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Diffstat (limited to 'erts/emulator/beam/beam_ranges.c')
| -rw-r--r-- | erts/emulator/beam/beam_ranges.c | 349 |
1 files changed, 349 insertions, 0 deletions
diff --git a/erts/emulator/beam/beam_ranges.c b/erts/emulator/beam/beam_ranges.c new file mode 100644 index 0000000000..0f2d5d0c2a --- /dev/null +++ b/erts/emulator/beam/beam_ranges.c @@ -0,0 +1,349 @@ +/* + * %CopyrightBegin% + * + * Copyright Ericsson AB 2012. All Rights Reserved. + * + * The contents of this file are subject to the Erlang Public License, + * Version 1.1, (the "License"); you may not use this file except in + * compliance with the License. You should have received a copy of the + * Erlang Public License along with this software. If not, it can be + * retrieved online at http://www.erlang.org/. + * + * Software distributed under the License is distributed on an "AS IS" + * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See + * the License for the specific language governing rights and limitations + * under the License. + * + * %CopyrightEnd% + */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include "sys.h" +#include "erl_vm.h" +#include "global.h" +#include "beam_load.h" + +typedef struct { + BeamInstr* start; /* Pointer to start of module. */ + erts_smp_atomic_t end; /* (BeamInstr*) Points one word beyond last function in module. */ +} Range; + +/* Range 'end' needs to be atomic as we purge module + by setting end=start in active code_ix */ +#define RANGE_END(R) ((BeamInstr*)erts_smp_atomic_read_nob(&(R)->end)) + +static Range* find_range(BeamInstr* pc); +static void lookup_loc(FunctionInfo* fi, BeamInstr* pc, + BeamInstr* modp, int idx); + +/* + * The following variables keep a sorted list of address ranges for + * each module. It allows us to quickly find a function given an + * instruction pointer. + */ +struct ranges { + Range* modules; /* Sorted lists of module addresses. */ + Sint n; /* Number of range entries. */ + Sint allocated; /* Number of allocated entries. */ + erts_smp_atomic_t mid; /* Cached search start point */ +}; +static struct ranges r[ERTS_NUM_CODE_IX]; +static erts_smp_atomic_t mem_used; + +#ifdef HARD_DEBUG +static void check_consistency(struct ranges* p) +{ + int i; + + ASSERT(p->n <= p->allocated); + ASSERT((Uint)(p->mid - p->modules) < p->n || + (p->mid == p->modules && p->n == 0)); + for (i = 0; i < p->n; i++) { + ASSERT(p->modules[i].start <= RANGE_END(&p->modules[i])); + ASSERT(!i || RANGE_END(&p->modules[i-1]) < p->modules[i].start); + } +} +# define CHECK(r) check_consistency(r) +#else +# define CHECK(r) +#endif /* HARD_DEBUG */ + + +void +erts_init_ranges(void) +{ + Sint i; + + erts_smp_atomic_init_nob(&mem_used, 0); + for (i = 0; i < ERTS_NUM_CODE_IX; i++) { + r[i].modules = 0; + r[i].n = 0; + r[i].allocated = 0; + erts_smp_atomic_init_nob(&r[i].mid, 0); + } +} + +void +erts_start_staging_ranges(void) +{ + ErtsCodeIndex dst = erts_staging_code_ix(); + + if (r[dst].modules) { + erts_smp_atomic_add_nob(&mem_used, -r[dst].allocated); + erts_free(ERTS_ALC_T_MODULE_REFS, r[dst].modules); + r[dst].modules = NULL; + } +} + +void +erts_end_staging_ranges(int commit) +{ + ErtsCodeIndex dst = erts_staging_code_ix(); + + if (commit && r[dst].modules == NULL) { + Sint i; + Sint n; + + /* No modules added, just clone src and remove purged code. */ + ErtsCodeIndex src = erts_active_code_ix(); + + erts_smp_atomic_add_nob(&mem_used, r[src].n); + r[dst].modules = erts_alloc(ERTS_ALC_T_MODULE_REFS, + r[src].n * sizeof(Range)); + r[dst].allocated = r[src].n; + n = 0; + for (i = 0; i < r[src].n; i++) { + Range* rp = r[src].modules+i; + if (rp->start < RANGE_END(rp)) { + /* Only insert a module that has not been purged. */ + r[dst].modules[n] = *rp; + n++; + } + } + r[dst].n = n; + erts_smp_atomic_set_nob(&r[dst].mid, + (erts_aint_t) (r[dst].modules + n / 2)); + } +} + +void +erts_update_ranges(BeamInstr* code, Uint size) +{ + ErtsCodeIndex dst = erts_staging_code_ix(); + ErtsCodeIndex src = erts_active_code_ix(); + Sint i; + Sint n; + Sint need; + + if (src == dst) { + ASSERT(!erts_initialized); + + /* + * During start-up of system, the indices are the same. + * Handle this by faking a source area. + */ + src = (src+1) % ERTS_NUM_CODE_IX; + if (r[src].modules) { + erts_smp_atomic_add_nob(&mem_used, -r[src].allocated); + erts_free(ERTS_ALC_T_MODULE_REFS, r[src].modules); + } + r[src] = r[dst]; + r[dst].modules = 0; + } + + CHECK(&r[src]); + + ASSERT(r[dst].modules == NULL); + need = r[dst].allocated = r[src].n + 1; + erts_smp_atomic_add_nob(&mem_used, need); + r[dst].modules = (Range *) erts_alloc(ERTS_ALC_T_MODULE_REFS, + need * sizeof(Range)); + n = 0; + for (i = 0; i < r[src].n; i++) { + Range* rp = r[src].modules+i; + if (code < rp->start) { + r[dst].modules[n].start = code; + erts_smp_atomic_init_nob(&r[dst].modules[n].end, + (erts_aint_t)(((byte *)code) + size)); + ASSERT(!n || RANGE_END(&r[dst].modules[n-1]) < code); + n++; + break; + } + if (rp->start < RANGE_END(rp)) { + /* Only insert a module that has not been purged. */ + r[dst].modules[n].start = rp->start; + erts_smp_atomic_init_nob(&r[dst].modules[n].end, + (erts_aint_t)(RANGE_END(rp))); + ASSERT(!n || RANGE_END(&r[dst].modules[n-1]) < rp->start); + n++; + } + } + + while (i < r[src].n) { + Range* rp = r[src].modules+i; + if (rp->start < RANGE_END(rp)) { + /* Only insert a module that has not been purged. */ + r[dst].modules[n].start = rp->start; + erts_smp_atomic_init_nob(&r[dst].modules[n].end, + (erts_aint_t)(RANGE_END(rp))); + ASSERT(!n || RANGE_END(&r[dst].modules[n-1]) < rp->start); + n++; + } + i++; + } + + if (n == 0 || code > r[dst].modules[n-1].start) { + r[dst].modules[n].start = code; + erts_smp_atomic_init_nob(&r[dst].modules[n].end, + (erts_aint_t)(((byte *)code) + size)); + ASSERT(!n || RANGE_END(&r[dst].modules[n-1]) < code); + n++; + } + + ASSERT(n <= r[src].n+1); + r[dst].n = n; + erts_smp_atomic_set_nob(&r[dst].mid, + (erts_aint_t) (r[dst].modules + n / 2)); + + CHECK(&r[dst]); + CHECK(&r[src]); +} + +void +erts_remove_from_ranges(BeamInstr* code) +{ + Range* rp = find_range(code); + erts_smp_atomic_set_nob(&rp->end, (erts_aint_t)rp->start); +} + +UWord +erts_ranges_sz(void) +{ + return erts_smp_atomic_read_nob(&mem_used) * sizeof(Range); +} + +/* + * Find a function from the given pc and fill information in + * the FunctionInfo struct. If the full_info is non-zero, fill + * in all available information (including location in the + * source code). If no function is found, the 'current' field + * will be set to NULL. + */ + +void +erts_lookup_function_info(FunctionInfo* fi, BeamInstr* pc, int full_info) +{ + BeamInstr** low; + BeamInstr** high; + BeamInstr** mid; + Range* rp; + + fi->current = NULL; + fi->needed = 5; + fi->loc = LINE_INVALID_LOCATION; + rp = find_range(pc); + if (rp == 0) { + return; + } + + low = (BeamInstr **) (rp->start + MI_FUNCTIONS); + high = low + rp->start[MI_NUM_FUNCTIONS]; + while (low < high) { + mid = low + (high-low) / 2; + if (pc < mid[0]) { + high = mid; + } else if (pc < mid[1]) { + fi->current = mid[0]+2; + if (full_info) { + BeamInstr** fp = (BeamInstr **) (rp->start + + MI_FUNCTIONS); + int idx = mid - fp; + lookup_loc(fi, pc, rp->start, idx); + } + return; + } else { + low = mid + 1; + } + } +} + +static Range* +find_range(BeamInstr* pc) +{ + ErtsCodeIndex active = erts_active_code_ix(); + Range* low = r[active].modules; + Range* high = low + r[active].n; + Range* mid = (Range *) erts_smp_atomic_read_nob(&r[active].mid); + + CHECK(&r[active]); + while (low < high) { + if (pc < mid->start) { + high = mid; + } else if (pc > RANGE_END(mid)) { + low = mid + 1; + } else { + erts_smp_atomic_set_nob(&r[active].mid, (erts_aint_t) mid); + return mid; + } + mid = low + (high-low) / 2; + } + return 0; +} + +static void +lookup_loc(FunctionInfo* fi, BeamInstr* orig_pc, BeamInstr* modp, int idx) +{ + Eterm* line = (Eterm *) modp[MI_LINE_TABLE]; + Eterm* low; + Eterm* high; + Eterm* mid; + Eterm pc; + + if (line == 0) { + return; + } + + pc = (Eterm) (BeamInstr) orig_pc; + fi->fname_ptr = (Eterm *) (BeamInstr) line[MI_LINE_FNAME_PTR]; + low = (Eterm *) (BeamInstr) line[MI_LINE_FUNC_TAB+idx]; + high = (Eterm *) (BeamInstr) line[MI_LINE_FUNC_TAB+idx+1]; + while (high > low) { + mid = low + (high-low) / 2; + if (pc < mid[0]) { + high = mid; + } else if (pc < mid[1]) { + int file; + int index = mid - (Eterm *) (BeamInstr) line[MI_LINE_FUNC_TAB]; + + if (line[MI_LINE_LOC_SIZE] == 2) { + Uint16* loc_table = + (Uint16 *) (BeamInstr) line[MI_LINE_LOC_TAB]; + fi->loc = loc_table[index]; + } else { + Uint32* loc_table = + (Uint32 *) (BeamInstr) line[MI_LINE_LOC_TAB]; + ASSERT(line[MI_LINE_LOC_SIZE] == 4); + fi->loc = loc_table[index]; + } + if (fi->loc == LINE_INVALID_LOCATION) { + return; + } + fi->needed += 3+2+3+2; + file = LOC_FILE(fi->loc); + if (file == 0) { + /* Special case: Module name with ".erl" appended */ + Atom* mod_atom = atom_tab(atom_val(fi->current[0])); + fi->needed += 2*(mod_atom->len+4); + } else { + Atom* ap = atom_tab(atom_val((fi->fname_ptr)[file-1])); + fi->needed += 2*ap->len; + } + return; + } else { + low = mid + 1; + } + } +} |