumed_old;
+                       break;
+               }
+       } while(atomic_cmpxchg(&ltt_buf->consumed, consumed_old, consumed_new)
+                                               != consumed_old);
+
+       if(consumed_old != consumed_new) {
+               /* Reader pushed : we are the winner of the push, we can therefore
+                        reequilibrate reserve and commit. Atomic increment of the commit
+                        count permits other writers to play around with this variable
+                        before us. We keep track of corrupted_subbuffers even in overwrite mode :
+                        we never want to write over a non completely committed sub-buffer : 
+                        possible causes : the buffer size is too low compared to the unordered
+                        data input, or there is a writer who died between the reserve and the
+                        commit. */
+               if(reserve_commit_diff) {
+                       /* We have to alter the sub-buffer commit count : a sub-buffer is
+                                corrupted. We do not deliver it. */
+                       atomic_add(reserve_commit_diff,
+                                                               &ltt_buf->commit_count[SUBBUF_INDEX(offset_begin, ltt_buf)]);
+                       atomic_inc(&ltt_buf->corrupted_subbuffers);
+               }
+       }
+
+
+       if(end_switch_old) {
+               /* old subbuffer */
+               /* Concurrency safe because we are the last and only thread to alter this
+                        sub-buffer. As long as it is not delivered and read, no other thread can
+                        alter the offset, alter the reserve_count or call the
+                        client_buffer_end_callback on this sub-buffer.
+                        The only remaining threads could be the ones with pending commits. They
+                        will have to do the deliver themself.
+                        Not concurrency safe in overwrite mode. We detect corrupted subbuffers 
+                        with commit and reserve counts. We keep a corrupted sub-buffers count
+                        and push the readers across these sub-buffers.
+                        Not concurrency safe if a writer is stalled in a subbuffer and
+                        another writer switches in, finding out it's corrupted. The result will
+                        be than the old (uncommited) subbuffer will be declared corrupted, and
+                        that the new subbuffer will be declared corrupted too because of the
+                        commit count adjustment.
+                        Note : offset_old should never be 0 here.*/
+               ltt_buffer_end_callback(ltt_buf, *tsc, offset_old, 
+                                                                                                               SUBBUF_INDEX((offset_old-1), ltt_buf));
+               /* Setting this reserve_count will allow the sub-buffer to be delivered by
+                        the last committer. */
+               reserve_count = 
+                                                atomic_add_return((SUBBUF_OFFSET((offset_old-1), ltt_buf)+1),
+                                                &ltt_buf->reserve_count[SUBBUF_INDEX((offset_old-1), ltt_buf)]);
+               if(reserve_count 
+                                       == atomic_read(&ltt_buf->commit_count[SUBBUF_INDEX((offset_old-1),
+                                                                                                                                                                                                                                                       ltt_buf)])) {
+                       ltt_deliver_callback(ltt_buf, SUBBUF_INDEX((offset_old-1), ltt_buf),
+                                                                                                                NULL);
+               }
+       }
+
+       if(begin_switch) {
+               /* New sub-buffer */
+               /* This code can be executed unordered : writers may already have written
+                        to the sub-buffer before this code gets executed, caution. */
+               /* The commit makes sure that this code is executed before the deliver
+                        of this sub-buffer */
+               ltt_buffer_begin_callback(ltt_buf, *tsc, SUBBUF_INDEX(offset_begin, ltt_buf));
+               commit_count = atomic_add_return(ltt_subbuf_header_len(ltt_buf),
+                                                        &ltt_buf->commit_count[SUBBUF_INDEX(offset_begin, ltt_buf)]);
+               /* Check if the written buffer has to be delivered */
+               if(commit_count
+                                       == atomic_read(&ltt_buf->reserve_count[SUBBUF_INDEX(offset_begin,
