From f81dd5da827e86af3bf6fedadeaaeb5fb3347c32 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Thu, 19 Jan 2012 11:00:01 +0100 Subject: beam_ranges: Make ranges safe with multi-scheduling active --- erts/emulator/beam/beam_load.c | 6 +- erts/emulator/beam/beam_ranges.c | 253 +++++++++++++++++++++++++++++---------- erts/emulator/beam/global.h | 4 +- 3 files changed, 195 insertions(+), 68 deletions(-) (limited to 'erts/emulator') diff --git a/erts/emulator/beam/beam_load.c b/erts/emulator/beam/beam_load.c index 873b94d175..6cabc6f558 100644 --- a/erts/emulator/beam/beam_load.c +++ b/erts/emulator/beam/beam_load.c @@ -5987,9 +5987,7 @@ void erts_start_loader_code_ix(void) beam_catches_start_load(); export_start_load(); module_start_load(); - /*SVERK and more to come I guess... - : - */ + erts_start_load_ranges(); CIX_TRACE("start"); } @@ -5999,6 +5997,7 @@ void erts_commit_loader_code_ix(void) beam_catches_end_load(1); export_end_load(1); module_end_load(1); + erts_end_load_ranges(1); { ErtsCodeIndex ix; ix = erts_loader_code_ix(); @@ -6014,6 +6013,7 @@ void erts_abort_loader_code_ix(void) beam_catches_end_load(0); export_end_load(0); module_end_load(0); + erts_end_load_ranges(0); CIX_TRACE("abort"); } diff --git a/erts/emulator/beam/beam_ranges.c b/erts/emulator/beam/beam_ranges.c index 063b319f7a..ae701ea0c9 100644 --- a/erts/emulator/beam/beam_ranges.c +++ b/erts/emulator/beam/beam_ranges.c @@ -26,6 +26,7 @@ #include "global.h" #include "beam_load.h" +static Range* find_range(BeamInstr* pc); static void lookup_loc(FunctionInfo* fi, BeamInstr* pc, BeamInstr* modp, int idx); @@ -34,67 +35,175 @@ static void lookup_loc(FunctionInfo* fi, BeamInstr* pc, * each module. It allows us to quickly find a function given an * instruction pointer. */ -static Range* modules = NULL; /* Sorted lists of module addresses. */ -static int num_loaded_modules; /* Number of loaded modules. */ -static int allocated_modules; /* Number of slots allocated. */ -static Range* mid_module = NULL; /* Cached search start point */ +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 <= p->modules[i].end); + ASSERT(!i || p->modules[i-1].end < p->modules[i].start); + } +} +# define CHECK(r) check_consistency(r) +#else +# define CHECK(r) +#endif /* HARD_DEBUG */ + void erts_init_ranges(void) { - allocated_modules = 128; - modules = (Range *) erts_alloc(ERTS_ALC_T_MODULE_REFS, - allocated_modules*sizeof(Range)); - mid_module = modules; - num_loaded_modules = 0; + 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_update_ranges(BeamInstr* code, Uint size) +erts_start_load_ranges(void) { - int i; + ErtsCodeIndex dst = erts_loader_code_ix(); - if (num_loaded_modules == allocated_modules) { - allocated_modules *= 2; - modules = (Range *) erts_realloc(ERTS_ALC_T_MODULE_REFS, - (void *) modules, - allocated_modules * sizeof(Range)); + 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; } - for (i = num_loaded_modules; i > 0; i--) { - if (code > modules[i-1].start) { - break; +} + +void +erts_end_load_ranges(int commit) +{ + ErtsCodeIndex dst = erts_loader_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 < rp->end) { + /* Only insert a module that has not been purged. */ + r[dst].modules[n] = *rp; + n++; + } } - modules[i] = modules[i-1]; + r[dst].n = n; + erts_smp_atomic_set_nob(&r[dst].mid, + (erts_aint_t) (r[dst].modules + n / 2)); } - modules[i].start = code; - modules[i].end = (BeamInstr *) (((byte *)code) + size); - num_loaded_modules++; - mid_module = &modules[num_loaded_modules/2]; } void -erts_remove_from_ranges(BeamInstr* code) +erts_update_ranges(BeamInstr* code, Uint size) { - int i; + ErtsCodeIndex dst = erts_loader_code_ix(); + ErtsCodeIndex src = erts_active_code_ix(); + Sint i; + Sint n; + Sint need; - for (i = 0; i < num_loaded_modules; i++) { - if (modules[i].start == code) { - num_loaded_modules--; - while (i < num_loaded_modules) { - modules[i] = modules[i+1]; - i++; - } - mid_module = &modules[num_loaded_modules/2]; - return; + 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; + r[dst].modules[n].end = (BeamInstr *) (((byte *)code) + size); + n++; + break; + } + if (rp->start < rp->end) { + /* Only insert a module that has not been purged. */ + r[dst].modules[n] = *rp; + n++; } } - ASSERT(0); /* Not found? */ + + while (i < r[src].n) { + Range* rp = r[src].modules+i; + if (rp->start < rp->end) { + /* Only insert a module that has not been purged. */ + r[dst].modules[n] = *rp; + n++; + } + i++; + } + + if (n == 0 || code > r[dst].modules[n-1].start) { + r[dst].modules[n].start = code; + r[dst].modules[n].end = (BeamInstr *) (((byte *)code) + size); + 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); + rp->end = rp->start; } -Uint +UWord erts_ranges_sz(void) { - return allocated_modules*sizeof(Range); + return erts_smp_atomic_read_nob(&mem_used) * sizeof(Range); } /* @@ -108,45 +217,61 @@ erts_ranges_sz(void) void erts_lookup_function_info(FunctionInfo* fi, BeamInstr* pc, int full_info) { - Range* low = modules; - Range* high = low + num_loaded_modules; - Range* mid = mid_module; + 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 > mid->end) { low = mid + 1; } else { - BeamInstr** low1 = (BeamInstr **) (mid->start + MI_FUNCTIONS); - BeamInstr** high1 = low1 + mid->start[MI_NUM_FUNCTIONS]; - BeamInstr** mid1; - - while (low1 < high1) { - mid1 = low1 + (high1-low1) / 2; - if (pc < mid1[0]) { - high1 = mid1; - } else if (pc < mid1[1]) { - mid_module = mid; - fi->current = mid1[0]+2; - if (full_info) { - BeamInstr** fp = (BeamInstr **) (mid->start + - MI_FUNCTIONS); - int idx = mid1 - fp; - lookup_loc(fi, pc, mid->start, idx); - } - return; - } else { - low1 = mid1 + 1; - } - } - return; + erts_smp_atomic_set_nob(&r[active].mid, (erts_aint_t) mid); + return mid; } mid = low + (high-low) / 2; } + return 0; } static void diff --git a/erts/emulator/beam/global.h b/erts/emulator/beam/global.h index 05517ac9e8..e6ff9d8577 100644 --- a/erts/emulator/beam/global.h +++ b/erts/emulator/beam/global.h @@ -891,9 +891,11 @@ Eterm erts_make_stub_module(Process* p, Eterm Mod, Eterm Beam, Eterm Info); /* beam_ranges.c */ void erts_init_ranges(void); +void erts_start_load_ranges(void); +void erts_end_load_ranges(int commit); void erts_update_ranges(BeamInstr* code, Uint size); void erts_remove_from_ranges(BeamInstr* code); -Uint erts_ranges_sz(void); +UWord erts_ranges_sz(void); void erts_lookup_function_info(FunctionInfo* fi, BeamInstr* pc, int full_info); /* break.c */ -- cgit v1.2.3