eBookReaderSwitch/mupdf/source/fitz/memory.c

370 lines
7.3 KiB
C

#include "mupdf/fitz.h"
#include "fitz-imp.h"
#include <limits.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
/* Enable FITZ_DEBUG_LOCKING_TIMES below if you want to check the times
* for which locks are held too. */
#ifdef FITZ_DEBUG_LOCKING
#undef FITZ_DEBUG_LOCKING_TIMES
#endif
/*
* The malloc family of functions will always try scavenging when they run out of memory.
* They will only fail when scavenging cannot free up memory from caches in the fz_context.
* All the functions will throw an exception when no memory can be allocated,
* except the _no_throw family which instead silently returns NULL.
*/
static void *
do_scavenging_malloc(fz_context *ctx, size_t size)
{
void *p;
int phase = 0;
fz_lock(ctx, FZ_LOCK_ALLOC);
do {
p = ctx->alloc.malloc(ctx->alloc.user, size);
if (p != NULL)
{
fz_unlock(ctx, FZ_LOCK_ALLOC);
return p;
}
} while (fz_store_scavenge(ctx, size, &phase));
fz_unlock(ctx, FZ_LOCK_ALLOC);
return NULL;
}
static void *
do_scavenging_realloc(fz_context *ctx, void *p, size_t size)
{
void *q;
int phase = 0;
fz_lock(ctx, FZ_LOCK_ALLOC);
do {
q = ctx->alloc.realloc(ctx->alloc.user, p, size);
if (q != NULL)
{
fz_unlock(ctx, FZ_LOCK_ALLOC);
return q;
}
} while (fz_store_scavenge(ctx, size, &phase));
fz_unlock(ctx, FZ_LOCK_ALLOC);
return NULL;
}
void *
fz_malloc(fz_context *ctx, size_t size)
{
void *p;
if (size == 0)
return NULL;
p = do_scavenging_malloc(ctx, size);
if (!p)
fz_throw(ctx, FZ_ERROR_MEMORY, "malloc of %zu bytes failed", size);
return p;
}
void *
fz_malloc_no_throw(fz_context *ctx, size_t size)
{
if (size == 0)
return NULL;
return do_scavenging_malloc(ctx, size);
}
void *
fz_calloc(fz_context *ctx, size_t count, size_t size)
{
void *p;
if (count == 0 || size == 0)
return NULL;
if (count > SIZE_MAX / size)
fz_throw(ctx, FZ_ERROR_MEMORY, "calloc (%zu x %zu bytes) failed (size_t overflow)", count, size);
p = do_scavenging_malloc(ctx, count * size);
if (!p)
fz_throw(ctx, FZ_ERROR_MEMORY, "calloc (%zu x %zu bytes) failed", count, size);
memset(p, 0, count*size);
return p;
}
void *
fz_calloc_no_throw(fz_context *ctx, size_t count, size_t size)
{
void *p;
if (count == 0 || size == 0)
return NULL;
if (count > SIZE_MAX / size)
return NULL;
p = do_scavenging_malloc(ctx, count * size);
if (p)
memset(p, 0, count * size);
return p;
}
void *
fz_realloc(fz_context *ctx, void *p, size_t size)
{
if (size == 0)
{
fz_free(ctx, p);
return NULL;
}
p = do_scavenging_realloc(ctx, p, size);
if (!p)
fz_throw(ctx, FZ_ERROR_MEMORY, "realloc (%zu bytes) failed", size);
return p;
}
void *
fz_realloc_no_throw(fz_context *ctx, void *p, size_t size)
{
if (size == 0)
{
fz_free(ctx, p);
return NULL;
}
return do_scavenging_realloc(ctx, p, size);
}
void
fz_free(fz_context *ctx, void *p)
{
if (p)
{
fz_lock(ctx, FZ_LOCK_ALLOC);
ctx->alloc.free(ctx->alloc.user, p);
fz_unlock(ctx, FZ_LOCK_ALLOC);
}
}
char *
fz_strdup(fz_context *ctx, const char *s)
{
size_t len = strlen(s) + 1;
char *ns = fz_malloc(ctx, len);
memcpy(ns, s, len);
return ns;
}
static void *
fz_malloc_default(void *opaque, size_t size)
{
return malloc(size);
}
static void *
fz_realloc_default(void *opaque, void *old, size_t size)
{
return realloc(old, size);
}
static void
fz_free_default(void *opaque, void *ptr)
{
free(ptr);
}
fz_alloc_context fz_alloc_default =
{
NULL,
fz_malloc_default,
fz_realloc_default,
fz_free_default
};
static void
fz_lock_default(void *user, int lock)
{
}
static void
fz_unlock_default(void *user, int lock)
{
}
fz_locks_context fz_locks_default =