+                                                                                                                                                                                                                                                       ltt_buf)])) {
+                       ltt_deliver_callback(ltt_buf, SUBBUF_INDEX(offset_begin, ltt_buf), NULL);
+               }
+       }
+
+       if(end_switch_current) {
+               /* current subbuffer */
+               /* Concurrency safe because we are the last and only thread to alter this
+                        sub-buffer. As long as it is not delivered and read, no other thread can
+                        alter the offset, alter the reserve_count or call the
+                        client_buffer_end_callback on this sub-buffer.
+                        The only remaining threads could be the ones with pending commits. They
+                        will have to do the deliver themself.
+                        Not concurrency safe in overwrite mode. We detect corrupted subbuffers 
+                        with commit and reserve counts. We keep a corrupted sub-buffers count
+                        and push the readers across these sub-buffers.
+                        Not concurrency safe if a writer is stalled in a subbuffer and
+                        another writer switches in, finding out it's corrupted. The result will
+                        be than the old (uncommited) subbuffer will be declared corrupted, and
+                        that the new subbuffer will be declared corrupted too because of the
+                        commit count adjustment. */
+               ltt_buffer_end_callback(ltt_buf, *tsc, offset_end,
+                                                                                                               SUBBUF_INDEX((offset_end-1), ltt_buf));
+               /* Setting this reserve_count will allow the sub-buffer to be delivered by
+                        the last committer. */
+               reserve_count = 
+      atomic_add_return((SUBBUF_OFFSET((offset_end-1), ltt_buf)+1),
+                       &ltt_buf->reserve_count[SUBBUF_INDEX((offset_end-1), ltt_buf)]);
+               if(reserve_count 
+                                       == atomic_read(&ltt_buf->commit_count[SUBBUF_INDEX((offset_end-1),
+                                                                                                                                                                                                                                                       ltt_buf)])) {
+                       ltt_deliver_callback(ltt_buf, SUBBUF_INDEX((offset_end-1), ltt_buf), NULL);
+               }
+       }
+
+       *slot_size = size;
+
+       //BUG_ON(*slot_size != (data_size + *before_hdr_pad + *after_hdr_pad + *header_size));
+       //BUG_ON(*slot_size != (offset_end - offset_begin));
+       
+       return ltt_buf->start + BUFFER_OFFSET(offset_begin, ltt_buf);
+}
+       
+       
+/* ltt_commit_slot
+ *
+ * Atomic unordered slot commit. Increments the commit count in the
+ * specified sub-buffer, and delivers it if necessary.
+ *
+ * Parameters:
+ *
+ * @buf : the buffer to commit to.
+ * @reserved : address of the beginnig of the reserved slot.
+ * @slot_size : size of the reserved slot.
+ *
+ */
+static inline void __attribute__((no_instrument_function)) ltt_commit_slot(
+                                                                                                                       struct ltt_buf *ltt_buf,
+                                                                                                                       void *reserved,
+                                                                                                                       unsigned int slot_size)
+{
+       unsigned int offset_begin = reserved - ltt_buf->start;
+       int commit_count;
+
+       commit_count = atomic_add_return(slot_size,
+                                                                                                       &ltt_buf->commit_count[SUBBUF_INDEX(offset_begin,
+                                                                                                                                                                                                                                                       ltt_buf)]);
+       
+       /* Check if all commits have been done */
+       if(commit_count ==
+       atomic_read(&ltt_buf->reserve_count[SUBBUF_INDEX(offset_begin, ltt_buf)])) {
+               ltt_deliver_callback(ltt_buf, SUBBUF_INDEX(offset_begin, ltt_buf), NULL);
+       }
+}
+       
+
+#endif //LTT_TRACE
+
+
+#endif //_LTT_USERTRACE_FAST_H
index 8ac69eb5d7c1759763f3003a7f31eb2aaf083a8d..4960c0bcda033acafb767c7ee18cdec0c27c485a 100644 (file)
@@ -4,7 +4,7 @@
 #include <unistd.h>
 #include <stdlib.h>
 
-#include "ltt-usertrace-fast.h"
+#include <ltt/ltt-usertrace-fast.h>
 
 
 
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