{
NULL,
fz_lock_default,
fz_unlock_default
};
#ifdef FITZ_DEBUG_LOCKING
enum
{
FZ_LOCK_DEBUG_CONTEXT_MAX = 100
};
fz_context *fz_lock_debug_contexts[FZ_LOCK_DEBUG_CONTEXT_MAX];
int fz_locks_debug[FZ_LOCK_DEBUG_CONTEXT_MAX][FZ_LOCK_MAX];
#ifdef FITZ_DEBUG_LOCKING_TIMES
int fz_debug_locking_inited = 0;
int fz_lock_program_start;
int fz_lock_time[FZ_LOCK_DEBUG_CONTEXT_MAX][FZ_LOCK_MAX] = { { 0 } };
int fz_lock_taken[FZ_LOCK_DEBUG_CONTEXT_MAX][FZ_LOCK_MAX] = { { 0 } };
/* We implement our own millisecond clock, as clock() cannot be trusted
* when threads are involved. */
static int ms_clock(void)
{
#ifdef _WIN32
return (int)GetTickCount();
#else
struct timeval tp;
gettimeofday(&tp, NULL);
return (tp.tv_sec*1000) + (tp.tv_usec/1000);
#endif
}
static void dump_lock_times(void)
{
int i, j;
int prog_time = ms_clock() - fz_lock_program_start;
for (j = 0; j < FZ_LOCK_MAX; j++)
{
int total = 0;
for (i = 0; i < FZ_LOCK_DEBUG_CONTEXT_MAX; i++)
{
total += fz_lock_time[i][j];
}
printf("Lock %d held for %g seconds (%g%%)\n", j, total / 1000.0f, 100.0f*total/prog_time);
}
printf("Total program time %g seconds\n", prog_time / 1000.0f);
}
#endif
static int find_context(fz_context *ctx)
{
int i;
for (i = 0; i < FZ_LOCK_DEBUG_CONTEXT_MAX; i++)
{
if (fz_lock_debug_contexts[i] == ctx)
return i;
if (fz_lock_debug_contexts[i] == NULL)
{
int gottit = 0;
/* We've not locked on this context before, so use
* this one for this new context. We might have other
* threads trying here too though so, so claim it
* atomically. No one has locked on this context
* before, so we are safe to take the ALLOC lock. */
ctx->locks.lock(ctx->locks.user, FZ_LOCK_ALLOC);
/* If it's still free, then claim it as ours,
* otherwise we'll keep hunting. */
if (fz_lock_debug_contexts[i] == NULL)
{
gottit = 1;
fz_lock_debug_contexts[i] = ctx;
#ifdef FITZ_DEBUG_LOCKING_TIMES
if (fz_debug_locking_inited == 0)
{
fz_debug_locking_inited = 1;
fz_lock_program_start = ms_clock();
atexit(dump_lock_times);
}
#endif
}
ctx->locks.unlock(ctx->locks.user, FZ_LOCK_ALLOC);
if (gottit)
return i;
}
}
return -1;
}
void
fz_assert_lock_held(fz_context *ctx, int lock)
{
int idx;
if (ctx->locks.lock != fz_lock_default)
return;
idx = find_context(ctx);
if (idx < 0)
return;
if (fz_locks_debug[idx][lock] == 0)
fprintf(stderr, "Lock %d not held when expected\n", lock);
}
void
fz_assert_lock_not_held(fz_context *ctx, int lock)
{
int idx;
if (ctx->locks.lock != fz_lock_default)
return;
idx = find_context(ctx);
if (idx < 0)
return;
if (fz_locks_debug[idx][lock] != 0)
fprintf(stderr, "Lock %d held when not expected\n", lock);
}
void fz_lock_debug_lock(fz_context *ctx, int lock)
{
int i, idx;
if (ctx->locks.lock != fz_lock_default)
return;
idx = find_context(ctx);
if (idx < 0)
return;
if (fz_locks_debug[idx][lock] != 0)
{
fprintf(stderr, "Attempt to take lock %d when held already!\n", lock);
}
for (i = lock-1; i >= 0; i--)
{
if (fz_locks_debug[idx][i] != 0)
{
fprintf(stderr, "Lock ordering violation: Attempt to take lock %d when %d held already!\n", lock, i);
}
}
fz_locks_debug[idx][lock] = 1;
#ifdef FITZ_DEBUG_LOCKING_TIMES
fz_lock_taken[idx][lock] = ms_clock();
#endif
}
void fz_lock_debug_unlock(fz_context *ctx, int lock)
{
int idx;
if (ctx->locks.lock != fz_lock_default)
return;
idx = find_context(ctx);
if (idx < 0)
return;
if (fz_locks_debug[idx][lock] == 0)
{
fprintf(stderr, "Attempt to release lock %d when not held!\n", lock);
}
fz_locks_debug[idx][lock] = 0;
#ifdef FITZ_DEBUG_LOCKING_TIMES
fz_lock_time[idx][lock] += ms_clock() - fz_lock_taken[idx][lock];
#endif
}
#endif